A runoff reduction calculation method considering the influence of reservoir regulation

Abstract

The application provides a runoff reduction calculation method considering the reservoir regulation and storage influence, and the steps are as follows: determining a target section of runoff reduction calculation and a catchment range controlled by the target section, determining a start time and an end time of the reduction calculation, and obtaining a daily scale measured flow process of the target section in the time range; determining reservoirs located upstream of the target section and operation time of each reservoir in the catchment range of the target section, and obtaining a daily scale measured water level process of each reservoir site; based on the water level-storage capacity curve of each reservoir and the measured water level process, the regulation and storage flow process of each reservoir is deduced; the regulation and storage flow of each reservoir is evolved to the downstream target section, and the regulation and storage influence flow process of each reservoir is obtained; according to the regulation and storage influence flow of each reservoir and the measured flow of the target section, the natural flow process of the target section is deduced. The application can accurately restore the regulation and storage influence of the reservoir and accurately simulate the translation effect of the river channel, and efficiently and accurately deduce the natural runoff series of the river section.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of hydrological calculation, and particularly relates to a runoff reduction calculation method considering the influence of reservoir regulation and storage. BACKGROUND

[0002] The medium and long term runoff prediction plays a key supporting role in the efficient utilization of water resources of cascade hydropower stations, and is a strategic technical means for promoting the cascade hydropower stations to "use every water well and regulate every degree of electricity". Generally speaking, the medium and long term runoff prediction is based on the natural runoff series, that is, the bottom plate data should meet the consistency condition. However, with the influence of human activities such as water diversion, water lifting, water regulation and storage, the measured runoff series usually does not meet the consistency condition. Therefore, the influence of human activities on the runoff process needs to be eliminated through runoff reduction calculation to obtain the natural runoff series. Among various influencing factors, the regulation and storage of reservoirs, especially large reservoirs, have a greater influence on the runoff process, and can be considered as the main factor in runoff reduction calculation. Therefore, the application provides a runoff reduction calculation method considering the influence of reservoir regulation and storage. SUMMARY

[0003] The technical problem to be solved by the application is how to accurately reduce the influence of reservoir regulation and storage and accurately simulate the river translation effect in a water system with greater influence of reservoir regulation and storage, and then efficiently and accurately obtain the natural runoff series of the river section.

[0004] To solve the above technical problem, the technical scheme adopted by the application is as follows: a runoff reduction calculation method considering the influence of reservoir regulation and storage, comprising the following steps:

[0005] S1, determining a target section of runoff reduction calculation and a catchment range controlled by the section, determining the start time and end time of the reduction calculation, and obtaining the daily scale flow process of the target section in the reduction calculation time range;

[0006] S2, determining the reservoirs located upstream of the target section and the operation time of each reservoir in the catchment range of the target section, and obtaining the daily scale measured water level process of each reservoir site;

[0007] S3, based on the water level-storage capacity curve of each reservoir and the measured water level process, the regulation and storage flow process of each reservoir is obtained;

[0008] S4, the regulation and storage flow process of each reservoir is evolved to the downstream target section, and the regulation and storage influence flow process of each reservoir is obtained;

[0009] S5. Based on the flow rate affected by the regulation and storage of each reservoir and the measured flow rate at the target section, the natural flow process at the target section is deduced.

[0010] Preferably, the start time of the restoration calculation is set in S1 as follows: The completion time of the restoration calculation is The time range for the restoration calculation is The daily-scale flow process is as follows:

[0011] ;

[0012] In the formula, For the target cross section in time t The actual measured flow rate.

[0013] Preferably, the operation time of the reservoirs and each reservoir in S2 is as follows: The daily measured water level process at each reservoir station is as follows:

[0014] ;

[0015] In the formula, For the first i The reservoir in time t The actual measured water level.

[0016] Preferably, the flow regulation process of each reservoir in S3 is as follows:

[0017] ;

[0018] In the formula, For the first i The reservoir in time t Regulating flow.

[0019] Preferably, the water level and storage capacity curves of each reservoir in S3 are as follows:

[0020] ;

[0021] In the formula, V For the reservoir capacity, Z For the reservoir water level, , , For parameters, For the first i Water level and storage capacity curve of the reservoir.

[0022] Preferably, the specific steps for calculating the regulation flow of each reservoir in step S3 are as follows:

[0023] S3.1, based on the situation of each reservoir t Measured water level at the beginning of the period , the storage capacity of each reservoir at the beginning of the time interval is calculated by using the water level-storage capacity curve according to the measured water level of each reservoir at the beginning of the time interval t , i.e. ; ;

[0024] S3.2, the storage capacity of each reservoir at the end of the time interval is calculated by using the water level-storage capacity curve according to the measured water level of each reservoir at the end of the time interval t ; t , i.e. ; ;

[0025] S3.3, the regulating and storage flow of each reservoir at time t is calculated by using the water balance calculation method, and is , is the time length of the time interval t .

[0026] Preferably, the regulating and storage impact flow process of each reservoir in S4 is:

[0027] ;

[0028] In the formula, is the regulating and storage impact flow of the i-th reservoir on the target section at time i . t

[0029] Preferably, the specific steps of calculating the regulating and storage impact flow process of each reservoir in S4 are as follows:

[0030] S4.1, the river flow propagation time of each reservoir to the target section is determined , is the impact lag time of the i-th reservoir; i

[0031] S4.2, the regulating and storage flow process of each reservoir is shifted to the past by using the time delay method, and the regulating and storage impact flow of each reservoir on the target section at time t is calculated , wherein .

[0032] Preferably, the natural flow process of the target section in S5 is:

[0033] ;

[0034] In the formula, is the natural flow of the target section at time t .

[0035] Preferably, the calculation formula of calculating the natural flow process of the target section in S5 is: ​​​

[0036] ;

[0037] In the formula, M is the number of reservoirs upstream of the target section.

[0038] The present application has the following beneficial effects:

[0039] The method of the present application is based on the water balance principle to restore the regulation and storage effect of the reservoir on the runoff process, and uses the time delay method to process the translation effect of the river channel on the runoff process, which can accurately restore the regulation and storage effect of the reservoir and accurately simulate the translation effect of the river channel, efficiently and accurately calculates the natural runoff series of the river section, and provides a feasible method for runoff restoration calculation of a river with large reservoir regulation and storage effect. BRIEF DESCRIPTION OF DRAWINGS

[0040] The present application will be further described below in conjunction with the drawings and examples.

[0041] Figure 1 A flowchart of a runoff restoration calculation method considering the regulation and storage effect of a reservoir provided by the present application.

[0042] Figure 2 A topological relationship diagram of reservoir groups in the upper reaches of the Yangtze River provided by the present application.

[0043] Figure 3 The natural inflow process and the measured inflow process of the Three Gorges Reservoir provided by the present application. DETAILED DESCRIPTION

[0044] The present application will be further described in detail below in conjunction with the drawings and examples, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout the drawings. The examples described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application.

[0045] Example 1:

[0046] Referring to Figure 1 , a runoff restoration calculation method considering the regulation and storage effect of a reservoir, comprising the following steps:

[0047] S1, determining the target section of runoff restoration calculation and the catchment range controlled by the section, and determining the start time and end time of the restoration calculation and , obtaining the daily scale flow process of the target section within the time range , , is the measured flow of the target section at time t ;

[0048] S2, within the catchment area of ​​the target section, determine the reservoirs located upstream of the target section and their commissioning time. Obtain the daily measured water level process at each reservoir station. , For the first i The reservoir in time t The measured water level;

[0049] S3, based on the water level-capacity curves and measured water level processes of each reservoir, deduce the regulation flow process of each reservoir. , For the first i The reservoir in time t The flow rate for regulation;

[0050] S3.1, based on the situation of each reservoir t Measured water level at the beginning of the period Using water level-reservoir capacity curves, the values ​​of each reservoir at different water levels were calculated. t Initial storage capacity ,Right now

[0051] S3.2, based on the situation of each reservoir t Measured water level at the end of the time period Using water level-reservoir capacity curves, the values ​​of each reservoir at different water levels were calculated. t Storage capacity at the end of the period ,Right now ;

[0052] S3.3, using the water balance calculation method, calculates the time for each reservoir. t The storage flow is , For time period t The length of time.

[0053] S4, by extending the regulation flow of each reservoir to the downstream target section, derives the regulation impact flow process of each reservoir. , For the first i The reservoir in time t The impact of water storage regulation on downstream target sections;

[0054] S4.1 Determine the river flow propagation time from each reservoir to the downstream target section. , For the first i The effects of the reservoir are delayed;

[0055] S4.2, using the time delay method, shifts the regulation flow process of each reservoir back to the past to estimate the time delay of each reservoir. t Impact of water storage on downstream target sections wherein .

[0056] S5, according to the regulation and storage influence flow of each reservoir and the measured flow of the target section, the natural flow process of the target section is derived , is the natural flow of the target section at time t .

[0057] Further, the water level-storage capacity curve of each reservoir in the step S3 is wherein, V is the reservoir storage capacity, and Z is the reservoir water level, , , is a parameter, is the water level-storage capacity curve of the i-th reservoir. i

[0058] Further, the calculation formula for deriving the natural flow process of the target section in the step S5 is wherein M is the number of reservoirs upstream of the target section.

[0059] By using the above specific method, the regulation and storage influence of the reservoir can be accurately restored, the translation effect of the river channel can be accurately simulated, the natural runoff series of the river section can be efficiently and accurately derived, and a feasible method for the runoff restoration calculation of the river with large reservoir regulation and storage influence is provided.

[0060] Embodiment 2:

[0061] In this embodiment, the Three Gorges Reservoir is selected as a target section for case study, the catchment area of the Three Gorges Reservoir is the upper reaches of the Yangtze River, Figure 2 The topological relationship of the reservoir group in the catchment area is given. In this case, the daily scale measured flow process of the Three Gorges Reservoir in a year is considered, the regulation and storage influence of the reservoirs such as Lijian, Ahai, Jinanqiao, Longkaikou, Ludila, Guanyinyan in the middle reaches of the Jinsha River, Jinping II, Jinping I, Ertan, Tongzilin in the Yalong River, Wudongde, Baihetan, Xiluodu, Xiangjiaba in the lower reaches of the Jinsha River, Zipingpu, Pubugou in the Minjiang River, Bikou, Baozhisi, Tingzikou in the Jialing River, Hongjiadu, Dongfeng, Wujiangdu, Goupitan, Silin, Shatuo, Pengshui, Yingpan, Jiangkou, etc. is considered, the runoff restoration calculation is carried out by using the method of the present application, and the natural inflow process of the Three Gorges Reservoir is obtained.

[0062] Figure 3 ​The natural inflow process and the measured inflow process of the Three Gorges Reservoir are given. By comparing the natural inflow process with the measured inflow process, it can be known that in the dry season (from January to June and from November to December), the reservoir group above the Three Gorges Reservoir is supplementing water to the downstream, while in the wet season (from July to October), the reservoir group above the Three Gorges Reservoir is storing water, which means that the reservoir group above the Three Gorges Reservoir plays a role of'storing water in wet season and supplementing water in dry season' from the whole year. The analysis result is matched with the actual dispatching rule of the reservoir group, that is, the natural inflow process of the Three Gorges calculated by the method of the application conforms to the general rule and is accurate and reliable. Thus, the effectiveness and accuracy of the method of the application are proved.

[0063] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and the spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A runoff reduction calculation method considering the influence of reservoir regulation, characterized in that, The method comprises the following steps: S1, determining a target section of runoff reduction calculation and a catchment range controlled by the section, determining a start time and an end time of the reduction calculation, and obtaining a measured flow process of the target section in a reduction calculation time range; S2, determining reservoirs located upstream of the target section and operation time of each reservoir in the catchment range of the target section, and obtaining a daily scale measured water level process of each reservoir site; S3, based on a water level-storage capacity curve of each reservoir and the measured water level process, deducing a regulation and storage flow process of each reservoir; S4, evolving the regulation and storage flow of each reservoir to a downstream target section to obtain a regulation and storage influence flow process of each reservoir; S5, according to the regulation and storage influence flow of each reservoir and the measured flow of the target section, deducing a natural flow process of the target section; The regulation and storage influence flow process of each reservoir in S4 is: ； In the formula, As the i Reservoirs in time t The impact of the downstream target section of the storage flow; The specific steps of deducing the regulation and storage influence flow process of each reservoir in S4 are as follows: S4.1, determining the river flow propagation time from each reservoir to the target section downstream , the first i reservoirs' influence time lag; S4.2, using the time delay method, the process of each reservoir storage flow to the past translation, to calculate the time t The storage impact flow of the downstream target section wherein ; The natural flow process of the target section in S5 is: ； In the formula, the natural flow of the target section at time t t; The calculation formula of deducing the natural flow process of the target section in S5 is: ； In the formula, M N is the number of reservoirs upstream of the target section. 2.The runoff reduction calculation method considering the influence of reservoir storage according to claim 1, wherein, The start time of the reduction calculation in the S1 is set to The end time of the reduction calculation is The reduction calculation time range is The actual flow process is: ； In the formula, is the measured flow rate of the target section at time t . 3.The runoff reduction calculation method considering the influence of reservoir storage according to claim 2, wherein, The input running time of the reservoirs in S2 and each reservoir is ; the daily scale measured water level process of each reservoir site is: ； In the formula, is the first i Reservoir in time t of the measured water level.

4. The runoff reduction calculation method considering the influence of reservoir regulation according to claim 3, characterized in that, The regulation and storage flow process of each reservoir in S3 is: ； In the formula, is the first i The reservoir in time t The storage flow.

5. The runoff reduction calculation method considering the influence of reservoir storage according to claim 4, characterized in that, The water level-storage capacity curve of each reservoir in S3 is: ； wherein V is the reservoir capacity, Z is the reservoir water level, , , is a parameter, is the water level-capacity curve of the i reservoir.

6. The runoff reduction calculation method considering the influence of reservoir storage according to claim 5, wherein, The specific steps of deducing the regulation and storage flow process of each reservoir in S3 are as follows: S3.1, according to each reservoir in t the initial measured water level , using the water level storage curve, calculate each reservoir in t the initial storage , that is ; S3.2, according to each reservoir in t the measured water level at the end of the period , using the water level storage curve, calculate the reservoir in t the end of the period of storage , namely ; S3.3, using the water balance calculation method, to deduce the time t of each reservoir in the storage flow is , the time length of the time period t .

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