River comprehensive resistance coefficient prediction method and device

Abstract

The application relates to the technical field of water conservancy projects, in particular to a river comprehensive resistance coefficient prediction method and device, wherein the method comprises the following steps: acquiring actual water flow, vegetation information and sediment data of a target area in a river to calculate a vegetation blocking coefficient, a vegetation interface, a riverbed and a riverbank resistance coefficient; acquiring at least one interface area among an interface area between vegetation groups and water, an interface area between a riverbed and water and an interface area between a riverbank and water under a unit river length; and predicting the river comprehensive resistance coefficient of the target area according to the vegetation blocking coefficient, the vegetation interface, the riverbed and the riverbank resistance coefficient and the at least one interface area. The application can comprehensively consider the influence of different factors on the river resistance, effectively improve the accuracy of the river comprehensive resistance coefficient prediction result, and then quantitatively analyze the contribution of different factors to the river resistance coefficient and the water level-flow relationship change according to the prediction result, thereby providing a basis for river and channel management.

Description

Technical Field

[0001] This application relates to the field of water conservancy engineering technology, and in particular to a method and device for predicting the comprehensive resistance coefficient of a river channel. Background Technology

[0002] In related technologies, research indicates that after the reservoir's operation, the downstream river level at the same flow rate decreases significantly during the dry season, while the level at the same flow rate remains largely unchanged or even rises slightly. Some studies, when investigating the driving factors of changes in the same flow rate level downstream of the Three Gorges Reservoir, consider scouring and deposition (scour and downcutting) as the main cause of the decline in the same flow rate during the dry season, while the slight increase in the same flow rate during the flood season is mainly due to increased channel resistance caused by factors such as bed sediment coarsening and riparian vegetation cover. Furthermore, most studies on the causes of changes in the water level-discharge relationship in the middle reaches of the Yangtze River are primarily qualitative analyses, with only a few studies quantifying the specific effects of certain factors (such as bed sediment coarsening or scouring and deposition) on the same flow rate-water level changes. For example, the calculation of resistance coefficients in water-sediment models downstream of the Three Gorges Reservoir typically employs empirical methods, including inversion methods, curve methods, and table lookup methods, and the resulting resistance coefficients are usually the spatiotemporal average values ​​of the entire river channel.

[0003] However, research on river resistance coefficients in related technologies is mostly based on experience. When faced with situations such as continuous scouring of the downstream riverbed or complex water and sediment conditions in the river channel, it is difficult to effectively determine the comprehensive river resistance coefficient and distinguish the specific contributions of changes in various influencing factors to changes in the river resistance coefficient and water level-discharge relationship. How to comprehensively consider the influencing factors of river resistance to calculate an effective comprehensive river resistance coefficient and analyze its impact on changes in water level-discharge relationship is an urgent problem to be solved. Summary of the Invention

[0004] This application provides a method and apparatus for predicting the comprehensive resistance coefficient of a river channel, addressing the problem that research on river channel resistance coefficients in related technologies is mostly based on experience. When faced with situations such as continuous scouring of the downstream riverbed or complex water and sediment conditions in the river channel, it is difficult to effectively determine the comprehensive resistance coefficient of the river channel and to distinguish the specific contributions of changes in various influencing factors to changes in the river channel resistance coefficient and the water level-discharge relationship. The application aims to solve the problems of how to comprehensively consider the influencing factors of river channel resistance to calculate an effective comprehensive resistance coefficient and analyze its impact on changes in the water level-discharge relationship.

[0005] The first aspect of this application provides a method for predicting the comprehensive resistance coefficient of a river channel, comprising the following steps: acquiring actual water flow, vegetation information, and sediment data of a target area in a river channel to calculate a vegetation blocking coefficient, a vegetation interface, and a riverbed and bank resistance coefficient; acquiring at least one of the interface areas of vegetation-water body, riverbed-water body, and riverbank-water body per unit river channel length; and predicting the comprehensive resistance coefficient of the target area based on the vegetation blocking coefficient, the vegetation interface, the riverbed and bank resistance coefficient, and the at least one interface area.

[0006] Optionally, in one embodiment of this application, the formula for calculating the comprehensive resistance coefficient of the river channel is:

[0007] ,

[0008] in, The comprehensive resistance coefficient of the river channel is given. Because of the water depth, It is the acceleration due to gravity. The vegetation blocking coefficient is... and These are the cross-sectional area of ​​the water passage and the projected area of ​​the vegetation zone in the water body, respectively. , and These refer to the vegetation interface, the riverbed, and the riverbank resistance coefficient, respectively. , and These refer to the interface area between vegetation and water, the interface area between riverbed and water, and the interface area between riverbank and water, respectively, per unit river length.

[0009] Optionally, in one embodiment of this application, obtaining the actual water flow, vegetation information and sediment data of the target area in the river channel includes: collecting basic parameters of the target area, the basic parameters including at least one of the river channel length, river channel width and river channel gradient; and obtaining the actual water flow, vegetation information and sediment data of the target area based on the basic parameters.

[0010] Optionally, in one embodiment of this application, the actual water flow includes the water level along the river and the water flow velocity, the vegetation information includes at least one of vegetation height, vegetation weight, water-facing area, and blocking coefficient, and the sediment data includes bed sediment gradation and suspended sediment concentration.

[0011] A second aspect of this application provides a device for predicting the comprehensive resistance coefficient of a river channel, comprising: a calculation module for acquiring actual water flow, vegetation information, and sediment data of a target area in a river channel to calculate a vegetation blocking coefficient, a vegetation interface, and a riverbed and bank resistance coefficient; an acquisition module for acquiring at least one of the interface areas of vegetation-water body, riverbed-water body, and riverbank-water body per unit river channel length; and a prediction module for predicting the comprehensive resistance coefficient of the target area based on the vegetation blocking coefficient, the vegetation interface, the riverbed and bank resistance coefficient, and the at least one interface area.

[0012] Optionally, in one embodiment of this application, the formula for calculating the comprehensive resistance coefficient of the river channel is:

[0013] ,

[0014] in, The comprehensive resistance coefficient of the river channel is given. Because of the water depth, It is the acceleration due to gravity. The vegetation blocking coefficient is... and These are the cross-sectional area of ​​the water passage and the projected area of ​​the vegetation zone in the water body, respectively. , and These refer to the vegetation interface, the riverbed, and the riverbank resistance coefficient, respectively. , and These refer to the interface area between vegetation and water, the interface area between riverbed and water, and the interface area between riverbank and water, respectively, per unit river length.

[0015] Optionally, in one embodiment of this application, the calculation module includes: a collection unit for collecting basic parameters of the target area, the basic parameters including at least one of river length, river width and river gradient; and an acquisition unit for acquiring actual water flow, vegetation information and sediment data of the target area based on the basic parameters.

[0016] Optionally, in one embodiment of this application, the actual water flow includes the water level along the river and the water flow velocity, the vegetation information includes at least one of vegetation height, vegetation weight, water-facing area, and blocking coefficient, and the sediment data includes bed sediment gradation and suspended sediment concentration.

[0017] A third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for predicting the comprehensive resistance coefficient of a river channel as described in the above embodiments.

[0018] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for predicting the comprehensive resistance coefficient of a river channel.

[0019] A fifth aspect of this application provides a computer program product, including a computer program that, when executed, is used to implement the above-described method for predicting the comprehensive resistance coefficient of a river channel.

[0020] This application's embodiments can calculate the vegetation blocking coefficient, vegetation interface, and riverbed and bank resistance coefficients based on the actual water flow, vegetation information, and sediment data of the target area in the river channel. Then, by combining at least one of the interface areas between the vegetation and water body, the riverbed and water body, and the bank and water body per unit river length, the comprehensive river resistance coefficient of the target area can be predicted. This achieves a comprehensive consideration of the impact of factors such as bed sediment coarsening, riverbed scouring and incision, and vegetation cover on river resistance, effectively improving the accuracy of the predicted comprehensive river resistance coefficient. Furthermore, it allows for the quantitative analysis of the contribution of different factors to changes in the river resistance coefficient and water level-discharge relationship based on the prediction results, thereby analyzing changes in measured water level-discharge relationships, bed sediment gradation, riverbed scouring and deposition, and changes in the thalweg line, providing a basis for river and waterway management. This addresses the problem that many studies on river resistance coefficients in related technologies rely primarily on experience. When faced with situations such as continuous scouring of the downstream riverbed or complex water and sediment conditions within the river channel, it is difficult to effectively determine the comprehensive river resistance coefficient and distinguish the specific contributions of changes in various influencing factors to changes in the river resistance coefficient and water level-discharge relationship. The solution also addresses the issues of how to comprehensively consider the influencing factors of river resistance to calculate an effective comprehensive river resistance coefficient and analyze its impact on changes in the water level-discharge relationship.

[0021] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0022] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0023] Figure 1 This is a schematic diagram of the framework of a river comprehensive resistance coefficient prediction system according to an embodiment of this application;

[0024] Figure 2 This is a flowchart of a method for predicting the comprehensive resistance coefficient of a river channel according to an embodiment of this application;

[0025] Figure 3 This is a flowchart of a method for predicting the comprehensive resistance coefficient of a river channel according to an embodiment of this application;

[0026] Figure 4 This is a schematic diagram of a measured river cross-section according to an embodiment of this application;

[0027] Figure 5 This is a schematic diagram comparing field observations and model calculations of the drag coefficient according to one embodiment of this application;

[0028] Figure 6 This is a simplified map and a measured cross-sectional view of the geographical location of a hydrological station according to an embodiment of this application;

[0029] Figure 7 This is a schematic diagram illustrating the calculation results of the water level-discharge relationship at a hydrological station according to an embodiment of this application;

[0030] Figure 8 This is a schematic diagram of the measured results of the water level-discharge relationship at a hydrological station according to an embodiment of this application;

[0031] Figure 9 This is a schematic diagram of the structure of the river comprehensive resistance coefficient prediction device provided according to the embodiments of this application;

[0032] Figure 10 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application.

[0033] Figure label:

[0034] 10-River channel comprehensive resistance coefficient prediction device: 100-Calculation module, 200-Acquisition module and 300-Prediction module; 1001-Memory, 1002-Processor and 1003-Communication interface. Detailed Implementation

[0035] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0036] The following describes a method and apparatus for predicting the comprehensive resistance coefficient of a river channel according to embodiments of this application, with reference to the accompanying drawings. In the aforementioned background art, research on the river channel resistance coefficient is largely based on experience. When faced with situations such as continuous scouring of the downstream riverbed or complex water and sediment conditions within the river channel, it is difficult to effectively determine the comprehensive resistance coefficient and distinguish the specific contributions of changes in various influencing factors to the river channel resistance coefficient and the change in the water level-discharge relationship. This application addresses the problem of how to comprehensively consider the influencing factors of river channel resistance to calculate an effective comprehensive resistance coefficient and analyze its impact on changes in the water level-discharge relationship. This application provides a method for predicting the comprehensive resistance coefficient of a river channel. In this method, the vegetation blocking coefficient, vegetation interface, and riverbed and bank resistance coefficients can be calculated based on the actual water flow, vegetation information, and sediment data of the target area in the river channel. Then, by combining at least one of the interface areas of vegetation and water body per unit river channel length, the interface areas of riverbed and water body, and the interface areas of riverbank and water body, the comprehensive resistance coefficient of the target area can be predicted. This approach comprehensively considers the impacts of factors such as bed sediment coarsening, channel scouring and downcutting, and vegetation cover on channel resistance, effectively improving the accuracy of the predicted comprehensive channel resistance coefficient. Furthermore, it allows for the quantitative analysis of the contributions of different factors to changes in the channel resistance coefficient and water level-discharge relationship based on the predicted results. This enables the analysis of changes in measured water level-discharge relationships, bed sediment gradation, channel scouring and deposition, and thorhombic changes, providing a basis for river and waterway management. This approach also addresses the challenges of relying primarily on experience in current technologies for studying channel resistance coefficients. In situations where the downstream riverbed is under continuous scouring or the water and sediment conditions within the channel are complex, it is difficult to effectively determine the comprehensive channel resistance coefficient and distinguish the specific contributions of various influencing factors to changes in the channel resistance coefficient and water level-discharge relationship. The goal is to comprehensively consider the influencing factors of channel resistance to calculate an effective comprehensive channel resistance coefficient and analyze its impact on changes in the water level-discharge relationship.

[0037] Before explaining the method for predicting the comprehensive resistance coefficient of a river in this application, the framework of the system for predicting the comprehensive resistance coefficient of a river in this application will be explained first.

[0038] Figure 1 This is a schematic diagram of the framework of a river channel comprehensive resistance coefficient prediction system according to an embodiment of this application. Figure 1 As shown, the river comprehensive resistance coefficient prediction system in this application embodiment mainly includes, but is not limited to: data acquisition module M1, data processing module M2, and prediction result module M3.

[0039] The data acquisition module M1 is used to acquire basic information about the river channel as well as observation data on water flow, vegetation, and sediment. The basic information about the river channel includes, but is not limited to, information such as the length, width, and gradient of the river channel. The water flow monitoring data includes data such as water depth and average cross-sectional velocity. The vegetation monitoring data includes, but is not limited to, data such as the interface area between the vegetation group and the water body and the projected area of ​​the vegetation area on the water body. The sediment monitoring data includes, but is not limited to, data such as the median particle size of the bed sediment and the density of sediment particles.

[0040] The data processing module M2 processes the acquired data and calculates the resistance coefficient of the vegetation interface, the resistance coefficient of the riverbed, the resistance coefficient of the riverbank, and the vegetation blocking coefficient.

[0041] The prediction results module M3 predicts the comprehensive resistance coefficient of the river channel based on the results of the data processing module, and then predicts the contribution of various factors, including but not limited to changes in vegetation cover, bed sediment particle size, and river channel morphology. It can further analyze changes in measured water level-discharge relationships, bed sediment gradation, river channel scouring and deposition, and changes in the thalweg line, providing a basis for river and waterway management.

[0042] Specifically, Figure 2 This is a flowchart illustrating a method for predicting the comprehensive resistance coefficient of a river channel, as provided in an embodiment of this application.

[0043] like Figure 2 As shown, the method for predicting the comprehensive resistance coefficient of a river channel includes the following steps:

[0044] In step S201, the actual water flow, vegetation information and sediment data of the target area in the river channel are obtained in order to calculate the vegetation blocking coefficient, vegetation interface, riverbed and riverbank resistance coefficient.

[0045] In some embodiments, the water level-discharge relationship is an important aspect of river research, with significant application value for navigation planning and management, water conservancy project construction, and ecological protection. When a large reservoir is in operation, the downstream inflow, sediment load, and flow process will undergo significant changes. Clear water scouring will cause coarsening and morphological adjustment of the riverbed, resulting in changes in the water level-discharge relationship of the downstream river section.

[0046] Based on this, considering that factors such as bed sand coarsening, riverbed scouring and downcutting, and vegetation cover all have a certain impact on the resistance coefficient, this application may, but is not limited to, obtain actual water flow information, vegetation information, and some sediment data in the target area of ​​the river as the main data, so as to calculate the corresponding vegetation blocking coefficient, vegetation interface resistance coefficient, riverbed resistance coefficient, and riverbank resistance coefficient.

[0047] In this context, the target area in the river channel can be understood as the river channel area where the comprehensive resistance coefficient needs to be calculated. After calculating resistance coefficients such as vegetation blocking coefficient, vegetation interface resistance coefficient, riverbed resistance coefficient, and riverbank resistance coefficient, this embodiment of the application can use these data to calculate the subsequent river channel resistance coefficient.

[0048] For example, the vegetation blocking coefficient can be determined using the cross-sectional area of ​​the water passage and the projected area of ​​the vegetation zone over the water body, as shown below:

[0049] (1)

[0050] in, The vegetation blocking coefficient, and These are the cross-sectional area of ​​the water passage and the projected area of ​​the vegetation zone in the water body, respectively.

[0051] Furthermore, the resistance coefficient at the vegetation interface, the resistance coefficient of the riverbed, and the resistance coefficient of the riverbank... , and Can be compared with Manning's drag coefficient Transformation:

[0052] (2)

[0053] in, These are the resistance coefficients at the vegetation interface, the riverbed resistance coefficient, and the riverbank resistance coefficient. This is the Manning drag coefficient. It is the acceleration due to gravity. The water is deep.

[0054] Specifically, the resistance coefficient at the vegetation interface can be determined from existing data to be within the range of 0.005 to 0.13. For example, in autumn when the vegetation is relatively dense, a value of 0.079 can be used. ， Alternatively, it can be obtained by simulation experiments conducted by those skilled in the art based on actual conditions. The embodiments in this application are merely illustrative and do not impose specific limitations.

[0055] Riverbed resistance coefficient Besides formula (2), it can also be expressed as:

[0056] (3)

[0057] in, The median particle size of the sediment on the bed surface.

[0058] Riverbank resistance coefficient The riverbank resistance coefficient can be estimated using empirical formulas for the bed surface. In the absence of available data, the value recommended by relevant materials such as the Sediment Handbook can also be used. For example, in this embodiment, the riverbank resistance coefficient can be a constant of 0.020 to 0.023, or it can be calculated using formula (2), which can be expressed as follows:

[0059] (4)

[0060] in, This is the Manning drag coefficient. It is the acceleration due to gravity. Because of the water depth, This represents the riverbank resistance coefficient.

[0061] Optionally, in one embodiment of this application, obtaining actual water flow, vegetation information, and sediment data of a target area in a river channel includes: collecting basic parameters of the target area, including at least one of river channel length, river channel width, and river channel gradient; and obtaining actual water flow, vegetation information, and sediment data of the target area based on the basic parameters. The actual water flow includes the water level and flow velocity along the river channel; the vegetation information includes at least one of vegetation height, vegetation weight, water-facing area, and blocking coefficient; and the sediment data includes bed sediment gradation and suspended sediment concentration.

[0062] Based on the descriptions of other embodiments, it is understood that this application can calculate the relevant resistance coefficient by obtaining the actual water flow, vegetation information and sediment data of the target area in the river channel, and then calculate the comprehensive resistance coefficient of the river channel.

[0063] Specifically, the embodiments of this application require obtaining basic parameters of the target area in the river channel, including but not limited to at least one of the following: river channel length, river channel width, and river channel gradient (the ratio of the elevation difference between the upstream and downstream of the river channel to the river channel length (or horizontal distance)).

[0064] Then, the obtained river length, width, or gradient are used to acquire actual water flow, vegetation information, and sediment data for the target area. Actual water flow includes, but is not limited to, water level and flow velocity along the river course; vegetation information includes, but is not limited to, at least one of vegetation height, vegetation weight, water-facing area, and obstruction coefficient; and sediment data includes, but is not limited to, bed sediment gradation and suspended sediment concentration.

[0065] Step S202: Obtain at least one of the following interface areas per unit river length: the interface area between vegetation and water, the interface area between riverbed and water, and the interface area between riverbank and water.

[0066] It is understandable that the resistance coefficients obtained above, such as the vegetation interface resistance coefficient, riverbed resistance coefficient, and riverbank resistance coefficient, are all resistance coefficients per unit area.

[0067] In actual implementation, the size of vegetation, riverbed, and riverbank within the target area of ​​the river channel may have different resistance levels. Therefore, before calculating the comprehensive resistance coefficient of the river channel in the target area, this embodiment of the application needs to obtain at least one of the interface areas of vegetation and water, riverbed and water, and riverbank and water per unit river channel length. Then, it combines these interfaces with resistance coefficients such as vegetation interface resistance coefficient, riverbed resistance coefficient, and riverbank resistance coefficient to calculate the comprehensive resistance coefficient of the river channel.

[0068] Step S203: Predict the overall river resistance coefficient of the target area based on the vegetation blocking coefficient, vegetation interface, riverbed and bank resistance coefficients, and the area of ​​at least one interface. The formula for calculating the overall river resistance coefficient is as follows:

[0069] ,

[0070] in, The comprehensive resistance coefficient of the river channel. Because of the water depth, It is the acceleration due to gravity. The vegetation blocking coefficient, and These are the cross-sectional area of ​​the water passage and the projected area of ​​the vegetation zone in the water body, respectively. , and These represent the resistance coefficients at the vegetation interface, riverbed, and riverbank, respectively. , and These represent the interface area between vegetation and water, the interface area between riverbed and water, and the interface area between riverbank and water, respectively, per unit length of river channel.

[0071] Based on the descriptions of other embodiments, it is understood that this application can comprehensively consider the influence of multiple factors such as bed sand coarsening, riverbed scouring and downcutting, and vegetation cover on the resistance coefficient in the river channel. That is, it combines the vegetation blocking coefficient, vegetation interface resistance coefficient, riverbed resistance coefficient, and riverbank resistance coefficient with the area of ​​at least one interface to comprehensively predict the comprehensive river resistance coefficient of the target area.

[0072] Specifically, the embodiments of this application can distinguish between three types of resistance: vegetation, riverbed, and riverbank. A comprehensive resistance coefficient model is established based on the momentum equation, and then the effects of three factors—bed sand coarsening, channel scouring and downcutting, and vegetation cover—are considered to obtain the final formula for calculating the comprehensive channel resistance coefficient. The process can be expressed as follows:

[0073] In natural rivers, the problem of determining water level and discharge can generally be solved using the one-dimensional Saint-Venant equations. In the case of one-dimensional steady uniform flow without side inflows, the inertial and additional gradient terms in the Saint-Venant equations can be neglected. In this case, the cross-sectional discharge of the steady uniform flow in the river channel... The formula can be expressed as:

[0074] (5)

[0075] in, The cross-sectional area of ​​the water passage is... The hydraulic radius of the river channel cross section. For the riverbed gradient, This is the Manning coefficient.

[0076] The momentum equation for a unit length of unvegetated area can be expressed as:

[0077] (6)

[0078] in, For water density, It is the acceleration due to gravity. and These are the cross-sectional area of ​​the water passage and the projected area of ​​the vegetation zone in the water body, respectively. , and These represent the interface area between vegetation and water, the interface area between the riverbed and water, and the interface area between the riverbank and water, respectively, per unit length of river channel. , and These represent the shear stress at the interface between vegetated and unvegetated areas, and the shear stress in the riverbed and bank within the unvegetated area. The shear stress can be expressed as:

[0079] (7)

[0080] in, For the shear stress in the specified area, The drag coefficient for a specified area. The average flow velocity is the cross-sectional velocity in the unvegetated area.

[0081] By combining equations (7) and (8), the flow velocity in the unvegetated area can be obtained. , can be represented as follows:

[0082] (8)

[0083] in, , and These are the resistance coefficients at the vegetation interface, riverbed, and riverbank, respectively.

[0084] Average flow velocity of river cross section U It can then be expressed as:

[0085] (9)

[0086] in, The vegetation blocking coefficient, Due to the flow velocity within the vegetated area Much smaller than the flow velocity in areas without vegetation And under normal circumstances Therefore, the average flow velocity of the river cross section U This can be simplified as follows:

[0087] (10)

[0088] Combining the previously calculated vegetation blocking coefficient, vegetation interface resistance coefficient, riverbed resistance coefficient, and riverbank resistance coefficient with the area of ​​at least one interface, the final formula for calculating the comprehensive river channel resistance coefficient can be obtained, which can be expressed as:

[0089] (11)

[0090] in, The comprehensive resistance coefficient of the river channel. Because of the water depth, It is the acceleration due to gravity. The vegetation blocking coefficient, and These are the cross-sectional area of ​​the water passage and the projected area of ​​the vegetation zone in the water body, respectively. , and These represent the resistance coefficients at the vegetation interface, riverbed, and riverbank, respectively. , and These represent the interface area between vegetation and water, the interface area between riverbed and water, and the interface area between riverbank and water, respectively, per unit length of river channel.

[0091] Additionally, this application embodiment also considers that in natural rivers, the factors affecting the drag coefficient and the water level-discharge relationship are intertwined. Therefore, this application embodiment may, but is not limited to, adopt the idea of ​​separating variables, assuming that a certain factor changes in the analysis, thereby quantitatively generalizing the contribution of the three factors to the changes in the drag coefficient and the water level-discharge relationship, and then combining the prediction results to further analyze the changes in the measured water level-discharge relationship, the changes in bed sediment gradation, the changes in riverbed scouring and deposition, and the changes in the thalweg line, so as to provide a basis for river and waterway management.

[0092] For example, embodiments of this application may assume that the function under the influence of multiple factors can be expressed as follows: Using Taylor series expansion and ignoring higher-order small quantities, the increment of the dependent variable is... This can be approximated as the sum of the increments caused by the individual changes of each factor. Therefore, the contribution of each factor in formula (11) can be calculated as follows:

[0093] (12)

[0094] (13)

[0095] (14)

[0096] in, As the dependent variable, 、 、 This indicates various factors, such as changes in vegetation cover. and Changes in bed sand particle size River morphology changes and wait.

[0097] The present application will be described in detail below with reference to two specific embodiments.

[0098] Figure 3 This is a flowchart illustrating a method for predicting the comprehensive resistance coefficient of a river channel according to an embodiment of this application. Figure 3 As shown:

[0099] First, obtain the basic parameters of the target area, such as the length, width and gradient of the river channel;

[0100] Next, field observation data of the target area in the river channel at different times were obtained, such as water flow, vegetation and sediment parameters in the river channel;

[0101] Subsequently, based on parameters such as water flow, vegetation, and sediment in the river channel, the resistance coefficients of the vegetation interface, riverbed, and riverbank were calculated. At the same time, the interface area between vegetation and water, the interface area between riverbed and water, the interface area between riverbank and water, and the vegetation blocking coefficient per unit river channel length were obtained.

[0102] Finally, by combining the obtained resistance coefficients of vegetation interface, riverbed, riverbank, vegetation blocking coefficient, and the interface areas of vegetation community and water body, riverbed and water body, and riverbank and water body, the comprehensive resistance coefficient of the river channel is calculated.

[0103] Additionally, the results will be input into the results prediction module, which can predict the contribution of each factor and analyze changes in the measured water level-discharge relationship, bed sediment gradation, riverbed scouring and deposition, and thalweg line, providing a basis for river and waterway management.

[0104] Example 1:

[0105] This application's embodiment selected a field observation experiment based on an artificially excavated river channel. Figure 4 This is a schematic diagram of a measured river cross-section according to an embodiment of this application. Figure 4 As shown, the river channel is 850 m long and 0.5–7.0 m wide, with a gradient ranging from 0.001 to 0.002. Water flow, vegetation, and sediment parameters were observed in the river channel during five typical time periods. Water flow parameters included water level and flow velocity along the channel; vegetation parameters included vegetation height, vegetation weight, water-facing area, and blocking coefficient; and sediment parameters included bed sediment gradation and suspended sediment concentration.

[0106] Assuming the water flow in the river channel is a steady, uniform flow, the following calculations are obtained based on measured flow and cross-sectional parameters, combined with Manning's formula. n (This is called the measured value).

[0107] Figure 5 This is a schematic diagram comparing the field observation values ​​and model calculation values ​​of the drag coefficient. To facilitate model calculations, the measured cross-section is simplified to... Figure 4 The figure shows a regular polygon. As can be seen from the figure, the results calculated by the method for predicting the comprehensive resistance coefficient of the river channel in this embodiment are basically consistent with the measured results.

[0108] Example 2:

[0109] Figure 6 This is a simplified geographical location map and a measured cross-sectional view of a hydrological station according to one embodiment of this application. Figure 6 As shown, the embodiments of this application focus on the Shashi section of the Jingjiang River. Figure 6 This study collected data on water level, flow rate, and bed sediment gradation from the Shashi Hydrological Station in 2003, 2013, and 2016 (data sourced from the Hydrology Bureau of the Yangtze River Water Resources Commission). Combined with relevant literature, the study first analyzed changes in the measured water level-flow rate relationship, bed sediment gradation, channel scouring and deposition, and thorium line. Furthermore, a comprehensive resistance coefficient model was applied to explore the contributions of bed sediment coarsening, channel scouring and incision, and vegetation cover to changes in the water level-flow rate relationship after reservoir operation.

[0110] Table 1 shows the design values ​​of eight typical operating condition parameters for one embodiment of this application, as follows:

[0111] Table 1

[0112]

[0113] Wherein, "B" represents the basic working condition, indicating no coarsening, no scouring, and no vegetation; "A" represents bed sand coarsening; "E" represents riverbed scouring and downcutting; "V" represents vegetation cover; a represents the riverbed scouring depth relative to working condition B; and "-" represents no vegetation growth.

[0114] Different combinations indicate that multiple factors are considered comprehensively. For example, "AE" indicates that the working condition includes the effects of bed sand coarsening and riverbed scouring and downcutting. Since the Jingjiang River section underwent a waterway improvement project from 2013 to 2015, during which ecological revetment was vigorously developed, this application uses the Jingjiang River section waterway improvement project as the time boundary to compare the impact of vegetation factors. That is, it is assumed that before 2013, riverbank vegetation was relatively scarce and negligible; after 2013, ecological revetment was vigorously developed, and the riverbanks were covered with lush vegetation. Furthermore, in the waterway improvement project, the construction water level controlled by the ecological revetment section elevation design is generally the low-water platform. Therefore, the working condition design considers the vegetation growth starting point corresponding to the low-water level of Shashi Station, i.e., z = 32.7 m, and the vegetation is emergent vegetation represented by reeds.

[0115] It can be seen that conditions B, AE, and AEV correspond to the conditions at the Shashi hydrological station in 2003, 2013, and 2016, respectively. The purpose of designing other conditions is to analyze the impact of single-factor changes on the drag coefficient using the controlled variable method. Furthermore, to simplify the calculation, the complex measured cross-section is generalized into a regular polygon during the actual calculation process. Figure 6 ).

[0116] Figure 7 This is a schematic diagram illustrating the calculation results of the water level-discharge relationship at a hydrological station according to one embodiment of this application. Figure 7 The figures show the calculation results for working conditions B (2003), AE (2013), and (2016), respectively. The resistance coefficient is calculated based on formula (10), and the water level-flow relationship is solved based on formula (1). Figure 8 This is a schematic diagram illustrating the measured results of the water level-discharge relationship at a hydrological station according to an embodiment of this application. (Combined with...) Figure 7 and Figure 8 It can be seen that the calculated flow-water level relationship is consistent with the trend of the measured data in the embodiments of this application, that is, the water level decreases with the same flow rate during the dry season and increases with the same flow rate during the flood season.

[0117] The calculation results of the river comprehensive resistance coefficient prediction method in this application are basically consistent with the measured results, which proves the accuracy of the river comprehensive resistance coefficient prediction method proposed in this invention.

[0118] Furthermore, based on the prediction results of the embodiments of this application, the changes in measured water level-discharge relationship, bed sediment gradation, channel scouring and deposition, and thorhombic line can be further analyzed to provide a basis for river and waterway management. For example, under low flow conditions: channel scouring and downcutting are the main controlling factors causing the decline in the same flow-dry water level at Shashi Station, while bed sediment coarsening, to a certain extent, inhibits the downward trend of the same flow-dry water level. Under high flow conditions, bed sediment coarsening and the increase in drag coefficient due to vegetation cover are the main controlling factors causing the rise in the same flow-flood water level at Shashi Station. When there is no vegetation, bed sediment coarsening contributes the most to the rise in water level; when there is vegetation, vegetation contributes the most to the rise in water level, followed by bed sediment coarsening.

[0119] The method for predicting the comprehensive river resistance coefficient proposed in this application can calculate the vegetation blocking coefficient, vegetation interface, and riverbed and bank resistance coefficients based on the actual water flow, vegetation information, and sediment data of the target area in the river channel. Then, by combining at least one of the interface areas between the vegetation and water body, the riverbed and water body, and the bank and water body per unit river length, the comprehensive river resistance coefficient of the target area can be predicted. This method comprehensively considers the impact of factors such as bed sediment coarsening, riverbed scouring and incision, and vegetation cover on river resistance, effectively improving the accuracy of the predicted comprehensive river resistance coefficient. Furthermore, it can quantitatively analyze the contribution of different factors to changes in the river resistance coefficient and water level-discharge relationship based on the prediction results, thereby analyzing changes in measured water level-discharge relationship, bed sediment gradation, riverbed scouring and deposition, and changes in the thalweg line, providing a basis for river and waterway management. This addresses the problem that many studies on river resistance coefficients in related technologies rely primarily on experience. When faced with situations such as continuous scouring of the downstream riverbed or complex water and sediment conditions within the river channel, it is difficult to effectively determine the comprehensive river resistance coefficient and distinguish the specific contributions of changes in various influencing factors to changes in the river resistance coefficient and water level-discharge relationship. The solution also addresses the issues of how to comprehensively consider the influencing factors of river resistance to calculate an effective comprehensive river resistance coefficient and analyze its impact on changes in the water level-discharge relationship.

[0120] Next, the device for predicting the comprehensive resistance coefficient of a river channel according to an embodiment of this application is described with reference to the accompanying drawings.

[0121] Figure 9 This is a schematic diagram of the structure of the river comprehensive resistance coefficient prediction device according to an embodiment of this application.

[0122] like Figure 9 As shown, the river channel comprehensive resistance coefficient prediction device 10 includes: a calculation module 100, an acquisition module 200, and a prediction module 300.

[0123] The calculation module 100 is used to acquire the actual water flow, vegetation information and sediment data of the target area in the river channel, so as to calculate the vegetation blocking coefficient, vegetation interface, riverbed and riverbank resistance coefficient.

[0124] The acquisition module 200 is used to acquire at least one of the following interface areas per unit river length: the interface area between vegetation and water, the interface area between riverbed and water, and the interface area between riverbank and water.

[0125] The prediction module 300 is used to predict the overall river resistance coefficient of the target area based on the vegetation blocking coefficient, vegetation interface, riverbed and riverbank resistance coefficient and the area of ​​at least one of the interfaces.

[0126] Optionally, in one embodiment of this application, the formula for calculating the comprehensive resistance coefficient of the river channel can be expressed as:

[0127] ,

[0128] in, The comprehensive resistance coefficient of the river channel. Because of the water depth, It is the acceleration due to gravity. The vegetation blocking coefficient, and These are the cross-sectional area of ​​the water passage and the projected area of ​​the vegetation zone in the water body, respectively. 、 and These represent the resistance coefficients at the vegetation interface, riverbed, and riverbank, respectively. 、 and These represent the interface area between vegetation and water, the interface area between riverbed and water, and the interface area between riverbank and water, respectively, per unit length of river channel.

[0129] Optionally, in one embodiment of this application, the calculation module 100 includes: a collection unit and an acquisition unit.

[0130] The acquisition unit is used to acquire basic parameters of the target area, including at least one of the following: river length, river width, and river gradient.

[0131] The acquisition unit is used to obtain the actual water flow, vegetation information and sediment data of the target area based on basic parameters.

[0132] Optionally, in one embodiment of this application, the actual water flow includes the water level and flow velocity along the river channel, the vegetation information includes at least one of the following: vegetation height, vegetation weight, water-facing area, and blocking coefficient, and the sediment data includes the sediment gradation and suspended sediment concentration on the bed surface.

[0133] It should be noted that the foregoing explanation of the embodiment of the method for predicting the comprehensive resistance coefficient of a river channel also applies to the device for predicting the comprehensive resistance coefficient of a river channel in this embodiment, and will not be repeated here.

[0134] The river comprehensive resistance coefficient prediction device proposed in this application can calculate the vegetation blocking coefficient, vegetation interface, and riverbed and bank resistance coefficients based on the actual water flow, vegetation information, and sediment data of the target area in the river. Then, by combining at least one of the interface areas between vegetation and water, riverbed and water, and riverbank and water per unit river length, the comprehensive river resistance coefficient of the target area can be predicted. This achieves a comprehensive consideration of the impact of factors such as bed sediment coarsening, riverbed scouring and incision, and vegetation cover on river resistance, effectively improving the accuracy of the predicted comprehensive river resistance coefficient. Furthermore, it can quantitatively analyze the contribution of different factors to changes in the river resistance coefficient and water level-discharge relationship based on the prediction results, thereby analyzing changes in measured water level-discharge relationship, bed sediment gradation, riverbed scouring and deposition, and changes in the thalweg line, providing a basis for river and waterway management. This addresses the problem that many studies on river resistance coefficients in related technologies rely primarily on experience. When faced with situations such as continuous scouring of the downstream riverbed or complex water and sediment conditions within the river channel, it is difficult to effectively determine the comprehensive river resistance coefficient and distinguish the specific contributions of changes in various influencing factors to changes in the river resistance coefficient and water level-discharge relationship. The solution also addresses the issues of how to comprehensively consider the influencing factors of river resistance to calculate an effective comprehensive river resistance coefficient and analyze its impact on changes in the water level-discharge relationship.

[0135] Figure 10 A schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include:

[0136] The memory 1001, the processor 1002, and the computer program stored on the memory 1001 and capable of running on the processor 1002.

[0137] When the processor 1002 executes the program, it implements the method for predicting the comprehensive resistance coefficient of the river channel provided in the above embodiments.

[0138] Furthermore, electronic devices also include:

[0139] Communication interface 1003 is used for communication between memory 1001 and processor 1002.

[0140] The memory 1001 is used to store computer programs that can run on the processor 1002.

[0141] The memory 1001 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0142] If the memory 1001, processor 1002, and communication interface 1003 are implemented independently, then the communication interface 1003, memory 1001, and processor 1002 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized into address buses, data buses, control buses, etc. For ease of representation, Figure 10 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0143] Optionally, in a specific implementation, if the memory 1001, processor 1002, and communication interface 1003 are integrated on a single chip, then the memory 1001, processor 1002, and communication interface 1003 can communicate with each other through an internal interface.

[0144] The processor 1002 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0145] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for predicting the comprehensive resistance coefficient of a river channel.

[0146] This application also provides a computer program product, including a computer program that can run computer instructions. When the computer instructions are executed by a processor, they implement the method for predicting the comprehensive resistance coefficient of a river channel provided in this application.

[0147] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0148] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0149] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0150] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0151] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or more of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0152] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0153] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0154] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A method for predicting the comprehensive resistance coefficient of a river channel, characterized in that, Includes the following steps: Obtain actual water flow, vegetation information and sediment data for the target area in the river channel in order to calculate vegetation blocking coefficient, vegetation interface, riverbed and bank resistance coefficient; Obtain the interface area between vegetation and water, the interface area between riverbed and water, and the interface area between riverbank and water per unit river length; Based on the vegetation blocking coefficient, the vegetation interface, the riverbed and bank resistance coefficient, and the interface area between vegetation and water, the interface area between riverbed and water, and the interface area between riverbank and water per unit river length, the comprehensive river resistance coefficient of the target area is predicted. The formula for calculating the comprehensive resistance coefficient of the river channel is as follows: ， in, The comprehensive resistance coefficient of the river channel is given. Because of the water depth, It is the acceleration due to gravity. The vegetation blocking coefficient is... and These are the cross-sectional area of ​​the water passage and the projected area of ​​the vegetation zone in the water body, respectively. , and These refer to the resistance coefficients of the vegetation interface, the riverbed, and the riverbank, respectively. , and These refer to the interface area between vegetation and water, the interface area between riverbed and water, and the interface area between riverbank and water, respectively, per unit river length.

2. The method according to claim 1, characterized in that, The acquisition of actual water flow, vegetation information, and sediment data for the target area in the river channel includes: Collect basic parameters of the target area, including at least one of the river length, river width and river gradient; Based on the aforementioned basic parameters, the actual water flow, vegetation information, and sediment data of the target area are obtained.

3. The method according to claim 1, characterized in that, The actual water flow includes the water level and flow velocity along the river channel; the vegetation information includes at least one of the following: vegetation height, vegetation weight, water-facing area, and barrier coefficient; and the sediment data includes the sediment gradation and suspended sediment concentration on the bed surface.

4. A device for predicting the comprehensive resistance coefficient of a river channel, characterized in that, include: The calculation module is used to obtain the actual water flow, vegetation information and sediment data of the target area in the river channel, so as to calculate the vegetation blocking coefficient, vegetation interface, riverbed and riverbank resistance coefficient. The acquisition module is used to acquire the interface area between vegetation and water, the interface area between riverbed and water, and the interface area between riverbank and water per unit river length. The prediction module is used to predict the comprehensive resistance coefficient of the river in the target area based on the vegetation blocking coefficient, the vegetation interface, the riverbed and bank resistance coefficient, and the interface area between the vegetation group and the water body, the interface area between the riverbed and the water body, and the interface area between the riverbank and the water body per unit river length. The formula for calculating the comprehensive resistance coefficient of the river channel is as follows: ， in, The comprehensive resistance coefficient of the river channel is given. Because of the water depth, It is the acceleration due to gravity. The vegetation blocking coefficient is... and These are the cross-sectional area of ​​the water passage and the projected area of ​​the vegetation zone in the water body, respectively. , and These refer to the resistance coefficients of the vegetation interface, the riverbed, and the riverbank, respectively. , and These refer to the interface area between vegetation and water, the interface area between riverbed and water, and the interface area between riverbank and water, respectively, per unit river length.

5. The apparatus according to claim 4, characterized in that, The computing module includes: A data acquisition unit is used to acquire basic parameters of the target area, including at least one of the river length, river width, and river gradient. The acquisition unit is used to acquire the actual water flow, vegetation information and sediment data of the target area based on the basic parameters.

6. An electronic device, characterized in that, include: The memory, the processor, and the computer program stored in the memory and executable on the processor, the processor executing the program to implement the method for predicting the comprehensive resistance coefficient of a river channel as described in any one of claims 1-3.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the method for predicting the comprehensive resistance coefficient of a river channel as described in any one of claims 1-3.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed, it is used to implement the method for predicting the comprehensive resistance coefficient of a river channel as described in any one of claims 1-3.

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