Canal river aquatic ecology influence evaluation system construction method and device, computer equipment and readable storage medium

Abstract

The invention discloses a canal river aquatic ecology influence evaluation system construction method and device, computer equipment and a readable storage medium, and the method comprises the steps: determining river obstruction through comprehensively considering river connectivity and a hub fishway fish passing effect, and determining river fragmentation degree according to river curvature and river self-cleaning capability of a bent section; river water ecological loss is determined based on benthic organism loss and biological loss caused by suspended solids, river aquatic ecological change is determined according to river biogenic factor change and fish population distribution change, and finally an evaluation system is constructed by combining river obstruction, river breakage degree, river water ecological loss and river aquatic ecological change. According to the design, various factors are comprehensively and systematically considered, and the influence of canal construction on river aquatic ecology can be accurately evaluated.

Description

Technical Field

[0001] The present invention relates to the field of ecological management, and in particular to a method, device, computer equipment and readable storage medium for constructing a canal river aquatic ecological impact assessment system. Background Art

[0002] The construction and operation of canals have many impacts on river aquatic ecosystems. With the development of infrastructure construction, canal projects are increasing, and it is crucial to accurately assess their impact on aquatic ecology. Traditional ecological impact assessment methods often lack comprehensiveness and systematicness based on the characteristics of canals. Summary of the invention

[0003] The purpose of the present invention is to provide a method, device, computer equipment and readable storage medium for constructing a canal river aquatic ecological impact assessment system.

[0004] In a first aspect, an embodiment of the present invention provides a method for constructing a canal river aquatic ecological impact assessment system, comprising:

[0005] Determine river barriers based on river connectivity and the effectiveness of pivotal fishways;

[0006] Determine river fragmentation based on river sinuosity and the self-purification capacity of the river at the bend section;

[0007] Determine river water ecological losses based on benthic biomass losses and biomass losses due to suspended matter;

[0008] Determine changes in river aquatic ecology based on changes in river biogenic factors and changes in fish population distribution;

[0009] Based on the river barriers, the river fragmentation, the river water ecological losses and the river aquatic ecological changes, a canal river aquatic ecological impact assessment system is constructed.

[0010] In a possible implementation, determining river barriers based on river connectivity and fish passage effects of hub fishways includes:

[0011] The river connectivity is determined according to the longitudinal connectivity index of the river; the longitudinal connectivity index of the river is calculated by the formula: Determine; where C is the longitudinal connectivity index of the river, a is the barrier coefficient corresponding to the i-th hub, b is the position correction coefficient of the i-th hub, and L is the length of the river;

[0012] The fish passing effect of the hub fishway is determined according to the fish passing efficiency and the proportion of migratory fish population; the fish passing efficiency is calculated by the formula: Determine the proportion of migratory fish populations through the formula: Determine; where n is the fish passing efficiency, N1 is the number of fish at the fishway entrance, N2 is the number of fish at the fishway exit, p is the proportion of migratory fish population, N is the population size, and N0 is the number of migratory fish population;

[0013] The river barrier is constructed according to the river connectivity and the fish passing effect of the hub fishway.

[0014] In a possible implementation manner, determining the river fragmentation based on the river curvature and the self-purification capacity of the river at the bend section includes:

[0015] The river curvature is determined according to the ratio of the canal curvature to the original river curvature; the ratio of the canal curvature to the original river curvature is determined by the formula: Determine; where S is the ratio of the canal curvature to the original river curvature, L T is the length of the original river channel measured along the center line of the river channel; L0 is the straight-line distance between the upstream and downstream sections of the original river channel; L T ' is the length of the original river channel measured along the center line of the river channel; L0' is the straight-line distance between the upstream and downstream sections of the original river channel;

[0016] The self-purification capacity of the river in the bend section is determined according to the water quality reduction rate of the river section before and after the bend cutting; the water quality reduction rate of the river section before and after the bend cutting is calculated by the formula: Determine; where R is the water quality reduction rate of the river section before and after the bend cutting, C0 is the concentration of the river water quality in the bend cutting section before the bend cutting, C1 is the concentration of the river water quality in the bend cutting section after the bend cutting, L c is the length of the river at the bend;

[0017] The river fragmentation is constructed according to the river curvature and the self-purification capacity of the river in the bend section.

[0018] In a possible implementation, determining the river water ecological loss based on the bio-loss caused by the benthic bio-loss and the suspended matter includes:

[0019] The benthic organism loss is determined according to the organism loss caused by underwater construction; the organism loss caused by underwater construction is determined by the formula: W i =D i ×S i Determine; among them, W i D is the biological loss caused by underwater construction of the i-th biological resource. i To evaluate the density of biological resources of the i-th type in the region, S i is the water area occupied by the i-th species of organisms;

[0020] Determine the biological loss caused by the suspended matter based on the number of fish eggs and larvae, the loss of zooplankton and the loss of phytoplankton caused by the diffusion of the suspended matter;

[0021] The river water ecological loss is constructed according to the benthic biological loss and the biological loss caused by the suspended matter.

[0022] In a possible implementation, determining river aquatic ecological changes based on changes in river biogenesis factors and changes in fish population distribution includes:

[0023] Determine the change of the river biogenic factor according to the change of oxygen content in the water before and after the canal was built, the change of ammonia nitrogen in the water before and after the canal was built, and the change of total phosphorus in the water before and after the canal was built;

[0024] Determine the distribution changes of the fish populations based on fish stock index, species occurrence frequency and species relative abundance;

[0025] The changes in the river's aquatic ecology are constructed based on the changes in the river's biogenic factors and the changes in the fish population distribution.

[0026] In a possible implementation, the canal river aquatic ecological impact assessment system is constructed based on the river barrier, the river fragmentation, the river water ecological loss and the river aquatic ecological change, including:

[0027] The element layer is based on the river connectivity, the fish passing effect of the hub fishway, the river curvature, the self-purification capacity of the river in the bend section, the loss of benthic organisms, the biological loss caused by suspended matter, the change of the river biogenic factor and the change of the fish population distribution;

[0028] The river barrier, the river fragmentation, the river water ecological loss and the river aquatic ecological change are used as criterion layers;

[0029] The impact on aquatic ecology of canals and rivers is taken as the target layer;

[0030] The element layer and the criterion layer are weighted based on the AHP hierarchy analysis method, and the canal river aquatic ecological impact assessment system is constructed according to the target layer, the element layer with weights assigned, and the criterion layer.

[0031] In a possible implementation, the river connectivity includes the longitudinal connectivity index of the river, the fish passage effect of the hub fishway includes the fish passage efficiency of fish schools and the proportion of migratory fish populations, the river curvature includes the ratio of the canal curvature to the original river curvature, the self-purification capacity of the river in the bend section includes the reduction rate of water quality indicators in the river section before and after the bend, the benthic biological loss includes the biological loss caused by underwater construction, the biological loss caused by suspended matter includes the number of fish eggs and larvae caused by the diffusion of suspended matter, the loss of zooplankton and the loss of phytoplankton, the change of the river biogenic factors includes the change of oxygen content in the water body before and after the construction of the canal, the change of ammonia nitrogen in the water body before and after the construction of the canal, and the change of total phosphorus in the water body before and after the construction of the canal, and the change of fish population distribution includes fish retention index, species occurrence frequency and species relative abundance;

[0032] The canal river aquatic ecological impact assessment system constructed based on the river barrier, the river fragmentation, the river water ecological loss and the river aquatic ecological change also includes:

[0033] The longitudinal connectivity index of the river, the fish passage efficiency, the proportion of migratory fish populations, the ratio of the canal curvature to the original river curvature, the reduction rate of water quality indicators in the river section before and after the bend, the biological loss caused by the underwater construction, the number of fish eggs and larvae caused by the diffusion of suspended matter, the loss of zooplankton and the loss of phytoplankton, the change in oxygen content in the water before and after the construction of the canal, the change in ammonia nitrogen in the water before and after the construction of the canal, the change in total phosphorus in the water before and after the construction of the canal, the fish retention index, the frequency of occurrence of the species and the relative abundance of the species are used as indicator layers;

[0034] Based on the AHP hierarchical analysis method, weights are assigned to the element layer, the criterion layer and the indicator layer, and the canal river aquatic ecological impact assessment system is constructed according to the target layer, the weighted element layer, the criterion layer and the indicator layer.

[0035] In a second aspect, an embodiment of the present invention provides a device for constructing a canal river aquatic ecological impact assessment system, comprising:

[0036] Acquisition module, used to determine river barriers based on river connectivity and the effect of fish passage in hub fishways; determine river fragmentation based on river curvature and the self-purification capacity of the river in the bend section; determine river water ecological losses based on the loss of benthic organisms and biological losses caused by suspended matter; determine river aquatic ecological changes based on changes in river provenance factors and changes in fish population distribution;

[0037] A construction module is used to construct a canal river aquatic ecological impact assessment system based on the river barrier, the river fragmentation, the river water ecological loss and the river aquatic ecological change.

[0038] In a third aspect, an embodiment of the present invention provides a computer device, comprising a processor and a non-volatile memory storing computer instructions, wherein when the computer instructions are executed by the processor, the computer device executes the method described in the first aspect.

[0039] In a fourth aspect, an embodiment of the present invention provides a readable storage medium, wherein the readable storage medium includes a computer program, and when the computer program is executed, the computer device where the readable storage medium is located is controlled to execute the method described in the first aspect.

[0040] Compared with the prior art, the beneficial effects provided by the present invention include: using a canal river aquatic ecological impact assessment system construction method, device, computer equipment and readable storage medium disclosed by the present invention, including: determining river barriers by comprehensively considering river connectivity and the effect of fish passage in the hub fishway, determining river fragmentation based on river curvature and the self-purification capacity of the river in the bend section, determining river water ecological losses based on biomass losses caused by benthic organisms and suspended matter, determining river aquatic ecological changes based on changes in river provenance factors and changes in fish population distribution, and finally constructing an assessment system combining river barriers, river fragmentation, river water ecological losses and river aquatic ecological changes. Such a design comprehensively and systematically considers multiple factors, which helps to accurately assess the impact of canal construction on river aquatic ecology. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative work.

[0042] Figure 1 A schematic diagram of the steps of the method for constructing a canal river aquatic ecological impact assessment system provided by an embodiment of the present invention;

[0043] Figure 2 A schematic block diagram of the structure of a device for constructing a canal river aquatic ecological impact assessment system provided by an embodiment of the present invention;

[0044] Figure 3 A schematic block diagram of the structure of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0046] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0047] In order to solve the technical problems in the aforementioned background technology, Figure 1 This is a flow chart of the method for constructing a canal river aquatic ecological impact assessment system provided in the embodiment of the present disclosure. The method for constructing a canal river aquatic ecological impact assessment system is introduced in detail below.

[0048] Step S201, determining river barriers based on river connectivity and fish passage effects of hub fishways;

[0049] Step S202, determining the river fragmentation based on the river curvature and the self-purification capacity of the river in the bend section;

[0050] Step S203, determining the river water ecological loss based on the biomass loss caused by benthic organisms and suspended matter;

[0051] Step S204, determining river aquatic ecological changes based on changes in river biogenic factors and changes in fish population distribution;

[0052] Step S205, constructing a canal river aquatic ecological impact assessment system based on the river barrier, the river fragmentation, the river water ecological loss and the river aquatic ecological change.

[0053] In the embodiment of the present invention, illustratively,

[0054] Assume that the server receives data about a canal and its associated rivers, and there are multiple hub facilities in the canal. The server starts to calculate the longitudinal connectivity index of the river to determine the river connectivity.

[0055] For each type of hub in a river (such as a sluice gate, dam, etc.), there is a corresponding barrier coefficient. For example, a large sluice gate has a high barrier coefficient because it almost completely blocks the natural longitudinal connectivity of the water flow, which is set to 0.8; while some small control gates have a relatively low barrier coefficient, which is set to 0.3.

[0056] In terms of the location correction factor, if the hub is located in the middle of the river, the impact on overall connectivity may be different than if it is located upstream or downstream. Assume that the location correction factor of a hub located in the middle of the river is 1.2, while that of a hub located upstream is 1.5 and that of a hub located downstream is 0.8.

[0057] Assuming that the length of a river is 100 kilometers, the server calculates the impact of each hub on river connectivity based on these data, and finally determines the longitudinal connectivity index of the river, thereby obtaining the river connectivity.

[0058] For example, there are three types of hubs. The first hub (large sluice gate) has a barrier coefficient of 0.8 and a position correction coefficient of 1.2; the second hub (small regulating gate) has a barrier coefficient of 0.3 and a position correction coefficient of 1.5; the third hub (another small regulating gate) has a barrier coefficient of 0.3 and a position correction coefficient of 0.8. According to the corresponding calculation logic, the server combines the influence of these hubs and the length of the river to derive the longitudinal connectivity index of the river. This index reflects the change in the longitudinal connectivity of the river in its natural state. If the index is high, it means that the connectivity of the river is greatly hindered; if the index is low, it means that the connectivity of the river is relatively good.

[0059] The server obtains data on the number of fish at the entrance and exit of the fishway. For example, at a fishway monitoring point in a canal, through underwater cameras and intelligent image recognition technology (the server can receive data collected by these devices), it is found that the number of fish at the entrance of the fishway is 1,000 and the number of fish at the exit of the fishway is 800.

[0060] Calculate the fish passage efficiency, which reflects the actual effect of the fishway on the passage of fish. In this example, according to the calculation logic of the fish passage efficiency, the value of the fish passage efficiency can be obtained. If this value is low, it means that there may be some factors in the fishway that hinder the passage of fish, such as inappropriate water flow speed, unreasonable fishway structure, etc.

[0061] The server obtains the data of the population and the number of migratory fish populations from the fishery resource survey database. Assume that in the area involved in the canal, the total population is 5,000 and the number of migratory fish populations is 1,000.

[0062] According to the corresponding calculation logic, the proportion of migratory fish population is calculated. This proportion reflects the proportion of migratory fish in the entire fish population. If the proportion is low, it may mean that the canal and its related facilities have a greater impact on the survival and reproduction of migratory fish.

[0063] The server will comprehensively consider the calculated river connectivity and the fish passage effect of the hub fishway. For example, if the river connectivity shows that the river is severely blocked by multiple hubs, and the fish passage effect of the hub fishway is not ideal, such as the fish passage efficiency is low and the proportion of migratory fish populations is small, then the server will determine that the river has a high degree of obstruction. On the contrary, if the river connectivity is reduced to a certain extent but the fish passage effect of the hub fishway is good, such as the fish passage efficiency is high and the proportion of migratory fish populations is normal, then the river is relatively low. In this way, the server constructs the factor of river obstruction, which is an important part of evaluating the impact of canal rivers on aquatic ecology.

[0064] The server obtains relevant measurement data about the original river channel. Assume that the length of the original river channel measured along the center line of the river channel is 50 kilometers, and the straight-line distance between the upstream and downstream sections of the original river channel is 30 kilometers.

[0065] After the canal is built, the relevant data is measured again, assuming that the curvature of the canal has changed from that of the original river channel. According to the calculation logic of the ratio of the curvature of the canal to that of the original river channel, the server calculates the ratio of the curvature of the canal to that of the original river channel by comparing the relevant data of the curvature characteristics of the canal and the original river channel.

[0066] For example, if the calculated ratio is 80%, it means that the curvature of the canal has been reduced to a certain extent compared with the original river channel. The change of this ratio will affect the ecological characteristics of the river, such as water flow speed, biological habitat, etc. The change of curvature may cause the water flow to be more turbulent or gentle, which in turn affects the living environment of aquatic organisms.

[0067] The server obtains the concentration data of the river water quality in the bend section before and after the bend is straightened, as well as the length data of the river in the bend section. For example, the ammonia nitrogen concentration of the river water quality in the bend section before the bend is straightened is 2 mg / L, the ammonia nitrogen concentration of the river water quality in the bend section after the bend is straightened is 1.5 mg / L, and the length of the river in the bend section is 5 kilometers.

[0068] According to the calculation logic of the water quality reduction rate of the river section before and after the bend cutting, the server calculates the water quality reduction rate of the river section before and after the bend cutting. This reduction rate reflects the impact of the bend cutting on the self-purification capacity of the river. If the reduction rate is high, it means that the bend cutting may have a positive effect on the self-purification capacity of the river; if the reduction rate is low or even negative, it may mean that the bend cutting process has a negative impact on the self-purification capacity of the river, such as destroying the microbial community in the river or changing the interaction between the water flow and the riverbed.

[0069] The server determines the river fragmentation by combining the river's curvature and the river's self-purification capacity at the bend section. For example, if the river's curvature decreases significantly and the river's self-purification capacity at the bend section also decreases, the river fragmentation is high. This means that the river's ecological integrity has been greatly damaged, the biological habitats in the river may be fragmented, and the migration and reproduction paths of organisms may be blocked. On the contrary, if the river's curvature changes but the river's self-purification capacity at the bend section improves, the river fragmentation may be relatively low, and the impact on the aquatic ecology is relatively small.

[0070] The server obtains the benthic biological resource density and the water area occupied by the i-th species of organisms in the assessment area from the biological resource survey data. Assume that in a canal construction area, the resource density of a benthic organism (such as river clams) is 10 per square meter, and the water area it occupies is 100 square meters.

[0071] According to the calculation logic of biological loss caused by underwater construction, the server calculates the biological loss of benthic organisms caused by underwater construction. Underwater construction may destroy the habitat of benthic organisms. For example, engineering activities such as digging riverbeds and piling will directly lead to the death or migration of benthic organisms.

[0072] For each benthic species, the server calculates the losses individually and aggregates them to determine the total benthic biomass loss.

[0073] The server obtains data on the number of fish eggs and larvae, the loss of zooplankton, and the loss of phytoplankton caused by the diffusion of suspended matter. For example, during the construction of the canal, a large amount of suspended matter was generated due to activities such as excavation and earthwork. Through monitoring of the water area, it was found that the diffusion of suspended matter caused the loss of 500 fish eggs and larvae, the loss of zooplankton was 1,000 per cubic meter (assuming that the loss was within a certain volume), and the loss of phytoplankton was 2,000 per cubic meter.

[0074] These organisms have different tolerances to suspended solids, which can clog the breathing holes of fish eggs, affect the feeding and reproduction of zooplankton, block the light of phytoplankton, etc. The server combines these data to determine the biological losses caused by suspended solids.

[0075] The server combines benthic biomass loss and biomass loss caused by suspended matter to determine river water ecological loss. For example, if benthic biomass loss is large and biomass loss caused by suspended matter is also severe, then river water ecological loss is very large. This indicates that canal construction or related activities have had a strong impact on the biological community in the river, which may lead to ecological problems such as reduced biodiversity and disruption of the food chain. If benthic biomass loss is small and biomass loss caused by suspended matter is also limited, river water ecological loss is relatively small.

[0076] The server obtains data on changes in water oxygen content, ammonia nitrogen content, and total phosphorus before and after the canal was built. For example, before the canal was built, the water oxygen content was 8 mg / L, and after it was built it became 6 mg / L; before the canal was built, the water ammonia nitrogen content was 1 mg / L, and after it was built it became 1.5 mg / L; before the canal was built, the water total phosphorus content was 0.1 mg / L, and after it was built it became 0.2 mg / L.

[0077] The changes in these biogenic factors reflect the impact of canal construction on the chemical properties of water bodies. The reduction in oxygen content may affect the respiration of aquatic organisms, and the increase in ammonia nitrogen and total phosphorus content may cause eutrophication of water bodies, which in turn affects the living environment and community structure of aquatic organisms. The server determines the changes in river biogenic factors based on these data.

[0078] The server obtains data on fish stock index, species occurrence frequency, and species relative abundance from fishery resource survey data. Assume that before the canal was built, the stock index of a certain fish was 0.8, and it became 0.6 after it was built; the frequency of the species' occurrence was 5 times a week before it was built, and it became 3 times a week after it was built; the relative abundance of the species was 30% before it was built, and it became 20% after it was built.

[0079] The fish conservation index reflects the number of fish species preserved in a certain area, the species occurrence frequency reflects the probability of the species appearing in the water, and the species relative abundance indicates the relative proportion of the species in the entire fish community. The server determines the changes in the distribution of fish populations based on these data. If these indicators have all dropped significantly, it means that the construction of the canal has had a significant impact on the distribution of fish populations, which may be due to habitat destruction, water quality changes, etc.

[0080] The server combines the changes in river biogenic factors and fish population distribution to determine changes in river aquatic ecology. For example, if changes in river biogenic factors indicate that the water environment is deteriorating and changes in fish population distribution indicate that the number and distribution range of fish are decreasing, then changes in river aquatic ecology are developing in a direction that is not conducive to ecological stability. On the contrary, if changes in river biogenic factors are small and changes in fish population distribution are not obvious, changes in river aquatic ecology are relatively small, indicating that the impact of canal construction on aquatic ecology is within an acceptable range.

[0081] The server will use river connectivity, fish passage effect of hub fishways, river curvature, river self-purification capacity of bend sections, benthic organism loss, biological loss caused by suspended matter, changes in river biogenic factors, and changes in fish population distribution as element layers.

[0082] For example, the server uses the previously calculated river connectivity related data (such as the barrier coefficient of various hubs, position correction coefficient and other information), the fish passage effect of hub fishways (fish passage efficiency and the proportion of migratory fish populations, etc.), river curvature (the ratio of canal curvature to the original river channel curvature), the self-purification capacity of the river in the bend section (the reduction rate of water quality indicators in the river section before and after the bend), the loss of benthic organisms (the loss of various benthic organisms), the biological loss caused by suspended matter (the number of fish eggs and larvae, the loss of zooplankton and phytoplankton), the changes in river biogenic factors (changes in water oxygen content, ammonia nitrogen and total phosphorus) and the changes in fish population distribution (fish retention index, species occurrence frequency and relative species abundance) as the data content of the feature layer.

[0083] The server uses river barrier, river fragmentation, river water ecological loss and river aquatic ecological change as the criterion layer. For example, based on the previously constructed river barrier (the degree of barrier obtained by combining river connectivity and the effect of fish passage through the hub fishway), river fragmentation (the result of comprehensive river tortuosity and the self-purification capacity of the river in the bend section), river water ecological loss (the combination of benthic biological loss and biological loss caused by suspended matter) and river aquatic ecological change (the combination of changes in river biological factors and changes in fish population distribution), these contents are used as the content of the criterion layer.

[0084] The server takes the impact on the aquatic ecology of canals and rivers as the target layer. This is the ultimate goal of the entire evaluation system, that is, to comprehensively evaluate the impact on the aquatic ecology of canals and rivers.

[0085] The server assigns weights to the element layer and the criterion layer based on the AHP. For example, by analyzing the relative importance of each element layer and the criterion layer in affecting the aquatic ecology of canal rivers, the server may determine that the weight of river barriers in the criterion layer is 0.3, the weight of river fragmentation is 0.2, the weight of river water ecological loss is 0.3, and the weight of river aquatic ecological change is 0.2.

[0086] In the element layer, for example, the weight of river connectivity in the element affecting river barriers may be 0.4, and the weight of the fish passage effect of the hub fishway may be 0.6 (this is just an example, and the actual weight needs to be determined based on detailed AHP analysis).

[0087] The server constructs an assessment system for the impact of canal and river aquatic ecology based on the target layer, the element layer after weighting, and the criterion layer. This assessment system can be used to quantitatively assess the impact of canal and river aquatic ecology. For example, by calculating the weighted scores of each element and criterion, the overall assessment result of the impact of canal and river aquatic ecology can be obtained. If the total score is high, it means that the canal construction or related activities have a greater impact on the aquatic ecology; if the total score is low, it means that the impact is relatively small.

[0088] If we further take the river's longitudinal connectivity index, fish passage efficiency, proportion of migratory fish populations, ratio of the canal's curvature to the original river's curvature, reduction rate of water quality indicators in the river section before and after the bend, biological losses caused by underwater construction, number of fish eggs and larvae caused by the diffusion of suspended matter, loss of zooplankton and loss of phytoplankton, changes in water oxygen content before and after the construction of the canal, changes in ammonia nitrogen content in the water before and after the construction of the canal, changes in total phosphorus in the water before the construction of the canal, fish retention index, species occurrence frequency and relative species abundance as indicator layers.

[0089] The server also assigns weights to the element layer, criterion layer, and indicator layer based on the AHP hierarchical analysis method. For example, in the indicator layer, the weight of fish passage efficiency in the indicators affecting the fish passage effect of the hub fishway may be 0.3, and the weight of the proportion of migratory fish populations is 0.7. Then, a more detailed canal river aquatic ecological impact assessment system is constructed based on the target layer, the weighted element layer, the criterion layer, and the indicator layer. This more detailed evaluation system can more accurately analyze various aspects of the canal river aquatic ecological impact, and provide a more comprehensive decision-making basis for the construction, management, and ecological protection of the canal.

[0090] In the embodiment of the present invention, the determination of river barriers based on river connectivity and the fish passage effect of a hub fishway may be implemented through the following examples.

[0091] The river connectivity is determined according to the longitudinal connectivity index of the river; the longitudinal connectivity index of the river is calculated by the formula: Determine; where C is the longitudinal connectivity index of the river, a is the barrier coefficient corresponding to the i-th hub, b is the position correction coefficient of the i-th hub, and L is the length of the river;

[0092] The fish passing effect of the hub fishway is determined according to the fish passing efficiency and the proportion of migratory fish population; the fish passing efficiency is calculated by the formula: Determine the proportion of migratory fish populations through the formula: Determine; where n is the fish passing efficiency, N1 is the number of fish at the fishway entrance, N2 is the number of fish at the fishway exit, p is the proportion of migratory fish population, N is the population size, and N0 is the number of migratory fish population;

[0093] The river barrier is constructed according to the river connectivity and the fish passing effect of the hub fishway.

[0094] In the embodiment of the present invention, the server starts to process data about a canal and its related rivers to determine the river connectivity. The canal includes various types of hub facilities, such as sluices, ship locks, and small dams.

[0095] For a type of hub, a sluice gate, due to its structural and functional characteristics, usually has a more obvious barrier effect on the longitudinal connectivity of the river. After studying a large number of similar sluice gates and analyzing the actual situation of the canal sluice gate, it was determined that the barrier coefficient of this sluice gate is 0.7. This is because the gate of the sluice gate completely blocks the natural flow of water when closed, and will only open to allow water to flow through under specific scheduling operations, which greatly affects the longitudinal connectivity of the river.

[0096] The lock has a relatively low barrier coefficient of 0.3. Although the lock will affect the water flow to a certain extent, it is mainly to meet the needs of ship navigation. The barrier to the water flow is intermittent during normal operation, and there are special water facilities to minimize the impact on river connectivity.

[0097] The barrier coefficient of small water dams is set to 0.5. Small water dams are mainly used to adjust local water levels or for simple irrigation and diversion. They do not completely block the water flow like large sluices, but they still have a certain obstruction effect on the longitudinal connectivity of the river.

[0098] Next, we analyze the impact of the location of the hub on river connectivity. For hubs located upstream of the river, the location correction factor is determined to be 1.3. This is because the hub upstream has a more critical initial impact on the water distribution and flow direction of the entire river. For example, if the upstream sluice is closed, it will directly affect a long section of the downstream river without sufficient water supply, thereby greatly changing the connectivity of the river.

[0099] The position correction coefficient of the hub located in the middle reaches is 1.1. Although the hub in the middle reaches does not affect the initial water flow state of the entire river like the hub in the upper reaches, it will change the continuity of the water flow in the middle area of ​​the river, affect the water exchange between the upstream and downstream and the migration path of organisms, etc., so it also needs to be corrected according to its location characteristics.

[0100] The position correction coefficient of the hub located downstream is set to 0.9. The impact of the hub in the downstream on river connectivity is relatively small, because most of the river ecosystems and water flow dynamics have been basically formed in the upper and middle reaches, and the hub in the downstream has more effects on local water levels and small-scale water flows.

[0101] The server obtained the precise length measurement data of the river. After a professional measurement team used advanced measurement technology (such as satellite remote sensing measurement combined with field measurement verification), it was determined that the length of the river was 200 kilometers.

[0102] Then, the server calculates the longitudinal connectivity index of the river according to the relevant calculation logic based on the barrier coefficient, position correction coefficient and river length of each hub determined above. For example, suppose there are 2 sluices (both located in the middle reaches), 3 ship locks (1 in the upper reaches and 2 in the middle reaches) and 1 small water barrier (located in the lower reaches) in the canal. The server calculates the impact of each hub on connectivity separately, and then combines them to derive the longitudinal connectivity index of the river. This index reflects the quantitative indicator of the degree of obstruction or connectivity of the river in the longitudinal direction due to the existence of these hub facilities. The higher the index, the greater the impact on the connectivity of the river.

[0103] The server receives data from the fishway monitoring system, which consists of underwater cameras, acoustic sensors and other equipment. At an important fishway in the canal, the underwater camera can clearly identify and count the number of fish.

[0104] During a specific period of time, the number of fish at the entrance of the fishway was counted as 1,500. These schools of fish included a variety of fish that were trying to reach other areas of the river through the fishway, driven by instinct or environmental factors.

[0105] At the same time, at the exit of the fishway, another set of underwater cameras monitored and counted the number of fish as 1,200. This data reflects the actual number of fish passing through the fishway. The difference from the number of fish at the entrance may be due to the knots inside the fishway, water flow conditions or other factors that caused some fish to fail to pass successfully.

[0106] The server calculates the fish passage efficiency based on the calculation logic of fish passage efficiency, using the fish number data at the fishway entrance and exit. In this example, the calculated fish passage efficiency reflects the effectiveness of the fishway for fish passage. If the fish passage efficiency is low, it may mean that there is a problem with the design of the fishway, such as the slope of the fishway is too steep, the water flow speed is uneven, or the channel width inside the fishway is not enough, which hinders the smooth passage of fish.

[0107] The server obtains detailed data on the number of species and migratory fish populations in the river area from the fishery resource survey database. The data in this database is obtained by a professional fishery survey team through long-term sampling, marking and statistical analysis.

[0108] A comprehensive survey of the canal and its surrounding waters has determined that the total population is 8,000, including local resident fish and fish that migrate seasonally through the area.

[0109] Among them, the number of migratory fish populations is 2,000. Migratory fish account for a certain proportion of the entire fish population, and their survival and reproduction often depend on the connectivity of rivers and suitable ecological environments. For example, some migratory fish need to migrate from the ocean to the upper reaches of the river to spawn and reproduce.

[0110] The server uses the population size and migratory fish population size data to calculate the migratory fish population ratio based on the calculation logic of the migratory fish population ratio. This ratio reflects the relative importance of migratory fish in the entire fish population. If the migratory fish population ratio changes significantly, it may mean that the canal and its related facilities have a significant impact on the survival and reproduction of migratory fish, such as poor fish passage in the fishway, or the destruction of river connectivity, which affects the normal migration path of migratory fish.

[0111] After determining the river connectivity and the fish passage effect of the hub fishway, the server began to comprehensively analyze the impact of these two factors on river barriers.

[0112] If the longitudinal connectivity index of a river is high, it means that the hub facilities in the river have a greater blocking effect on the water flow, which may affect the normal migration path of fish, including the migration of migratory fish. For example, when the longitudinal connectivity index shows that the river is severely blocked by multiple hubs, even if fishways exist, fish may find it difficult to reach various areas of the river smoothly.

[0113] At the same time, the fish passage effect of the hub fishway also has an important impact on river barriers. If the fish passage efficiency is low and the proportion of migratory fish populations is small, it means that the fishway is not playing its due role well. Even if the river connectivity exists in theory (there are fishways connecting the blocked areas), in reality it is still difficult for fish to effectively pass through these blocked areas.

[0114] The server determines the river barrier factor by comprehensively considering the river connectivity and the fish passage effect of the hub fishway. For example, if the river connectivity shows that there are multiple large hubs that seriously block the river, and the fish passage effect of the hub fishway is not good (such as the fish passage efficiency is less than 50% and the proportion of migratory fish populations is less than 20%), then the server determines that the river barrier is very high. In this case, organisms in the river, especially aquatic organisms such as fish that rely on river connectivity for survival and reproduction, will face great challenges to survival.

[0115] On the contrary, if the river connectivity is reduced to a certain extent (but the longitudinal connectivity index is relatively low), and the fish passage effect of the hub fishway is good (such as the fish passage efficiency is higher than 70% and the proportion of migratory fish population is normal), then the river barrier is relatively low. This means that although there are some hub facilities, through effective fishway construction and management, the impact of river barrier on aquatic ecosystems is relatively small, and organisms can still maintain their normal survival and reproduction activities to a certain extent.

[0116] The server will use the constructed river barrier elements as an important part of the canal river aquatic ecological impact assessment system, so as to further comprehensively analyze the status of the entire canal river aquatic ecology.

[0117] In the embodiment of the present invention, the determination of river fragmentation based on river curvature and the self-purification capacity of the river in the bend section may be implemented through the following examples.

[0118] The river curvature is determined according to the ratio of the canal curvature to the original river curvature; the ratio of the canal curvature to the original river curvature is determined by the formula: Determine; where S is the ratio of the canal curvature to the original river curvature, L T is the length of the original river channel measured along the center line of the river channel; L0 is the straight-line distance between the upstream and downstream sections of the original river channel; L T ' is the length of the original river channel measured along the center line of the river channel; L0' is the straight-line distance between the upstream and downstream sections of the original river channel;

[0119] The self-purification capacity of the river in the bend section is determined according to the water quality reduction rate of the river section before and after the bend cutting; the water quality reduction rate of the river section before and after the bend cutting is calculated by the formula: Determine; where R is the water quality reduction rate of the river section before and after the bend cutting, C0 is the concentration of the river water quality in the bend cutting section before the bend cutting, C1 is the concentration of the river water quality in the bend cutting section after the bend cutting, L c is the length of the river at the bend;

[0120] The river fragmentation is constructed according to the river curvature and the self-purification capacity of the river in the bend section.

[0121] In the embodiment of the present invention, illustratively, the server starts to process data about a canal and its original river channel to determine the river curvature. First, accurate measurement data of the original river channel needs to be obtained.

[0122] A professional surveying team used advanced surveying instruments, such as high-precision total stations and satellite positioning systems (GPS), to conduct measurements along the center line of the original river channel, and concluded that the length of the original river channel measured along the center line of the river channel was 80 kilometers.

[0123] At the same time, the straight-line distance between the upstream and downstream sections of the original river course was measured. The surveyors selected appropriate section locations upstream and downstream of the original river course, and measured the straight-line distance between the two sections, and the result was 50 kilometers. The accuracy of these measurement data is crucial for the subsequent calculation of the river curvature.

[0124] After the canal was built, the same surveying team measured the canal according to the same surveying standards. Assume that the length of the canal along the centerline is 60 kilometers, and the straight-line distance between the upstream and downstream sections of the canal is 40 kilometers.

[0125] The server calculates the ratio of the canal curvature to the original river curvature according to the obtained measurement data of the original river channel and the canal and the relevant calculation logic. This ratio can intuitively reflect the change in the curvature of the canal relative to the original river channel.

[0126] For example, the curvature of the original river channel is reflected by the relationship between the length of its centerline and the straight-line distance between the upstream and downstream sections, and the same is true for the canal. By comparing this relationship between the two, the ratio of the canal curvature to the original river channel curvature is obtained. If this ratio is high, it means that the curvature of the canal is better preserved relative to the original river channel; if the ratio is low, it means that the curvature of the canal has changed significantly relative to the original river channel. This change in curvature will have many impacts on the river ecosystem, such as water flow speed, biological habitat distribution, etc.

[0127] The server obtains the concentration data of the water quality of the river before the bend is cut from the water quality monitoring database. The data in this database is collected from multiple water quality monitoring stations distributed in the river of the bend.

[0128] Taking ammonia nitrogen concentration as an example, before the bend was straightened, the ammonia nitrogen concentration of the river water quality in the bend section was 3mg / L. These monitoring stations are equipped with high-precision water quality monitoring instruments, such as ammonia nitrogen analyzers, which can accurately measure the ammonia nitrogen content in river water quality.

[0129] In addition to ammonia nitrogen concentration, concentration data of other important water quality indicators were also obtained, such as chemical oxygen demand (COD) and total phosphorus concentration. It is assumed that the chemical oxygen demand concentration of the river water quality before the bend is straightened is 20 mg / L, and the total phosphorus concentration is 0.3 mg / L.

[0130] After the canal straightening project was completed, the same water quality monitoring station continued to monitor the water quality of the river in the straightened section.

[0131] For example, after the bend was straightened, the ammonia nitrogen concentration of the river water in the bend section became 2 mg / L, the chemical oxygen demand concentration became 15 mg / L, and the total phosphorus concentration became 0.2 mg / L. These data reflect the impact of the bend straightening project on the water quality of the river in the bend section.

[0132] The server obtains the length data of the river's bend section. After precise measurement by the surveying team, the length of the river's bend section is 10 kilometers.

[0133] Then, according to the calculation logic of the water quality reduction rate of the river section before and after the bend cutting, the water quality concentration data before and after the bend cutting and the length of the river in the bend cutting section are used to calculate the water quality reduction rate of the river section before and after the bend cutting. This reduction rate can reflect the changes in the self-purification capacity of the river in the bend cutting section. For example, for the calculation of the reduction rate of ammonia nitrogen concentration, by comparing the ammonia nitrogen concentration before and after the bend cutting and the length of the river in the bend cutting section, the reduction of ammonia nitrogen in the river in the bend cutting section can be obtained, thereby inferring the impact of bend cutting on the self-purification capacity of the river. If the water quality reduction rate is high, it means that bend cutting may improve the self-purification capacity of the river; if the reduction rate is low or negative, it may indicate that bend cutting has a negative impact on the self-purification capacity of the river.

[0134] After determining the river curvature and the self-purification capacity of the river in the bend section, the server began to comprehensively analyze the impact of these two factors on the fragmentation of the river.

[0135] Changes in river curvature will directly affect the ecological structure of the river. For example, when the canal curvature is lower than the original river curvature, it means that the canal is less curved, which may lead to faster water flow. Faster water flow will change the sediment deposition pattern at the bottom of the river, and some slow-flowing areas that were originally suitable for the survival of benthic organisms may disappear, thereby destroying the habitat of benthic organisms.

[0136] At the same time, the reduction in curvature may also affect the living environment of fish. Many fish rely on the diverse habitats such as slow-flowing areas, deep pools and shallows formed by curved rivers to reproduce, forage and avoid predators. If the curvature is reduced, these diverse habitats may decrease, resulting in changes in the number and distribution of fish populations.

[0137] The change in the self-purification capacity of the river in the bend section is also of great significance to the river ecology. If the water quality reduction rate of the river section before and after the bend is high, it means that the bend may have improved the self-purification capacity of the river. This may increase the dissolved oxygen content in the river, improve the water quality, and be beneficial to the survival of aquatic organisms. For example, some fish and aquatic plants with high water quality requirements may increase their population due to the improvement of water quality.

[0138] On the contrary, if the water quality reduction rate of the river section before and after the bend is low or even negative, it may mean that the bend cutting process has destroyed the ecological balance in the river, such as destroying the microbial community in the river or changing the interaction between the water flow and the riverbed, resulting in water quality deterioration. This will have a negative impact on the organisms in the river, such as causing the death or migration of some sensitive aquatic organisms.

[0139] The server determines the river fragmentation factor by comprehensively considering the river's curvature and the self-purification capacity of the river in the bend-cut section. For example, if the river's curvature is very low relative to the original river's curvature, and the water quality reduction rate of the river section before and after the bend is negative, then the server determines that the river fragmentation is very high. In this case, the ecological integrity of the river has been greatly damaged, the biological habitat in the river has been severely fragmented, the migration and reproduction paths of the organisms have been blocked, and the river's ecosystem is at risk of collapse.

[0140] On the contrary, if the river curvature has changed to a certain extent (but the ratio of the canal curvature to the original river curvature is relatively high), and the water quality reduction rate of the river section before and after the bend is high, then the river fragmentation is relatively low. This means that although the river curvature and self-purification capacity have changed to some extent, these changes have a relatively small impact on the river ecosystem, and organisms can still adapt to this change to a certain extent, and the ecological function of the river can still be well maintained.

[0141] The server will use the constructed river fragmentation factor as an important part of the canal river aquatic ecological impact assessment system, so as to further comprehensively analyze the status of the entire canal river aquatic ecology.

[0142] In the embodiment of the present invention, the determination of river water ecological loss based on benthic organism loss and biological loss caused by suspended matter can be implemented through the following examples.

[0143] The benthic organism loss is determined according to the organism loss caused by underwater construction; the organism loss caused by underwater construction is determined by the formula: W i =D i ×S i Determine; among them, W i D is the biological loss caused by underwater construction of the i-th biological resource. i To evaluate the density of biological resources of the i-th type in the region, S i is the water area occupied by the i-th species of organisms;

[0144] Determine the biological loss caused by the suspended matter based on the number of fish eggs and larvae, the loss of zooplankton and the loss of phytoplankton caused by the diffusion of the suspended matter;

[0145] The river water ecological loss is constructed according to the benthic biological loss and the biological loss caused by the suspended matter.

[0146] In the embodiment of the present invention, the server obtains data on the density of benthic biological resources in the assessment area from a biological resource survey agency. The survey team sets up multiple sampling points in the canal and its surrounding waters, uses standard sampling methods, such as using a mud sampler to collect riverbed mud samples, and then analyzes the samples in the laboratory to obtain the resource density of different types of benthic organisms.

[0147] Taking river clams as an example, after analyzing and counting a large number of samples, it was found that the resource density of river clams in the assessment area was 8 per square meter. This resource density was determined based on a comprehensive analysis of data from different sampling points, taking into account the distribution of river clams in the entire assessment area.

[0148] In addition to river clams, there are other benthic organisms such as snails. The density of snail resources was investigated to be 12 per square meter. These data accurately reflect the distribution of different types of benthic organisms in the assessment area.

[0149] The survey team also determined the area of ​​water occupied by each benthic organism. For river clams, a detailed geographic information system (GIS) analysis combined with field surveys determined that the area of ​​water occupied by river clams was 80 square meters. This area was determined based on the range of environments suitable for river clams to survive, including factors such as the type of riverbed substrate, water depth, and water flow rate.

[0150] The area of ​​water occupied by snails was found to be 100 square meters. These data were obtained through detailed mapping and analysis of snail habitats. For example, some shallow water areas and areas with abundant aquatic plants may be the habitats where snails are concentrated. The area of ​​water occupied by snails was obtained through accurate measurement of these areas.

[0151] The server uses the calculation logic of biological losses caused by underwater construction and the acquired data on benthic biological resource density and occupied water area to calculate the loss of each benthic organism.

[0152] For river clams, the loss of river clams was calculated based on the density of river clams and the area of ​​water they occupied due to the destruction of their habitats caused by underwater construction (such as excavation and piling in canal construction). This loss reflects the direct impact of underwater construction on the number of river clams, which may lead to the death of river clams, migration or reproduction obstruction.

[0153] Similarly, for snails, the loss of snails is calculated according to their resource density and the area of ​​water occupied. Then, the server summarizes the loss of various benthic organisms to obtain the total loss of benthic organisms. This total loss of benthic organisms is an important part of assessing the loss of river water ecology, which reflects the degree of damage to the benthic community caused by underwater construction.

[0154] The server receives data from fishery monitoring teams, which are obtained through specialized fish egg and larvae collection equipment and survey methods.

[0155] During the construction of the canal or related engineering activities, suspended matter generated by earthwork excavation, transportation and other operations spreads in the water. The monitoring team set up sampling points in different waters and collected fish egg and larvae samples using plankton nets.

[0156] After a period of monitoring and statistics, it was found that the number of fish eggs and fry lost due to the spread of suspended matter was 600. These fish eggs and fry may not hatch normally due to the coverage of suspended matter, or the young fish may die because the suspended matter affects their breathing, feeding and other physiological functions.

[0157] The loss of zooplankton was also determined through field sampling and laboratory analysis. The monitoring team used water samplers to collect water samples from different water layers, and then used microscopes in the laboratory to count and identify the zooplankton in the water samples.

[0158] Within the canal project's impact area, the living environment of zooplankton has changed due to the influence of suspended matter. For example, suspended matter may reduce the transparency of the water body, affecting the visual predation ability of zooplankton; it may also block the zooplankton's filter feeding organs, affecting its feeding efficiency. After detailed investigation and statistics, it was found that the loss of zooplankton was 1,200 per cubic meter (here expressed as the loss per unit volume).

[0159] For phytoplankton, water samples are also collected using a water sampler, and then the number of phytoplankton is determined in the laboratory through methods such as chlorophyll content measurement and cell counting.

[0160] Suspended matter diffuses in the water, blocking sunlight and reducing the photosynthesis of phytoplankton. At the same time, the precipitation of suspended matter may cover the surface of phytoplankton, affecting its normal growth and reproduction. According to investigation and statistics, the loss of phytoplankton is 1,800 per cubic meter.

[0161] The server combines the number of fish eggs and larvae, the amount of zooplankton loss, and the amount of phytoplankton loss caused by the spread of suspended matter to determine the biological loss caused by suspended matter. The loss of these different types of organisms reflects the impact of suspended matter on the structure of river aquatic biological communities, from primary producers (phytoplankton) to primary consumers (zooplankton) to the early life stages of fish (fish eggs and larvae), which will have a significant impact on the balance and function of the entire river water ecosystem.

[0162] After determining the biological losses caused by benthic organisms and suspended matter, the server began to comprehensively analyze the impact of these two factors on river water ecological losses.

[0163] Benthic organisms play an important role in river water ecosystems. For example, benthic organisms such as river clams and snails are decomposers and partial consumers in river ecosystems. They can decompose organic matter and promote material circulation. The loss of benthic organisms will slow down the decomposition of organic matter in river bottom sediments, affecting the release and circulation of nutrients.

[0164] At the same time, benthic organisms are also the food source for many fish and other aquatic organisms. The reduction in the number of benthic organisms will affect the survival and reproduction of organisms that feed on them, may lead to a chain reaction in the food chain, and affect the structure and stability of the entire river water ecosystem.

[0165] The biological loss caused by suspended matter also has a profound impact on the river water ecosystem. The loss of fish eggs and larvae directly affects the recruitment of fish populations. If a large number of fish eggs and larvae die, the number of fish populations in the future will decrease, which may change the structure of fish communities in the river, and some organisms that rely on fish eggs and larvae for food will also be affected.

[0166] The loss of zooplankton and phytoplankton is equally important. Phytoplankton is the primary producer in the river ecosystem. They convert solar energy into chemical energy through photosynthesis, providing energy source for the entire ecosystem. The reduction in the number of phytoplankton will lead to a reduction in energy input to the entire ecosystem. Zooplankton feeds on phytoplankton, and their loss will affect the transmission efficiency of the food chain, further affecting the survival of organisms at higher trophic levels.

[0167] The server comprehensively considers the loss of benthic organisms and the biological loss caused by suspended matter to determine the river water ecological loss factors. For example, if the loss of benthic organisms is large, such as the number of river clams and snails has decreased by more than 50%, and the biological loss caused by suspended matter is also serious, such as the loss of more than 800 fish eggs and fry, the loss of more than 1,500 zooplankton / cubic meter, and the loss of more than 2,000 phytoplankton / cubic meter, then the server determines that the river water ecological loss is very large. In this case, the river water ecosystem has been strongly impacted, biodiversity may be reduced, and the functions of the ecosystem such as material circulation and energy flow may be seriously disturbed.

[0168] On the contrary, if the loss of benthic organisms is relatively small, such as the reduction of the number of river clams and snails within 20%, and the biological loss caused by suspended matter is also limited, such as the loss of fish eggs and larvae within 300, the loss of zooplankton within 800 per cubic meter, and the loss of phytoplankton within 1,000 per cubic meter, then the river water ecological loss is relatively small. This means that although there is a certain ecological impact, the river water ecosystem can still maintain its basic structure and function.

[0169] The server will use the constructed river water ecological loss factors as an important part of the canal river aquatic ecological impact assessment system, so as to further comprehensively analyze the status of the entire canal river aquatic ecology.

[0170] In the embodiment of the present invention, the determination of river aquatic ecological changes based on changes in river bigenic factors and changes in fish population distribution can be implemented through the following examples.

[0171] Determine the change of the river biogenic factor according to the change of oxygen content in the water before and after the canal was built, the change of ammonia nitrogen in the water before and after the canal was built, and the change of total phosphorus in the water before and after the canal was built;

[0172] Determine the distribution changes of the fish populations based on fish stock index, species occurrence frequency and species relative abundance;

[0173] The changes in the river's aquatic ecology are constructed based on the changes in the river's biogenic factors and the changes in the fish population distribution.

[0174] In the embodiment of the present invention, the server obtains data on the oxygen content of the water body before the canal is built from the water quality monitoring system. Before the canal was built, the water quality monitoring agency set up multiple water quality monitoring stations along the canal and related waters. These monitoring stations are equipped with high-precision dissolved oxygen meters that can accurately measure the oxygen content in the water body in real time.

[0175] For example, at a representative monitoring site, after long-term monitoring (at least one full hydrological year), it was found that the average oxygen content of the water at the site was 8 mg / L before the canal was built. This data is a comprehensive statistics of measurement results in different seasons and time periods, taking into account the impact of factors such as water temperature and water flow rate on oxygen content.

[0176] Through the aggregation and analysis of data from multiple monitoring stations throughout the canal and its related waters, a relatively comprehensive and accurate picture of the oxygen content in the water before the canal was built was obtained.

[0177] Similarly, for the monitoring of ammonia nitrogen in water bodies, monitoring stations use ammonia nitrogen analyzers for measurement. Before the canal was built, each monitoring station collected water samples and analyzed the ammonia nitrogen content.

[0178] Taking a key monitoring area as an example, the average ammonia nitrogen content in the water of this area is 1mg / L. This data is obtained through multiple sampling (at least once a week) according to standard analysis methods. In the waters related to the entire canal, the data from multiple monitoring stations are combined to obtain a comprehensive picture of the ammonia nitrogen content in the water before the canal was built.

[0179] For the monitoring of total phosphorus in water bodies, a special method for determining phosphorus content is used. Before the canal was built, water quality monitoring personnel collected water samples at various monitoring sites and analyzed the total phosphorus content.

[0180] In a typical canal branch water area, the total phosphorus content in the water body was monitored to be 0.1 mg / L. By summarizing and analyzing the data from many monitoring stations throughout the canal water area, the overall status of total phosphorus in the water body before the canal was built was determined.

[0181] After the canal was built, the original water quality monitoring stations continued to monitor the oxygen content of the water. Since the construction of the canal may have changed the water flow speed, water depth and other factors, the oxygen content of the water has changed.

[0182] At the representative monitoring site mentioned above, after a period of time (for example, monitoring data one year after the canal was built and put into operation), it was found that the average oxygen content in the water changed to 6 mg / L. This change may be due to factors such as the canal construction changing the mixing degree of the water body and the distribution of aquatic plants.

[0183] Through a comprehensive analysis of the data from all monitoring stations throughout the canal and its related waters, the overall status of water oxygen content after the canal was completed was obtained.

[0184] As for the amount of ammonia nitrogen in the water, the monitoring stations continued to measure it after the canal was built. In the previous key monitoring areas, it was found that the amount of ammonia nitrogen in the water body changed to 1.5 mg / L. This change may be caused by factors such as changes in surrounding land use after the canal was built, changes in sewage discharge, or changes in water flow speed.

[0185] By summarizing the monitoring data of the relevant waters of the entire canal, we obtained a comprehensive picture of the amount of ammonia nitrogen in the water after the canal was built.

[0186] After the canal was built, the total phosphorus content in the typical canal branch waters was monitored to be 0.2 mg / L. The construction of the canal may have affected the sources of phosphorus (such as soil erosion, domestic sewage discharge, etc.) and removal pathways (such as sedimentation, aquatic plant absorption, etc.), leading to changes in total phosphorus content.

[0187] Through comprehensive analysis of data from all monitoring stations, the overall situation of total phosphorus in the water body after the completion of the canal was determined.

[0188] The server determined the impact of this biogenic factor on the river's aquatic ecology by comparing the changes in water oxygen content before and after the canal was built. The oxygen content dropped from 8mg / L to 6mg / L, a change that has a significant impact on aquatic life.

[0189] For example, for some fish that require high oxygen levels, such as salmon, lower oxygen levels may limit their survival range and reproduction capacity. Some aquatic insects and crustaceans are also sensitive to oxygen levels, and a decrease in oxygen levels may lead to a decrease in their population or a reduction in their distribution range.

[0190] Comparing the changes in ammonia nitrogen content in the water from 1 mg / L to 1.5 mg / L before and after the canal was built, the increase in ammonia nitrogen content may have a negative impact on the river's aquatic ecology.

[0191] Ammonia nitrogen is a nutrient, but excessive ammonia nitrogen can be toxic to aquatic organisms. Some aquatic plants may grow excessively due to increased ammonia nitrogen concentration, leading to aggravated eutrophication of water bodies. For fish, high concentrations of ammonia nitrogen can damage their gill tissues and affect their respiratory function, which in turn affects the growth and survival of fish.

[0192] Consider the change of total phosphorus in water from 0.1mg / L to 0.2mg / L. Total phosphorus is also one of the important factors leading to eutrophication of water bodies.

[0193] Increased total phosphorus content will promote the growth of phytoplankton and may lead to algae blooms. Excessive growth of algae will consume a large amount of dissolved oxygen, further reducing the oxygen content of the water body, while also affecting the transparency of the water body and having a negative impact on the living environment of underwater organisms, such as affecting the foraging ability of some fish and aquatic animals that rely on visual predation.

[0194] The server comprehensively analyzes the changes in oxygen content, ammonia nitrogen and total phosphorus content in these water bodies to determine the overall changes in river biogenic factors. These changes reflect the impact of canal construction on the aquatic ecological chemical environment of the river and are an important component in determining changes in the river's aquatic ecology.

[0195] The server obtains data on fish stock index from the Fishery Resources Survey Agency. The fishery survey team determines the fish stock index by conducting a large-scale fish census in the canal and its related waters.

[0196] Before the canal was built, the survey team used a variety of survey methods, such as gillnet fishing, electric fishing (within legal and scientific limits), sonar detection, etc., to conduct a comprehensive survey of fish in the canal waters. After detailed statistics and analysis, it was determined that the conservation index of a representative fish population was 0.8. This conservation index reflects the relative number of the fish population in the canal waters. The higher the value, the larger the population.

[0197] After the canal was built, the survey team used the same survey method to conduct a fish census in the same survey area. After analysis, it was found that the conservation index of the representative fish population had changed to 0.6. This change may be due to factors such as the canal construction changing the fish habitat and food source.

[0198] To determine the frequency of species occurrence, the fisheries survey team set up a number of long-term monitoring stations in the canal and its related waters. These stations conduct fish observations and records on a regular basis (for example, once a week).

[0199] Before the canal was built, for a particular fish species, the frequency of occurrence in a particular monitoring area was 4 times per week, which means that the species was found during most of the monitoring time, indicating that the species was relatively common in the area.

[0200] After the canal was built, the species was found to occur twice a week using the same monitoring method and cycle. This change suggests that the canal construction may have changed the habitat suitability or migration path of the species, resulting in a lower probability of its occurrence in the area.

[0201] Fisheries surveyors analyze fish census data to determine the relative abundance of species. Before the canal was built, the relative abundance of a particular fish species in the fish community within the canal waters was 30%. This means that the species accounted for 30% of the total fish community, reflecting the relative importance of the species in the community.

[0202] After the canal was built, the census data was reanalyzed and it was found that the relative abundance of the species had changed to 20%. This change may be due to the ecological environment changes caused by the construction of the canal, which changed the competitive advantage of the species in the community, or due to the changes in the number of other species, which changed the relative proportion of the species.

[0203] The server determines the changes in the distribution of fish populations based on the data obtained, including the fish stock index, species occurrence frequency, and species relative abundance. For example, the decline in the fish stock index, the decrease in species occurrence frequency, and the decrease in species relative abundance all indicate that the fish population has been affected to a certain extent after the construction of the canal, and its distribution range may have shrunk and the population may have decreased. This change may be caused by factors such as the canal construction changing the water environment, destroying the fish habitat, or affecting the fish's food source.

[0204] After determining the changes in river biogenic factors and fish population distribution, the server began to comprehensively analyze the impact of these two factors on changes in river aquatic ecology.

[0205] After the canal was built, changes in biogenic factors such as the decrease in water oxygen content and the increase in ammonia nitrogen and total phosphorus will directly affect the living environment of fish. For example, the decrease in oxygen content will cause some fish with high oxygen demand to reduce their activity range and even cause death. The eutrophication caused by the increase in ammonia nitrogen and total phosphorus may change the food structure of fish, and some fish that feed on zooplankton may be affected by changes in the number and type of zooplankton.

[0206] Changes in these biogenic factors can also affect fish reproduction. For example, insufficient oxygen may affect the hatching rate of fish eggs, and excessive ammonia nitrogen may be toxic to fish eggs and young fish, thus affecting the replenishment of fish populations.

[0207] Changes in the distribution of fish populations will also have a feedback effect on river aquatic ecosystems. For example, a decrease in the fish retention index, species occurrence frequency, and species relative abundance means that fish predation pressure on plankton, benthic organisms, etc. will decrease. This may lead to an increase in the number of plankton, which in turn affects the transparency and oxygen content of the water body. At the same time, as important consumers in the ecosystem, the reduction in the number of fish populations may affect the structure of the entire food chain, resulting in a decrease in the number of some organisms that feed on fish or a change in their foraging behavior.

[0208] The server determines the factors of river aquatic ecological change by comprehensively considering the changes in river biological factors and changes in fish population distribution. For example, if the changes in river biological factors show that the water environment has seriously deteriorated, such as a sharp drop in oxygen content, a significant increase in ammonia nitrogen and total phosphorus, and at the same time the changes in fish population distribution show that the number and distribution range of fish have been greatly reduced, then the server determines that the changes in river aquatic ecology are developing in a direction that is not conducive to ecological stability. In this case, the structure and function of the river aquatic ecosystem may be severely damaged, biodiversity may be reduced, and the self-regulation ability of the ecosystem will be weakened.

[0209] On the contrary, if the changes in river biogenic factors are small, such as only slight changes in oxygen content, ammonia nitrogen content and total phosphorus content, and the changes in fish population distribution are not obvious, such as changes in fish retention index, species occurrence frequency and species relative abundance are all within a small range, then the changes in river aquatic ecology are relatively small. This means that the impact of canal construction on river aquatic ecology is within an acceptable range, and the ecosystem can still maintain its basic structure and function.

[0210] The server will use the constructed river aquatic ecological change factors as an important part of the canal river aquatic ecological impact assessment system, so as to further comprehensively analyze the status of the entire canal river aquatic ecology.

[0211] In the embodiment of the present invention, the canal river aquatic ecological impact assessment system is constructed based on the river barrier, the river fragmentation, the river water ecological loss and the river aquatic ecological change, which can be implemented through the following examples.

[0212] The element layer is based on the river connectivity, the fish passing effect of the hub fishway, the river curvature, the self-purification capacity of the river in the bend section, the loss of benthic organisms, the biological loss caused by suspended matter, the change of the river biogenic factor and the change of the fish population distribution;

[0213] The river barrier, the river fragmentation, the river water ecological loss and the river aquatic ecological change are used as criterion layers;

[0214] The impact on aquatic ecology of canals and rivers is taken as the target layer;

[0215] The element layer and the criterion layer are weighted based on the AHP hierarchy analysis method, and the canal river aquatic ecological impact assessment system is constructed according to the target layer, the element layer with weights assigned, and the criterion layer.

[0216] In the embodiment of the present invention, illustratively, the server first processes the data related to river connectivity as part of the feature layer. In the previous calculation, the data related to river connectivity, such as the longitudinal connectivity index of the river, has been determined.

[0217] For example, for a canal and its related rivers, the server has analyzed the barrier coefficients, position correction coefficients, and river length of different hubs (such as sluices, ship locks, etc.) to derive the longitudinal connectivity index of the river. Assuming that there are three sluices and two ship locks in this canal, through a detailed analysis of each hub, including the structural characteristics of the sluices, the mode of operation, and the navigation frequency of the ship locks, the calculated river longitudinal connectivity index reflects the degree to which the longitudinal connectivity of the river in its natural state has been changed. These data describe the connectivity of the river in detail, and are integrated into the feature layer to provide basic data for the subsequent construction of the evaluation system.

[0218] Next, the server integrates data related to the fish passage effect of the hub fishway, including data such as the fish passage efficiency and the proportion of migratory fish populations.

[0219] Data obtained from the fishway monitoring system show that there are 1,200 fish at the entrance of a specific fishway and 900 fish at the exit of the fishway. The fish passage efficiency is calculated accordingly. At the same time, the fishery resource survey database shows that the population is 6,000 and the number of migratory fish is 1,500, and the proportion of migratory fish population is obtained. These data reflect the actual effect of the hub fishway in helping fish pass through the barrier area. Incorporating them into the element layer will help to comprehensively evaluate the impact of the canal river on aquatic ecology.

[0220] For river sinuosity, the server integrated the previously calculated canal sinuosity and original river sinuosity ratio data into the feature layer.

[0221] For example, by measuring the length of the original river along the centerline of the river, the straight-line distance between the upstream and downstream sections of the original river, and the corresponding data after the construction of the canal, it was found that the ratio of the canal curvature to the original river curvature was 70%. This ratio reflects the change in the curvature of the canal relative to the original river, which is an important factor affecting river ecology. Taking it as part of the element layer, it is possible to comprehensively consider the impact of river morphological changes on aquatic ecology when constructing an evaluation system.

[0222] The server integrates data related to the self-purification capacity of the river in the bend section, such as the water quality reduction rate of the river section before and after the bend, into the feature layer.

[0223] In a certain bend section, the ammonia nitrogen concentration of the river water quality in the bend section before straightening was 2.5 mg / L, and the ammonia nitrogen concentration of the river water quality in the bend section after straightening was 2 mg / L. The length of the river section was 8 kilometers. Through the corresponding analysis, the water quality reduction rate of the river section before and after the bend was obtained. This data reflects the impact of the bend cutting on the self-purification capacity of the river. Including it in the element layer will help to comprehensively evaluate the impact of canal construction on the self-purification function of river water quality.

[0224] The server integrates data related to the loss of benthic organisms. From the biological resource survey data, the loss of different types of benthic organisms (such as clams, snails, etc.) caused by underwater construction is obtained.

[0225] For example, the resource density of river clams is 10 per square meter, and the water area they occupy is 50 square meters. Through relevant calculations (based on the principle), the loss of river clams can be obtained. For snails, there are also corresponding density and area data, which can be used to obtain the loss of snails. These benthic biomass loss data are summarized and put into the element layer, so that the impact of underwater construction on benthic biomass can be considered in the evaluation system.

[0226] The server integrates data related to biological losses caused by suspended matter into the feature layer. This includes data on the number of fish eggs and larvae, the amount of zooplankton loss, and the amount of phytoplankton loss caused by the spread of suspended matter.

[0227] For example, during the construction of the canal, monitoring revealed that the spread of suspended matter caused a loss of 400 fish eggs and fry, a loss of 1,000 zooplankton per cubic meter, and a loss of 1,500 phytoplankton per cubic meter. These data reflect the impact of suspended matter on aquatic organisms, and incorporating them into the element layer will help to comprehensively assess the extent of damage to the river water ecology caused by suspended matter during the canal construction process.

[0228] The server integrates data related to changes in river biogenic factors, including changes in oxygen content, ammonia nitrogen and total phosphorus in the water before and after the canal was built.

[0229] For example, the oxygen content of the water body was 7mg / L before the canal was built, and it became 5mg / L after it was built; the ammonia nitrogen content of the water body was 1.2mg / L before it was built, and it became 1.6mg / L after it was built; the total phosphorus content of the water body was 0.15mg / L before it was built, and it became 0.2mg / L after it was built. These data reflect the impact of the canal construction on the chemical properties of the water body. Putting them into the element layer can consider the impact of changes in river biogenic factors on aquatic ecology when constructing the evaluation system.

[0230] Finally, the server integrates data related to changes in fish population distribution into the feature layer. This includes data such as fish abundance index, species occurrence frequency, and species relative abundance.

[0231] For example, the retention index of a certain fish population was 0.7 before the canal was built, and it became 0.5 after it was built; the frequency of species appearance was 3 times a week before the canal was built, and it became 2 times a week after it was built; the relative abundance of species was 25% before the canal was built, and it became 20% after it was built. These data reflect the changes in the distribution of fish populations before and after the canal was built, and incorporating them into the element layer will help to comprehensively evaluate the impact of canal construction on fish communities.

[0232] The server determines river barriers based on previous analysis of river connectivity and the effectiveness of pivotal fishways as part of the criteria layer.

[0233] For example, if the longitudinal connectivity index of a river is high, it indicates that the hub facilities in the river have a greater barrier effect on the water flow. At the same time, if the fish passage effect of the hub fishway is not good (such as low fish passage efficiency and a small proportion of migratory fish populations), then it can be determined that the river barrier is high. This kind of river barrier will have an important impact on the migration and reproduction of aquatic organisms. Taking it as the content of the criterion layer can highlight the importance of river barrier on the aquatic ecology of canals and rivers in the evaluation system.

[0234] Based on the previous analysis of river sinuosity and the self-purification capacity of the river in the bend section, the river fragmentation was determined and included in the criterion layer.

[0235] If the river curvature is relatively low relative to the original river curvature, and the water quality reduction rate before and after the bend is not ideal (such as negative or very low), it means that the river fragmentation is high. The increase in river fragmentation means that the integrity of the river ecology is destroyed and the biological habitat is fragmented. Taking it as an element of the criterion layer will help consider the comprehensive impact of changes in river morphology and self-purification capacity on aquatic ecology in the evaluation system.

[0236] The server determines the river water ecological loss based on the biomass loss caused by benthic organisms and suspended matter, and places it into the criterion layer.

[0237] When the loss of benthic organisms is large (such as a significant reduction in the number of many benthic organisms) and the biological loss caused by suspended matter is serious (such as a large number of fish eggs, larvae, zooplankton and phytoplankton), the river water ecological loss is very large. The river water ecological loss reflects the degree of damage to the river aquatic biological community caused by the canal construction. Taking it as part of the criterion layer can reflect the impact of the damage to the biological community on the aquatic ecology of the canal river in the evaluation system.

[0238] Based on the previous analysis of changes in river biogenic factors and fish population distribution, changes in river aquatic ecology were determined and used as the content of the criterion layer.

[0239] If changes in river biogenic factors indicate deterioration of the water environment (such as decreased oxygen content, increased ammonia nitrogen and total phosphorus) and changes in fish population distribution indicate a decrease in the number and distribution of fish, then changes in river aquatic ecology are developing in a direction that is not conducive to ecological stability. Changes in river aquatic ecology comprehensively reflect the overall impact of canal construction on river aquatic ecosystems. Taking it as an element of the criterion layer will help to comprehensively evaluate this impact in the evaluation system.

[0240] The server identifies the impact of canal river aquatic ecology as the target layer. This is the ultimate goal of the entire evaluation system, that is, to comprehensively and comprehensively evaluate the impact of canal construction and related activities on river aquatic ecology.

[0241] This goal covers all aspects of impact, from river barriers, river fragmentation, river water ecological loss to river aquatic ecological changes. By constructing an evaluation system, we can ultimately obtain quantitative or qualitative evaluation results of the impact of the canal river aquatic ecology, providing a decision-making basis for the planning, construction, management and ecological protection of the canal.

[0242] The server constructs a judgment matrix for the element layer, taking eight elements as examples: river connectivity, fish passage effect of hub fishways, river curvature, river self-purification capacity of the bend section, loss of benthic organisms, biological loss caused by suspended matter, changes in river biogenic factors, and changes in fish population distribution.

[0243] Based on expert knowledge, historical data, and understanding of the canal river aquatic ecosystem, the server compares these eight elements in pairs to determine the proportional relationship of their relative importance. For example, for river connectivity and the effect of fish passage through the hub fishway, after analysis, it is believed that river connectivity is more important than the effect of fish passage through the hub fishway in affecting the aquatic ecology of the canal river, and its relative importance ratio may be determined to be 3:1 (this is just an example, the actual ratio will be determined based on detailed analysis). In this way, all elements are compared in pairs to construct a judgment matrix at the element level.

[0244] For the criterion layer, namely the four criteria of river barrier, river fragmentation, river water ecological loss and river aquatic ecological change, the server also constructs a judgment matrix.

[0245] By analyzing the relative importance of these four criteria in affecting the aquatic ecology of canal rivers, for example, it is believed that river barriers may have a more critical impact on aquatic ecology than river fragmentation in some cases, and their relative importance ratio is determined to be 2:1 (also an example). All criteria in the criterion layer are compared pairwise to construct a judgment matrix of the criterion layer.

[0246] The server obtains the weight vector of each element of the element layer through mathematical calculation (such as eigenvector method, etc.) based on the constructed element layer judgment matrix.

[0247] For example, the weight of river connectivity is calculated to be 0.2, the weight of the fish passage effect of the hub fishway is 0.1, the weight of river curvature is 0.15, the weight of the self-purification capacity of the river in the bend section is 0.12, the weight of benthic organism loss is 0.13, the weight of biological loss caused by suspended matter is 0.1, the weight of river source factor change is 0.15, and the weight of fish population distribution change is 0.05 (these are just example weights, and the actual weights are calculated in detail). These weights reflect the relative importance of each factor in affecting the aquatic ecology of the canal river.

[0248] Similarly, the weight vector of each criterion in the criterion layer is calculated according to the criterion layer judgment matrix.

[0249] Assuming the calculation results, the weight of river barrier is 0.35, the weight of river fragmentation is 0.25, the weight of river water ecological loss is 0.2, and the weight of river aquatic ecological change is 0.2 (these are also example weights). These weights indicate the relative importance of each criterion in evaluating the impact of canal river aquatic ecology.

[0250] The server performs consistency check on the element layer judgment matrix, and determines whether the consistency of the judgment matrix is ​​acceptable by calculating the consistency index (CI) and consistency ratio (CR).

[0251] If CR is less than 0.1 (the general acceptance standard), it means that the consistency of the factor-level judgment matrix is ​​acceptable, that is, the relative importance ratio between the factors previously determined is reasonable; if CR is greater than 0.1, the judgment matrix needs to be readjusted until the consistency requirements are met.

[0252] The consistency check is also performed on the criterion layer judgment matrix. CI and CR are calculated in the same way.

[0253] If CR is less than 0.1, it means that the consistency of the criterion layer judgment matrix is ​​good and the relative importance ratio between the criteria determined previously is reliable; if CR is greater than 0.1, the criterion layer judgment matrix needs to be readjusted to ensure the accuracy of the evaluation system.

[0254] The server constructs a comprehensive evaluation model based on the target layer, the weighted element layer, and the criterion layer.

[0255] For each element in the element layer, its score is multiplied by the corresponding weight and then summarized in the criterion layer. For example, for the river barrier criterion, it is composed of elements such as river connectivity and the effect of fish passage through the hub fishway. The score of river connectivity (assuming it is obtained according to a certain scoring standard) is multiplied by its weight 0.2, and the score of the effect of fish passage through the hub fishway is multiplied by its weight 0.1. The two are added together to obtain the score of the river barrier criterion. In the same way, the scores of river fragmentation, river water ecological loss, and river aquatic ecological change criteria are calculated.

[0256] Then, the score of each criterion in the criterion layer is multiplied by its corresponding weight (such as the score of river barrier multiplied by its weight 0.35, the score of river fragmentation multiplied by its weight 0.25, etc.), and finally the comprehensive evaluation score of the aquatic ecological impact of the canal river is obtained by summing up.

[0257] Based on the comprehensive evaluation scores, the server interprets the impact on the aquatic ecology of the canal rivers.

[0258] If the comprehensive evaluation score is high (for example, greater than 0.7, the threshold here is just an example), it means that the canal construction and related activities have a greater impact on the river aquatic ecology, and there may be serious river obstruction, greater river water ecological loss, or obvious river aquatic ecological changes. If the score is low (for example, less than 0.3), it means that the canal construction has a relatively small impact on the river aquatic ecology and the ecosystem is relatively stable.

[0259] In addition to quantitative evaluation scores, qualitative interpretations can also be performed. For example, according to the specific conditions of each criterion layer and element layer, it is possible to analyze which factors mainly lead to higher or lower evaluation scores, such as hub facility problems in river barriers or suspended solids impact in river water ecological losses, so as to provide specific directions and suggestions for the management, protection and improvement measures of the canal.

[0260] Through the canal river aquatic ecological impact assessment system constructed in this way, it is possible to comprehensively and scientifically evaluate the impact of canal construction on river aquatic ecology, and provide strong decision-making support for the sustainable development of the canal.

[0261] In an embodiment of the present invention, the river connectivity includes the longitudinal connectivity index of the river, the fish passage effect of the hub fishway includes the fish passage efficiency of the fish school and the proportion of the migratory fish population, the river curvature includes the ratio of the canal curvature to the original river curvature, the self-purification capacity of the river in the bend section includes the reduction rate of the water quality index of the river section before and after the bend, the benthic biological loss includes the biological loss caused by underwater construction, the biological loss caused by suspended matter includes the number of fish eggs and larvae caused by the diffusion of suspended matter, the loss of zooplankton and the loss of phytoplankton, the change of the river biogenic factor includes the change of oxygen content in the water body before and after the construction of the canal, the change of ammonia nitrogen in the water body before and after the construction of the canal, and the change of total phosphorus in the water body before and after the construction of the canal, and the change of fish population distribution includes fish retention index, species occurrence frequency and species relative abundance;

[0262] Based on the river barriers, the river fragmentation, the river water ecological loss and the river aquatic ecological changes, a canal river aquatic ecological impact assessment system is constructed, and the following implementation methods are also provided.

[0263] The longitudinal connectivity index of the river, the fish passage efficiency, the proportion of migratory fish populations, the ratio of the canal curvature to the original river curvature, the reduction rate of water quality indicators in the river section before and after the bend, the biological loss caused by the underwater construction, the number of fish eggs and larvae caused by the diffusion of suspended matter, the loss of zooplankton and the loss of phytoplankton, the change in oxygen content in the water before and after the construction of the canal, the change in ammonia nitrogen in the water before and after the construction of the canal, the change in total phosphorus in the water before and after the construction of the canal, the fish retention index, the frequency of occurrence of the species and the relative abundance of the species are used as indicator layers;

[0264] Based on the AHP hierarchical analysis method, weights are assigned to the element layer, the criterion layer and the indicator layer, and the canal river aquatic ecological impact assessment system is constructed according to the target layer, the weighted element layer, the criterion layer and the indicator layer.

[0265] In an embodiment of the present invention, illustratively, the server extracts the longitudinal connectivity index data of the river from the previous calculation results of the river connectivity. For example, in a canal system, after a detailed analysis of each hub (such as a sluice, dam, etc.), including the structural characteristics, operation mode and position of each hub in the river, the longitudinal connectivity index calculated is 0.6 (here is just an example value). This value is obtained by comprehensively considering the impact of different hubs on the longitudinal water flow barriers of the river. It reflects the degree to which the natural longitudinal connectivity of the river has been changed, and is an important indicator for measuring the connectivity of the river.

[0266] The server obtains data from the fishway monitoring system to determine the efficiency of fish passage. At a specific fishway in the canal, through monitoring by underwater cameras, sensors and other equipment, it was found that the number of fish at the entrance of the fishway was 1,000 and the number of fish at the exit of the fishway was 700. According to the corresponding calculation logic, the fish passage efficiency was 70%. This efficiency reflects the actual effect of the fishway in helping fish pass through the blocking area and is one of the key indicators for evaluating the fish passage effect of the hub fishway.

[0267] The server obtains data on population size and migratory fish population size from the fishery resource survey database. In the canal and its related waters, after a comprehensive survey and statistics, the total population size is 5,000 and the migratory fish population size is 1,000. According to the relevant calculation logic (based on the principle), it is calculated that the proportion of migratory fish population is 20%. The proportion of migratory fish population reflects the proportion of migratory fish in the entire fish population, which is of great significance for evaluating the fish passage effect of the hub fishway and the aquatic ecological impact of the entire canal river.

[0268] The server obtains the previously calculated ratio data of the canal curvature to the original river curvature. For example, the survey team accurately measured the length of the original river along the center line of the river as 60 kilometers, and the straight-line distance between the upstream and downstream sections of the original river was 40 kilometers. After the canal was built, the length of the river measured along the center line of the river was 50 kilometers, and the straight-line distance between the upstream and downstream sections of the canal was 35 kilometers. According to the relevant calculation logic, the ratio of the canal curvature to the original river curvature is 80%. This ratio intuitively reflects the change in the curvature of the canal relative to the original river, and is an important indicator for measuring the curvature of the river.

[0269] The server obtains the concentration data of the water quality of the river section before and after the bend is cut from the water quality monitoring database, as well as the length data of the river section. For example, taking ammonia nitrogen concentration as an example, the ammonia nitrogen concentration of the river water quality of the bend section before the bend is cut is 3 mg / L, and the ammonia nitrogen concentration of the river water quality of the bend section after the bend is cut is 2 mg / L, and the length of the river section is 8 kilometers. According to the calculation logic of the water quality reduction rate of the river section before and after the bend is cut, the water quality reduction rate of ammonia nitrogen in the river section before and after the bend is obtained. Similarly, similar calculations are performed for other water quality indicators (such as chemical oxygen demand, total phosphorus, etc.). These reduction rate data reflect the impact of bend cutting on the self-purification capacity of the river, and are important indicators of the self-purification capacity of the river section.

[0270] The server obtains data on biological losses of different types of benthic organisms in the assessment area due to underwater construction from biological resource survey data. Taking river clams as an example, in the canal construction area, the resource density of river clams is 12 per square meter, and the water area it occupies is 60 square meters. According to the calculation logic of biological losses caused by underwater construction, the amount of biological losses of river clams caused by underwater construction is obtained. Similar calculations are also performed for other benthic organisms (such as snails, shrimps, etc.). The amount of biological losses caused by these underwater constructions reflects the degree of damage to the benthic community caused by the canal construction, and is an important indicator of benthic biological losses.

[0271] The server obtains the number of fish eggs and fry caused by the spread of suspended matter from the fishery monitoring data. During the construction of the canal, a large amount of suspended matter was generated due to earthwork excavation, transportation and other activities. The fishery monitoring team set up sampling points in different waters, used special sampling equipment to collect fish egg and fry samples and conducted statistics, and concluded that the number of fish eggs and fry lost due to the spread of suspended matter was 500. This data directly reflects the impact of suspended matter on the early life stage of fish and is one of the important indicators of biological losses caused by suspended matter.

[0272] The server obtains the zooplankton loss from the zooplankton monitoring data. The monitoring team collected water samples from different water layers and used a microscope in the laboratory to count and identify the zooplankton in the water samples. It was concluded that due to the influence of suspended matter, the zooplankton loss was 1,000 per cubic meter (expressed here as the loss per unit volume). Zooplankton is at an important trophic level in aquatic ecosystems, and its loss is an important indicator to measure the impact of suspended matter on aquatic communities.

[0273] The server obtains the amount of phytoplankton loss from phytoplankton monitoring data. Through chlorophyll content determination, cell counting and other analytical methods on the collected water samples, it is concluded that the amount of phytoplankton loss is 1,500 per cubic meter. Phytoplankton is the primary producer in the aquatic ecosystem. Its loss has an important impact on the energy flow and material cycle of the entire ecosystem, and is an important indicator of biological loss caused by suspended matter.

[0274] The server obtains data on the oxygen content of the water before and after the construction of the canal from the water quality monitoring system. Before the construction of the canal, after long-term monitoring (covering at least one full hydrological year), data was collected at multiple monitoring stations and comprehensively analyzed, and it was concluded that the average oxygen content of the water before the construction of the canal was 8 mg / L. After the construction of the canal, monitoring continued through these monitoring stations, and it was concluded that the average oxygen content of the water after construction was 6 mg / L. Changes in the oxygen content of the water directly affect the respiration, growth and reproduction of aquatic organisms, and are an important indicator for measuring changes in river biogenic factors.

[0275] The server obtains the changes in ammonia nitrogen content in the water body before and after the construction of the canal from the water quality monitoring data. Before the construction of the canal, the water samples collected from each monitoring station were analyzed by an ammonia nitrogen analyzer, and the average ammonia nitrogen content in the water body before construction was 1 mg / L. After the construction of the canal, another analysis showed that the average ammonia nitrogen content in the water body was 1.5 mg / L. Changes in ammonia nitrogen content will affect the nutritional status of the water body and its toxicity to aquatic organisms, and is an important indicator of changes in river biogenic factors.

[0276] The server obtains the changes in total phosphorus content in the water body before and after the construction of the canal from the water quality monitoring data. Before the construction of the canal, the total phosphorus content of water samples at each monitoring station was measured, and it was found that the total phosphorus content of the water body before construction was 0.1mg / L. After the construction of the canal, the total phosphorus content of the water body was measured to be 0.2mg / L. Total phosphorus is one of the key factors in eutrophication of water bodies. The change in its content has an important impact on the aquatic ecosystem and is an important indicator of changes in river biogenic factors.

[0277] The server obtains the fish retention index from the fishery resource survey data. Before the canal was built, the fishery survey team conducted a comprehensive survey of fish in the canal waters using a variety of survey methods (such as gillnet fishing, electrofishing - within legal and scientific limits, sonar detection, etc.), and found that the retention index of a representative fish population was 0.8. After the canal was built, the same survey method was used again to conduct a survey, and the retention index of the fish population was 0.6. The fish retention index reflects the relative number of fish populations in the canal waters and is an important indicator for assessing changes in the distribution of fish populations.

[0278] The server obtains the species occurrence frequency from the fish monitoring data. Fishery investigators set up multiple long-term monitoring stations in the canal and its related waters to observe and record fish regularly (for example, once a week). Before the construction of the canal, for a specific fish species, the frequency of occurrence of the species in a specific monitoring area was 3 times a week. After the construction of the canal, using the same monitoring method and cycle, it was found that the frequency of occurrence of the species was 2 times a week. The frequency of species occurrence reflects the probability of occurrence of the species in the waters and is an important indicator of changes in the distribution of fish populations.

[0279] The server obtains the relative abundance of species from the fish census data. Before the canal was built, the fish census data was analyzed and the relative abundance of a particular fish species in the fish community in the canal waters was 30%. After the canal was built, the census data was reanalyzed and the relative abundance of the species was 20%. The relative abundance of a species indicates the relative proportion of the species in the entire fish community and is an important indicator for evaluating changes in the distribution of fish populations.

[0280] The server first constructs a judgment matrix between the element layer and the criterion layer. For example, for the two elements of river connectivity and the effect of fish passage through the hub fishway and the criterion of river isolation, based on expert knowledge, historical data, and in-depth understanding of the aquatic ecosystem of canal rivers, it is judged that river connectivity is more important than the effect of fish passage through the hub fishway in affecting river isolation, and the relative importance ratio may be determined to be 3:1 (this is just an example, the actual ratio is determined based on detailed analysis). In this way, all elements in the element layer are compared with all criteria in the criterion layer in pairs to construct the element layer-criterion layer judgment matrix.

[0281] Next, a judgment matrix between the criterion layer and the target layer is constructed. For example, when judging the relative importance of the four criteria of river barrier, river fragmentation, river water ecological loss and river aquatic ecological change on the target layer of the impact of canal river aquatic ecology, it is considered that river barrier is more important than river fragmentation in affecting the aquatic ecology of canal rivers, and the relative importance ratio is determined to be 2:1 (also an example). Through such a pairwise comparison, a judgment matrix of the criterion layer-target layer is constructed.

[0282] Finally, a judgment matrix between the indicator layer and the factor layer is constructed. Taking the two indicators of river longitudinal connectivity index and fish passing efficiency and the factor of river connectivity as examples, based on the analysis of their relative importance in affecting river connectivity, their relative importance ratio is determined, such as 2:1 (for example). In this way, all indicators in the indicator layer and all elements in the factor layer are compared pairwise to construct an indicator layer-factor layer judgment matrix.

[0283] Based on the constructed feature layer-criterion layer judgment matrix, the server uses mathematical calculations (such as the eigenvector method, etc.) to obtain the weight vector of each element in the feature layer relative to the criterion layer. For example, the weight of river connectivity relative to the river barrier criterion is calculated to be 0.25, and the weight of the fish passage effect of the hub fishway relative to the river barrier criterion is 0.08 (these are just example weights, and the actual weights are obtained based on detailed calculations). In the same way, the weight vectors of other elements in the feature layer relative to their respective related criteria are calculated.

[0284] According to the criterion layer-target layer judgment matrix, the weight vector of each criterion layer relative to the target layer is calculated. Assume that the weight of river barrier relative to the target layer of canal river aquatic ecological impact is 0.3, the weight of river fragmentation is 0.25, the weight of river water ecological loss is 0.2, and the weight of river aquatic ecological change is 0.25 (these are also example weights).

[0285] According to the indicator layer-element layer judgment matrix, the weight vector of each indicator in the indicator layer relative to the element layer is calculated. For example, for the longitudinal connectivity index of the river relative to the element of river connectivity, its weight is calculated to be 0.3 (this is just an example). In this way, the weight vector of all indicators in the indicator layer relative to their respective related elements is calculated.

[0286] The server performs consistency checks on the element layer-criterion layer judgment matrix, the criterion layer-target layer judgment matrix, and the indicator layer-element layer judgment matrix respectively.

[0287] For the element-criterion level judgment matrix, the consistency index (CI) and consistency ratio (CR) are calculated to determine whether its consistency is acceptable. If the CR is less than 0.1 (the general acceptance standard), it means that the consistency of the element-criterion level judgment matrix is ​​acceptable, that is, the relative importance ratio between the elements and the criteria determined before is reasonable; if the CR is greater than 0.1, the judgment matrix needs to be readjusted until the consistency requirements are met.

[0288] Similarly, the consistency test is also performed on the criterion layer-target layer judgment matrix and the indicator layer-element layer judgment matrix in the same way. If CR is less than 0.1, it means that the corresponding judgment matrix has good consistency and the previously determined relative importance ratio is reliable; if CR is greater than 0.1, the judgment matrix needs to be readjusted.

[0289] The server constructs a comprehensive evaluation model based on the target layer, the factor layer after weighting, the criterion layer and the indicator layer.

[0290] For each indicator in the indicator layer, its score is multiplied by the corresponding weight (the weight of the indicator layer relative to the feature layer) and then aggregated in the feature layer. For example, for the river connectivity feature, the score of the river's longitudinal connectivity index (assuming it is derived according to some scoring criteria) is multiplied by its weight 0.3 and then aggregated with other related indicators to obtain the score of the river connectivity feature.

[0291] Next, the scores of each element in the element layer are multiplied by the corresponding weight (the weight of the element layer relative to the criterion layer) and summarized in the criterion layer. For example, the score of the river connectivity element is multiplied by its weight relative to the river barrier criterion of 0.25, and the score of the key fishway fish passage effect element is multiplied by its weight relative to the river barrier criterion of 0.08. The two are added together to obtain the score of the river barrier criterion.

[0292] Finally, the score of each criterion in the criterion layer is multiplied by its corresponding weight (the weight of the criterion layer relative to the target layer) to obtain the comprehensive evaluation score of the aquatic ecological impact of the canal river.

[0293] Based on the comprehensive evaluation scores, the server interprets the impact on the aquatic ecology of the canal rivers.

[0294] If the comprehensive evaluation score is high (for example, greater than 0.7, the threshold here is just an example), it means that the canal construction and related activities have a greater impact on the river aquatic ecology, which may be due to serious river barriers (such as low longitudinal connectivity index, low fish passage efficiency, etc.), large river water ecological losses (such as large losses of benthic organisms, serious biological losses caused by suspended matter, etc.), or obvious changes in river aquatic ecology (such as decreased water oxygen content, large changes in fish population distribution, etc.). If the score is low (for example, less than 0.3), it means that the canal construction has a relatively small impact on the river aquatic ecology and the ecosystem is relatively stable.

[0295] In addition to quantitative evaluation scores, qualitative interpretations can also be performed. For example, based on the specific conditions of each criterion layer, element layer, and indicator layer, analyze which factors mainly lead to higher or lower evaluation scores. If the fish passage efficiency index in the river barrier criterion scores low, then the design or management of the fishway may need to be improved; if the zooplankton loss index in the river water ecological loss criterion scores high, then measures may need to be taken to reduce the generation of suspended solids, etc. Through such interpretations, specific directions and suggestions can be provided for the management, protection, and improvement measures of the canal.

[0296] Through the canal river aquatic ecological impact assessment system constructed in this way, it is possible to more comprehensively and meticulously evaluate the impact of canal construction on river aquatic ecology, and provide more powerful decision-making support for the sustainable development of the canal.

[0297] In order to more clearly describe the solution provided by the embodiment of the present invention, a relatively complete implementation method is provided below.

[0298] The construction of the canal hub will lead to the obstruction of river connectivity, and even the interruption of river flow and shrinkage of river channels. Due to the hub's isolation, the complete river environment is divided into different fragments, resulting in the blockage of fish exchanges between upstream and downstream of the basin. After the hub is put into operation, the hydrological situation of the river will change, affecting the river's source of life, thereby changing the river's aquatic ecology and also affecting migratory fish.

[0299] River Connectivity:

[0300] The connectivity of a river system refers to the degree of interconnection between ecological units in a river basin. It is a basic attribute of a river basin system and a basic condition for maintaining smooth transmission of material flow, energy flow, information flow and species flow between upstream and downstream, rivers and lakes, river channels and floodplains. River connectivity can be mainly divided into four dimensions: longitudinal, transverse, vertical and temporal dynamics. Among them, the longitudinal connectivity of a river is the dimension most directly and seriously affected by obstructions. The embodiment of the present invention takes into account both the barrier coefficient method and position correction, and proposes an evaluation index for the longitudinal connectivity of a canal hub. Please refer to Table 1 in conjunction with the barrier coefficient value. Table 1 shows the barrier coefficient value.

[0301] Table 1:

[0302]

[0303] The embodiment of the present invention considers that when the river-blocking structure is located in the middle of the river, the blocking effect on the river is the greatest, and as the river-blocking structure shifts from the middle of the river to both ends, the blocking effect on the river gradually decreases. Where: L a is the distance between the hub location and the river source; L b is the distance between the hub location and the estuary; L is the total length of the river; α is the standardization coefficient, which is 0.78.

[0304] On the basis of the connectivity index, the barrier coefficient method and the position correction coefficient are introduced to indicate the degree of barrier of the canal hub to the river connectivity. The calculation formula is as follows: In the formula: C is the longitudinal connectivity index of the river; a is the barrier coefficient corresponding to the i-th hub; b is the position correction coefficient of the i-th hub; L is the length of the river.

[0305] The effect of fish passing through the hub fishway:

[0306] Fishways are an important ecological compensation project in hub construction, which can meet the needs of fish reproduction, feeding and wintering in the river to a certain extent. Fishways are an effective way to solve the problem of artificial structures in rivers hindering the upstream and downstream communication of aquatic organisms. Monitoring the effect of fish passage is an important means to evaluate the function of fishways.

[0307] Record the number of fish at the fishway entrance N1, record the number of fish at the fishway exit N2, then the fish passing efficiency is the ratio of the two numbers. Collect the fish passing through the fishway using the interception method or the netting method, record the population number N, and record the number of migratory fish populations N0.

[0308]

[0309] Evaluation index of river fragmentation:

[0310] The construction of the canal required the use of straightening projects on many parts of the original river channel, which not only shortened the waterway, but also increased the tidal capacity, deepened and widened the waterway, and adapted to the requirements of the increase in the number of ships and the development of larger ships, while facilitating ship navigation and ensuring navigation safety.

[0311] However, after the artificial bend of the river, the original natural river bank disappeared, the material exchange in the river weakened, the reduction of deep pools and shallows led to the homogenization of the ecological environment, and the self-purification ability of the river was weakened. Studies have shown that straightening the river not only dredges the river and lowers the flood level, but also destroys the flow pattern of the original river, making the flow pattern of the river worse and reducing the living space for fish.

[0312] The embodiment of the present invention draws on the theory of landscape ecology and introduces a fragmentation evaluation index to evaluate the impact of straightening on the ecology of natural rivers from aspects such as the change in river curvature and the self-purification capacity of the river in the curvature section. The curvature of a river is an index that characterizes the degree of linear meandering of a river. The embodiment of the present invention introduces a river curvature calculation formula to evaluate the degree of change in the curvature of the river after the canal is built.

[0313] Where, L T is the length of the original river channel measured along the center line of the river channel; L0 is the straight-line distance between the upstream and downstream sections of the original river channel; L T’ L is the length of the original river measured along the center line of the river; 0’ It is the straight-line distance between the upstream and downstream sections of the original river channel.

[0314] The self-purification capacity of the river in the bend section refers to the characterization indicators of the river self-purification capacity, and the reduction rates of nine water quality indicators such as TP, NH3-N, NO2-N, NO3-N, CODcr, TOC, DOC, chlorophyll and blue-green algae phycocyanin are used as evaluation indicators of the self-purification capacity of the river in the bend section.

[0315] Where C0 and C1 are the concentrations of water quality indicators of the river before and after the bend is straightened, L c It is the length of the river at the bend section.

[0316] Estimation of river water ecological loss:

[0317] The impacts on aquatic life during the canal construction period are mainly manifested in dredging, reef clearing, widening, revetment, cascade hub construction, bridge reconstruction and water service area wharf construction, which lead to an increase in suspended solids in the water body in the construction area, resulting in a decrease in aquatic life and even changes in community structure. Channel dredging will dig out all the riverbed mud, and reef blasting projects will cause direct deaths of a certain amount of aquatic life.

[0318] Estimated loss of benthic organisms:

[0319] During the canal construction period, activities such as dredging, widening, and hub construction will cause the loss of river benthic habitats, resulting in direct losses of benthic organisms. The damage to various types of biological resources is calculated using the following formula:

[0320] W i =D i ×S i , where: Wi is the amount of damage to the i-th type of biological resources, in kilograms (kg); Di is the density of the i-th type of biological resources in the assessment area, in kilograms per square kilometer (kg / km 2 ); Si is the water area occupied by the i-th species of organisms, in square kilometers (km 2 ), the occupied area includes the canal channel dredged area and the anchorage dredged area.

[0321] Biological losses caused by the spread of suspended matter:

[0322] The spread of suspended matter caused by underwater construction such as canal channel dredging will cause the loss of aquatic organisms such as phytoplankton, zooplankton and fish. The method for estimating the amount of damage to aquatic ecology caused by the spread of suspended matter is: the increase in the concentration of a certain pollutant exceeds the Class II standard value in GB11607 or GB3097 (the standard value of pollutants not included in GB11607 or GB3097 is inferred according to the toxicity test results). Please refer to Table 2 for damage to marine biological resources. Table 2 shows the loss rate of pollutants to various organisms, calculated according to the formula:

[0323] Where: Wi is the average one-time loss of biological resources of the i-th type, in units of (tails), pieces (pieces), and kilograms (kg); Dij is the density of biological resources of the i-th type in the j-th concentration increment area of ​​a certain pollutant, in units of tails per square kilometer (tails / km 2 ), square kilometers ( / km 2 ), kilogram per square kilometer (kg / km 2 ); Sj is the area of ​​the j-th concentration increment zone of a certain pollutant, in square kilometers (km 2 ) ; Kij is the loss rate of biological resources of the i-th type in the j-th concentration increment zone of a certain pollutant, in percent (%); n is the total number of zones with a certain pollutant concentration increment.

[0324] Table 2:

[0325]

[0326] Among them, Table 2 lists the multiples (Bi) of pollutant i exceeding the standard, which refers to the multiples exceeding the "Fishery Water Quality Standard" or the Class II "Seawater Quality Standard". For pollutants not listed in the standard, they can be determined by referring to relevant standards or according to the toxicity test data of the actual pollutant types; when multiple pollutants exist at the same time, the pollutant with the largest multiple exceeding the standard shall be used as the basis for evaluation. The loss rate refers to a comprehensive coefficient that takes into account the impact of pollutants on biological reproduction, growth or death, as well as the decline in biological quality. The loss rates of various organisms listed in this table are used as reference values ​​for the assessment of damage to marine organisms caused by the project. The loss rates of various pollutants generated by the project to marine organisms can be adjusted accordingly according to the actual types of pollutants and toxicity test data. This table is not applicable to pH and dissolved oxygen parameters.

[0327] Evaluation indicators of river aquatic habitat:

[0328] The development and construction of the canal is achieved by expanding and dredging the existing river channel, and the water flow of the river channel has increased significantly. The water depth increases the aquatic habitat space and expands the habitat range of aquatic organisms that like quiet water. However, the winding and complex habitat structure of the original river channel has been replaced by the canalized river channel, and the degree of influence of artificial control has increased. The water flow conditions in the original river channel have changed, the natural rhythm of the water flow in the river channel will be weakened, and the habitat conditions tend to be single.

[0329] After the canal is completed and put into operation, the habitat of the reservoir area will change from river type to lake type, the flow velocity upstream of the hub will slow down, and a still water area will be formed. The non-biological ecological factors with greater impact mainly include: water depth, flow velocity, transparency, temperature, light, bottom quality, dissolved oxygen and nutrients. Among them, changes in hydrological conditions are the dominant factor causing changes in these factors.

[0330] In addition, the number, frequency and tonnage of ships sailing during the operation of the canal will increase, and the disturbance to aquatic habitats will increase accordingly. At the same time, if ship wastewater and waste oil are not properly treated, they will pollute the water quality of the river section and have an adverse impact on the habitat of aquatic organisms.

[0331] Changes in student source factors:

[0332] As important primary producers in river ecosystems and the basis of aquatic food chains, phytoplankton responds quickly to changes in pollutants and nutrient levels in water bodies, and is often used as an indicator organism for water quality monitoring and a basis for water quality assessment. Compared with the use of fish and aquatic higher plants to construct a biological integrity index, an evaluation based on the phytoplankton integrity index may be more effective. Studies have shown that the growth and distribution of phytoplankton are affected by various environmental factors, such as water temperature, water flow rate, water oxygen content, turbidity, NH3-N, pH and total phosphorus (TP).

[0333] The embodiment of the present invention selects the changes in water oxygen content, NH3-N and total phosphorus concentration before and after the canal construction as river aquatic habitat evaluation indicators.

[0334] Changes in fish population distribution:

[0335] After the construction of the canal cascade hub, the natural river was cut into multiple lake-phase waters, and the river habitat changed, which had an important impact on the spatial distribution of fish populations and changes in ecological types. The composition and spatial structure of fish communities are an adaptive feature to changes in environmental characteristics. Changes in species composition are manifested as species gain or loss, while changes in spatial distribution are manifested as changes in species flora composition and relative abundance during environmental changes.

[0336] The embodiment of the present invention uses three indicators, namely, fish stock index, species occurrence frequency, and species relative abundance, to evaluate changes in river aquatic habitats.

[0337] (1) Fish Stock Index

[0338] Evaluate the difference between the current fish species and the historical reference point fish species. For evaluation areas where historical fish monitoring data is not available, expert consultation can be used to determine the number of fish species. The number of fish species surveyed does not include exotic fish species.

[0339]

[0340] Where FOEI is the fish abundance index (%); FO is the number of fish species obtained from the survey of rivers and lakes (excluding alien species) (species); FE is the number of fish species evaluated in rivers and lakes before 1980s (species).

[0341] (2) Species frequency

[0342] The occurrence frequency Fi of a species is determined based on the ratio of the number of sample points where the species occurs to the total number of sample points.

[0343]

[0344] In the formula, S i is the number of sample points where the species occurs; S is the total number of sample points. i ≥40% are common species, 10% ≤F i <40% are occasional species, F i <10% are rare species.

[0345] (3) Relative abundance of species

[0346] The relative abundance P is determined by the ratio of the number of individuals of a species to the total number of fish caught at the sampling point. i .

[0347]

[0348] Where N iis the number of individuals of a species, and N is the number of individuals of all species.

[0349] River Ecological Impact Index System:

[0350] Based on the characteristics and content of canal engineering construction, the embodiment of the present invention selects river barriers, river fragmentation, river ecological loss, and river aquatic habitat changes as the criterion layer for the impact of the project on river water ecology, selects 15 indicators to construct a canal river ecological impact evaluation index system, and uses the AHP hierarchical analysis method combined with the expert scoring method to assign weights. Please refer to Table 3, which is the canal engineering river ecological impact evaluation index system. Table 3:

[0351]

[0352] Please refer to Figure 2 , Figure 2 A canal river aquatic ecological impact assessment system construction device 110 provided in an embodiment of the present invention includes:

[0353] Acquisition module 1101 is used to determine river barriers based on river connectivity and the effect of fish passage in hub fishways; determine river fragmentation based on river curvature and the self-purification capacity of the river in the bend section; determine river water ecological losses based on benthic organism losses and biological losses caused by suspended matter; determine river aquatic ecological changes based on changes in river provenance factors and changes in fish population distribution;

[0354] The construction module 1102 is used to construct a canal river aquatic ecological impact assessment system based on the river barrier, the river fragmentation, the river water ecological loss and the river aquatic ecological change.

[0355] It should be noted that the implementation principle of the aforementioned canal river aquatic ecological impact assessment system construction device 110 can refer to the implementation principle of the aforementioned canal river aquatic ecological impact assessment system construction method, which will not be repeated here. It should be understood that the division of the various modules of the above device is only a division of logical functions. In actual implementation, they can be fully or partially integrated into a physical entity, or they can be physically separated. And these modules can all be implemented in the form of software called by processing elements; they can also be implemented in the form of hardware; some modules can also be implemented in the form of software called by processing elements, and some modules can be implemented in the form of hardware. For example, the canal river aquatic ecological impact assessment system construction device 110 can be a separately established processing element, or it can be integrated in a chip of the above device. In addition, it can also be stored in the memory of the above device in the form of program code, and a processing element of the above device can be called and execute the function of the above canal river aquatic ecological impact assessment system construction device 110. The implementation of other modules is similar. In addition, these modules can be fully or partially integrated together, or they can be implemented independently. The processing element described here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each module above can be completed by an integrated logic circuit of hardware in a processor element or an instruction in software form.

[0356] For example, the above modules may be one or more integrated circuits configured to implement the above methods, such as one or more application specific integrated circuits (ASIC), or one or more microprocessors (digital signal processors, DSP), or one or more field programmable gate arrays (FPGA), etc. For another example, when a module above is implemented in the form of a processing element scheduling program code, the processing element may be a general-purpose processor, such as a central processing unit (CPU) or other processor that can call program code. For another example, these modules may be integrated together and implemented in the form of a system-on-a-chip (SOC).

[0357] The embodiment of the present invention provides a computer device 100, which includes a processor and a non-volatile memory storing computer instructions. When the computer instructions are executed by the processor, the computer device 100 executes the aforementioned canal river aquatic ecological impact assessment system construction device 110. Figure 3 As shown, Figure 3The computer device 100 provided in the embodiment of the present invention is a structural block diagram. The computer device 100 includes a canal river aquatic ecological impact assessment system construction device 110, a memory 111, a processor 112 and a communication unit 113.

[0358] To achieve data transmission or interaction, the memory 111, processor 112 and communication unit 113 are electrically connected to each other directly or indirectly. For example, these elements can be electrically connected to each other through one or more communication buses or signal lines. The canal river aquatic ecological impact assessment system construction device 110 includes at least one software function module that can be stored in the memory 111 in the form of software or firmware or solidified in the operating system (OS) of the computer device 100. The processor 112 is used to execute the canal river aquatic ecological impact assessment system construction device 110 stored in the memory 111, such as the software function modules and computer programs included in the canal river aquatic ecological impact assessment system construction device 110.

[0359] An embodiment of the present invention provides a readable storage medium, which includes a computer program. When the computer program is running, it controls the computer device where the readable storage medium is located to execute the aforementioned canal river aquatic ecological impact assessment system construction device 110.

[0360] For illustrative purposes, the foregoing description is made with reference to specific embodiments. However, the above illustrative discussion is not intended to be exhaustive or to limit the present disclosure to the precise form disclosed. Numerous modifications and variations are possible in accordance with the above teachings. These embodiments are selected and described in order to best illustrate the principles of the present disclosure and its practical application, so that those skilled in the art can best utilize the present disclosure and utilize various embodiments with different modifications to suit the intended specific application.

Claims

1. A method for constructing a canal river aquatic ecological impact assessment system, characterized in that: include: Determine river barriers based on river connectivity and the effectiveness of pivotal fishways; Determine river fragmentation based on river sinuosity and the self-purification capacity of the river at the bend section; Determine river water ecological losses based on benthic biomass losses and biomass losses due to suspended matter; Determine changes in river aquatic ecology based on changes in river biogenic factors and changes in fish population distribution; Based on the river barriers, the river fragmentation, the river water ecological losses and the river aquatic ecological changes, a canal river aquatic ecological impact assessment system is constructed.

2. The method according to claim 1, characterized in that Determining river barriers based on river connectivity and the fish passage effect of hub fishways includes: The river connectivity is determined according to the longitudinal connectivity index of the river; the longitudinal connectivity index of the river is calculated by the formula: Determine; where C is the longitudinal connectivity index of the river, a is the barrier coefficient corresponding to the i-th hub, b is the position correction coefficient of the i-th hub, and L is the length of the river; The fish passing effect of the hub fishway is determined according to the fish passing efficiency and the proportion of migratory fish population; the fish passing efficiency is calculated by the formula: Determine the proportion of migratory fish populations through the formula: Determine; where n is the fish passing efficiency, N1 is the number of fish at the fishway entrance, N2 is the number of fish at the fishway exit, p is the proportion of migratory fish population, N is the population size, and N0 is the number of migratory fish population; The river barrier is constructed according to the river connectivity and the fish passing effect of the hub fishway.

3. The method according to claim 1, characterized in that The method of determining the river fragmentation based on the river curvature and the self-purification capacity of the river at the bend section includes: The river curvature is determined according to the ratio of the canal curvature to the original river curvature; the ratio of the canal curvature to the original river curvature is determined by the formula: Determine; where S is the ratio of the canal curvature to the original river curvature, L T is the length of the original river channel measured along the center line of the river channel; L0 is the straight-line distance between the upstream and downstream sections of the original river channel; L T ' is the length of the original river channel measured along the center line of the river channel; L0' is the straight-line distance between the upstream and downstream sections of the original river channel; The self-purification capacity of the river in the bend section is determined according to the water quality reduction rate of the river section before and after the bend cutting; the water quality reduction rate of the river section before and after the bend cutting is calculated by the formula: Determine; where R is the water quality reduction rate of the river section before and after the bend cutting, C0 is the concentration of the river water quality in the bend cutting section before the bend cutting, C1 is the concentration of the river water quality in the bend cutting section after the bend cutting, L c is the length of the river at the bend; The river fragmentation is constructed according to the river curvature and the self-purification capacity of the river in the bend section.

4. The method according to claim 1, characterized in that: The determination of river water ecological losses based on benthic organism losses and biological losses caused by suspended matter includes: The benthic organism loss is determined based on the organism loss caused by underwater construction; the organism loss caused by underwater construction is determined by the formula: W i =D i ×S i Determine; among them, W i D is the biological loss caused by underwater construction of the i-th biological resource. i To evaluate the density of biological resources of the i-th type in the region, S i is the water area occupied by the i-th species of organisms; Determine the biological loss caused by the suspended matter based on the number of fish eggs and larvae, the loss of zooplankton and the loss of phytoplankton caused by the diffusion of the suspended matter; The river water ecological loss is constructed according to the benthic biological loss and the biological loss caused by the suspended matter.

5. The method according to claim 1, characterized in that The determination of river aquatic ecological changes based on changes in river biogenic factors and changes in fish population distribution includes: Determine the change of the river biogenic factor according to the change of oxygen content in the water before and after the canal was built, the change of ammonia nitrogen in the water before and after the canal was built, and the change of total phosphorus in the water before and after the canal was built; Determine the distribution changes of the fish populations based on fish stock index, species occurrence frequency and species relative abundance; The changes in the river's aquatic ecology are constructed based on the changes in the river's biogenic factors and the changes in the fish population distribution.

6. The method according to claim 1, characterized in that The canal river aquatic ecological impact assessment system is constructed based on the river barrier, the river fragmentation, the river water ecological loss and the river aquatic ecological change, including: The element layer is based on the river connectivity, the fish passing effect of the hub fishway, the river curvature, the self-purification capacity of the river in the bend section, the loss of benthic organisms, the biological loss caused by suspended matter, the change of the river biogenic factor and the change of the fish population distribution; The river barrier, the river fragmentation, the river water ecological loss and the river aquatic ecological change are used as criterion layers; The impact on aquatic ecology of canals and rivers is taken as the target layer; The element layer and the criterion layer are weighted based on the AHP hierarchy analysis method, and the canal river aquatic ecological impact assessment system is constructed according to the target layer, the element layer with weights assigned, and the criterion layer.

7. The method according to claim 6, characterized in that The river connectivity includes the longitudinal connectivity index of the river, the fish passage effect of the hub fishway includes the fish passage efficiency and the proportion of migratory fish populations, the river curvature includes the ratio of the canal curvature to the original river curvature, the self-purification capacity of the river in the bend section includes the reduction rate of water quality indicators in the river section before and after the bend, the benthic organism loss includes the organism loss caused by underwater construction, the organism loss caused by suspended matter includes the number of fish eggs and larvae caused by the diffusion of suspended matter, the loss of zooplankton and the loss of phytoplankton, the changes in the river's biogenic factors include the changes in the oxygen content of the water body before and after the construction of the canal, the changes in the ammonia nitrogen content of the water body before and after the construction of the canal, and the changes in the total phosphorus of the water body before and after the construction of the canal, and the changes in the distribution of fish populations include the fish retention index, the frequency of species occurrence and the relative abundance of species; The canal river aquatic ecological impact assessment system constructed based on the river barrier, the river fragmentation, the river water ecological loss and the river aquatic ecological change also includes: The longitudinal connectivity index of the river, the fish passage efficiency, the proportion of migratory fish populations, the ratio of the canal curvature to the original river curvature, the reduction rate of water quality indicators in the river section before and after the bend, the biological loss caused by the underwater construction, the number of fish eggs and larvae caused by the diffusion of suspended matter, the loss of zooplankton and the loss of phytoplankton, the change in oxygen content in the water before and after the construction of the canal, the change in ammonia nitrogen in the water before and after the construction of the canal, the change in total phosphorus in the water before and after the construction of the canal, the fish retention index, the frequency of occurrence of the species and the relative abundance of the species are used as indicator layers; Based on the AHP hierarchical analysis method, weights are assigned to the element layer, the criterion layer and the indicator layer, and the canal river aquatic ecological impact assessment system is constructed according to the target layer, the weighted element layer, the criterion layer and the indicator layer.

8. A device for constructing a canal river aquatic ecological impact assessment system, characterized in that: include: Acquisition module, used to determine river barriers based on river connectivity and the effect of fish passage in hub fishways; determine river fragmentation based on river curvature and the self-purification capacity of the river in the bend section; determine river water ecological losses based on the loss of benthic organisms and biological losses caused by suspended matter; determine river aquatic ecological changes based on changes in river provenance factors and changes in fish population distribution; A construction module is used to construct a canal river aquatic ecological impact assessment system based on the river barrier, the river fragmentation, the river water ecological loss and the river aquatic ecological change.

9. A computer device, characterized in that: The computer device comprises a processor and a non-volatile memory storing computer instructions. When the computer instructions are executed by the processor, the computer device executes the method according to any one of claims 1 to 7.

10. A readable storage medium, characterized in that: The readable storage medium includes a computer program, and when the computer program is executed, the computer device where the readable storage medium is located is controlled to execute the method according to any one of claims 1 to 7.

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