Runoff reduction calculation method considering reservoir regulation and storage influence

Abstract

The invention provides a runoff reduction calculation method considering reservoir regulation and storage influence, which comprises the following steps of: determining a target section for runoff reduction calculation and a water collection range controlled by the section, determining starting time and ending time of reduction calculation, and obtaining a daily scale actual measurement flow process of the target section within the time range; in the water collection range of the target section, determining a reservoir located at the upstream of the target section and the input operation time of each reservoir, and obtaining the daily scale actual measurement water level process of each reservoir station; on the basis of the water level storage capacity curve and the actually measured water level process of each reservoir, the regulation and storage flow process of each reservoir is deduced; the regulation and storage flow of each reservoir is evolved to a downstream target section, and the regulation and storage influence flow process of each reservoir is deduced; and according to the regulation and storage influence flow of each reservoir and the actually measured flow of the target section, the natural flow process of the target section is deduced. According to the method, the regulation and storage influence of the reservoir can be accurately restored, the translation effect of the river channel can be accurately simulated, and the natural runoff series of the river section is efficiently and accurately deduced.

Description

Technical Field

[0001] The invention belongs to the field of hydrological calculation, and particularly relates to a runoff restoration calculation method taking into account the influence of reservoir storage and regulation. Background Art

[0002] Medium- and long-term runoff forecasts play a key supporting role in the efficient use of water resources in cascade hydropower stations in the basin, and are a strategic technical means to promote cascade hydropower stations to "make good use of every cubic meter of water and adjust every kilowatt-hour of electricity". Generally speaking, medium- and long-term runoff forecasts are based on natural runoff series, that is, the base plate data should meet the consistency condition. However, with the influence of human activities such as water diversion, water lifting, water transfer, and water storage, the measured runoff series usually does not meet the consistency condition. Therefore, it is necessary to eliminate the impact of human activities on the runoff process through runoff restoration calculations and obtain a natural runoff series. Among various influencing factors, the regulation and storage of reservoirs, especially large reservoirs, has a greater impact on the river runoff process, and can be considered as the main factor in runoff restoration calculations. To this end, the present invention proposes a runoff restoration calculation method that takes into account the impact of reservoir storage and regulation. The invention restores the storage and regulation impact of the reservoir on the runoff process based on the water balance principle, and uses the time-delay method to deal with the translational effect of the river channel on the runoff process. It can efficiently deduce the natural runoff series of the river section, and is particularly suitable for rivers with large reservoir storage and regulation effects, such as the upper reaches of the Yangtze River. Summary of the invention

[0003] The technical problem to be solved by the present invention is how to accurately restore the impact of reservoir regulation and accurately simulate the river channel translation in a water system with a greater impact of reservoir regulation, and then efficiently and accurately deduce the natural runoff series of the river section.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a runoff restoration calculation method considering the influence of reservoir regulation and storage, comprising the following steps: S1, determine the target section for runoff restoration calculation and the catchment range controlled by the section, clarify the start and end time of the restoration calculation, and obtain the daily flow process of the target section within the restoration calculation time range; S2, within the water collection range of the target section, determine the reservoirs located upstream of the target section and the time when each reservoir is put into operation, and obtain the daily-scale measured water level process of each reservoir station; S3, based on the water level storage capacity curve and measured water level process of each reservoir, deduce the storage flow process of each reservoir; S4, evolve the storage flow of each reservoir to the downstream target section, and deduce the flow process affected by the storage of each reservoir; S5, based on the storage and regulation flow of each reservoir and the measured flow of the target section, the natural flow process of the target section is deduced.

[0005] Preferably, the start time of the reduction calculation in S1 is , and the end time of the reduction calculation is , and the reduction calculation time range is ; The daily-scale flow process is: ; In the formula, is the measured flow of the target section at time t .

[0006] Preferably, the commissioning time of the reservoir and each reservoir in S2 is ; The daily-scale measured water level process of each reservoir site is: ; In the formula, is the i th reservoir's measured water level at time t .

[0007] Preferably, the regulated flow process of each reservoir in S3 is: ; In the formula, is the regulated flow of the i th reservoir at time t .

[0008] Preferably, the water level-storage capacity curve of each reservoir in S3 is: ; In the formula, V is the reservoir storage capacity, Z is the reservoir water level, , , are parameters, is the i th reservoir's water level-storage capacity curve.

[0009] Preferably, the specific steps to derive the regulated flow process of each reservoir in S3 are as follows: S3.1, According to the measured water level t at the beginning of the period of each reservoir, use the water level-storage capacity curve to calculate the storage capacity t of each reservoir at the beginning of the period, that is ; S3.2, According to the measured water level t at the end of the period of each reservoir, use the water level-storage capacity curve to calculate the storage capacity t of each reservoir at the end of the period, that is ; S3.3. Use the water balance calculation method to derive the regulated flow of each reservoir at time t as , is the time length of time period t .

[0010] Preferably, the regulated influence flow process of each reservoir in S4 is as follows: ; In the formula, is the regulated influence flow of the i th reservoir on the downstream target section at time t .

[0011] Preferably, the specific steps for deriving the regulated influence flow process of each reservoir in S4 are as follows: S4.1. Determine the river water flow propagation time from each reservoir to the downstream target section, where i is the influence lag time of the th reservoir; t S4.2. Use the time delay method to shift the regulated flow process of each reservoir backward in time to derive the regulated influence flow of each reservoir on the downstream target section at time , where

[0012] Preferably, the natural flow process of the target section in S5 is as follows: ; In the formula, is the natural flow of the target section at time t .

[0013] Preferably, the calculation formula for deriving the natural flow process of the target section in S5 is: ; In the formula, M is the number of reservoirs upstream of the target section.

[0014] The present invention has the following beneficial effects: The method of the present invention restores the regulation influence of the reservoir on the runoff process based on the water balance principle, and uses the time delay method to handle the translation effect of the river channel on the runoff process. It can accurately restore the regulation influence of the reservoir and precisely simulate the translation effect of the river channel, and efficiently and accurately derive the natural runoff series of the river section, providing a feasible method for the runoff restoration calculation of rivers with large reservoir regulation influence. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0016] Figure 1 It is a schematic flow chart of a runoff restoration calculation method considering the impact of reservoir regulation provided by the present invention.

[0017] Figure 2 It is a topological relationship diagram of reservoir groups in the upper reaches of the Yangtze River provided by the present invention.

[0018] Figure 3 It is the natural inflow hydrograph and measured inflow hydrograph of the Three Gorges Reservoir provided by the present invention. Specific Embodiments

[0019] The present invention will be further described in detail below in conjunction with the embodiments of the accompanying drawings. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0020] Embodiment 1: Refer to Figure 1 , a runoff restoration calculation method considering the impact of reservoir regulation, includes the following steps: S1. Determine the target section for runoff restoration calculation and the catchment area controlled by this section, clarify the start time and end time of the restoration calculation, and obtain the daily-scale flow process of the target section within the time range , , is the measured flow of the target section at time t ; S2. Within the catchment area of the target section, determine the reservoirs located upstream of the target section and the commissioning time of each reservoir , and obtain the daily-scale measured water level process of each reservoir site , is the measured water level of the i th reservoir at time t ; S3. Based on the water level-storage capacity curve and the measured water level process of each reservoir, deduce the regulated flow process of each reservoir , is the regulated flow of the i th reservoir at time t ; S3.1. According to the measured water level t at the beginning of the period of each reservoir, use the water level-storage capacity curve to calculate the storage volume of each reservoir at the beginning of the tStorage capacity at the beginning of the time period , that is

[0021] S3.2. According to the measured water levels of each reservoir at t the end of the time period , using the water level - storage capacity curve, calculate the storage capacity of each reservoir at t the end of the time period , that is ; S3.3. Adopt the water - balance calculation method to derive the regulated discharge of each reservoir at time t as , is the time length of the time period t .

[0022] S4. Propagate the regulated discharge of each reservoir to the downstream target section to obtain the regulated influence discharge process of each reservoir , is the regulated influence discharge of the i th reservoir on the downstream target section at time t ; S4.1. Determine the river - flow propagation time from each reservoir to the downstream target section , i is the influence lag time of the th reservoir; t S4.2. Adopt the time - delay method to translate the regulated discharge process of each reservoir backward in time to derive the regulated influence discharge of each reservoir on the downstream target section at time , where .

[0023] S5. According to the regulated influence discharge of each reservoir and the measured discharge at the target section, derive the natural discharge process of the target section , is the natural discharge of the target section at time t .

[0024] Furthermore, the water - level storage - capacity curve of each reservoir in step S3 is , where V is the reservoir storage capacity, Z is the reservoir water level, , , are parameters, is the water - level storage - capacity curve of the i th reservoir.

[0025] Furthermore, the calculation formula for deriving the natural discharge process of the target section in step S5 is , where MThe number of reservoirs upstream of the target cross-section.

[0026] By adopting the above specific method, the regulation influence of the reservoir can be accurately restored, the translation effect of the river channel can be accurately simulated, and the natural runoff series of the river cross-section can be efficiently and accurately deduced, providing a feasible method for the runoff restoration calculation of rivers with large reservoir regulation influence.

[0027] Embodiment 2: In this embodiment, the Three Gorges Reservoir is selected as the target cross-section for case study. The catchment area of the Three Gorges Reservoir is the upper reaches of the Yangtze River basin. Figure 2 The topological relationship of the reservoir group within the catchment area is given. For the daily-scale measured flow process of the Three Gorges Reservoir in a certain year in this case, considering the regulation influence of reservoirs such as Liyuan, Ahai, Jin'anqiao, 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 Min River, Bikou, Baozhusi, Tingzikou in the Jialing River, Hongjiadu, Dongfeng, Wujiangdu, Goupitan, Silin, Shatuo, Pengshui, Yinpan, Jiangkou in the Wujiang River, etc., the runoff restoration calculation is carried out by using the method of the present invention to obtain the natural inflow process of the Three Gorges Reservoir.

[0028] Figure 3 The natural inflow process and the measured inflow process of the Three Gorges Reservoir are given. By comparing and analyzing the natural flow process and the measured flow process, it can be seen that in the dry season (from January to June and from November to December), the reservoir group above the Three Gorges Reservoir replenishes water downstream, while in the wet season (from July to October), the upstream reservoir group stores water, which means that the upstream reservoir group plays a role of "storing the abundant and supplementing the dry" throughout the year. This analysis result is consistent with the actual operation rules of the reservoir group. That is to say, the natural inflow process of the Three Gorges calculated by the method of the present invention conforms to the general rules and is accurate and reliable. Thus, the effectiveness and accuracy of the method of the present invention are proved.

[0029] Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirits of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A runoff restoration calculation method considering the impact of reservoir regulation, characterized in that: The following steps are involved: S1, determine the target section for runoff restoration calculation and the catchment range controlled by the section, clarify the start and end time of the restoration calculation, and obtain the daily flow process of the target section within the restoration calculation time range; S2, within the water collection range of the target section, determine the reservoirs located upstream of the target section and the time when each reservoir is put into operation, and obtain the daily-scale measured water level process of each reservoir station; S3, based on the water level storage capacity curve and measured water level process of each reservoir, deduce the storage flow process of each reservoir; S4, evolve the storage flow of each reservoir to the downstream target section, and deduce the flow process affected by the storage of each reservoir; S5, based on the storage and regulation flow of each reservoir and the measured flow of the target section, the natural flow process of the target section is deduced.

2. A runoff restoration calculation method considering the impact of reservoir regulation according to claim 1, characterized in that: The start time of the restoration calculation is set in S1 as , the end time of the restoration calculation is , the restoration calculation time range is ; The daily flow process is: ； In the formula, For the target section at time t The measured flow rate.

3. A runoff restoration calculation method considering the impact of reservoir regulation according to claim 2, characterized in that: The operation time of the reservoir in S2 and each reservoir is ; The daily scale measured water level process of each reservoir station is: ； In the formula, For the i Reservoir at time t The measured water level.

4. A runoff restoration calculation method considering the impact of reservoir regulation according to claim 3, characterized in that: The flow regulation process of each reservoir in S3 is as follows: ； In the formula, For the i Reservoir at time t The storage flow.

5. A runoff restoration calculation method considering the impact of reservoir regulation according to claim 4, characterized in that: The water level and storage capacity curves of each reservoir in S3 are: ； In the formula, V is the reservoir capacity, Z is the reservoir water level, , , As parameters, For the i Water level and storage capacity curve of a reservoir.

6. A runoff restoration calculation method considering the impact of reservoir regulation according to claim 5, characterized in that: The specific steps of the process of deriving the storage flow of each reservoir in S3 are as follows: S3.1, according to the reservoir t Measured water level at the beginning of the period , using the water level storage capacity curve, calculate the water level of each reservoir t Storage capacity at the beginning of the period ,Right now ; S3.2, according to the reservoir t Measured water level at the end of the period , using the water level storage capacity curve, calculate the water level of each reservoir t Storage capacity at the end of the period ,Right now ; S3.3, using the water balance calculation method, deduce the water balance of each reservoir in time t The storage flow is , For the period t length of time.

7. A runoff restoration calculation method considering the impact of reservoir regulation according to claim 6, characterized in that: The flow process affected by the regulation and storage of each reservoir in S4 is as follows: ； In the formula, For the i Reservoir at time t The regulation and storage of downstream target sections affects flow.

8. A runoff restoration calculation method considering the impact of reservoir regulation according to claim 7, characterized in that: The specific steps of deducing the process of the flow rate affected by the regulation and storage of each reservoir in S4 are as follows: S4.1, determine the river flow propagation time from each reservoir to the downstream target section , For the i The impact lag of the reservoir; S4.2, using the time-delay method, shift the storage flow process of each reservoir to the past and deduce the storage flow of each reservoir at time t The regulation and storage of downstream target sections affects the flow ,in .

9. A runoff restoration calculation method considering the impact of reservoir regulation according to claim 8, characterized in that: The natural flow process of the target section in S5 is: ； In the formula, For the target section at time t of natural traffic.

10. A runoff restoration calculation method considering the impact of reservoir regulation according to claim 9, characterized in that: The calculation formula for the natural flow process of the target section in S5 is: ； In the formula, M is the number of reservoirs upstream of the target section.

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