Method and device for determining drought warning water level of long-distance water transfer saltwater reservoir group

Abstract

The application provides a long-distance water transfer saltwater reservoir group drought warning water level determination method and device, first, based on the long series of incoming water quantity of the control section of the reservoir group located basin, a typical drought year is determined; then, based on the saltwater flow series of the control section of the basin, the first water supply quantity series of each reservoir in the reservoir group and the incoming water quantity series of the reservoir group in the typical drought year, the total water shortage quantity series of the reservoir group is generated; thereafter, based on the total water shortage quantity series and the beneficial reservoir capacity, the first water supply quantity series, the minimum ecological water discharge quantity series and the incoming water quantity series of each reservoir in the reservoir group, the water shortage quantity series of each reservoir in the reservoir group is generated; finally, based on the water shortage quantity series of each reservoir in the reservoir group, the dead water level and the water level-reservoir capacity relationship, the drought warning water level of each reservoir in the reservoir group is determined through the inverse order recursion method. The application can alleviate the problem that the prior art cannot scientifically and reasonably determine the drought warning water level of the reservoir group.

Description

Technical Field

[0001] This invention relates to the field of water resource allocation technology, and in particular to a method and device for determining drought warning water levels in a long-distance water allocation system for saline reservoirs. Background Technology

[0002] The water supply of urban clusters located in estuary areas is susceptible to saltwater intrusion. To ensure the water supply security of estuary cities, it is often necessary to coordinate at the basin level and use the effective water storage capacity of upstream key reservoirs to transfer water downstream over long distances to suppress salinity during periods affected by saltwater intrusion. Therefore, it is crucial for key reservoirs to maintain a certain water storage capacity during the dry season for the water supply of key downstream areas.

[0003] The drought warning level of a reservoir refers to the water level at which insufficient inflow will affect the safety of water use for daily life, production, and ecology in the relevant areas, requiring attention or drought relief measures. It is a crucial indicator of the reservoir's drought early warning level. For reservoirs undertaking long-distance water transfer and salinity control tasks, the drought warning level is even more important for determining the level of drought in the basin and initiating the basin's drought relief emergency response. Therefore, scientifically and rationally determining the drought warning level of reservoirs undertaking long-distance water transfer and salinity control tasks is fundamental to effective basin-wide drought relief command and dispatch, and is of great significance for ensuring the water supply security of the basin and key areas.

[0004] Currently, existing technologies can generally determine the drought warning water level of a reservoir that guarantees water supply through single reservoir scheduling. However, for a group of reservoirs with upstream and downstream hydraulic connections and jointly undertaking long-distance water regulation and salinity control tasks, the determination of their drought warning water level differs from that of a single reservoir. In addition to considering the overall water regulation and salinity control scheduling tasks, it is also necessary to consider the scheduling tasks and constraints undertaken by each reservoir, such as flood control, water supply, ecology, power generation, and navigation. Existing technologies cannot scientifically and reasonably determine the drought warning water level of a group of reservoirs. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method and apparatus for determining the drought warning water level of a long-distance water-regulating saline reservoir group, so as to alleviate the above-mentioned problems existing in the related technologies.

[0006] In a first aspect, embodiments of the present invention provide a method for determining drought warning water levels in a long-distance water regulation and salinity suppression reservoir group, comprising: determining a typical drought year based on a long series of inflow from the control section of the watershed where the reservoir group is located; generating a total water shortage series for the reservoir group based on the salinity suppression flow series of the control section of the watershed, the first water supply series of each reservoir in the reservoir group, and the inflow series of the reservoir group in a typical drought year; generating a water shortage series for each reservoir in the reservoir group based on the total water shortage series, the beneficial storage capacity, the first water supply series, the minimum downstream ecological water volume series, and the inflow series of each reservoir in the reservoir group; and determining the drought warning water level of each reservoir in the reservoir group by means of a reverse recursive method based on the water shortage series, dead water level, and water level-storage capacity relationship of each reservoir in the reservoir group; wherein the drought warning water level corresponds to the dry season of the reservoir group.

[0007] Secondly, embodiments of the present invention also provide a device for determining drought warning water levels in a long-distance water regulation and salinity suppression reservoir group, comprising: a first determining module, used to determine a typical drought year based on a long series of inflow from the control section of the watershed where the reservoir group is located; a first generating module, used to generate a total water shortage series for the reservoir group based on the salinity suppression flow series of the control section of the watershed, the first water supply series of each reservoir in the reservoir group, and the inflow series of the reservoir group in a typical drought year; a second generating module, used to generate a water shortage series for each reservoir in the reservoir group based on the total water shortage series, the beneficial storage capacity, the first water supply series, the minimum outflow ecological water series, and the inflow series of each reservoir in the reservoir group; and a second determining module, used to determine the drought warning water level of each reservoir in the reservoir group by a reverse recursive method based on the water shortage series, dead water level, and water level-storage capacity relationship of each reservoir in the reservoir group; wherein the drought warning water level corresponds to the dry season of the reservoir group.

[0008] This invention provides a method and apparatus for determining drought warning water levels in a long-distance water regulation and salinity suppression reservoir group. First, a typical drought year is determined based on the long-term inflow series of the control section of the watershed where the reservoir group is located. Then, based on the salinity suppression flow series of the watershed control section, the first water supply series of each reservoir in the reservoir group, and the inflow series of the reservoir group in a typical drought year, a total water shortage series for the reservoir group is generated. Next, based on the total water shortage series, the beneficial storage capacity, first water supply series, minimum downstream ecological water volume series, and inflow series of each reservoir in the reservoir group, a water shortage series for each reservoir in the reservoir group is generated. Finally, based on the water shortage series of each reservoir in the reservoir group, the dead water level, and the water level-storage capacity relationship, the drought warning water level of each reservoir in the reservoir group is determined using a reverse recursive method. By adopting the above-mentioned technology, the complexity and importance of determining the drought warning water level of the reservoir group that jointly undertakes the task of long-distance water regulation and salinity control in the basin are fully considered. The drought warning water level of the reservoir group can be determined by combining various water volume information of the reservoir group through a reverse recursive method. Moreover, the determined drought warning water level can meet the long-term water supply guarantee, which alleviates the problem that existing technologies are difficult to scientifically and reasonably determine the drought warning water level of the reservoir group. This is of great significance for ensuring the water supply security of the basin and key areas.

[0009] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained in accordance with the structures particularly pointed out in the description, claims and drawings.

[0010] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0011] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0012] Figure 1 This is a flowchart illustrating a method for determining drought warning water levels in a long-distance water-regulating saline reservoir group according to an embodiment of the present invention.

[0013] Figure 2 This is a schematic diagram of the forward (reverse) order recursion method in an embodiment of the present invention;

[0014] Figure 3 This is a flowchart illustrating the process of determining the drought warning water level of a long-distance water-regulating saline reservoir group in an embodiment of the present invention.

[0015] Figure 4 This is a schematic diagram of a long-distance water regulation and pressure saline reservoir group drought warning water level determination device in an embodiment of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Currently, existing technologies can generally determine the drought warning water level of a reservoir that guarantees water supply through single reservoir scheduling. However, for a group of reservoirs with upstream and downstream hydraulic connections and jointly undertaking long-distance water regulation and salinity control tasks, the determination of their drought warning water level differs from that of a single reservoir. In addition to considering the overall water regulation and salinity control scheduling tasks, it is also necessary to consider the scheduling tasks and constraints undertaken by each reservoir, such as flood control, water supply, ecology, power generation, and navigation. Existing technologies cannot scientifically and reasonably determine the drought warning water level of a group of reservoirs.

[0018] Based on this, the present invention provides a method and apparatus for determining the drought warning water level of a long-distance water regulation and pressure saline reservoir group, which can alleviate the above-mentioned problems existing in related technologies.

[0019] To facilitate understanding of this embodiment, a detailed description of the method for determining drought warning water levels in a long-distance water-regulating saline reservoir group, as disclosed in this embodiment of the invention, will be provided first. (See [link to relevant documentation]). Figure 1 As shown, the method may include the following steps:

[0020] Step S102: Based on the long series of water inflow at the control sections of the watershed where the reservoir group is located, determine the typical drought year.

[0021] Step S104: Based on the salinity flow series of the watershed control section, the first water supply series of each reservoir in the reservoir group, and the inflow series of the reservoir group in a typical drought year, generate the total water shortage series of the reservoir group.

[0022] Step S106: Based on the total water shortage series and the beneficial storage capacity, first water supply series, minimum ecological water discharge series and inflow series of each reservoir in the reservoir group, generate the water shortage series of each reservoir in the reservoir group.

[0023] Step S108: Based on the water shortage series, dead water level, and water level-storage capacity relationship of each reservoir in the reservoir group, the drought warning water level of each reservoir in the reservoir group is determined by the reverse recursive method.

[0024] The drought warning water level corresponds to the dry season of the reservoir group.

[0025] This invention provides a method for determining drought warning water levels in a long-distance water regulation and salinity suppression reservoir group. First, a typical drought year is determined based on the long-term inflow series of the control sections of the watershed where the reservoir group is located. Then, based on the salinity suppression flow series of the watershed control sections, the first water supply series of each reservoir in the reservoir group, and the inflow series of the reservoir group in a typical drought year, a total water shortage series for the reservoir group is generated. Next, based on the total water shortage series, the beneficial storage capacity, first water supply series, minimum downstream ecological water volume series, and inflow series of each reservoir in the reservoir group, a water shortage series for each reservoir in the reservoir group is generated. Finally, based on the water shortage series of each reservoir in the reservoir group, the dead water level, and the water level-storage capacity relationship, the drought warning water level of each reservoir in the reservoir group is determined using a reverse recursive method. By adopting the above-mentioned technology, the complexity and importance of determining the drought warning water level of the reservoir group that jointly undertakes the task of long-distance water regulation and salinity control in the basin are fully considered. The drought warning water level of the reservoir group can be determined by combining various water volume information of the reservoir group through a reverse recursive method. Moreover, the determined drought warning water level can meet the long-term water supply guarantee, which alleviates the problem that existing technologies are difficult to scientifically and reasonably determine the drought warning water level of the reservoir group. This is of great significance for ensuring the water supply security of the basin and key areas.

[0026] As one possible implementation, before step S102 (i.e., determining a typical drought year based on the long series of inflows from the control section of the watershed where the reservoir group is located), the above-mentioned method for determining the drought warning water level of the long-distance water regulation and saline water reservoir group may also include: determining the dry season based on the first long series of inflows and the long series of outflows from the reservoir group.

[0027] For example, mathematical statistics can be used to calculate the multi-year average monthly inflow of the reservoir group (e.g., a long series of average monthly inflows of the reservoir group over at least 30 years) and the multi-year average monthly outflow of the control section of the watershed where the reservoir group is located (e.g., a long series of average monthly outflows of the control section of the watershed where the reservoir group is located over at least 30 years). Then, for the multi-year average monthly inflow of the reservoir group, identify 6 consecutive months where the monthly inflow is low as a percentage of the annual average inflow (e.g., below a certain percentage). At the same time, for the multi-year average monthly outflow of the control section of the watershed where the reservoir group is located, identify 6 consecutive months where the monthly outflow is low as a percentage of the annual average outflow (e.g., below a certain percentage). If the six months corresponding to the multi-year average monthly inflow of the reservoir group and the multi-year average monthly inflow of the control section of the watershed where the reservoir group is located are consistent, then these six months can be selected as the dry season (i.e., the reservoir drought warning period) for the reservoir group and its watershed, thus realizing the staging of reservoir drought warnings and obtaining the start and end months of the dry season for which the drought warning water level of the reservoir group needs to be determined; if the six months corresponding to the multi-year average monthly inflow of the reservoir group and the multi-year average monthly inflow of the control section of the watershed where the reservoir group is located are inconsistent, then the six months corresponding to the multi-year average monthly inflow of the control section of the watershed where the reservoir group is located can be selected as the dry season, thus obtaining the start and end months of the dry season.

[0028] In practical applications, drought early warning staging also needs to be coordinated with the key scheduling periods of water resource allocation and emergency water allocation during the dry season in the basin. In addition, drought early warning staging can also be achieved by directly specifying the dry season, thereby obtaining the start and end months of the dry season.

[0029] As one possible implementation, step S102 (i.e., determining typical drought years based on the long series of inflows from the control sections of the watershed where the reservoir group is located) may include: determining the years that meet the preset conditions corresponding to the preset frequency as typical drought years based on the long series of inflows; wherein, meeting the preset conditions includes: the water volume during the wet season is greater than the multi-year average water volume during the wet season and the water volume during the dry season is less than the multi-year average water volume during the dry season.

[0030] For example, based on the long-term monthly water volume data of the control section of the watershed where the reservoir group is located (such as the long-term water volume data of the control section of the watershed where the reservoir group is located for at least 30 consecutive months), the water volume data with an annual water volume design frequency of 75% can be selected, and then the years that simultaneously meet the two conditions of the annual water volume during the wet season being greater than the multi-year average water volume during the wet season and the water volume during the dry season being less than the multi-year average water volume during the dry season can be selected as typical drought years.

[0031] As one possible implementation, step S104 (i.e., generating a total water shortage series for the reservoir group based on the salinity flow series of the watershed control section, the first water supply series of each reservoir in the reservoir group, and the inflow series of the reservoir group in a typical dry year) may include: generating a second water supply series for the reservoir group based on the target salinity flow series of the watershed control section and the first water supply series of each reservoir in the reservoir group; and generating a total water shortage series based on the second water supply series and the inflow series of the reservoir group in a typical dry year.

[0032] For example, based on the long-distance water regulation and salinity suppression tasks undertaken by the reservoir group and the salinity suppression flow targets of the control sections in the watershed where the reservoir group is located, combined with other water supply, navigation, ecological, and power generation tasks undertaken by the reservoir group itself, the water supply security needs and targets of the reservoir group can be analyzed and determined, resulting in the monthly target salinity suppression water volume (denoted as ) for the control sections that the reservoir group needs to undertake. ) and the monthly water supply guarantee target water volume process undertaken by each reservoir in the reservoir group (denoted as ) , Indicates a reservoir. The process of determining the monthly water supply target for the reservoir group (representing a time period) is as follows: Alternatively, it can also be obtained directly by specifying the method. as well as .

[0033] Continuing the previous example, a group of reservoirs with upstream and downstream hydraulic connections and jointly undertaking the task of long-distance downstream water diversion to suppress salinity can be considered as a convergent reservoir. The overall water supply objective of the convergent reservoir is to ensure the amount of water used to suppress salinity at the downstream control section (i.e., ) and the water supply volume undertaken by each reservoir (i.e. The total water supply target of the aggregated reservoir is... It can collect monthly inflow data of Juhe Reservoir in typical years (i.e., a continuous series of monthly inflows to Juhe Reservoir in typical years). In conjunction with the amount of saline water that the Juhe Reservoir needs to guarantee, and water supply The total water shortage of Juhe Reservoir is calculated using the following formula:

[0034] (1)

[0035] in: This refers to the inflow of water into the reservoir. This represents the total water shortage in the Juhe Reservoir. For the first Other water supply provided by the reservoir; To control the flow rate under cross-sectional salinity.

[0036] Since the inflow of water into the reservoir can be obtained through monitoring stations, It can be obtained directly. Taking a cascade reservoir group as an example, the inflow of water into the aggregated reservoirs... Equal to the natural inflow of the downstream reservoir in the reservoir group Specifically, it can be expressed as the following formula:

[0037] (2)

[0038] As one possible implementation, step S106 (i.e., generating the water shortage series for each reservoir in the reservoir group based on the total water shortage series and the beneficial storage capacity, first water supply series, minimum downstream ecological water volume series, and inflow series of each reservoir in the reservoir group) may include:

[0039] Step A1: Based on the total water shortage series and the beneficial storage capacity of each reservoir in the reservoir group, generate the first water shortage series for each reservoir in the reservoir group.

[0040] Continuing from the previous example, after calculating the total water shortage of the aggregated reservoirs, the total water shortage can be decomposed based on the proportion of the beneficial storage capacity (i.e., the storage capacity between the normal water level and the dead water level) of each reservoir in the reservoir group to the total beneficial storage capacity of all reservoirs in the reservoir group. This decomposed water shortage can be obtained for each reservoir in the reservoir group. The specific decomposed water shortage can be calculated according to the following formula:

[0041] (3)

[0042] in: For the first The amount of water shortage after the decomposition of each reservoir; For the first The beneficial storage capacity of each reservoir.

[0043] Step A2: Based on the inflow series of each reservoir in the reservoir group, generate the interval flow series from each reservoir in the reservoir group to the downstream reservoir in the reservoir group.

[0044] Step A3: Based on the first water shortage series, first water supply series, minimum downstream ecological water volume series, inflow series, and interval flow series of each reservoir in the reservoir group, generate the water shortage series of each reservoir in the reservoir group.

[0045] Continuing from the previous example, after obtaining the water deficit after decomposition of each reservoir in the reservoir group, the next step is to determine the water supply task undertaken by each reservoir in the reservoir group (i.e., the first...). The reservoir in the first Water supply corresponding to each time period ), downstream minimum outflow ecological flow (the first The reservoir in the first The minimum outflow of ecological water volume corresponding to each time period The calculation of water shortage for each reservoir needs to consider the hydraulic connection between upstream and downstream reservoirs and water balance constraints. The specific water shortage can be calculated using the following formula:

[0046] (4)

[0047] (5)

[0048] in: For the first The water shortage of each reservoir; For the first The reservoir in the first Water supply corresponding to each time period; For the first The reservoir in the first The minimum ecological water discharge volume corresponding to each time period; For the first The reservoir in the first The corresponding time period is the inflow volume after regulation by the upstream reservoir (if the first time period is the inflow volume after regulation by the upstream reservoir). If a reservoir has no upstream reservoir, then Can refer to the first (Natural inflow of water from each reservoir). For the downstream reservoir at the first Each time period corresponds to the inflow of water after regulation by the upstream reservoir. This refers to the number of upstream reservoirs of the downstream reservoir; For the first From the first reservoir to the downstreamest reservoir, in the... The interval flow corresponding to each time period (which can be based on the flow rate of all reservoirs in the reservoir group at the [number]th time period) The water inflow for each time period is calculated or directly obtained.

[0049] Continuing the previous example, step A3 above can include the following operations: 1) Based on the first water supply series, minimum outflow ecological water series, inflow series, and interval flow series of each reservoir in the reservoir group, generate the second water shortage series of each reservoir in the reservoir group (e.g., according to...). 1) Calculated and generated; 2) Based on the first and second water shortage series of each reservoir in the reservoir group (e.g., according to...). (Generated), generating a series of water shortage amounts for each reservoir in the reservoir group (e.g., generated after calculating the water shortage amount according to the specific calculation formula).

[0050] As one possible implementation, step S108 (i.e., determining the drought warning level of each reservoir in the reservoir group based on the series of water shortages, dead water levels, and water level-storage capacity relationships of each reservoir in the reservoir group using a reverse recursive method) may include:

[0051] Step B1: Determine the calculation period for each reservoir in the reservoir group based on the start and end times of the dry season.

[0052] Step B2: For each reservoir in the reservoir group, the water level of the reservoir at the end of the last calculation period is exactly at the dead water level of the reservoir as the initial condition for the reverse recursive method. Based on the water shortage series and water level-storage capacity relationship of the reservoir, the reverse recursive calculation is performed from the last calculation period to the first calculation period to obtain the first water level of the reservoir at the beginning of each calculation period.

[0053] For example, the water shortage series may include the water shortage of the corresponding reservoir in each calculation period; based on this, the reverse recursive calculation in step B2 above, based on the water shortage series of the reservoir and the water level-storage capacity relationship, from the last calculation period to the first calculation period, may include: from the last calculation period to the first calculation period, performing the following recursive calculation for each calculation period: A) superimposing the reservoir capacity at the end of the current calculation period with the water shortage of the reservoir in the current calculation period to obtain the reservoir capacity at the beginning of the current calculation period; wherein, the reservoir capacity at the end of the last calculation period is the dead storage capacity corresponding to the dead water level of the reservoir; B) calculating the first water level of the reservoir at the beginning of the current calculation period based on the reservoir capacity at the beginning of the current calculation period and the water level-storage capacity relationship of the reservoir.

[0054] Step B3: Based on the calculated first water levels of each reservoir in the reservoir group, determine the drought warning water level of each reservoir in the reservoir group.

[0055] For example, step B3 above may include: for each reservoir in the reservoir group, determining the drought warning water level of the reservoir based on the highest first water level calculated for that reservoir during the dry season.

[0056] Following the previous example, see Figure 2 As shown, it can be assumed that the water level at the end of the drought warning period reaches the minimum required water level (i.e., the dead water level). Based on the principle of reservoir beneficial regulation, the initial water level of the reservoir during the drought warning period can be obtained by reverse recursion. Specifically, the following formula can be used for reverse recursion calculation:

[0057] (6)

[0058] (7)

[0059] (8)

[0060] In equations (6)-(8): This refers to the number of months (i.e., the total number of calculation periods) during the drought warning period for the reservoir. For the reservoir during the drought warning period The reservoir capacity corresponding to the water level at each time period; For the reservoir during the drought warning period The reservoir capacity corresponding to the water level at each time period; For the first time during the drought warning period, the reservoir Water level at the beginning of each period; For the reservoir during the drought warning period At the end of the period (i.e., the first period) Water level at the beginning of each period; This is the water level-capacity curve function of the reservoir. For the reservoir during the drought warning period The water shortage corresponding to each time period; This is the dead water level of the reservoir; the reservoir is located in the initial period of the reverse recursion (i.e., the last period within the drought warning period, also known as the [missing information] period within the drought warning period). The water level at the end of each time period is set as follows: ;

[0061] Through the above reverse recursive calculation process, the water level of each reservoir in the reservoir group at the beginning of different periods during the drought warning period can be obtained;

[0062] Finally, for each reservoir, the highest water level during the drought warning period is taken as the drought warning water level for that reservoir.

[0063] As one possible implementation, after step S108 (i.e., determining the drought warning level of each reservoir in the reservoir group by reverse recursion method based on the water shortage series, dead water level, and water level-storage capacity relationship of each reservoir in the reservoir group), the following operations can also be performed:

[0064] Step C1: For each reservoir in the reservoir group, the water level of the reservoir at the beginning of the first calculation period is set as the drought warning water level of the reservoir. Based on the second inflow series, the water shortage series, and the water level-storage capacity relationship of the reservoir, the second water level of the reservoir at the end of the last calculation period in different years is obtained by performing a forward recursive calculation from the first calculation period to the last calculation period. The second inflow series includes the inflow series of the corresponding reservoir in different years.

[0065] Step C2: For each reservoir in the reservoir group, if the proportion of the number of second water levels corresponding to the reservoir that are not lower than its dead water level to the total number of second water levels corresponding to the reservoir is less than a preset proportion threshold, then the typical drought year determination step is repeated. If the proportion of the number of second water levels corresponding to the reservoir that are not lower than its dead water level to the total number of second water levels corresponding to the reservoir is not less than the preset proportion threshold, then the highest first water level calculated for the reservoir during the dry season is determined as the final drought warning water level for the reservoir.

[0066] Continuing the previous example, for each reservoir in the reservoir group, the initial regulating water level at the beginning of the drought warning period can be set as the drought warning level. The monthly inflow of the reservoir over the years (i.e., the long series of continuous monthly inflow of the reservoir over many years) can be used to superimpose the monthly water shortage of the reservoir in ascending order from the beginning of the drought warning period. The process is repeated until the end of the drought warning period to obtain the reservoir's water storage and corresponding water level (calculated using the reservoir's water level-capacity curve function). Then, for each year's monthly inflow, the reservoir's water level at the end of the drought warning period is statistically analyzed to determine if it is higher than or equal to the reservoir's dead water level. If it is (i.e., the reservoir's water level at the end of the drought warning period is higher than or equal to the dead water level), it indicates that the reservoir's water supply meets demand during the drought warning period. If not (i.e., the reservoir's water level at the end of the drought warning period is lower than the dead water level), it indicates that the reservoir's water supply meets demand during the drought warning period. If the internal water supply does not meet the demand, the percentage of years in which the reservoir's water supply meets the demand during the drought warning period is calculated out of the total number of years corresponding to the monthly water inflow. When this percentage is greater than or equal to 75%, the drought warning water level calculated for the reservoir during the drought warning period is considered to be able to guarantee water supply security well (i.e., the current drought warning water level calculated for the reservoir is reasonable). When this percentage is less than 75%, a typical year needs to be selected again to calculate the drought warning water level until the percentage of years in which the reservoir's water supply meets the demand during the drought warning period reaches (i.e., greater than or equal to) 75%.

[0067] In practical applications, for each reservoir in a reservoir group, the maximum value of all drought warning water levels calculated for that reservoir can be taken when the percentage of years in which the reservoir meets the water demand during the drought warning period is greater than or equal to 75% of the total number of years corresponding to the monthly water inflow over the years. This maximum value is then used as the final drought warning water level for that reservoir, thereby further optimizing the drought warning water level calculation results for that reservoir.

[0068] For ease of understanding, the implementation process of the above-mentioned method for determining drought warning water levels in a long-distance water regulation and saline reservoir group is described exemplarily below, using a specific application as an example.

[0069] The aforementioned method for determining the drought warning water level of a long-distance water-regulating saline reservoir group can solve for the drought warning water level by using a pre-set aggregation-decomposition model combined with a reverse recursive method, and then using a forward recursive method to verify the rationality of the drought warning water level results, ultimately scientifically determining the drought warning water level of the reservoir group. See also Figure 3 As shown, the process for determining the drought warning water level of a long-distance water regulation and saline reservoir group is as follows:

[0070] Step S1: Determine the monthly water supply guarantee target for the reservoir group.

[0071] Specifically, data on the target salinity of the reservoir group and its control sections in the basin can be collected, as well as data on the minimum downstream discharge and target water supply of the reservoir group. This allows for the analysis and determination of the monthly water supply guarantee target for the reservoir group (i.e., the aforementioned total water supply target).

[0072] As a specific example, a reservoir group consisting of three reservoirs forms a convergent reservoir system. The target salinity control volume of this reservoir group at the downstream control section of its basin is 5.534 billion cubic meters per month. 3 The Juhe Reservoir also needs to supply water to the downstream reservoir group, with a monthly water supply target of 1.065 billion cubic meters. 3 Apart from this, none of the three reservoirs undertake any other water supply tasks.

[0073] Step S2, drought early warning staging.

[0074] Specifically, monthly water volume data of the control sections of the watershed where the reservoir group is located can be collected over the years. Mathematical statistics can be used to calculate the average monthly water volume data and the average annual water volume data over many years. Then, the six consecutive months in which the proportion of the current month's water volume to the average annual water volume is low can be used as the drought warning period, thereby realizing the drought warning periodization.

[0075] As a specific example, the basin where Juhe Reservoir is located has a flood season from May to October each year and a dry season from November to April of the following year. The runoff during the dry season accounts for 20.3% of the total annual runoff. The proportion of monthly inflow to the average annual inflow is low for six consecutive months from November to May of the following year. These six months (i.e., November to May of the following year) can be regarded as the dry season (i.e., the drought warning period).

[0076] Step S3: Select a typical drought year.

[0077] As a specific example, the annual and dry season design runoff data of the control sections in the watershed where the reservoir group is located were 5820 m³. 3 / s (frequency at 75%), 2230m 3 / s (frequency of 75%), based on the annual water volume and dry season inflow data of the control section, May 1966 to April 1967 and May 2004 to April 2005 were selected as typical drought years.

[0078] Step S4: Based on the preset aggregation-decomposition model, calculate the total water shortage of the reservoir group and the water shortage of individual reservoirs.

[0079] Among them, the above-mentioned preset aggregation-decomposition model may include formulas (1) to (5); step S4 can be specifically divided into: calculation of the total water shortage of the aggregation reservoir and calculation of the water shortage of a single reservoir.

[0080] (a) Calculation of the total water shortage of Juhe Reservoir:

[0081] The inflow to Juhe Reservoir is the natural inflow from the downstream reservoir. The water supply process is a monthly process that considers socio-economic water demand, such as the target salinity control flow and the minimum outflow from the reservoir. As a specific example, calculated in reverse order from April of the following year, Juhe Reservoir experiences water shortages mostly from December to April of the following year. Taking the typical year of 1966 as an example, the total water shortage in Juhe Reservoir in December was 1.634 billion m³. 3 The cumulative water shortage is 8.101 billion cubic meters. 3 The calculation process for the total water shortage in Juhe Reservoir is shown in Table 1.

[0082] Table 1. Example of the calculation process for the total water shortage in Juhe Reservoir

[0083]

[0084] (II) Calculation of water shortage for a single reservoir:

[0085] After obtaining the total water shortage of the reservoirs, in the decomposition stage, the water shortage of each reservoir after decomposition is calculated using formula (3) based on the proportion of the beneficial storage capacity of each reservoir; then, formulas (4) and (5) are used to calculate the water shortage of each reservoir in each time period. As a specific example, taking the typical year of 1966 as an example, the water shortage of reservoirs A, B and C in December was 490 million m³. 3 163 million m 3 and 980 million m 3 The calculation process for the water shortage of a single reservoir is shown in Table 2.

[0086] Table 2. Example of the calculation process for water shortage in a single reservoir.

[0087]

[0088] In Table 2, the inbound flow rate is related to the flow rate in formula (4). The meanings correspond to each other, using the water consumption flow rate and the formula (4) The meanings correspond.

[0089] Step S5: Solve the drought warning water level of each reservoir in reverse order.

[0090] As a specific example, starting from the end of April of the following year, the initial water storage capacity of Reservoir A, Reservoir B, and Reservoir C are all the water storage capacity corresponding to the dead water level. For each reservoir, the water shortage of each month during the drought warning period is superimposed in reverse order to obtain the reservoir capacity of each month during the drought warning period. The maximum value of the water level corresponding to the reservoir capacity in all months during the drought warning period is taken as the drought warning water level of the reservoir. Taking Reservoir C as an example, the drought warning water level from October to February of the following year is 360.0m (early October), and the drought warning water level from March to April is 345.5m (early March). The process of calculating the drought warning water level of Reservoir C by the reverse recursive method is shown in Table 3.

[0091] Table 3. Example of calculating reservoir drought warning water level using the reverse recursive method.

[0092]

[0093] Step S6: Verification of the rationality of the drought warning water level.

[0094] As a specific example, monthly inflow data for three reservoirs (Reservoir A, Reservoir B, and Reservoir C) were collected over the years. First, the starting water level for each reservoir in October was set as the drought warning level for October. The monthly water shortage was then overlaid in ascending order, and the water level in May of the following year was calculated. If the reservoir's water level in May of the following year was not lower than the dead water level, the reservoir's water supply for that year met the demand (the drought warning level was deemed reasonable); otherwise, the reservoir's water supply for that year did not meet the demand (the drought warning level was deemed unreasonable). The frequency of the reservoirs meeting the demand over the years was calculated (the number of years in which the water supply met the demand). It was then found that the frequency of each of the three reservoirs meeting the demand (the proportion of years in which the water supply met the demand to the total number of years) was over 75%. The results of the rationality test of the drought warning levels for Reservoir A, Reservoir B, and Reservoir C are shown in Table 4.

[0095] Table 4 Results of the test on the rationality of the reservoir drought warning water level

[0096]

[0097] Step S7: Determine the final drought warning water level for each reservoir.

[0098] As a specific example, following steps S1 to S7 above, the following can be recommended or determined: the drought warning water level of Reservoir A is 756.8m, the drought warning water level of Reservoir B is 712.2m, and the drought warning water level of Reservoir C is 360m.

[0099] Compared with existing technologies, the above-mentioned method for determining the drought warning water level of a long-distance water regulation and salinity suppression reservoir group has the following beneficial effects: Unlike a single reservoir that only undertakes the water supply task for the area near the reservoir, the above-mentioned method for determining the drought warning water level of a long-distance water regulation and salinity suppression reservoir group fully considers the complexity and importance of determining the drought warning water level of the reservoir group that jointly undertakes the task of long-distance water regulation and salinity suppression in the basin. It proposes to combine the aggregation-decomposition model with the reverse recursive method to solve the drought warning water level of the reservoir group, and uses the forward recursive method to verify the rationality of the drought warning water level results. Finally, it scientifically determines the drought warning water level results that can meet the long-term water supply needs, fills the gap in the drought warning water level calculation method for long-distance water regulation and salinity suppression reservoir groups, and is of great significance for ensuring the water supply security of the basin and key areas.

[0100] Based on the above-mentioned method for determining the drought warning water level of a long-distance water-regulating saline reservoir group, this invention also provides a device for determining the drought warning water level of a long-distance water-regulating saline reservoir group. (See [link to device]). Figure 4 As shown, the device may include:

[0101] The first determining module 402 is used to determine typical drought years based on the long series of water inflow at the control section of the watershed where the reservoir group is located.

[0102] The first generation module 404 is used to generate a total water shortage series of the reservoir group based on the salinity flow series of the watershed control section, the first water supply series of each reservoir in the reservoir group, and the inflow series of the reservoir group in a typical drought year.

[0103] The second generation module 406 is used to generate a water shortage series for each reservoir in the reservoir group based on the total water shortage series and the beneficial storage capacity, first water supply series, minimum downstream ecological water volume series and inflow series of each reservoir in the reservoir group.

[0104] The second determining module 408 is used to determine the drought warning water level of each reservoir in the reservoir group based on the series of water shortages, dead water levels, and water level-reservoir capacity relationships of each reservoir in the reservoir group, by means of a reverse recursive method; wherein the drought warning water level corresponds to the dry season of the reservoir group.

[0105] The aforementioned long-distance water regulation and salinity suppression reservoir group drought warning water level determination device fully considers the complexity and importance of determining the drought warning water level of the reservoir group that jointly undertakes the task of long-distance water regulation and salinity suppression in the basin. It can determine the drought warning water level of the reservoir group by combining various water volume information of the reservoir group through a reverse recursive method. Moreover, the determined drought warning water level can meet the long-term water supply guarantee, alleviate the problem that existing technologies are difficult to scientifically and reasonably determine the drought warning water level of the reservoir group, and have important significance for ensuring the water supply security of the basin and key areas.

[0106] The long-distance water regulation and saline reservoir group drought warning water level determination device provided in this embodiment of the invention has the same implementation principle and technical effect as the aforementioned long-distance water regulation and saline reservoir group drought warning water level determination method embodiment. For the sake of brevity, for the parts not mentioned in the device embodiment, please refer to the corresponding content in the aforementioned method embodiment.

[0107] Unless otherwise specifically stated, the relative steps, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0108] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0109] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0110] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for determining drought warning water levels in a long-distance water-regulating saline reservoir group, characterized in that, include: Typical drought years are determined based on the long series of water inflow from the control sections of the watershed where the reservoir group is located; wherein, the long series of water inflow is the multi-year average monthly water inflow from the control sections of the watershed where the reservoir group is located. Based on the salinity control section's salinity discharge series, the first water supply series of each reservoir in the reservoir group, and the inflow series of the reservoir group in a typical drought year, a total water shortage series for the reservoir group is generated. The salinity control discharge series uses the monthly target salinity control volume that the reservoir group needs to handle at the control section; the first water supply series uses the monthly target water supply volume guaranteed by the corresponding reservoir in the reservoir group; the inflow series uses the monthly inflow volume of the reservoir group in a typical drought year; and the total water shortage series uses the monthly total water shortage of the reservoir group. Based on the total water shortage series and the beneficial storage capacity, first water supply series, minimum ecological discharge series, and inflow series of each reservoir in the reservoir group, a water shortage series for each reservoir in the reservoir group is generated; wherein, the minimum ecological discharge series adopts the monthly minimum ecological discharge of the corresponding reservoir, and the water shortage series adopts the monthly water shortage of the corresponding reservoir. Based on the water shortage series, dead water level, and water level-storage capacity relationship of each reservoir in the reservoir group, the drought warning water level of each reservoir in the reservoir group is determined by the reverse recursive method; wherein, the drought warning water level corresponds to the dry season of the reservoir group. Based on the water shortage series, dead water level, and water level-storage capacity relationship of each reservoir in the reservoir group, the drought warning water level of each reservoir in the reservoir group is determined by a reverse recursive method, including: Based on the start and end times of the dry season, the calculation period for each reservoir in the reservoir group is determined; For each reservoir in the reservoir group, the water level of the reservoir at the end of the last calculation period is exactly at the dead water level of the reservoir as the initial condition of the reverse recursive method. Based on the water shortage series and water level-storage capacity relationship of the reservoir, the reverse recursive calculation is performed from the last calculation period to the first calculation period to obtain the first water level of the reservoir at the beginning of each calculation period. Based on all the first water levels calculated for each reservoir in the reservoir group, the drought warning water level for each reservoir in the reservoir group is determined. The water shortage series includes the water shortage of the corresponding reservoir in each calculation period; based on the water shortage series of the reservoir and the water level-storage capacity relationship, a reverse recursive calculation is performed from the last calculation period to the first calculation period, including: From the last calculation period to the first calculation period, the following recursive calculation is performed for each calculation period: the reservoir capacity at the end of the current calculation period is added to the reservoir's water shortage at the beginning of the current calculation period to obtain the reservoir capacity at the beginning of the current calculation period; wherein, the reservoir capacity at the end of the last calculation period is the dead capacity corresponding to the dead water level of the reservoir; based on the reservoir capacity at the beginning of the current calculation period and the water level-capacity relationship of the reservoir, the first water level of the reservoir at the beginning of the current calculation period is calculated.

2. The method for determining drought warning water levels in a long-distance water-regulating saline reservoir group according to claim 1, characterized in that, Before determining typical drought years based on long-term inflow series of watershed control sections in the watershed where the reservoir group is located, the following also includes: The dry season is determined based on the first long series of inflow water volume and the long series of outflow water volume of the reservoir group; wherein, the first long series of inflow water volume adopts the multi-year average monthly inflow water volume of the reservoir group.

3. The method for determining drought warning water levels in a long-distance water-regulating saline reservoir group according to claim 2, characterized in that, Based on the long-term water inflow series of the control sections of the watershed where the reservoir group is located, typical drought years are determined, including: Based on the aforementioned long series of water inflows, the years corresponding to preset frequencies that meet preset conditions are determined as typical drought years; wherein, meeting the preset conditions includes: the water volume during the wet season is greater than the multi-year average water volume during the wet season and the water volume during the dry season is less than the multi-year average water volume during the dry season.

4. The method for determining drought warning water levels in a long-distance water-regulating saline reservoir group according to claim 1, characterized in that, Based on the salinity discharge series of the aforementioned watershed control sections, the first water supply series of each reservoir in the reservoir group, and the inflow series of the reservoir group in a typical drought year, a total water shortage series for the reservoir group is generated, including: Based on the target salinity discharge series of the watershed control section and the first water supply series of each reservoir in the reservoir group, a second water supply series of the reservoir group is generated; wherein, the second water supply series characterizes the monthly water supply guarantee target water volume process of the reservoir group. Based on the second water supply series and the inflow series of the reservoir group in a typical drought year, the total water shortage series is generated.

5. The method for determining drought warning water levels in a long-distance water-regulating saline reservoir group according to claim 1, characterized in that, Based on the total water shortage series and the beneficial storage capacity, first water supply series, minimum downstream ecological water volume series, and inflow series of each reservoir in the reservoir group, a water shortage series for each reservoir in the reservoir group is generated, including: Based on the total water shortage series and the beneficial storage capacity of each reservoir in the reservoir group, a first water shortage series for each reservoir in the reservoir group is generated; wherein, the first water shortage series adopts the monthly decomposed water shortage of the corresponding reservoir. Based on the inflow series of each reservoir in the reservoir group, an interval flow series from each reservoir in the reservoir group to the downstream reservoir in the reservoir group is generated; wherein, the interval flow series adopts the monthly interval flow from the corresponding reservoir to the downstream reservoir, and the inflow series adopts the monthly inflow of the corresponding reservoir. Based on the first water shortage series, first water supply series, minimum downstream ecological water volume series, inflow series, and interval flow series of each reservoir in the reservoir group, the water shortage series of each reservoir in the reservoir group is generated.

6. The method for determining drought warning water levels in a long-distance water-regulating saline reservoir group according to claim 5, characterized in that, Based on the first water shortage series, first water supply series, minimum downstream ecological water volume series, inflow series, and interval flow series of each reservoir in the reservoir group, a water shortage series for each reservoir in the reservoir group is generated, including: Based on the first water supply series, minimum downstream ecological water volume series, inflow series and interval flow series of each reservoir in the reservoir group, the second water shortage series of each reservoir in the reservoir group is generated. Based on the first and second water shortage series of each reservoir in the reservoir group, a water shortage series for each reservoir in the reservoir group is generated.

7. The method for determining drought warning water levels in a long-distance water-regulating saline reservoir group according to claim 1, characterized in that, Based on all the first water levels calculated for each reservoir in the reservoir group, the drought warning water level of each reservoir in the reservoir group is determined, including: for each reservoir in the reservoir group, the drought warning water level of the reservoir is determined based on the highest first water level calculated for that reservoir during the dry season. After determining the drought warning water level of each reservoir in the reservoir group based on the water shortage series, dead water level, and water level-storage capacity relationship of each reservoir in the reservoir group using a reverse recursive method, the process also includes: For each reservoir in the reservoir group, the water level at the beginning of the first calculation period is set as the drought warning level for that reservoir. Based on the second inflow series, the water shortage series, and the water level-storage capacity relationship of the reservoir, a forward recursive calculation is performed for each calculation period of different years from the first calculation period to the last calculation period to obtain the second water level of the reservoir at the end of the last calculation period in different years; wherein, the second inflow series includes the inflow series of the corresponding reservoir in different years; For each reservoir in the reservoir group, if the proportion of the number of second water levels corresponding to the reservoir that are not lower than its dead water level to the total number of second water levels corresponding to the reservoir is less than a preset proportion threshold, then the typical drought year determination step is repeated. If the proportion of the number of second water levels corresponding to the reservoir that are not lower than its dead water level to the total number of second water levels corresponding to the reservoir is not less than the preset proportion threshold, then the highest first water level calculated for the reservoir during the dry season is determined as the final drought warning water level for the reservoir.

8. A device for determining the drought warning water level of a long-distance water-regulating saline reservoir group, characterized in that, The method for determining the drought warning water level of a long-distance water-regulating saline reservoir group as described in any one of claims 1-7 includes: The first determining module is used to determine a typical drought year based on the long series of inflows from the control sections of the watershed where the reservoir group is located; wherein, the long series of inflows adopts the multi-year average monthly inflows from the control sections of the watershed where the reservoir group is located. The first generation module is used to generate a total water shortage series for the reservoir group based on the salinity control section series, the first water supply series of each reservoir in the reservoir group, and the inflow series of the reservoir group in a typical drought year. The salinity control section series uses the monthly target salinity control volume that the reservoir group needs to handle at the control section; the first water supply series uses the monthly target water supply volume guaranteed by the corresponding reservoir in the reservoir group; the inflow series uses the monthly inflow volume of the reservoir group in a typical drought year; and the total water shortage series uses the monthly total water shortage of the reservoir group. The second generation module is used to generate a water shortage series for each reservoir in the reservoir group based on the total water shortage series and the beneficial storage capacity, first water supply series, minimum ecological discharge series and inflow series of each reservoir in the reservoir group; wherein, the minimum ecological discharge series adopts the monthly minimum ecological discharge of the corresponding reservoir, and the water shortage series adopts the monthly water shortage of the corresponding reservoir; The second determining module is used to determine the drought warning water level of each reservoir in the reservoir group based on the series of water shortages, dead water levels, and water level-storage capacity relationships of each reservoir in the reservoir group, by using a reverse recursive method; wherein the drought warning water level corresponds to the dry season of the reservoir group.

Images