Cross-year runoff simulation adjustment method and system for series reservoir group and storage medium

Abstract

The invention discloses a runoff cross-year simulation adjustment method and system for a series reservoir group and a storage medium. The method comprises the steps that 1, basic parameters of the series reservoir group are collected to establish a reservoir capacity-siltation amount relation formula; 2, drawing up a continuous desilting scheduling sequence of the inter-year series reservoir group; 3, according to actually measured runoff sediment data, designing a water and sediment representative series with periodic changes of wet water, flat water and low water; 4, calculating the outbound flow of the upper-level reservoir and the lower-level reservoir; 5, calculating hydraulic elements of the upper-level reservoir and the lower-level reservoir by utilizing water flow motion characteristics; 6, calculating sediment erosion and deposition factors of each section of the upper-level reservoir and the lower-level reservoir; 7, calculating the terrain of the last river channel in the current time period, and judging whether the simulation end moment is reached or not to obtain a first judgment result; and 8, determining that the combined dispatching application mode proposed by the reservoir group is feasible. According to the method, the runoff cross-year regulation is realized on the basis of keeping the effective storage capacity of the reservoir group by drawing up the combined dispatching application mode, and the accuracy of runoff cross-year regulation simulation is improved.

Description

Technical Field

[0001] This invention relates to the field of water conservancy engineering scheduling technology, specifically to a method, system, and storage medium for cross-year simulation regulation of runoff in a series of reservoirs, which is particularly suitable for the joint scheduling of a series of reservoirs in rivers with high sediment content and severe siltation. Background Technology

[0002] The runoff of rivers in my country generally exhibits significant seasonal variations, with a substantial difference in runoff between flood and dry seasons. This creates a contradiction for sectors with relatively stable seasonal water consumption, such as power generation, navigation, domestic water supply, and industrial water supply, resulting in insufficient water during the dry season and excessive water during the flood season. This necessitates the construction of large-capacity reservoirs to readjust and redistribute natural runoff over a yearly or multi-year timescale to meet the needs of economic and social development. For clear-water rivers, annual or interannual runoff regulation is generally achieved through the storage and utilization of large reservoirs. However, for sediment-laden rivers, due to the high sediment content and large sediment load, especially during the flood season when sediment arrives with the floodwaters, simply impounding floodwaters to meet runoff regulation requirements can easily lead to severe siltation in the reservoir area, making it difficult to maintain the effective storage capacity. Therefore, a difficult contradiction exists between reservoir storage and utilization and the maintenance of effective storage capacity, hindering the full realization of runoff regulation, especially interannual regulation. Taking the Sanmenxia Reservoir as an example, its effective storage capacity below the flood control water level is nearly 6 billion cubic meters. 3 However, to control siltation, the flood control limit level of the reservoir is only set at 305m, and it needs to be emptied before floods to prepare for them and to release sediment, thus failing to fully utilize the reservoir's regulation and storage function. Taking the Xiaolangdi Reservoir as another example, after its construction and operation, the average annual inflow is 25.61 billion cubic meters. 3 The sand content entering the reservoir is 11.20 kg / m³. 3 To slow down the rate of sediment deposition, the reservoir needs to conduct water and sediment regulation or low-water-level sediment discharge operations every year, resulting in approximately 2.4 billion cubic meters of sediment below the reservoir's designed flood control limit of 254 meters. 3 The effective storage capacity is insufficient to regulate runoff across years.

[0003] This reveals two major challenges for the interannual regulation of runoff in reservoirs along sandy rivers: first, the concentrated sedimentation during flood season leads to rapid loss of effective storage capacity; second, traditional scheduling methods struggle to balance storage capacity maintenance with interannual water resource allocation. Therefore, reservoirs along sandy rivers need to develop reasonable scheduling methods to coordinate effective storage capacity maintenance with interannual runoff regulation.

[0004] Based on extensive experience in the operation of existing projects, tandem reservoir groups can enhance their ability to regulate runoff and sediment through joint operation. However, at present, tandem reservoir groups mainly focus on short-term joint sediment discharge operations, lacking a systematic strategy for long-term joint operation. For example, during the flood season, joint water and sediment regulation requires both upstream and downstream reservoirs to simultaneously release large amounts of water below the flood control limit to create a high-flow process. This leads to a reduction in the water storage capacity of the upstream reservoir, while the downstream reservoir cannot absorb the water released from the upstream reservoir. Therefore, the joint regulation capacity of upstream and downstream reservoirs for water resources is weakened, and the cross-year regulation and utilization of water resources cannot be achieved.

[0005] If a suitable joint operation mode can be formulated, whereby the upper-level reservoir maintains a high flood control level as much as possible when the lower-level reservoir releases water and sediment during the flood season, or the lower-level reservoir appropriately impounds water released by the upper-level reservoir when the upper-level reservoir releases water and sediment, the cross-year runoff regulation capacity of the series of reservoirs can be fully utilized. However, the current joint operation mode is still mainly based on joint water and sediment regulation, which requires the release of a large amount of stored water to reduce sedimentation, thus affecting the cross-year runoff regulation effect. Therefore, how to achieve cross-year runoff regulation while ensuring the long-term maintenance of effective storage capacity under the condition of two or more large reservoirs connected in series is a research challenge for the joint operation of series of reservoirs in sediment-prone rivers.

[0006] Furthermore, the rationality of the operation of reservoir groups connected in series along sediment-rich rivers is mostly demonstrated through numerical simulations. Currently, reservoir group sedimentation calculations use reservoir sedimentation hydrodynamic models, while interannual runoff regulation uses runoff regulation models. These two models are independent of each other. Interannual runoff regulation calculations can only use the fixed reservoir capacity and cannot consider the impact of sedimentation changes in the reservoir area, leading to discrepancies with reality. Consequently, the accuracy of interannual runoff regulation simulations is low, and the robustness of the operation plan is poor. Summary of the Invention

[0007] In view of this, the present invention provides a method, system and storage medium for cross-year simulation regulation of runoff in a series of reservoirs, which achieves cross-year runoff regulation while maintaining the effective storage capacity of the reservoir group in the long term, and improves the accuracy of cross-year runoff regulation simulation.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: The method for cross-year simulation and regulation of runoff in a series of reservoirs as described in this invention includes the following steps: Step 1: Collect the basic parameters and relevant data of the series of reservoirs. Based on the basic parameters and relevant data of the series of reservoirs, analyze the sediment discharge and siltation patterns of the series of reservoirs and establish a formula for the relationship between reservoir capacity and siltation volume: in,V t,i Let ∆ represent the remaining reservoir capacity at water level i during time period t. V s,i ( t The total amount of silt deposited is 100%. Based on the analysis results of the sediment discharge and siltation patterns of the aforementioned series of reservoirs, and in conjunction with the sediment characteristics of the inflow runoff and the sedimentation control targets, the sediment discharge operation methods of the upper and lower level reservoirs are proposed respectively, and the sediment discharge initiation conditions, timing of sediment discharge, control water level and other indicators are determined. Step 2: Based on the proposed sediment discharge operation methods of the upper and lower level reservoirs, further propose the inter-year sequence of sediment discharge scheduling for the series of tandem reservoirs, forming a joint scheduling and operation method for the series of reservoirs, specifically including: Step 2.1, First Year: When the downstream reservoir encounters suitable water and sediment conditions during the flood season, sediment discharge scheduling is initiated to restore effective reservoir capacity. During the flood season, the upstream reservoir maintains the flood limit water level as much as possible. When conditions permit, joint water and sediment regulation scheduling is carried out in a timely manner to provide subsequent water flow power for sediment discharge from the downstream reservoir. Step 2.2, the following year: When the upper-level reservoir encounters suitable water and sediment conditions during the flood season, it will initiate sediment discharge scheduling to restore effective reservoir capacity. During the flood season, the lower-level reservoir will appropriately impound water discharged from the upper-level reservoir to maintain the flood limit water level as much as possible. Step 2.3 repeats steps 2.1 to 2.2 to form a reservoir capacity alternating recovery mechanism in a long series of reservoirs, while ensuring that each year there is a reservoir that can appropriately store water below the flood limit level for use in the following year, thereby achieving cross-year regulation of runoff; Step 3: Based on measured runoff and sediment data, design representative series of water and sediment cycles for high-water, normal-water, and low-water periods; Step 4: Based on the water and sediment representative series of the designed water-rich, normal, and dry water cycles, and in conjunction with the joint scheduling and operation mode of the series of reservoirs, calculate the outflow of the upper-level and lower-level reservoirs. Step 5: Calculate the hydraulic elements of the upper and lower reservoirs based on the outflow rates of the upper and lower reservoirs using the characteristics of water flow. Step 6: Based on the hydraulic elements of the upper and lower reservoirs, calculate the sediment erosion and deposition elements of each section of the upper and lower reservoirs. Step 7: Based on the hydraulic elements and the sediment erosion and deposition elements, calculate the topography of the river channel at the end of the current time period, determine whether the simulation end time has been reached, and obtain the first judgment result; Step 7.1: If the first judgment result is negative, update the basic parameters of the next time period according to the topography of the river channel at the end of the current time period, and return to step 4; Step 7.2: If the first judgment result is yes, then generate simulation results and calculate the interannual regulating runoff of the series reservoir group; Step 8: Based on the simulation results and the interannual regulating runoff of the series of reservoirs, determine the feasibility of the proposed joint operation mode of the series of reservoirs; that is: if the cumulative sediment deposition of the series of reservoirs in the long series, after deducting the designed sediment interception amount, does not exceed 5% of the long-term effective storage capacity, and the interannual regulating runoff is greater than 0, then the proposed joint operation mode of the reservoirs is deemed feasible.

[0009] Optionally, in step 5, the hydraulic elements of the upper and lower reservoirs are calculated, including: Using formula Calculate the water storage capacity of the upstream and downstream reservoirs; where... V t For the first t Reservoir water storage at the end of the period V t-1 For the first t -1 Reservoir water storage at the end of the period Q it For the first t Average inflow to the reservoir during the period Q ot For the first t Average outflow from the reservoir during the period, ∆ t To calculate the time step; Using the water level-capacity curves of the upstream and downstream reservoirs, calculate the water level at the dam front section corresponding to the reservoir's storage capacity; Using formula Calculate the flow rates at various cross-sections within the reservoir areas of both the upstream and downstream reservoirs; where... Q i For the reservoir area i Cross-sectional flow rate Dis i For the reservoir i Distance from the cross section to the dam; Dis This refers to the total length of the reservoir area; Using formula Trial calculations were performed to obtain the water levels and flow areas at various sections of the upstream and downstream reservoirs; among which... Q i-1 For the reservoir area i -1 cross-sectional flow rate Q i For the reservoir area i Cross-sectional flow rate A i-1 For the reservoir area i -1 cross-sectional water flow area A i For the reservoir area i Cross-sectional water flow area Z i-1 For the reservoir area i-1 section water level Z i For the reservoir area i Cross-sectional water level, ∆ X i For the reservoir area i -1 section and the first i Spacing between sections g It is the acceleration due to gravity. , J i-1 For the reservoir area i -1 cross-section energy slope, J i For the reservoir area i Cross-sectional slope, ; The average water depth of each cross-section is obtained by dividing the cross-sectional area of ​​each cross-section by the cross-sectional width of the river. The average flow velocity of each cross-section is obtained by dividing the flow rate of each cross-section by the water flow area of ​​the corresponding cross-section.

[0010] Optionally, in step 6, the sediment erosion and deposition factors of each section of the upper and lower reservoirs are calculated, including: Using formula Calculate the sediment-carrying capacity of the water flow in the upstream and downstream reservoirs; Substituting the sediment-carrying capacity of the water flow into the formula The sediment-carrying capacity of the grouped water flow in the upper and lower level reservoirs is obtained; Substituting the sediment-carrying capacity of the grouped water flow into the formula The sediment content of each cross-section group of the upstream and downstream reservoirs was obtained; Substitute the sediment content of the sand in each cross-section group into the formula. The thickness of sediment deposition and erosion in each cross section of the upper and lower reservoirs was obtained. in Q i+1 For the reservoir area i +1 cross-sectional flow rate Q i For the reservoir area i Cross-sectional flow rate S For sand content, S k,i+1 For the reservoir area i +1 cross-section k The sand content of the grouped sand S k,i For the reservoir area i Section 1 k The sand content of the grouped sand; S * The force of water flow carrying sand; S *k,iFor the reservoir area i Section 1 k The sand-carrying capacity of the sand dunes; γ The dry density of the sediment; ∆ A dk,i+1 ∆ A dk,i The first reservoir area i +1 section, the first i Section 1 k The area of ​​erosion and deposition of the sand in the group; ∆ t To calculate the time step; ∆ X i For the reservoir area i +1 section and the first i Spacing between sections; ∆ Z bk,i For the reservoir area i Section 1 k The thickness of sediment deposition in the grouped sand; α To restore the saturation coefficient; ω For sediment settling speed, ω k For the first k Sediment settling velocity of the grouped sand; D 50 The median particle size of the bed sand; γ s The bulk density of sand particles; γ m The density of turbid water; h For water depth; V The cross-sectional velocity; κ Kármán's constant S v The average sand content at the inlet section is calculated using the volume ratio. S *k For the first k The sand-carrying capacity of the sand dunes; P k For the sediment gradation of the upstream section; P uk For surface bed sand gradation; n The number of groups for sediment particle size.

[0011] Optionally, in step 7.2, the interannual regulating runoff of the series of reservoirs is calculated, i.e.: Using formula Calculate the interannual regulated runoff of a series of reservoirs; in, W cr To regulate the runoff volume across the year for a series of reservoirs; V uy2 , V uy1These represent the water storage capacity of the upstream reservoir at the end of this year and the end of last year, respectively. V ly2 , V ly1 These represent the water storage capacity of the lower-level reservoirs at the end of the current year and the end of the previous year, respectively.

[0012] The system for implementing the interannual simulation and regulation method of runoff in a series of reservoirs in a sedimentary river, as described in this invention, includes: The basic parameter collection module is used to collect the basic parameters of the tandem reservoir group; The outflow calculation module is used to calculate the outflow of the upper-level reservoir and the lower-level reservoir based on the basic parameters and the proposed joint scheduling and operation mode for the series of reservoirs. The hydraulic element calculation module is used to calculate the hydraulic elements of the upper and lower reservoirs based on the outflow from the upper and lower reservoirs and the characteristics of water flow. The sediment scouring and deposition element calculation module is used to calculate the sediment scouring and deposition elements of each section of the upper and lower reservoirs based on the hydraulic elements of the upper and lower reservoirs. The terrain update module is used to calculate the terrain of the river channel at the end of the current time period based on hydraulic elements and the sediment erosion and deposition elements. The judgment module is used to determine whether the simulation end time has been reached and obtain the first judgment result; The return module is used to update the basic parameters of the next time period based on the topography of the river channel at the end of the current time period if the first judgment result is negative, and then return to the outflow calculation module. The interannual regulating runoff calculation module is used to generate simulation results and calculate the interannual regulating runoff of the series of reservoirs if the first judgment result is yes. The feasibility assessment module determines the feasibility of the proposed joint scheduling and operation mode of the series of reservoirs based on the simulation results and the inter-year regulating runoff of the series of reservoirs.

[0013] Furthermore, the hydraulic element calculation module includes: The reservoir storage capacity calculation unit is used to calculate the water storage capacity using the formula. Calculate the water storage capacity of the upstream reservoir and the downstream reservoir; wherein V t For the first t Reservoir water storage at the end of the period V t-1 For the first t -1 Reservoir water storage at the end of the period Q it For the first t Average inflow to the reservoir during the period Q ot For the firstt Average outflow from the reservoir during the period, ∆ t To calculate the time step; The dam-front section water level calculation unit is used to calculate the dam-front section water level corresponding to the reservoir's storage capacity using the water level-storage capacity curves of the upper and lower reservoirs. The reservoir cross-sectional flow calculation unit is used to calculate the flow rate using the formula. Calculate the flow rates at various cross-sections within the reservoir areas of both the upstream and downstream reservoirs; where... Q i For the reservoir area i Cross-sectional flow rate Dis i For the reservoir i Distance from the cross section to the dam; Dis This refers to the total length of the reservoir area; The reservoir cross-sectional water level and area calculation unit is used to calculate the water level and area using formulas. Trial calculations were performed to obtain the water levels and flow areas at various sections of the upstream and downstream reservoirs; among which... Q i-1 For the reservoir area i -1 cross-sectional flow rate Q i For the reservoir area i Cross-sectional flow rate A i-1 For the reservoir area i -1 cross-sectional water flow area A i For the reservoir area i Cross-sectional water flow area Z i-1 For the reservoir area i -1 section water level Z i For the reservoir area i Cross-sectional water level, ∆ X i For the reservoir area i -1 section and the first i Spacing between sections g It is the acceleration due to gravity. , J i-1 For the reservoir area i -1 cross-section energy slope, J i For the reservoir area i Cross-sectional slope, ; The reservoir average water depth calculation unit is used to divide the water flow area of ​​each cross section by the water flow width of the corresponding cross section to obtain the average water depth of each cross section. The reservoir average flow velocity calculation unit is used to divide the flow rate of each cross-section by the water flow area of ​​the corresponding cross-section to obtain the average flow velocity of each cross-section.

[0014] Furthermore, the sediment erosion and deposition element calculation module includes: The sediment-carrying capacity calculation unit is used to calculate the sediment-carrying capacity of water flow using formulas. Calculate the sediment-carrying capacity of the water flow in the upstream and downstream reservoirs; The grouped sediment-carrying capacity calculation unit is used to substitute the sediment-carrying capacity into the formula. The sediment-carrying capacity of the grouped water flow in the upper and lower level reservoirs is obtained; The sediment content calculation unit for each cross-section group is used to substitute the sediment-carrying capacity of the water flow into the formula. The sediment content of each cross-section group of the upstream and downstream reservoirs was obtained; The calculation unit for the thickness of sand erosion and siltation in each cross-section group is used to substitute the sand content of each cross-section group into the formula. The thickness of sediment deposition and erosion in each cross section of the upper and lower reservoirs was obtained. in Q i+1 For the reservoir area i +1 cross-sectional flow rate Q i For the reservoir area i Cross-sectional flow rate S For sand content, S k,i+1 For the reservoir area i +1 cross-section k The sand content of the grouped sand S k,i For the reservoir area i Section 1 k The sand content of the grouped sand; S * The force of water flow carrying sand; S *k,i For the reservoir area i Section 1 k The sand-carrying capacity of the sand dunes; γ The dry density of the sediment; ∆ A dk,i+1 ∆ A dk,i The first reservoir area i +1 section, the first i Section 1 k The area of ​​erosion and deposition of the sand in the group; ∆ t To calculate the time step; ∆ X i For the reservoir area i +1 section and the first iSpacing between sections; ∆ Z bk,i For the reservoir area i Section 1 k The thickness of sediment deposition in the grouped sand; α To restore the saturation coefficient; ω For sediment settling speed, ω k For the first k Sediment settling velocity of the grouped sand; D 50 The median particle size of the bed sand; γ s The bulk density of sand particles; γ m The density of turbid water; h For water depth; V The cross-sectional velocity; κ Kármán's constant S v The average sand content at the inlet section is calculated using the volume ratio. S *k For the first k The sand-carrying capacity of the sand dunes; P k For the sediment gradation of the upstream section; P uk For surface bed sand gradation; n The number of groups for sediment particle size.

[0015] Furthermore, the inter-annual regulating runoff calculation module includes: The interannual regulating runoff calculation unit is used to calculate runoff using the formula. Calculate the interannual regulating runoff of the aforementioned series of reservoirs; in, W cr The interannual regulating runoff of the cascaded reservoir group; V uy2 , V uy1 These refer to the water storage capacity of the upstream reservoir at the end of this year and the end of last year, respectively. V ly2 , V ly1 These refer to the water storage capacity of the lower-level reservoir at the end of the current year and the end of the previous year, respectively.

[0016] The storage medium of the present invention stores a computer program that includes a basic parameter collection module, an outflow calculation module, a hydraulic element calculation module, a sediment erosion and deposition element calculation module, a terrain update module, a judgment module, a return module, an interannual regulation runoff calculation module, and a feasibility judgment module. When the computer program is executed by a microcontroller processor, it implements the steps as described in claims 1-4 to complete the interannual simulation regulation method for runoff of a series of reservoirs in a river with high sediment content.

[0017] This invention proposes a joint operation mode for a series of reservoirs, and simulates the changes in river topography after siltation and scouring, and updates basic parameters in a timely manner. This enables cross-year runoff regulation while maintaining the effective storage capacity of the reservoir group in the long term, and improves the accuracy of cross-year runoff regulation simulation. Attached Figure Description

[0018] Figure 1 This is a flowchart of the inter-year simulation and regulation method for runoff of a series of reservoirs as described in this invention.

[0019] Figure 2 This is a schematic diagram of the system structure for implementing the cross-year simulation and regulation method for runoff of a series of reservoirs as described in this invention.

[0020] Figure 3 This is a logic diagram of the optimized operation of Guxian Reservoir and Xiaolangdi Reservoir as described in Example 1.

[0021] Figure 4 This is a schematic diagram of the cumulative siltation process of Xiaolangdi Reservoir as described in Example 1.

[0022] Figure 5 This is a schematic diagram illustrating the cumulative siltation process of the Guxian Reservoir as described in Example 1. Detailed Implementation

[0023] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. These embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given. However, the scope of protection of the present invention is not limited to the following embodiments.

[0024] It should be noted that, in the description of this invention, relational terms such as “first” and “second” are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0025] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] like Figure 1 As shown, the interannual simulation and regulation method for runoff of a series of reservoirs according to the present invention includes the following steps: Step 1: Collect the basic parameters and relevant data of the selected series of reservoirs. Based on the basic parameters and relevant data of the series of reservoirs, analyze the sediment discharge and siltation patterns of the series of reservoirs and establish the formula for the relationship between reservoir capacity and siltation volume: in, V t,i Let ∆ represent the remaining reservoir capacity at water level i during time period t. V s,i ( t The total amount of silt deposited is 100%. Based on the analysis results of the sediment discharge and siltation patterns of the aforementioned series of reservoirs, and in conjunction with the sediment characteristics of the inflow runoff and the sedimentation control targets, the sediment discharge operation methods of the upper and lower level reservoirs are proposed respectively, and the sediment discharge initiation conditions, timing of sediment discharge, control water level and other indicators are determined. Step 2: Based on the proposed sediment discharge operation methods of the upper and lower level reservoirs, further propose the inter-year sequence of sediment discharge scheduling for the series of tandem reservoirs, forming a joint scheduling and operation method for the series of reservoirs, specifically including: Step 2.1, Selected first year: When the lower-level reservoir encounters suitable water and sediment conditions during the flood season, it shall initiate sediment discharge scheduling to restore effective reservoir capacity. The upper-level reservoir shall maintain the flood limit water level as much as possible during the flood season. When conditions permit, joint water and sediment regulation scheduling shall be carried out in a timely manner to provide subsequent water flow power for sediment discharge from the lower-level reservoir. Step 2.2, Selected year: When the upper-level reservoir encounters suitable water and sediment conditions during the flood season, sediment discharge scheduling is initiated to restore effective reservoir capacity. During the flood season, the lower-level reservoir appropriately impounds water discharged from the upper-level reservoir to maintain the flood limit water level as much as possible. Step 2.3 repeats steps 2.1 to 2.2 to form a reservoir capacity alternating recovery mechanism in a long series of reservoirs, while ensuring that each year there is a reservoir that can appropriately store water below the flood limit level for use in the following year, thereby achieving cross-year regulation of runoff; Step 3: Based on measured runoff and sediment data, design representative series of water and sediment cycles for high-water, normal-water, and low-water periods; Step 4: Based on the water and sediment representative series of the designed water-rich, normal, and dry water cycles, and in conjunction with the joint scheduling and operation mode of the series of reservoirs, calculate the outflow of the upper-level and lower-level reservoirs. Step 5: Calculate the hydraulic elements of the upper and lower reservoirs based on the outflow rates of the upper and lower reservoirs using the characteristics of water flow. Step 6: Based on the hydraulic elements of the upper and lower reservoirs, calculate the sediment erosion and deposition elements of each section of the upper and lower reservoirs. Step 7: Based on the hydraulic elements and the sediment erosion and deposition elements, calculate the topography of the river channel at the end of the current time period, determine whether the simulation end time has been reached, and obtain the first judgment result; Step 7.1: If the first judgment result is negative, update the basic parameters of the next time period according to the topography of the river channel at the end of the current time period, and return to step 4; Step 7.2: If the first judgment result is yes, then generate simulation results and calculate the interannual regulating runoff of the series reservoir group; Step 8: Based on the simulation results and the interannual regulating runoff of the series of reservoirs, determine the feasibility of the proposed joint operation mode of the series of reservoirs; that is: if the cumulative sediment deposition of the series of reservoirs in the long series, after deducting the designed sediment interception amount, does not exceed 5% of the long-term effective storage capacity, and the interannual regulating runoff is greater than 0, then the proposed joint operation mode of the reservoirs is deemed feasible.

[0027] like Figure 2 As shown, the system for implementing the interannual simulation and regulation method for runoff of a series of reservoirs as described in this invention includes: The basic parameter collection module is used to collect the basic parameters of the tandem reservoir group; The outflow calculation module is used to calculate the outflow of the upper-level reservoir and the lower-level reservoir based on the basic parameters and the proposed joint scheduling and operation mode for the series of reservoirs. The hydraulic element calculation module is used to calculate the hydraulic elements of the upper and lower reservoirs based on the outflow from the upper and lower reservoirs and the characteristics of water flow. The sediment scouring and deposition element calculation module is used to calculate the sediment scouring and deposition elements of each section of the upper and lower reservoirs based on the hydraulic elements of the upper and lower reservoirs. The terrain update module is used to calculate the terrain of the river channel at the end of the current time period based on hydraulic elements and the sediment erosion and deposition elements. The judgment module is used to determine whether the simulation end time has been reached and obtain the first judgment result; The return module is used to update the basic parameters of the next time period based on the topography of the river channel at the end of the current time period if the first judgment result is negative, and then return to the outflow calculation module. The interannual regulating runoff calculation module is used to generate simulation results and calculate the interannual regulating runoff of the series of reservoirs if the first judgment result is yes. The feasibility assessment module determines the feasibility of the proposed joint scheduling and operation mode of the series of reservoirs based on the simulation results and the inter-year regulating runoff of the series of reservoirs.

[0028] The storage medium of this invention stores computer programs for a basic parameter collection module, an outflow calculation module, a hydraulic element calculation module, a sediment erosion and deposition element calculation module, a terrain update module, a judgment module, a return module, an interannual regulation runoff calculation module, and a feasibility judgment module. When the computer program is executed by a microcontroller processor, it implements the steps of this invention and completes the interannual simulation regulation method for runoff of a series of reservoirs in a river with high sediment content.

[0029] It is understood that if the method of this invention is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of this embodiment. The storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0030] Example 1, taking the Guxian Reservoir and Xiaolangdi Reservoir on the Yellow River as examples, will be described in detail below: After the completion and operation of the Guxian Reservoir, it can jointly regulate water and sediment with the Xiaolangdi Reservoir. Through the process of releasing large flow rates, it can flush the Xiaolangdi Reservoir area and the lower reaches of the Yellow River, thereby coordinating the water-sediment relationship and improving the efficiency of reservoir sediment discharge and river sediment transport. The current joint water and sediment regulation operation mode of the Guxian and Xiaolangdi Reservoirs (hereinafter referred to as the original operation mode) was demonstrated and proposed during the feasibility study stage of the Guxian project. It mainly considers the scenario of a large sediment load from the Yellow River (design sediment load of 800 million tons), and aims to give full play to the sediment discharge and silt reduction function of the reservoirs. During the flood season from July to September, when the river inflow and the water storage of the Guxian and Xiaolangdi Reservoirs meet the water and sediment regulation requirements, that is, according to the controlled flow rate (4000 m³ / h), the water is regulated. 3The water and sediment regulation operations are required to be carried out in accordance with the requirements of approximately 5 days and 600 km / s, to maintain the flow capacity of the main channel of the downstream river, improve the sedimentation pattern of Xiaolangdi Reservoir, extend the service life of Xiaolangdi Reservoir, and reduce the water level of Guxian Reservoir to the lowest level of dead water.

[0031] Given the increasingly precious water resources of the Yellow River, continuing to conduct reservoir sediment regulation and ensuring the cross-year flow regulation function of the interconnected reservoir group within a long series, and maximizing the comprehensive utilization benefits of water resources, is of great practical significance. Therefore, it is necessary to optimize the original proposed joint water and sediment regulation operation mode. Based on the large interannual variations in Yellow River water and sediment inflow, a joint water and sediment regulation operation mode of "regulation during wet seasons and storage during dry seasons" for the Guxian and Xiaolangdi reservoirs is proposed (hereinafter referred to as the optimized operation mode). The strategy for wet seasons is to lower the water level to the dead water level when the upper-level Guxian reservoir and the lower-level Xiaolangdi reservoir jointly regulate water and sediment, thereby increasing sediment discharge from the reservoir. The strategy for normal seasons is to release a large flow for only 5 days to flush the Xiaolangdi reservoir area, thereby increasing sediment discharge from the Xiaolangdi reservoir. The strategy for dry seasons is that neither reservoir will conduct water and sediment regulation. The logic of the optimized operation mode is explained below. Figure 3 , Figure 3 This indicates that the annual regulation of runoff in the series of reservoirs connecting high-sediment rivers, represented by the Guxian Reservoir and the Xiaolangdi Reservoir, is mainly affected by the hydrological cycle and changes in inflow. The hydrological cycle mainly consists of high-water years, normal-water years, and low-water years. At the same time, the annual changes in inflow are taken into account to dynamically adjust water and sediment regulation. When the inflow is large, the high-water year water and sediment regulation scheme is adopted; when the inflow is normal, the normal-water year water and sediment regulation scheme is adopted; when the inflow is small, the low-water year scheduling method is adopted, that is, no water and sediment regulation is carried out.

[0032] Using the measured water and sediment processes from 2000 to 2020 as the design water and sediment series, a mathematical model was used to simulate and calculate the cumulative sedimentation and interannual regulating runoff of the Guxian and Xiaolangdi reservoirs. The results are shown in Table 1 and 2. Figure 4 , Figure 5 .

[0033] As shown in Table 1, when the Guxian Reservoir and Xiaolangdi Reservoir adopt optimized operation methods, their average annual water storage capacity increases by 2.96 billion m³. 3 The multi-year average annual regulating runoff increased by 342 million m³. 3 After adopting an optimized operation mode, considering that the Guxian Reservoir will begin operation in 2034, the cumulative siltation volume of the Xiaolangdi Reservoir will be the same under both the original and optimized operation modes from 2022 to 2034. However, from 2035 to 2084, compared to the original operation mode, the cumulative siltation volume of the Xiaolangdi Reservoir will increase by 100 million cubic meters after adopting the optimized operation mode. 3 After adopting optimized operation methods, the cumulative siltation in the Guxian Reservoir area increased by 159 million cubic meters compared to the original operation methods. 3Since the Guxian Reservoir began operation, under optimized management, the average annual siltation volume in the Xiaolangdi Reservoir has increased by 0.019 billion cubic meters. 3 The average annual siltation volume of Guxian Reservoir increases by 0.031 billion cubic meters. 3 However, it significantly increases the amount of water stored and the annual runoff regulation, thus demonstrating the advantages of this invention.

[0034] Table 1. Multi-year average annual regulating runoff of Guxian and Xiaolangdi Reservoirs Finally, it should be emphasized that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for cross-year simulation and regulation of runoff in a series of reservoirs, characterized in that: Includes the following steps: Step 1: Collect the basic parameters and relevant data of the series of reservoirs. Based on the basic parameters and relevant data of the series of reservoirs, analyze the sediment discharge and siltation patterns of the series of reservoirs and establish a formula for the relationship between reservoir capacity and siltation volume: in, V t,i Let ∆ represent the remaining reservoir capacity at water level i during time period t. V s,i ( t The total amount of silt deposited is 100%. Based on the analysis results of the sediment discharge and siltation patterns of the aforementioned series of reservoirs, and in conjunction with the sediment characteristics of the inflow runoff and the sedimentation control targets, the sediment discharge operation methods of the upper and lower level reservoirs are proposed respectively, and the sediment discharge initiation conditions, timing of sediment discharge, control water level and other indicators are determined. Step 2: Based on the proposed sediment discharge operation methods of the upper and lower level reservoirs, further propose the inter-year sequence of sediment discharge scheduling for the series of tandem reservoirs, forming a joint scheduling and operation method for the series of reservoirs, specifically including: Step 2.1, First year: During the flood season, the lower-level reservoir initiates sediment flushing to restore effective storage capacity, while the upper-level reservoir maintains the flood control limit level during the flood season; Step 2.2, the following year: During the flood season, the upper-level reservoir initiates sediment discharge scheduling to restore effective reservoir capacity, and during the flood season, the lower-level reservoir impounds water released from the upper-level reservoir to maintain the flood limit water level; Step 2.3 repeats steps 2.1 to 2.2 to form a mechanism for alternating recovery of reservoir capacity in a series of reservoirs, while ensuring that there is always one reservoir storing water below the flood limit level for use in the following year, thereby achieving cross-year regulation of runoff. Step 3: Based on measured runoff and sediment data, design representative series of water and sediment cycles for high-water, normal-water, and low-water periods; Step 4: Based on the water and sediment representative series of the designed water-rich, normal, and dry water cycles, and in conjunction with the joint scheduling and operation mode of the series of reservoirs, calculate the outflow of the upper-level and lower-level reservoirs. Step 5: Calculate the hydraulic elements of the upper and lower reservoirs based on the outflow rates of the upper and lower reservoirs using the characteristics of water flow. Step 6: Based on the hydraulic elements of the upper and lower reservoirs, calculate the sediment erosion and deposition elements of each section of the upper and lower reservoirs. Step 7: Based on the hydraulic elements and the sediment erosion and deposition elements, calculate the topography of the river channel at the end of the current time period, determine whether the simulation end time has been reached, and obtain the first judgment result; Step 7.1: If the first judgment result is negative, update the basic parameters of the next time period according to the topography of the river channel at the end of the current time period, and return to step 4; Step 7.2: If the first judgment result is yes, then generate simulation results and calculate the interannual regulating runoff of the series reservoir group; Step 8: Based on the simulation results and the interannual regulating runoff of the series of reservoirs, determine the feasibility of the proposed joint operation mode of the series of reservoirs; that is: if the cumulative sediment deposition of the series of reservoirs in the long series, after deducting the designed sediment interception amount, does not exceed 5% of the long-term effective storage capacity, and the interannual regulating runoff is greater than 0, then the proposed joint operation mode of the reservoirs is deemed feasible.

2. The method for cross-year simulation and regulation of runoff in a series of reservoirs according to claim 1, characterized in that: Step 5 involves calculating the hydraulic elements of the upstream and downstream reservoirs, including: Using formula Calculate the water storage capacity of the upstream and downstream reservoirs; where... V t For the first t Reservoir water storage at the end of the period V t-1 For the first t -1 Reservoir water storage at the end of the period Q it For the first t Average inflow to the reservoir during the period Q ot For the first t Average outflow from the reservoir during the period, ∆ t To calculate the time step; Using the water level-capacity curves of the upstream and downstream reservoirs, calculate the water level at the dam front section corresponding to the reservoir's storage capacity; Using formula Calculate the flow rates at various cross-sections within the reservoir areas of both the upstream and downstream reservoirs; where... Q i For the reservoir area i Cross-sectional flow rate Dis i For the reservoir i Distance from the cross section to the dam; Dis This refers to the total length of the reservoir area; Using formula Trial calculations were performed to obtain the water levels and flow areas at various sections of the upstream and downstream reservoirs; among which... Q i-1 For the reservoir area i -1 cross-sectional flow rate Q i For the reservoir area i Cross-sectional flow rate A i-1 For the reservoir area i -1 cross-sectional water flow area A i For the reservoir area i Cross-sectional water flow area Z i-1 For the reservoir area i -1 section water level Z i For the reservoir area i Cross-sectional water level, ∆ X i For the reservoir area i -1 section and the first i Spacing between sections g It is the acceleration due to gravity. , J i-1 For the reservoir area i -1 cross-section energy slope, J i For the reservoir area i Cross-sectional slope, ; The average water depth of each cross-section is obtained by dividing the cross-sectional area of ​​each cross-section by the cross-sectional width of the river. The average flow velocity of each cross-section is obtained by dividing the flow rate of each cross-section by the water flow area of ​​the corresponding cross-section.

3. The method for cross-year simulation and regulation of runoff in a series of reservoirs according to claim 1, characterized in that: In step 6, the sediment erosion and deposition factors of each section of the upper and lower reservoirs are calculated, including: Using formula Calculate the sediment-carrying capacity of the water flow in the upstream and downstream reservoirs; Substituting the sediment-carrying capacity of the water flow into the formula The sediment-carrying capacity of the grouped water flow in the upper and lower level reservoirs is obtained; Substituting the sediment-carrying capacity of the grouped water flow into the formula The sediment content of each cross-section group of the upstream and downstream reservoirs was obtained; Substitute the sediment content of the sand in each cross-section group into the formula. The thickness of sediment deposition and erosion in each cross section of the upper and lower reservoirs was obtained. in Q i+1 For the reservoir area i +1 cross-sectional flow rate Q i For the reservoir area i Cross-sectional flow rate S For sand content, S k,i+1 For the reservoir area i +1 cross-section k The sand content of the grouped sand S k,i For the reservoir area i Section 1 k The sand content of the grouped sand; S * The force of water flow carrying sand; S *k,i For the reservoir area i Section 1 k The sand-carrying capacity of the sand dunes; γ The dry density of the sediment; ∆ A dk,i+1 ∆ A dk,i The first reservoir area i +1 section, the first i Section 1 k The area of ​​erosion and deposition of the sand in the group; ∆ t To calculate the time step; ∆ X i For the reservoir area i +1 section and the first i Spacing between sections; ∆ Z bk,i For the reservoir area i Section 1 k The thickness of sediment deposition in the grouped sand; α To restore the saturation coefficient; ω For sediment settling speed, ω k For the first k Sediment settling velocity of the grouped sand; D 50 The median particle size of the bed sand; γ s The bulk density of sand particles; γ m The density of turbid water; h For water depth; V The cross-sectional velocity; κ Kármán's constant S v The average sand content at the inlet section is calculated using the volume ratio. S *k For the first k The sand-carrying capacity of the sand dunes; P k For the sediment gradation of the upstream section; P uk For surface bed sand gradation; n The number of groups for sediment particle size.

4. The method for cross-year simulation and regulation of runoff in a series of reservoirs according to claim 1, characterized in that: In step 7.2, the interannual regulating runoff of the series of reservoirs is calculated, i.e.: Using formula Calculate the interannual regulated runoff of a series of reservoirs; in, W cr To regulate the runoff volume across the year for a series of reservoirs; V uy2 , V uy1 These represent the water storage capacity of the upstream reservoir at the end of this year and the end of last year, respectively. V ly2 , V ly1 These represent the water storage capacity of the lower-level reservoirs at the end of the current year and the end of the previous year, respectively.

5. A system for implementing the interannual simulation and regulation method for runoff of a series of reservoirs as described in claim 1, characterized in that: include: The basic parameter collection module is used to collect the basic parameters of the tandem reservoir group; The outflow calculation module is used to calculate the outflow of the upper-level reservoir and the lower-level reservoir based on the basic parameters and the proposed joint scheduling and operation mode for the series of reservoirs. The hydraulic element calculation module is used to calculate the hydraulic elements of the upper and lower reservoirs based on the outflow from the upper and lower reservoirs and the characteristics of water flow. The sediment scouring and deposition element calculation module is used to calculate the sediment scouring and deposition elements of each section of the upper and lower reservoirs based on the hydraulic elements of the upper and lower reservoirs. The terrain update module is used to calculate the terrain of the river channel at the end of the current time period based on hydraulic elements and the sediment erosion and deposition elements. The judgment module is used to determine whether the simulation end time has been reached and obtain the first judgment result; The return module is used to update the basic parameters of the next time period based on the topography of the river channel at the end of the current time period if the first judgment result is negative, and then return to the outflow calculation module. The interannual regulating runoff calculation module is used to generate simulation results and calculate the interannual regulating runoff of the series of reservoirs if the first judgment result is yes. The feasibility assessment module determines the feasibility of the proposed joint scheduling and operation mode of the series of reservoirs based on the simulation results and the inter-year regulating runoff of the series of reservoirs.

6. The system according to claim 5, characterized in that: The hydraulic element calculation module includes: The reservoir storage capacity calculation unit is used to calculate the water storage capacity using the formula. Calculate the water storage capacity of the upstream reservoir and the downstream reservoir; wherein V t For the first t Reservoir water storage at the end of the period V t-1 For the first t -1 Reservoir water storage at the end of the period Q it For the first t Average inflow to the reservoir during the period Q ot For the first t Average outflow from the reservoir during the period, ∆ t To calculate the time step; The dam-front section water level calculation unit is used to calculate the dam-front section water level corresponding to the reservoir's storage capacity using the water level-storage capacity curves of the upper and lower reservoirs. The reservoir cross-sectional flow calculation unit is used to calculate the flow rate using the formula. Calculate the flow rates at various cross-sections within the reservoir areas of both the upstream and downstream reservoirs; where... Q i For the reservoir area i Cross-sectional flow rate Dis i For the reservoir i Distance from the cross section to the dam; Dis This refers to the total length of the reservoir area; The reservoir cross-sectional water level and area calculation unit is used to calculate the water level and area using formulas. Trial calculations were performed to obtain the water levels and flow areas at various sections of the upstream and downstream reservoirs; among which... Q i-1 For the reservoir area i -1 cross-sectional flow rate Q i For the reservoir area i Cross-sectional flow rate A i-1 For the reservoir area i -1 cross-sectional water flow area A i For the reservoir area i Cross-sectional water flow area Z i-1 For the reservoir area i -1 section water level Z i For the reservoir area i Cross-sectional water level, ∆ X i For the reservoir area i -1 section and the first i Spacing between sections g It is the acceleration due to gravity. , J i-1 For the reservoir area i -1 cross-section energy slope, J i For the reservoir area i Cross-sectional slope, ; The reservoir average water depth calculation unit is used to divide the water flow area of ​​each cross section by the water flow width of the corresponding cross section to obtain the average water depth of each cross section. The reservoir average flow velocity calculation unit is used to divide the flow rate of each cross-section by the water flow area of ​​the corresponding cross-section to obtain the average flow velocity of each cross-section.

7. The system according to claim 5, characterized in that: The sediment erosion and deposition element calculation module includes: The sediment-carrying capacity calculation unit is used to calculate the sediment-carrying capacity of water flow using formulas. Calculate the sediment-carrying capacity of the water flow in the upstream and downstream reservoirs; The grouped sediment-carrying capacity calculation unit is used to substitute the sediment-carrying capacity into the formula. The sediment-carrying capacity of the grouped water flow in the upper and lower level reservoirs is obtained; The sediment content calculation unit for each cross-section group is used to substitute the sediment-carrying capacity of the water flow into the formula. The sediment content of each cross-section group of the upstream and downstream reservoirs was obtained; The calculation unit for the thickness of sand erosion and siltation in each cross-section group is used to substitute the sand content of each cross-section group into the formula. The thickness of sediment deposition and erosion in each cross section of the upper and lower reservoirs was obtained. in Q i+1 For the reservoir area i +1 cross-sectional flow rate Q i For the reservoir area i Cross-sectional flow rate S For sand content, S k,i+1 For the reservoir area i +1 cross-section k The sand content of the grouped sand S k,i For the reservoir area i Section 1 k The sand content of the grouped sand; S * The force of water flow carrying sand; S *k,i For the reservoir area i Section 1 k The sand-carrying capacity of the sand dunes; γ The dry density of the sediment; ∆ A dk,i+1 ∆ A dk,i The first reservoir area i +1 section, the first i Section 1 k The area of ​​erosion and deposition of the sand in the group; ∆ t To calculate the time step; ∆ X i For the reservoir area i +1 section and the first i Spacing between sections; ∆ Z bk,i For the reservoir area i Section 1 k The thickness of sediment deposition in the grouped sand; α To restore the saturation coefficient; ω For sediment settling speed, ω k For the first k Sediment settling velocity of the grouped sand; D 50 The median particle size of the bed sand; γ s The bulk density of sand particles; γ m The density of turbid water; h For water depth; V The cross-sectional velocity; κ Kármán's constant S v The average sand content at the inlet section is calculated using the volume ratio. S *k For the first k The sand-carrying capacity of the sand dunes; P k For the sediment gradation of the upstream section; P uk For surface bed sand gradation; n The number of groups for sediment particle size.

8. The system according to claim 5, characterized in that: The inter-year regulating runoff calculation module includes: The interannual regulating runoff calculation unit is used to calculate runoff using the formula. Calculate the interannual regulating runoff of the aforementioned series of reservoirs; in, W cr The interannual regulating runoff of the cascaded reservoir group; V uy2 , V uy1 These refer to the water storage capacity of the upstream reservoir at the end of this year and the end of last year, respectively. V ly2 , V ly1 These refer to the water storage capacity of the lower-level reservoir at the end of the current year and the end of the previous year, respectively.

9. A storage medium, characterized in that: The storage medium is a computer storage medium, which stores computer programs for executing basic parameter collection modules, outflow calculation modules, hydraulic element calculation modules, sediment erosion and deposition element calculation modules, terrain update modules, judgment modules, return modules, interannual regulation runoff calculation modules, and feasibility judgment modules. When the computer program is executed by the microcontroller processor, it implements the steps as described in claims 1-4.

Images