Method and system for establishing flood forecasting model of hydropower station
By dividing the watershed into sub-basins and calibrating the hydrological model parameters, the problems of data accuracy and response speed in existing flood forecasting methods have been solved, enabling rapid and accurate flood forecasting for hydropower stations and ensuring the safe and stable operation of dams.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-07
- Publication Date
- 2026-03-10
AI Technical Summary
Existing flood forecasting methods have shortcomings in data acquisition, model parameter calibration, and computational response speed, resulting in low flood forecast accuracy and failing to meet the needs of rapid flood control decision-making for hydropower stations.
By dividing the watershed into sub-basins, calculating underlying surface parameters, simulating hydrological models, and calibrating key cross-section parameters, combined with spatial interpolation techniques and comprehensive parameter optimization, a rapid and accurate flood forecasting model is established.
It enables rapid and accurate prediction of upstream water flow for hydropower stations, improves data support for flood control and dam safety and stability, and enhances the efficiency and accuracy of flood forecasting.
Smart Images
Figure CN121638532A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of flood forecasting of hydropower stations, and particularly relates to a method and system for establishing a flood forecasting model of a hydropower station. BACKGROUND
[0002] The normal operation of a hydropower station is closely related to flood. Flood is one of the major natural disasters faced by hydropower stations, and accurate flood forecasting is crucial for flood control and flood mitigation of hydropower stations. If the inflow of the upstream watershed of a hydropower station can be accurately predicted in advance, the storage and flood discharge of the reservoir can be reasonably arranged, the damage to the dam of the hydropower station caused by flood can be avoided, and the safe and stable operation of the dam can be ensured. At the same time, accurate flood forecasting can also help the hydropower station to optimize power generation scheduling, improve power generation efficiency, and reduce power generation loss caused by flood.
[0003] In traditional flood forecasting, there may be limitations in data acquisition. For example, the distribution of rain gauges may not be dense enough, resulting in insufficient monitoring of rainfall in the watershed. Moreover, the data of rain gauges may only be point data, which cannot well reflect the spatial distribution of rainfall in the entire watershed. This makes the estimation of rainfall input not accurate enough when conducting flood forecasting, which in turn affects the accuracy of flood forecasting.
[0004] Existing watershed hydrological models may have deficiencies in simulating the watershed runoff process. Some models may not fully consider the underlying surface factors such as complex topography, soil properties, etc. in the watershed. These underlying surface factors have an important influence on the formation and evolution process of flood. For example, different soil types have different water-holding capacities, which will affect the infiltration of rainfall and the generation of surface runoff. If the model cannot well depict these underlying surface factors, the accuracy of flood forecasting will be reduced.
[0005] For the simulation of runoff process at key sections, existing methods may lack effective parameter calibration means. The runoff process at key sections is an important output of flood forecasting, and if the model parameters cannot be accurately calibrated according to the measured data, the simulation results of the model will deviate from the actual situation. Moreover, in the comprehensive consideration of model parameters of different sub-watersheds, existing methods may not have a scientific and reasonable comprehensive strategy, resulting in low prediction accuracy of the overall model.
[0006] Traditional flood forecasting methods may have slow response speed when dealing with a large amount of data and complex model calculations. In the event of a flood, time is of the essence, and if flood forecasting results cannot be provided quickly, it will affect the flood control decision of the hydropower station. For example, in heavy rain, the hydrological regime in the watershed changes rapidly, and flood forecasting needs to be updated in a timely manner, while existing methods may not meet the requirements of rapid response. SUMMARY
[0007] The main purpose of the present application is to provide a method for establishing a flood forecasting model of a hydropower station.
[0008] Another purpose of the present application is to provide a system for establishing a flood forecasting model of a hydropower station.
[0009] To achieve the above purpose, the first aspect of the present application provides a method for establishing a flood forecasting model of a hydropower station, comprising: S1, inputting the distribution of the river system of the basin, the location of the rainfall station and the characteristic data of the reservoir, dividing the basin into sub-basin blocks according to the topological relationship of the river system and the layout of the station, outputting the spatial boundary of each calculation unit; and based on geographic information data, calculating the underlying surface parameters of each sub-basin, and outputting the unit characteristic parameter set; S2, inputting the long sequence rainfall observation data of each rainfall station, combining the spatial range of the sub-basin obtained in S1, calculating the surface average rainfall process of each sub-basin according to the spatial proximity relationship, and outputting the long sequence rainfall input sequence of each unit; S3, taking the rainfall input sequence output by S2 as driving data, substituting it into the hydrological model, and simulating runoff and confluence for each sub-basin, and outputting the simulated runoff process of each key section; S4, inputting the measured runoff data of each key section and the simulated runoff process obtained in S3, and performing model parameter calibration through comparative analysis, and outputting the preliminary calibrated parameter set of each sub-basin; S5, according to the simulation accuracy evaluation result of each sub-basin, performing spatial coordination and comprehensive analysis on the parameter set obtained in S4, outputting a set of globally optimal and physically consistent model parameter combination as the recommended flood forecasting scheme.
[0010] To achieve the above purpose, the second aspect of the present application provides a system for establishing a flood forecasting model of a hydropower station, comprising: The sub-basin division and underlying surface parameter extraction module is used for inputting the distribution of the river system of the basin, the location of the rainfall station and the characteristic data of the reservoir, dividing the basin into sub-basin blocks according to the topological relationship of the river system and the layout of the station, outputting the spatial boundary of each calculation unit; and based on geographic information data, calculating the underlying surface parameters of each sub-basin, and outputting the unit characteristic parameter set; The surface rainfall calculation module is used for inputting the long sequence rainfall observation data of each rainfall station, combining the spatial range of the sub-basin, calculating the surface average rainfall process of each sub-basin according to the spatial proximity relationship, and outputting the long sequence rainfall input sequence of each unit; The runoff and confluence simulation module is used for taking the output rainfall input sequence as driving data, substituting it into the hydrological model, and simulating runoff and confluence for each sub-basin, and outputting the simulated runoff process of each key section; The model parameter calibration module is used to input measured runoff data and simulated runoff processes at each key cross section, calibrate model parameters through comparative analysis, and output preliminary calibration parameter sets for each sub-basin. The parameter integration and scheme recommendation module is used to perform spatial coordination and comprehensive analysis of the parameter set based on the simulation accuracy evaluation results of each sub-basin, and output a set of globally optimal and physically consistent model parameter combinations as recommended flood forecasting schemes.
[0011] The method and system for establishing a flood forecasting model for hydropower stations according to embodiments of the present invention can quickly and accurately predict the inflow of water in the upstream basin of hydropower stations, providing data support for flood control and flood season management of hydropower stations and safe and stable operation of dams. Attached Figure Description
[0012] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 A flowchart illustrating a method for establishing a flood forecasting model for a hydropower station, provided as an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a system for establishing a flood forecasting model for a hydropower station, provided in an embodiment of the present invention. Detailed Implementation
[0013] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0014] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.
[0015] The following describes, with reference to the accompanying drawings, a method and system for establishing a flood forecasting model for a hydropower station according to an embodiment of the present invention.
[0016] This embodiment provides a method for establishing a flood forecasting model for hydropower stations. For example... Figure 1 As shown, the method includes the following steps: S1 takes into account the distribution of the water system, the location of rain gauges, and the characteristics of reservoirs in the watershed. Based on the topological relationship of the water system and the layout of the monitoring stations, the watershed is divided into sub-watershed blocks, and the spatial boundaries of each calculation unit are output. Based on the geographic information data, the underlying surface parameters of each sub-watershed are calculated, and the set of unit characteristic parameters is output. S2, input each rainfall station long sequence precipitation observation data, combine the sub-basin spatial range obtained in S1, calculate the surface average rainfall process of each sub-basin according to the spatial adjacent relationship, and output the long sequence rainfall input sequence of each unit; S3, input the rainfall input sequence output by S2 as driving data, substitute into the hydrological model, simulate runoff and confluence for each sub-basin respectively, and output the simulated runoff process of each key section; S4, input the measured runoff data of each key section and the simulated runoff process obtained in S3, perform model parameter calibration through comparative analysis, and output a preliminary calibrated parameter set of each sub-basin; S5, according to the simulation accuracy evaluation result of each sub-basin, perform spatial coordination and comprehensive analysis on the parameter set obtained in S4, output a globally optimal and physically consistent model parameter combination, as a recommended flood forecasting scheme.
[0017] It can be understood that, according to the characteristics of the basin water system and the station distribution, the reservoir, the underlying surface parameters of each unit are calculated according to the divided sub-basin blocks; according to the spatial relationship of each calculation unit and the rainfall station, the long series rainfall process of each calculation unit is calculated; the runoff and confluence simulation is performed by using the hydrological model respectively, and the simulated runoff process of each key section is obtained; the model parameter calibration is performed according to the measured and simulated runoff processes of each key section. According to the simulation accuracy of each block model, the model parameters are synthesized, and the appropriate model parameters, i.e. the flood forecasting method, are recommended.
[0018] In an embodiment of the present application, in step S3, the hydrological model of the basin is established, the model structure refers to the main stages of runoff and confluence in the rainfall runoff process, the deduction relationship and generalization characteristics of the mathematical simulation of the hydrological physical phenomenon, and is composed of a series of mathematical functions and logical judgments. The model parameters are a kind of undetermined constant that distinguishes different hydrological characteristics of the basin. If the model structure is determined, the rainfall and evaporation data of the basin are taken as the input, the flow data of the outlet section of the basin are taken as the output, the model structure is regarded as a system, and then the model parameters can be determined by using the system analysis method. The simulation quantities of various hydrological elements on the basin, such as interception, infiltration, basin storage, slope flow, surface flow and underground runoff, are the state variables of the system.
[0019] In an embodiment of the present application, in step S3, one of the main components of the model is the evapotranspiration calculation, which is as follows: The formula used is as follows: When , , ,
[0020] When ,
[0021] If , ,
[0022] If and , ,
[0023] If and , , .
[0024] In one embodiment of the present application, in S3, one of the main components of the model, the runoff yield calculation, is as follows: ; In the formula: is the maximum point water storage capacity in the basin; is the water storage capacity of a point in the basin; is the water storage capacity the area of the basin; is the area of the basin; is the parabolic index.
[0025] Accordingly, the basin water storage capacity can be obtained as:
[0026] The corresponding ordinate (y) of the initial basin water storage (x) is:
[0027] When , no runoff is produced; when , then runoff is produced. Runoff is further divided into local runoff and full-basin runoff: When , the local runoff yield is:
[0028] When , the full-basin runoff yield is:
[0029] The input for the runoff yield calculation is The parameters include the watershed's water storage capacity. and parabolic index The output is the watershed runoff. and the water storage at the end of the period in the basin .
[0030] If the impervious area of the watershed is greater than hour,
[0031] At this point, the calculation formulas for each output flow will also change accordingly.
[0032] In one embodiment of the present invention, in step S3, one of the main components of the model, water source calculation, is performed through a free water reservoir.
[0033] The flow rate calculated using the full flow model Entering the free reservoir, along with the existing water that has not yet flowed out, constitutes the real-time free water storage. The water source is then divided. This reservoir has two outlets, with one bottom outlet forming underground runoff. A side hole forms a flow in the soil. The outflow patterns all follow the linear reservoir outflow model. This is because the modified model considers the runoff-generating area. The problem is that this free-water reservoir only occurs in the runoff-generating area, and its bottom width... It is variable, the flow rate Entering the reservoir, i.e., in terms of the runoff area, increases the water depth of the free water storage reservoir. When the free water storage depth... Exceeding its maximum value At that time, the excess portion becomes surface runoff. The model assumes that evaporation is consumed in tension water, and that the entire volume of water in the free water reservoir is runoff.
[0034] Bottom hole flow rate and the flow rate of the side hole The water flows into their respective reservoirs and out according to the receding patterns of linear reservoirs, thus becoming part of the total groundwater inflow. The main inflow of the middle stream of the river It is also assumed that the slope runoff confluence time is negligible, and surface runoff... It can be considered as the total inflow of surface runoff same.
[0035] Due to the area of runoff generation The water storage capacity of free water in the upper part of the body cannot be considered to be uniformly distributed, that is... Using a constant is not appropriate; it needs to be considered. the area distribution. This is actually the problem of the varying area of saturation overland flow. In the same way as the uneven distribution of tension water is treated, the distribution of free water storage capacity over the contributing area is also represented by a parabolic curve, i.e.
[0036] where: is the contributing area is the free water storage capacity at a certain point; is the contributing area is the free water storage capacity at the maximum point; is the free water storage capacity is the area of the watershed; is the exponent of the free water storage capacity curve of the watershed.
[0037] The average storage capacity depth over the contributing area is
[0038] The free water storage capacity curve of the watershed is the corresponding ordinate is
[0039] where: is the average storage depth of the free water over the contributing area on the free water storage capacity curve of the watershed; is the corresponding ordinate.
[0040] Obviously, and are functions of the contributing area and are undetermined variables. Here we assume that the relationship between and the contributing area and the free water storage capacity at the maximum point of the entire watershed is still a parabolic distribution:
[0041] Then:
[0042]
[0043] The average free water capacity of the watershed and the parabolic exponent are fixed for a watershed and are parameters of the model calibration. Given and , we can get .
[0044] known runoff area of the time interval and the average free water depth over the runoff area according to the runoff volume of the time interval the surface runoff, the interflow, the groundwater runoff and the runoff area of the time interval are calculated and the average free water depth over the runoff area the steps are:
[0045]
[0046]
[0047]
[0048]
[0049]
[0050] when then
[0051]
[0052]
[0053]
[0054] when then
[0055]
[0056]
[0057]
[0058] wherein: and are the outflow coefficients of the interflow and the groundwater runoff respectively.
[0059] In one embodiment of the present application, in step S3, one of the main components of the model, the confluence calculation, is as follows: the surface runoff, not taking into account the slope confluence, directly enters the river network: the groundwater runoff, after the surface free water flows downward with and then enters the river network by the groundwater reservoir confluence, and the recession coefficient is : The surface free water flows out laterally as RSS, and after the storage and regulation of the deep soil water reservoir, it enters the river network, and its recession coefficient is :
[0060] The total inflow of the river network is:
[0061] In the formula, : unit conversion coefficient, which can convert the runoff depth into flow, , and the unit is km2 / h. The total inflow of the river network flows to the outlet section through the river channel confluence, and the process is the outlet flow process of the river basin . The confluence unit line is used for the river flood confluence simulation.
[0062] The method can quickly and accurately predict the inflow of the upstream basin of the hydropower station, and provides reliable data support for the flood control and dam safety and stable operation of the hydropower station. Through fine sub-basin division and underlying surface parameter calculation, combined with spatial interpolation technology, the accuracy and representativeness of the rainfall data are improved. The hydrological model is used for runoff simulation, and the model parameters are calibrated through the measured and simulated runoff processes of the key sections, and the adaptability and accuracy of the model are further improved. Finally, through the comprehensive optimization of the model parameters, the high precision and reliability of the overall model are ensured, effectively solving the shortcomings of the existing flood forecasting method in data accuracy, model adaptability and timeliness, and significantly improving the efficiency and accuracy of the flood forecasting of the hydropower station.
[0063] The embodiment of the present application also provides a system 10 for establishing a flood forecasting model of a hydropower station, as shown in Figure 2 The system 10 comprises: A sub-basin division and underlying surface parameter extraction module 100 is used for inputting the basin water system distribution, rainfall station position and reservoir characteristic data, dividing the basin into sub-basin blocks according to the water system topological relationship and station layout, outputting the spatial boundary of each calculation unit, and calculating the underlying surface parameters of each sub-basin based on geographic information data, and outputting the unit characteristic parameter set; A surface rainfall calculation module 200 is used for inputting long sequence precipitation observation data of each rainfall station, combining the spatial range of the sub-basin, calculating the surface average rainfall process of each sub-basin according to the spatial proximity relationship, and outputting the long sequence rainfall input sequence of each unit; A runoff simulation module 300 is used for inputting the output rainfall input sequence as driving data into the hydrological model, and performing runoff and confluence simulation on each sub-basin, and outputting the simulated runoff process of each key section; The model parameter calibration module 400 is configured to input the measured runoff data of each key section and a simulated runoff process, calibrate the model parameters by comparative analysis, and output a preliminary calibrated parameter set of each sub-basin; The parameter synthesis and scheme recommendation module 500 is configured to perform spatial coordination and comprehensive analysis on the parameter set according to the simulation accuracy evaluation results of each sub-basin, and output a globally optimal and physically consistent model parameter combination as a recommended flood forecasting scheme.
[0064] The system of the present application can quickly and accurately predict the inflow of the upstream basin of the hydropower station, and provide reliable data support for the flood control and dam safety of the hydropower station. Through fine sub-basin division and underlying surface parameter calculation, combined with spatial interpolation technology, the accuracy and representativeness of the rainfall data are improved. The runoff generation and concentration simulation is carried out by using a scientific hydrological model, and the model parameters are calibrated by the measured and simulated runoff processes of the key sections, which further improves the adaptability and accuracy of the model. Finally, through the comprehensive optimization of the model parameters, the high accuracy and reliability of the overall model are ensured, effectively solving the shortcomings of the existing flood forecasting methods in data accuracy, model adaptability and timeliness, and significantly improving the efficiency and accuracy of the flood forecasting of the hydropower station.
[0065] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.
[0066] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms is not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or features of the embodiments or examples described in the present application without contradiction.
[0067] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise specifically limited.
Claims
1. A method for establishing a flood forecasting model of a hydropower station, characterized in that, Comprise: S1, input the flow field drainage distribution, rainfall station location and reservoir characteristic data, according to the drainage topological relation and station layout, the sub-basin block division is carried out to the basin, and the spatial boundary of each calculation unit is output;And based on geographic information data, the underlying surface parameters of each sub-basin are calculated, and the unit characteristic parameter set is output; S2, input the long sequence precipitation observation data of each rainfall station, combine the sub-basin spatial range obtained by S1, calculate the surface average rainfall process of each sub-basin according to the spatial adjacent relationship, and output the long series rainfall input sequence of each unit; S3, the rainfall input sequence output by S2 is taken as driving data, which is substituted into the hydrological model, and the runoff simulation of each sub-basin is carried out respectively, and the simulated runoff process of each key section is output; S4, input the measured runoff data of each key section and the simulated runoff process obtained by S3, and the model parameter calibration is carried out through comparison and analysis, and the preliminary calibrated parameter set of each sub-basin is output; S5, according to the simulation accuracy evaluation result of each sub-basin, the parameter set obtained by S4 is subjected to spatial coordination and comprehensive analysis, and a set of globally optimal and physically consistent model parameter combination is output as the recommended flood forecasting scheme.
2. The method of claim 1, wherein, Said S3, comprising: Based on the physical mechanism of rainfall runoff process, the hydrological model structure including the stages of runoff and confluence is established, the deduction relationship of interception, infiltration, water storage, slope flow, surface flow and underground runoff process is described through mathematical function and logical judgment, and a systematic model framework is formed, which takes rainfall and evaporation as input and takes the flow of basin outlet section as output; The rainfall and evaporation data of the basin are taken as system input, the simulation amount of each hydrological element in the model is taken as state variable, and the measured outlet flow is taken as output target, so as to build the dynamic system relationship of input-state-output; System analysis method is adopted to calibrate and optimize the model parameters, the parameters are adjusted to make the simulated flow approach the measured value, the optimal parameter set reflecting the hydrological response characteristics of the basin is output, and the parameterization and application of the model are completed.
3. The method of claim 2, wherein, The evapotranspiration calculation of S3 is as follows: the rainfall after deducting evaporation is: The formula is as follows: When time, ， ， When time, If then ， If and then ， If and then ， 。 4. The method of claim 3, wherein, The runoff calculation of S3 is as follows: wherein: is the largest point water storage capacity within the watershed; is the water storage capacity of a point within the watershed; is the water storage capacity is the watershed area; is the watershed area; is the parabolic exponent; The storage capacity of the basin is obtained as follows: With the initial basin storage The corresponding ordinate ( ) is: When no flow is produced; when flow is produced. Runoff is divided into local runoff and whole basin runoff: When The local production flow rate is then: When The total flow yield of the whole basin is: The input of the model in runoff calculation is , and the parameters include the water storage capacity of the basin and the parabolic index ; Output is the flow volume of the basin and the water storage at the end of the basin period ; If the impervious area ratio of the watershed is less than 0.5 when, At this time, the calculation formula of each runoff will also change accordingly.
5. The method of claim 4, wherein, The water source calculation of S3 is carried out through the free water reservoir as follows: The flow rate calculated by the full storage flow model Enter the free reservoir, along with the original reservoir has not yet run out of water, real-time free water storage Re-division of water sources; This reservoir has two outlets, with a bottom outlet forming underground runoff. A side hole forms a flow in the soil. The outflow patterns all follow the linear reservoir outflow pattern; this is because the modified model considers the runoff-generating area. The problem is that this free-water reservoir only occurs in the runoff-generating area, and its bottom width... It is variable, the flow rate Entering the reservoir, i.e., in terms of the runoff area, increases the water depth of the free water storage reservoir. When the free water storage depth... Exceeding its maximum value At that time, the excess portion becomes surface runoff. The model assumes that evaporation is consumed in tension water, and the entire volume of water in the free water reservoir is runoff. base flow and edge flow respectively into the respective reservoirs and out as linear reservoir recession and total inflow of interflow ; It is considered that the slope confluence time of surface runoff can be ignored, and the total inflow of surface runoff can be considered the same as the total inflow of surface runoff . Due to the area of runoff generation The water storage capacity of free water in the upper part of the body cannot be considered to be uniformly distributed, that is... Using a constant is not appropriate; it needs to be considered. The area distribution; this is actually the problem of the constantly changing runoff-generating area of saturated slope flow; mimicking the treatment of uneven distribution of tension water, the distribution of free water storage capacity over the runoff-generating area is also represented by a parabola, that is: where: is the contributing area is the free water capacity at a point above; is the contributing area is the free water storage capacity at the highest point above; is the free water storage capacity is the basin area; is the exponent of the basin free water storage capacity curve; average water storage capacity depth over contributing area is: On the free water storage capacity curve The corresponding ordinate is: In the formula: is the average water storage depth of free water on the contributing area on the free water storage capacity curve of the catchment area; is the corresponding ordinate; Assume The relationship between the contributing area and the free water storage capacity of the largest point on the entire watershed is still a parabolic distribution: Then: Average free water capacity of the basin and parabolic exponent For a basin, is fixed and is a model calibration parameter; known and , we get ; known over the time period and the average free water depth over the contributing area according to the time period discharge calculating the surface runoff, the interflow, the groundwater runoff and the contributing area over the time period and the average free water depth over the contributing area the steps are: When then When then where: and are the outflow coefficients for overland flow and subsurface flow, respectively.
6. The method of claim 5, wherein, The confluence calculation of S3 is as follows: Surface runoff, excluding slope runoff, flows directly into the river network: Groundwater runoff, surface free water After flowing downstream, it is then collected by an underground reservoir and enters the river network, with a recession coefficient of... : In the interflow of soil, surface free water flows laterally via RSS (Reduced Slope), and after being regulated by deep soil reservoirs, it enters the river network. Its recession coefficient is... : Total inflow of river network: ; In the formula : unit conversion coefficient, which converts runoff depth into flow, , with a unit of km2 / h; the total inflow of the river network flows to the outlet section as the outlet flow process of the watershed ; the flood routing method of the river channel uses the routing unit line.
7. A system for establishing a flood forecasting model of a hydropower station, characterized in that, Comprise: The sub-basin division and underlying surface parameter extraction module is used for inputting the drainage distribution, rainfall station location and reservoir characteristic data of the basin, dividing the sub-basin block of the basin according to the topological relation of drainage and station layout, and outputting the spatial boundary of each calculation unit;And based on geographic information data, the underlying surface parameters of each sub-basin are calculated, and the unit characteristic parameter set is output; The surface rainfall calculation module is used for inputting the long sequence precipitation observation data of each rainfall station, combining the sub-basin spatial range, calculating the surface average rainfall process of each sub-basin according to the spatial adjacent relationship, and outputting the long series rainfall input sequence of each unit; The runoff yield simulation module is configured to input the output rainfall input sequence as driving data into the hydrological model, to perform runoff yield and confluence simulation on each sub-basin respectively, and to output the simulated runoff process of each key section; The model parameter calibration module is configured to input the measured runoff data and the simulated runoff process of each key section, to perform model parameter calibration through comparative analysis, and to output a preliminary calibrated parameter set of each sub-basin; The parameter synthesis and scheme recommendation module is configured to perform spatial coordination and comprehensive analysis on the parameter set according to the simulation accuracy evaluation results of each sub-basin, to output a globally optimal and physically consistent model parameter combination as a recommended flood forecasting scheme.