Digital twinborn irrigation area mountain-along canal system flood prevention scheduling optimization method and system

Abstract

The invention discloses a flood prevention scheduling optimization method and system for a channel system along a mountain in a digital twinborn irrigation district, and the method comprises the steps: dividing a target digital twinborn irrigation district into a plurality of channel sections, and calculating a water level-available tank storage capacity relation curve and a water level-flow curve of each channel section; a runoff and confluence forecasting model of the target digital twinborn irrigation area is constructed, and flood processes of different channel entering point locations are forecasted; according to the flood process forecast result, the water level-available tank storage capacity relation curve and the water level-flow curve, scheduling strategies of all channel sections are set in a channel section dividing mode; constructing a one-dimensional hydrodynamic model of the target digital twinborn irrigation area, and simulating a flood routing process at different initial water levels according to a set scheduling strategy; and scheduling strategy optimization is carried out according to the simulation result of the flood routing process. The obtained scheduling scheme is more accurate.

Description

Technical Field

[0001] The present invention relates to the technology of flood control and dispatching optimization, and particularly to a method and system for optimizing flood control and dispatching of mountain-side canal systems in a digital twin irrigation area. Background Art

[0002] The canal system project in the irrigation area is an integral part of the backbone of the water network, and its scientific flood control is the key to the safe operation of the canal system project. At present, the mountain-side irrigation area has a complex canal system morphology, and the rainfall and flood entry points into the canal in the irrigation area are scattered. Traditional flood control and dispatching rely on manual experience to judge the real-time rise and fall of water levels at key points for gate dispatching, making it difficult to overall plan the entire irrigation area.

[0003] The patent document with the publication number CN118430190A discloses a method for warning the flood control water level of a reservoir. The method includes obtaining rainfall data along the upstream river in real time, and monitoring the water level changes at the reservoir entrance and key river sections; based on the obtained rainfall data and water level data, using a hydrological model to calculate the upstream incoming water flow, and predicting and analyzing the changing trend of the reservoir water level in a certain future period; according to the water level prediction result, evaluating the risk level of the reservoir encountering flood disasters in a certain future period, and issuing corresponding warnings; formulating and implementing a flood discharge dispatching plan based on the water level prediction result and risk assessment. However, this method is mainly applicable to the flood control of reservoirs and is not applicable to the flood control and dispatching of mountain-side canal systems in the irrigation area. Therefore, it is necessary to calculate a dispatching plan considering pre-discharge and flood storage for the mountain-side canal system in the irrigation area to guide the opening and closing operations of the canal check gates and flood discharge gates, and improve the scientific flood control and dispatching level of the irrigation area. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a method and system for optimizing flood control and dispatching of mountain-side canal systems in a digital twin irrigation area with a more accurate dispatching plan.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions: A method for optimizing flood control and dispatching of mountain-side canal systems in a digital twin irrigation area, comprising the following steps: (1) Obtain the topological information and runoff-yield and concentration information of the target digital twin irrigation area; (2) According to the topological information of the target digital twin irrigation area, divide the target digital twin irrigation area into several canal sections, construct a one-dimensional hydrodynamic model for each canal section, and calculate the water level-available storage relationship curve and water level-discharge curve of each canal section; (3) According to the runoff-yield and concentration information of the target digital twin irrigation area, construct a runoff-yield and concentration forecasting model for the target digital twin irrigation area to forecast the flood processes at different canal entry points; (4) According to the flood process forecasting results, water level-available storage relationship curve and water level-discharge curve, set the dispatching strategies for each canal section by canal section; (5) Construct a one-dimensional hydrodynamic model of the target digital twin irrigation area and simulate the flood evolution process under different initial water levels according to the set scheduling strategy; (6) Determine whether all preset indicators in the simulation results of the flood evolution process meet the preset requirements. If not, update the scheduling strategy until the preset requirements are met. The scheduling strategy of each channel section at this time is used as the optimal scheduling plan.

[0006] A digital twin irrigation area flood control dispatch optimization system along the mountain canal system, including: The information acquisition module is used to obtain the topological information and runoff information of the target digital twin irrigation area; The relationship curve fitting module is used to divide the target digital twin irrigation area into several canal sections according to the topological information of the target digital twin irrigation area, and to construct a one-dimensional hydrodynamic model of the canal section, and calculate the water level-available tank storage relationship curve and water level-flow curve of each canal section; The flood forecasting module is used to build a runoff forecasting model for the target digital twin irrigation area based on the runoff information of the target digital twin irrigation area, and to forecast the flood process at different inlet points; The scheduling strategy setting module is used to set the scheduling strategy for each channel section according to the flood process forecast results, the water level-available tank storage relationship curve and the water level-flow curve; The flood simulation module is used to construct a one-dimensional hydrodynamic model of the target digital twin irrigation area and simulate the flood evolution process under different initial water levels according to the set scheduling strategy; The scheduling optimization module is used to determine whether all preset indicators in the simulation results of the flood evolution process meet the preset requirements. If not, the scheduling strategy is updated until the preset requirements are met, and the scheduling strategy of each channel section at this time is used as the optimal scheduling plan.

[0007] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention obtains the optimal solution for channel sluice scheduling in different scenarios through preview simulation of channel flood process forecast and scheduling strategy, which is more accurate and safer, and improves the scheduling level of flood control scheduling along mountain canal systems in digital twin irrigation areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a flow chart of the optimization method for flood control dispatching along the mountain canal system of the digital twin irrigation area provided by the present invention; Figure 2 It is a schematic diagram of the channel section division, where (a) is a plan view and (b) is a side view; Figure 3 It is a water level-available tank storage relationship curve and a schematic diagram of the stage division of the flood process, where (a) is a schematic diagram of the flood process segment division, and (b) is a schematic diagram of the water level-available tank storage relationship curve; Figure 4 It is a schematic diagram of the canal section of the target digital twin irrigation area; Figure 5 It is the water level - available storage capacity curve of Canal Section 1 of the target digital twin irrigation area; Figure 6 It is the water level - discharge curve of Canal Section 1 of the target digital twin irrigation area; Figure 7 It is the flood inflow process into the canal. Specific implementation manners

[0009] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0010] Embodiment 1

[0011] The embodiment of the present invention provides an optimization method for flood control dispatching of the mountain - along canal system in a digital twin irrigation area, as Figure 1 shown, including the following steps: (1) Obtain the topological information and runoff - inflow information of the target digital twin irrigation area.

[0012] Among them, the topological information includes irrigation area terrain data, irrigation area canal system topological structure, irrigation area canal design parameters, check gate positions, flood discharge gate positions, etc. The runoff - inflow information includes rainfall, canal water level, monitored water flow, etc.

[0013] (2) According to the topological information of the target digital twin irrigation area, divide the target digital twin irrigation area into several canal sections, construct a one - dimensional hydrodynamic model for each canal section, and calculate the water level - available storage capacity relationship curve and water level - discharge curve of each canal section.

[0014] This step specifically includes: (2 - 1) According to the topological information of the channels in the target digital twin irrigation area, divide the channels into several canal sections with check gates as the dividing points; as Figure 2 shown; (2 - 2) Construct a one - dimensional hydrodynamic model for each canal section; among them, the one - dimensional hydrodynamic model can be represented by the Saint - Venant equations; (2 - 3) Solve the one - dimensional hydrodynamic model of each canal section to obtain the hydrodynamic process of the canal section under different initial water levels and different canal inflow conditions, that is, the water level change situation of the canal section under different initial water levels and different canal inflow conditions; (2 - 4) Obtain the available storage capacity of each canal section under different initial water levels and different canal inflow conditions according to the hydrodynamic process of the canal section, and fit it into a water level - available storage capacity relationship curve. The available storage capacity is the product of the duration from the current water level of the canal section rising to the warning water level and the canal inflow; The water level - available storage capacity relationship curve is as Figure 3As shown in (b), it is the storage volume in the canal for the inflow discharges from Q to Q + 5Δq, where Δq is the increase in discharge. (2 - 5) According to the hydrodynamic process of the canal section, obtain the water level lines of each canal section at different discharges under the condition that the downstream canal section regulating gate is opened, and fit them into the water level - discharge curve.

[0015] (3) According to the runoff - generation and concentration information of the target digital twin irrigation area, construct a runoff - generation and concentration prediction model for the target digital twin irrigation area to predict the flood process at different canal - inlet points.

[0016] This step specifically includes: (3 - 1) Establish a runoff - generation and concentration prediction model for the target digital twin irrigation area according to the runoff - generation and concentration information of the target digital twin irrigation area; among them, according to the runoff - generation and concentration information, model parameters such as the average tension water capacity, upper - layer, lower - layer, deep - layer tension water capacity, evaporation - transpiration conversion coefficient KC, and deep - layer evaporation - transpiration diffusion coefficient C can be calibrated, and a runoff - generation and concentration prediction model can be established according to the model parameters; (3 - 2) According to the runoff - generation and concentration prediction model of the target digital twin irrigation area, complete the evaporation - transpiration calculation, runoff - generation calculation, water - source separation calculation, and concentration calculation, so as to obtain the flood process at different future canal - inlet points, that is, the inflow discharge at each canal - inlet point in each time period.

[0017] (4) According to the flood - process prediction results, the water - level - available storage - volume relationship curve, and the water - level - discharge curve, set the scheduling strategies for each canal section by canal section.

[0018] This step specifically includes: (4 - 1) Judge whether there are multiple canal - inlet points in one canal section in the target digital twin irrigation area. If so, add the flood processes of all canal - inlet points belonging to the same canal section as one flood process. If each canal - inlet point is in a different canal section, take the flood process of each canal - inlet point as one flood process; (4 - 2) For each flood process, calculate the total inflow flood volume in the current flood process , and judge whether the total inflow flood volume exceeds the total flood - control volume or whether the peak - flood discharge exceeds the flood - control standard discharge of the canal, and query the water - level - discharge curve to judge whether the water level corresponding to the peak - flood discharge exceeds the warning water level; if so, execute (4 - 3), otherwise execute (4 - 4), represents the inflow discharge of the j - th canal - inlet point at the t - th time period, T represents the total number of time periods included in the current flood process, J represents the number of canal - inlet points belonging to the same canal section in the current flood process, is the time - period duration; (4-3) Set the scheduling strategy before the flood arrives as the first flood discharge operation strategy, that is: all flood discharge gates and check gates of each canal section downstream of the canal entry point are opened; thus emptying the canal for pre-discharge and making emergency disaster prevention preparations; at the end of the flood, when the future flood volume is less than the available storage capacity of the canal, appropriately store the flood and close the flood discharge gates and check gates step by step from downstream to upstream; (4-4)Set the scheduling strategy for each canal section according to the available storage capacity of the canal and the total incoming flood volume. The specific rules of the scheduling strategy are: when the total incoming flood volume is greater than or equal to the available storage capacity of the canal, perform flood discharge operations; when the total incoming flood volume is less than the available storage capacity of the canal, perform flood storage operations.

[0019] Step (4-4) specifically includes: (4-4-1)Divide the current flood process into M stages according to rising, peak, and falling, as shown in (a) of Figure 3 Set the initial value of the divided segment m to 1.

[0020] (4-4-2)For the mth stage, calculate the total incoming flood volume of the current stage according to the following formula , and the average incoming flow rate : , ,

[0021] In the formula, represents the flood flow rate at time t, represents the number of time periods included in the mth stage.

[0022] (4-4-3)For each canal section, find the corresponding water level - available storage capacity relationship curve, obtain the available storage capacity of each canal section under the average incoming flow rate and the preset initial water level, and calculate the sum of the available storage capacities of each canal section downstream of the canal entry point as the available storage capacity of the canal .

[0023] (4-4-4)Judge the size of the total incoming flood volume of the mth stage and the current available storage capacity of the canal : ① If , it is then determined whether there are subsequent flood stages after the m-th stage. If so, a second flood discharge operation is carried out, that is, the check gates are quickly opened from top to bottom, and flood discharge is carried out from the upstream channel section to the downstream channel section step by step. For adjacent channel sections, when the flood discharge capacity of the upstream channel section is insufficient and the water level in front of the check gate reaches the warning water level under the condition that the check gate is opened, the flood discharge gate of the upstream channel section is opened; when the downstream flood discharge capacity is insufficient and the water level in front of the check gate of the downstream check gate of the channel section reaches the warning water level, the flood discharge gate is opened. At the same time, when the capacity of the upstream channel section permits, the upstream check gate is closed, and the upstream channel section discharges flood through the flood discharge gate. The flood discharge gate discharges flood at the minimum value of the channel inflow value of the channel section and the maximum flow of the flood discharge gate. When m = 1, that is, the rising stage of the flood, the flood discharge gate of the channel in the initial state is in the closed state. If , the state of the channel gate at the beginning of the time period is the state adjusted in the previous time period. If m = M, that is, there is no next-stage flood, the scheduling strategy for this stage is set as the flood storage strategy, that is: close the flood discharge gates of all channel sections, close the upstream channel section check gates section by section from downstream to upstream, so that the water level in front of the check gate of each channel section reaches the warning water level one by one from downstream to upstream, and find the first channel section k that cannot reach the warning water level. According to the water level - available storage curve, calculate the water level in front of the check gate of channel section k in the current stage, and then the water level conditions of each channel section after scheduling can be obtained.

[0024] Among them, k is the channel section number that satisfies , , respectively represent the storage volumes of channel sections k and k' in the m-th stage. Specifically, it can be first determined whether is satisfied. If not, judge section by section up to the upstream channel section until , , to obtain channel section k, indicating that the downstream channel sections of channel section k are all full, and the water level of channel section k is calculated by the following formula: In the formula, , respectively represent the water levels of channel section k in the m-th and m - 1-th stages, represents the total flood inflow into the channel in the m - 1-th stage, , are the forward function and the inverse function of the water level - available storage relationship curve respectively.

[0025] ② If , then trace back from the (m - 1)-th stage, and adopt the pre-discharge operation strategy, that is, in the (m - 1)-th stage, open the flood discharge gates of all channel sections from upstream to downstream for pre-discharge, and close the flood discharge gates after the pre-discharge ends; and update the available storage volume of the channel according to the pre-discharge flow V m , and judge whether the updated channel inflow flood volume satisfies , if so, continue to backtrack to the previous stage m - 2 until reaching the first stage. If backtracking to m = 1 for pre - discharge still exists , then perform the second flood - discharge operation, that is, quickly open the check gates from top to bottom, and flood - discharge from the upstream channel sections to the downstream channel sections step by step. At the same time, open the flood - discharge gates to prevent over - flowing of the channel; if , then stop backtracking and jump to step ① to judge the subsequent stage.

[0026] Among them, the available storage volume of the channel is updated as follows: , , , In the formula, represents the pre - discharge flow rate at the (m - 1) - th stage, represents the flood inflow rate into the channel of the i - th upstream channel section of the (k + 1) - th channel section at the (m - 1) - th stage, represents the flood - discharge gate flow rate of the i - th upstream channel section of the (k + 1) - th channel section at the (m - 1) - th stage, I k represents the number of upstream channel sections of the (k + 1) - th channel section. When the channel sections are in parallel, I k > 1, when the channel sections are in series, I k = 1, C 1 represents the discharge coefficient without bottom sill, C 2 is the bottom - sill correction coefficient, C s is the submerged discharge coefficient, b is the width of the cross - sectional area of flow, e is the opening height of the gate, h is the upstream water depth including the velocity head of flow, h s is the tail - water depth above the sill, and g is the acceleration due to gravity.

[0027] (4 - 4 - 5) Set m = m + 1, and return to execute (4 - 4 - 2) until m = M to stop the loop.

[0028] (5) Construct a one - dimensional hydrodynamic model of the target digital twin irrigation area, and simulate the flood evolution process under different initial water levels according to the set scheduling strategy.

[0029] Specifically, taking different initial water levels and the flood inflow process into the channel as boundary conditions, according to the scheduling rules of the check gates and flood - discharge gates in the scheduling strategy of step (4), simulate and predict the flood evolution process with a certain time step. Calculate the water - level and flow - rate processes of typical channel cross - sections, the opening and closing times of the gates, the flood - discharge volume, and the water storage volume in the channel after the flood ends, so as to realize the flood - control pre - rehearsal of the channel.

[0030] (6) Determine whether all preset indicators in the simulation results of the flood evolution process meet the preset requirements. If not, update the scheduling strategy until the preset requirements are met. The scheduling strategy of each channel section at this time is used as the optimal scheduling plan.

[0031] For example, whether the channel overflows or other situations occur can be used as a preset indicator to judge, and whether the channel water storage capacity reaches the preset requirements after the flood ends can also be used as a preset indicator to judge. The scheduling strategy of the corresponding channel section can be updated according to the situation until the optimal scheduling plan is obtained.

[0032] Embodiment 2

[0033] The embodiment of the present invention provides a digital twin irrigation area along the mountain canal flood control dispatch optimization system. The system can be implemented in software and / or hardware, including: The information acquisition module is used to obtain the topological information and runoff information of the target digital twin irrigation area; The relationship curve fitting module is used to divide the target digital twin irrigation area into several canal sections according to the topological information of the target digital twin irrigation area, and to construct a one-dimensional hydrodynamic model of the canal section, and calculate the water level-available tank storage relationship curve and water level-flow curve of each canal section; The flood forecasting module is used to build a runoff forecasting model for the target digital twin irrigation area based on the runoff information of the target digital twin irrigation area, and to forecast the flood process at different inlet points; The scheduling strategy setting module is used to set the scheduling strategy for each channel section according to the flood process forecast results, the water level-available tank storage relationship curve and the water level-flow curve; The flood simulation module is used to construct a one-dimensional hydrodynamic model of the target digital twin irrigation area and simulate the flood evolution process under different initial water levels according to the set scheduling strategy; The scheduling optimization module is used to determine whether all preset indicators in the simulation results of the flood evolution process meet the preset requirements. If not, the scheduling strategy is updated until the preset requirements are met, and the scheduling strategy of each channel section at this time is used as the optimal scheduling plan.

[0034] Among them, the relationship curve fitting module specifically includes: The segmentation unit is used to divide the channel into several sections with the control gate as the dividing point according to the topological information of the channel of the target digital twin irrigation area; A model building unit, used for building a one-dimensional hydrodynamic model for each channel section; The hydrodynamic process solving unit is used to solve the one-dimensional hydrodynamic model of each channel section and obtain the hydrodynamic process of the channel section under different initial water levels and different inflow conditions; The water level - available storage capacity relationship curve fitting unit is used to obtain the available storage capacity of each canal section under different initial water levels and different canal inflow rates according to the hydrodynamic process of the canal section, and fit it into a water level - available storage capacity relationship curve. Among them, the available storage capacity is the product of the duration from the current water level of the canal section rising to the warning water level and the canal inflow rate; The water level - discharge curve fitting unit is used to obtain the water surface line of each canal section under different discharges under the condition that the regulating sluice of the downstream canal section is opened according to the hydrodynamic process of the canal section, and fit it into a water level - discharge curve.

[0035] Among them, the flood forecasting module specifically includes: The model establishment unit is used to establish a runoff - yield and concentration forecasting model for the target digital twin irrigation area according to the runoff - yield and concentration information of the target digital twin irrigation area; The flood process forecasting unit is used to complete evapotranspiration calculation, runoff - yield calculation, water source separation calculation and concentration calculation according to the runoff - yield and concentration forecasting model of the target digital twin irrigation area, so as to obtain the flood process of different future canal inlet points, that is, the canal inflow rate of each canal inlet point in each time period.

[0036] The scheduling strategy setting module specifically includes: The flood process confirmation unit is used to judge whether there are multiple canal inlet points in one canal section in the channels of the target digital twin irrigation area. If so, the flood processes of all canal inlet points belonging to the same canal section are added together as a flood process. If each canal inlet point is in a different canal section respectively, the flood process of each canal inlet point is used as a flood process; The judgment unit is used to calculate the total canal inflow volume in the current flood process for each flood process and judge whether the total canal inflow volume exceeds the total flood control volume or whether the peak flood flow exceeds the flood control standard flow of the channel; query the water level - discharge curve to judge whether the water level corresponding to the peak flood flow exceeds the warning water level; if so, the first flood discharge operation strategy unit, otherwise execute the scheduling strategy determination unit; The first flood discharge operation strategy unit is used to set the scheduling strategy before the flood comes as the first flood discharge operation strategy, that is: all flood discharge sluices and regulating sluices of the downstream canal sections of the canal inlet points are opened for pre - discharge; The scheduling strategy determination unit is used to obtain the available storage capacity of the channel according to the water level - available storage capacity relationship curve, and set the scheduling strategy of each canal section according to the size of the available storage capacity of the channel and the total canal inflow volume. The rules of the scheduling strategy are specifically: when the total canal inflow volume is greater than or equal to the available storage capacity of the channel, flood discharge operation is carried out. When the total canal inflow volume is less than the available storage capacity of the channel, flood storage operation is carried out. Among them, the available storage capacity of the channel is the sum of the storage capacities of the downstream canal sections of the canal inlet points.

[0037] The scheduling strategy determination unit specifically includes: The stage division sub - unit is used to divide the current flood process into M stages according to the rising, peak, and falling stages, and set the initial value of the stage number m to 1; The canal inflow and total volume calculation sub - unit is used to calculate the total flood volume flowing into the canal in the current stage for the m - th stage and calculate the average canal inflow according to the total flood volume flowing into the canal ; The available storage volume of the canal calculation sub - unit is used to, for each canal section, find the corresponding water level - available storage volume relationship curve, obtain the available storage volume of each canal section under the conditions of the average canal inflow and the preset initial water level, and calculate the sum of the available storage volumes of each canal section downstream of the canal entry point as the available storage volume of the canal ; The first judgment sub - unit is used to judge the size of the total flood volume flowing into the canal in the m - th stage and the current available storage volume of the canal ; The second judgment sub - unit is used to, if , judge whether there are subsequent flood stages after the m - th stage; If there are subsequent flood stages after the m - th stage, set the scheduling strategy for the m - th stage as the second flood - discharging operation strategy, that is: quickly open the check gates from top to bottom, and the upstream canal sections discharge flood to the downstream canal sections step by step; If there are no subsequent flood stages after the m - th stage, that is, when m = M, set the scheduling strategy for the m - th stage as the flood - storage strategy, that is: close the flood - discharging gates of all canal sections, close the check gates of the upstream canal sections from downstream to upstream for each canal section, so that the water levels in front of the check gates of each canal section reach the warning water level one by one from downstream to upstream, and find the first canal section k that cannot reach the warning water level, and calculate the water level of canal section k according to the water level - available storage volume curve; The third judgment sub - unit is used to, if , trace back from the m - 1 stage forward, and set the scheduling strategy for the m - 1 stage as the pre - discharging operation strategy, that is, in the m - 1 stage, open the flood - discharging gates of all canal sections from upstream to downstream for pre - discharging, and close the flood - discharging gates after pre - discharging; and update the available storage volume of the canal according to the pre - discharging flow V m , judge whether the updated flood volume flowing into the canal of the canal meets , if so, continue to trace back to the m - 2 stage until tracing back to the 1st stage. If there is still when pre - discharging at the 1st stage, then set the scheduling strategy for the m - th stage as the second flood - discharging operation strategy; until , stop tracing back; execute the traversal judgment sub - unit; The traversal judgment sub - unit is used to set m = m + 1, return to execute the canal inflow and total volume calculation sub - unit, and stop the loop until m = M.

[0038] The system provided by the embodiments of the present invention can be used to execute the method provided by the first embodiment of the present invention, and has the corresponding functions and beneficial effects for executing the method.

[0039] It should be noted that in the embodiments of the above system, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific names of the functional units are only for the convenience of mutual distinction and do not limit the protection scope of the present invention.

[0040] The embodiments described above are only illustrative. The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed to multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented only by hardware, as long as the functions or effects can be achieved.

[0041] Next, a simulation of the present invention is carried out, taking the canal system flood control and operation of a certain target digital twin irrigation area as an application case. In this irrigation area, sectional flood control limited water levels are set for the management sections of the main canal and the first and second main canals with flood discharge regulation facilities, and the operation responsibility systems of the check gates and flood discharge gates are strictly implemented to adjust the water diversion at any time. During the main flood season, special personnel are assigned to be on duty day and night at each water level observation point, and accurate water level records are reported to the water regime group of the central flood control headquarters at 8:00, 12:00, and 18:00 every day.

[0042] Some canal sections of the target digital twin irrigation area are selected for case application. According to the topological division, there are a total of 4 canal sections, as Figure 4 shown. The designed top width of the canal section is 8m, the designed bottom width is 8m, the depth of the canal is 4.3m, and the design parameters of the check gate and flood discharge gate are shown in Table 1. A one-dimensional hydrodynamic model is constructed to calculate the water level-available storage relationship curve and water level-discharge relationship curve of each canal section respectively. Figure 5 is the water level-available storage relationship curve of the target digital twin irrigation area, and Table 2 is the corresponding data. It can be seen that as the inflow into the canal increases, the available storage corresponding to the unit water level increment decreases. Figure 6 is the water level-discharge relationship curve of the target digital twin irrigation area, showing the relationship that the higher the flow rate, the higher the water level. In this embodiment, taking an inflow flood at one point as an example, the inflow flood process is calculated at the canal inlet point of the canal section, as Figure 7As shown in the figure, the flood process is segmented according to the rising stage - peak stage - falling stage, with a total of 6 segments. According to the flood forecast and the segmentation results, scheduling strategies are set for each canal section, and the flood storage volume, flood discharge volume, opening and closing states of the check gates and flood discharge gates of each canal section are calculated. The available storage volume of the canal section and the water level in front of the gates are updated stage by stage. The scheduling results are shown in Tables 3 and 4. The full flood discharge strategy (that is, the flood is discharged according to the flood discharge capacity of each canal section at each stage after the flood enters the canal, and the remaining flood volume after the flood ends is the stored flood volume) and the full storage and flood discharge strategy (that is, each channel stores flood from downstream to upstream section by section. If the incoming flood volume is greater than the available storage volume, flood discharge operations are carried out) are compared with the strategy of the present invention. It can be analyzed from the results that for the forecast flood of the embodiment, the full storage and flood discharge strategy fails to pre-discharge and empty the reservoir capacity during the rising stage of the flood. When dealing with a flood volume of 450,000 in segment 2, the overall available storage volume is insufficient, resulting in a flood volume of 11,970 m 3 overflowing the canal, and the flood storage volume at the end of the flood reaches 363,150 m 3 . The full flood discharge strategy adopts the form of fully opening the flood discharge gates to discharge the flood stage by stage, achieving full flood discharge for the forecast flood of the embodiment, and storing the flood at the end of the flood, with a flood storage volume of 96,480 m 3 . The strategy of the present invention effectively conducts flood discharge scheduling based on the forecast flood and stores the flood at the end of the flood, realizing the utilization of flood resources. It can be seen from Table 4 that the strategy of the present invention opens and closes the check gates and flood discharge gates according to the flood stage. The flood discharge operations are interspersed in different stages of the flood, ensuring the flood control safety of the channel while appropriately storing the flood volume and intercepting the rain and flood resources.

[0043] Table 1 Gate design parameters Gate Name Elevation (m) Design Discharge Number of Holes Hole Width Hole Height Length Check Gate of Canal Section 1 470.710 20 3 2 6 3 Check Gate of Canal Section 2 470.410 20 3 2 6 3 Check Gate of Canal Section 3 469.380 20 3 2 6 3 Check Gate of Canal Section 4 468.950 20 3 2 6 3 Flood Discharge Gate of Canal Section 1 470.710 20 1 2 6 3 Flood Discharge Gate of Canal Section 2 469.850 20 1 2 6 3 Flood Discharge Gate of Canal Section 3 468.920 20 1 2 6 3 Flood Discharge Gate of Canal Section 4 468.950 20 1 2 6 3 Table 2 Relationship between water level and available storage volume of Canal Section 1 in the target digital twin irrigation area

[0044] Table 3 Calculation results of gate opening and closing

[0045] Table 4 Calculation results of gate opening and closing

[0046] It should be understood that the above embodiments and the descriptions in the specification only illustrate the principles, main features and advantages of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the protection scope of the present invention.

Claims

1. A method for optimizing flood control scheduling of the mountain-channel system in a digital twin irrigation area, characterized in that, It includes the following steps: (1) Obtain the topological information and runoff-yield and concentration information of the target digital twin irrigation area; (2) According to the topological information of the target digital twin irrigation area, divide the target digital twin irrigation area into several canal sections, construct a one-dimensional hydrodynamic model for each canal section, and calculate the water level-available storage relationship curve and water level-discharge curve of each canal section; (3) According to the runoff-yield and concentration information of the target digital twin irrigation area, construct a runoff-yield and concentration prediction model for the target digital twin irrigation area to predict the flood process at different canal inlet points; (4) According to the flood process prediction results, water level-available storage relationship curve and water level-discharge curve, set the scheduling strategies for each canal section by canal section; (5) Construct a one-dimensional hydrodynamic model for the target digital twin irrigation area, and simulate the flood evolution process at different initial water levels according to the set scheduling strategies; (6) Judge whether all preset indicators in the simulation results of the flood evolution process meet the preset requirements. If not, update the scheduling strategies until the preset requirements are met, and use the scheduling strategies of each canal section at this time as the optimal scheduling plan.

2. The digital twin irrigation area mountain canal system flood control operation optimization method according to claim 1, wherein Step (2) specifically includes: (2-1) According to the topological information of the channels in the target digital twin irrigation area, divide the channels into several canal sections with the check gates as the dividing points; (2-2) Construct a one-dimensional hydrodynamic model for each canal section; (2-3) Solve the one-dimensional hydrodynamic model of each canal section to obtain the hydrodynamic process of the canal section under different initial water levels and different canal inlet flows; (2-4) Obtain the available storage of each canal section under different initial water levels and different canal inlet flows according to the canal section hydrodynamic process, and fit it into a water level-available storage relationship curve, where the available storage is the product of the duration from the current water level of the canal section rising to the warning water level and the canal inlet flow; (2-5) Obtain the water surface profile of each canal section at different flows under the condition that the check gate of the downstream canal section is opened according to the canal section hydrodynamic process, and fit it into a water level-discharge curve.

3. The digital twin irrigation area mountain canal system flood control scheduling optimization method according to claim 1, characterized in that, Step (3) specifically includes: (3-1) Establish a runoff-yield and concentration prediction model for the target digital twin irrigation area according to the runoff-yield and concentration information of the target digital twin irrigation area; (3-2) Complete evapotranspiration calculation, runoff-yield calculation, sub-source calculation and concentration calculation according to the runoff-yield and concentration prediction model of the target digital twin irrigation area, so as to obtain the flood process at different future canal inlet points, that is, the canal inlet flow at each canal inlet point in each time period.

4. The digital twin irrigation area mountain canal system flood control scheduling optimization method according to claim 1, characterized in that Step (4) specifically includes: (4-1) Judge whether there are multiple canal inlet points in one canal section in the channels of the target digital twin irrigation area. If so, add the flood processes of all canal inlet points belonging to the same canal section as one flood process. If each canal inlet point is in a different canal section, use the flood process of each canal inlet point as one flood process; (4-2) For each flood event, calculate the total flood volume entering the canal during the current flood event , and determine whether the total flood volume entering the canal exceeds the total flood control volume or whether the peak flood discharge exceeds the flood control standard discharge of the canal. Query the water level-discharge curve to determine whether the water level corresponding to the peak flood discharge exceeds the warning water level; if so, execute (4-3), otherwise execute (4-4); (4-3) Set the scheduling strategy before the flood comes as the first flood discharge operation strategy, that is: all flood discharge gates and check gates of the canal sections downstream of the canal inlet point are opened for pre-discharge; (4-4) The available channel storage capacity is obtained according to the water level-available channel storage capacity relationship curve, and the scheduling strategy of each channel section is set according to the available channel storage capacity and the total flood volume entering the channel. The specific rules of the scheduling strategy are: when the total flood volume entering the channel is greater than or equal to the available channel storage capacity, flood discharge operation is performed; when the total flood volume entering the channel is less than the available channel storage capacity, flood storage operation is performed, wherein the available channel storage capacity is the sum of the channel storage capacities of each channel section downstream of the channel entry point.

5. The digital twin irrigation area mountain canal system flood control scheduling optimization method according to claim 4, characterized in that Step (4-4) specifically includes: (4-4-1) Divide the current flood process into M stages according to the rise, peak and fall, and set the initial value of the stage number m to 1; For the m-th stage, calculate the total incoming flood water volume of the current stage , and calculate the average incoming flow rate based on the total incoming flood water volume ; (4-4-3) For each channel segment, find the corresponding water level - available storage volume relationship curve, obtain the available storage volume of each channel segment under the conditions of average inflow and preset initial water level, and calculate the sum of the available storage volumes of each channel segment downstream of the inflow point as the available storage volume of the channel ; (4-4-4) Determine the total incoming flood volume at the m-th stage and the available storage volume in the current channel for their magnitudes: ① If , then determine whether there is a subsequent flood stage after the m-th stage; If there is a subsequent flood stage after the mth stage, the dispatching strategy of the mth stage is set as the second flood discharge operation strategy, that is, the control gate is opened quickly from top to bottom, and the upstream channel section discharges flood water to the downstream channel section step by step; If there is no subsequent flood stage after the mth stage, that is, when m=M, the scheduling strategy of the mth stage is set as the flood storage strategy, that is: close the flood discharge gates of all canal sections, close the upstream canal section control gates from downstream to upstream, so that the water level in front of the control gates of each canal section reaches the warning water level one by one from downstream to upstream, and find the first canal section k that cannot reach the warning water level, and calculate the water level of canal section k according to the water level-available channel storage curve; ② If , then trace back from the (m - 1)-th stage. Set the scheduling strategy of the (m - 1)-th stage as the pre-discharge operation strategy, that is, open the flood discharge sluices of all canal sections from upstream to downstream for pre-discharge in the (m - 1)-th stage, and close the flood discharge sluices after the pre-discharge ends; and update the available storage capacity of the channel according to the pre-discharge flow rate V m , and judge whether the incoming flood volume of the updated channel satisfies . If so, continue to trace back to the (m - 2)-th stage until tracing back to the 1st stage. If there is still when pre-discharging at the 1st stage, then set the scheduling strategy of the m-th stage as the second flood discharge operation strategy; until , stop tracing back; (4-4-5) Set m=m+1 and return to execute (4-4-2) until m=M and the loop stops.

6. The digital twin irrigation area mountain canal system flood control scheduling optimization method according to claim 5, characterized in that: The total flood water volume flowing into the canal described in step (4-4-2) is calculated by the following formula: ， In the formula, represents the flood flow in the t time period, represents the duration of the time period, represents the number of time periods included in the m-th stage; The average inlet flow is calculated by the following formula: ， In the formula, represents the average inflow rate into the canal at the m-th stage.

7. The digital twin irrigation area mountain canal system flood control scheduling optimization method according to claim 5, characterized in that: The available storage volume of the channel Is updated according to the following formula: ， ， In the formula, represents the pre-discharge flow rate at the (m - 1)-th stage, represents the flood inflow rate into the i-th upstream channel section of channel section k + 1 at the (m - 1)-th stage, represents the flood discharge gate flow rate of the i-th upstream channel section of channel section k + 1 at the (m - 1)-th stage, I k represents the number of upstream channel sections of channel section k + 1.

8. The digital twin irrigation area mountain canal system flood control scheduling optimization method according to claim 7, characterized in that, The calculation formula for the discharge of the flood discharge gate of the ith upstream channel section k+1 in the m-1th stage is: ， In the formula, C 1 represents the discharge coefficient without a bottom sill, C 2 is the bottom sill correction coefficient, C s is the submerged discharge coefficient, b is the width of the cross-section of the flowing water, e is the opening height of the gate, h is the upstream water depth including the velocity head of the approaching flow, h s is the tail water depth above the sill, and g is the acceleration due to gravity.

9. The digital twin irrigation area mountain canal system flood control scheduling optimization method according to claim 5, wherein (4-4-4) The water level of the middle channel section k is calculated by the following formula: In the formula, and respectively represent the water levels of the k-th channel section at the m-th and (m - 1)-th stages, represents the total inflow flood volume into the channel at the (m - 1)-th stage, and are respectively the forward function and the reverse function of the water level - available storage relationship curve.

10. A digital twin irrigation area mountain canal system flood control and operation optimization system, characterized in that, include: The information acquisition module is used to obtain the topological information and runoff information of the target digital twin irrigation area; The relationship curve fitting module is used to divide the target digital twin irrigation area into several canal sections according to the topological information of the target digital twin irrigation area, and to construct a one-dimensional hydrodynamic model of the canal section, and calculate the water level-available tank storage relationship curve and water level-flow curve of each canal section; The flood forecasting module is used to build a runoff forecasting model for the target digital twin irrigation area based on the runoff information of the target digital twin irrigation area, and to forecast the flood process at different inlet points; The scheduling strategy setting module is used to set the scheduling strategy for each channel section according to the flood process forecast results, the water level-available tank storage relationship curve and the water level-flow curve; The flood simulation module is used to construct a one-dimensional hydrodynamic model of the target digital twin irrigation area and simulate the flood evolution process under different initial water levels according to the set scheduling strategy; The scheduling optimization module is used to determine whether all preset indicators in the simulation results of the flood evolution process meet the preset requirements. If not, the scheduling strategy is updated until the preset requirements are met, and the scheduling strategy of each channel section at this time is used as the optimal scheduling plan.

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