Method for optimizing layout of slope farmland catchment pool based on impoundment matching constraint

Abstract

The application discloses a slope farmland catchment pool layout optimization method based on irrigation and storage matching constraints, relates to the technical field of agricultural water conservancy engineering, and comprises the following steps: generating a water demand curve and an event storage sequence in a unified object, explicitly deducting evaporation, seepage and siltation to form an effective irrigable water volume, and determining a minimum effective water head; constructing an irrigation and storage matching constraint family: taking a key window period water supply reliability, an allowable level of flow abandonment and the minimum effective water head to uniformly act on the effective irrigable water volume to generate a feasible region and an infeasible boundary; progressively solving: determining a service domain mapping in the feasible region, and obtaining pool positions and pool capacities by the shortest delivery path and the minimum effective water head, and calculating a minimum nominal pool capacity; solidifying implementation: deriving seasonal rule curves and pre-discharge water carrying strategies from the optimized solution, setting overflow trigger conditions, and giving pre-sedimentation schemes, lining schemes and monitoring points to realize design operation linkage delivery.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of agricultural water conservancy, in particular to a slope farmland catchment pool layout optimization method based on irrigation and storage matching constraints. BACKGROUND

[0002] In a Chinese invention patent with the application publication number CN109376902A, a slope farmland ridge and furrow layout optimization method for crop water demand process is disclosed. First, according to the precipitation data and the crop growth period, a typical crop dry year is determined. Then, according to the crop water demand, evaporation data and precipitation data, the key field precipitation is determined. Based on this, the relevant parameters of the ridge and furrow layout are determined by comparing the theoretical ridge and furrow storage maximum value with the key field precipitation and the relationship between the infiltration amount and the evaporation amount during the rainfall period, combining the slope farmland water balance formula. This method fully considers the crop water demand, focuses on the precipitation characteristics of the crop dry year, can significantly improve the rainwater utilization rate in arid and semiarid areas, and improves the crop yield.

[0003] In the production scene of slope farmland rainwater utilization and supplemental irrigation, small catchment pools are often arranged to intercept runoff and supply water in the critical growth period. Existing projects often follow the general pond specification and experience scheduling, runoff estimation mainly uses the event method or empirical runoff coefficient, and site selection mainly depends on static indicators such as catchment area, slope, and construction convenience. Although the single body is checked sufficiently, the pool group cooperation is not paid enough attention. The common method does not align the time period water demand curve and the event storage sequence in the same time resolution, and the evaporation, leakage and sedimentation losses are often corrected after the operation period. The minimum effective water head and the pipe network path are not coupled enough, the service domain mapping is random, and it is difficult to form a traceable pool position-pool capacity-service domain integrated logic. The overflow trigger condition, water quality and sediment control, and monitoring point are also disconnected from the design, resulting in frequent abandoned flow, high energy consumption, rapid capacity attenuation, and unverifiable operation rules.

[0004] However, irrigation and storage lack calculable irrigation and storage matching constraints, which leads to the time and space mismatch formed in the layout stage to be exposed in the operation period. It is caused by the natural inconsistency between the time structure and the spatial accessibility of the event storage sequence formed by the short duration peak of the slope farmland rainfall and the time period water demand curve composed of the critical window period of crop water use. It occurs in the design which only determines the pool position and pool capacity according to the average inflow or the maximum catchment scale in a year, without taking the effective irrigable water volume as a unified object, without constructing the candidate solution feasible region with the critical window period water supply reliability and the abandoned flow allowable level, and without constraining the service domain mapping and the shortest delivery path with the minimum effective water head. The consequence is that in the scene where strong convective rain and land fragmentation coexist, individual pools frequently overflow and abandon flow while the window period is short of water, the self-flowing proportion decreases, leading to the increase of non-conventional pumping and leakage risk, the pre-sedimentation scheme and the lining scheme lagging behind, causing rapid capacity attenuation, seasonal rule curve difficult to execute, and the overall water supply reliability and operation economy declining simultaneously. SUMMARY

[0005] (I) Technical problems solved

[0006] In view of the deficiencies of the prior art, the present application provides a slope farmland catchment pool layout optimization method based on irrigation and storage matching constraints, which forms effective irrigable water volume by including generation period water demand curve and event storage sequence, explicitly deducting evaporation, seepage and sedimentation, and determining the minimum effective water head; the key window period water supply reliability, the allowable level of flow abandonment and the minimum effective water head uniformly act on the effective irrigable water volume to generate a feasible region and an infeasible boundary; the service domain mapping is determined in the feasible region, and the pool position and pool capacity are obtained by solving the minimum effective water head with the shortest delivery path, and the minimum nominal pool capacity is calculated; the seasonal rule curve and the pre-discharge water carrying strategy are derived from the optimal solution, the overflow trigger condition is set, and the pre-sedimentation scheme, the lining scheme and the monitoring point are given, and the design operation linkage delivery is realized; thereby solving the technical problems recorded in the background art.

[0007] (II) Technical solutions

[0008] To achieve the above purpose, the present application is implemented by the following technical solutions: a slope farmland catchment pool layout optimization method based on irrigation and storage matching constraints, including generating a period water demand curve and an event storage sequence, defining effective irrigable water volume by evaporation, seepage and sedimentation reduction, extracting terrain elevation data and irrigated land block elevation, determining whether the minimum effective water head is reachable, and forming a unified time resolution basis data for pool position-pool capacity-service domain solution;

[0009] The key window period water supply reliability, the allowable level of flow abandonment and the minimum effective water head constitute the irrigation and storage matching constraint family, which uniformly acts on the effective irrigable water volume; according to the period water demand curve and the event storage sequence, the candidate solution feasible region is generated and the infeasible boundary is marked;

[0010] The pool position-pool capacity-service domain is progressively solved in the candidate solution feasible region: first, the service domain mapping is determined according to the key window period water use intensity and the block adjacency relationship, then the pool position and pool capacity are determined by the minimum effective water head and the shortest delivery path, the minimum nominal pool capacity is calculated and the optimal solution set is formed;

[0011] The seasonal rule curve and the pre-discharge water carrying strategy are derived from the optimal solution set, the upper and lower limits of the target water level of each pool are determined according to the minimum nominal pool capacity and the water level-storage function, and the overflow trigger condition is set; the pool position-pool capacity-service domain and the seasonal rule curve form an implementation file.

[0012] Further, the period water demand curve is generated according to crop evapotranspiration and crop coefficient in a unified time step, and is marked on the growth period with key window period weight kernel;

[0013] The event inflow sequence is obtained by rainfall intensity, infiltration and runoff time distribution transformation; evaporation, leakage and silt reduction are deducted in time and recorded corresponding to the effective irrigable water volume.

[0014] Further, the accessibility of the minimum effective water head is determined by the difference between the terrain equipotential difference and the elevation of the irrigated land block. When the equipotential difference from the pool to the land block is not less than the minimum effective water head, it is recorded as accessible, and the accessible mapping set is formed as the upper limit set of the subsequent service domain mapping.

[0015] Further, the key window period water supply reliability is defined by the satisfaction ratio of the effective irrigable water volume to the time period water demand curve in the key window period set;

[0016] The allowable level of abandoned flow is limited by the proportion of the potential oversupply volume in the cumulative volume after deducting the loss of the event inflow sequence in the evaluation time domain, and the candidate solution feasible region is generated accordingly.

[0017] Further, the candidate solution feasible region needs to meet the inclusion relationship of the accessible mapping set and the threshold constraints of the key window period water supply reliability lower limit and the abandoned flow allowable level upper limit;

[0018] And mark the infeasible boundary when the reliability hits the bottom, the abandoned flow hits the top or the minimum effective water head is insufficient, record the failure reason of the corresponding pool-land boundary.

[0019] Further, the service domain mapping is minimized in the accessible mapping set with the path impedance composed of water head margin and shortest delivery path as the target, and the coverage constraint that each irrigated land block is covered by at least one pool body is applied; The service domain mapping is only composed of pool-land boundaries that meet the minimum effective water head.

[0020] Further, the minimum nominal pool capacity is calculated by the upper bound of cumulative surplus, and in the evaluation time domain, the event inflow sequence is sequentially deducted by the service domain demand summarized by the service domain mapping, evaporation loss, leakage loss and dynamic silt effective coefficient, and the upper bound of non-negative cumulative surplus is taken as the lower bound of the capacity of each pool body.

[0021] Further, the screening of the preferred solution set takes the synthesis target of normalized path impedance total amount and inflow connectivity indicator as the minimization criterion, completes the pool site selection within the candidate solution feasible region and with the service domain mapping as the fixed input, and generates the pre-sedimentation scheme requirement label for channels with significant peak value of runoff time distribution.

[0022] Further, the lower limit of the target water level of the seasonal rule curve is determined according to the proportion of the cumulative gap of the service domain demand and the effective available irrigation water in the key window period to the minimum nominal pool capacity, and is inversely calculated into a water level sequence through the water level-storage function, for describing the lower rail of the target water level of each pool.

[0023] Further, the upper limit of the target water level is determined by the buffer proportion of the allowable spillage level and the inflow connectivity indicator, and a spillway trigger condition is set at the upper limit of the target water level; the pre-discharge water-carrying strategy is directed back to supply in sequence according to the service domain mapping and the shortest delivery path when the measured water level exceeds the upper limit of the target water level.

[0024] (Three) beneficial effects

[0025] The application provides a slope farmland catchment pool layout optimization method based on irrigation and storage matching constraints, which has the following beneficial effects:

[0026] The loss is explicitly taken into account in the effective available irrigation water, and the minimum effective water head is determined in combination with the terrain elevation data and the elevation of the irrigated land block, so as to eliminate unit conversion errors and information fragmentation, directly support subsequent comparison and calling, and significantly improve the matching accuracy and availability of the period water demand curve and the event inflow sequence.

[0027] The irrigation and storage matching constraint family is constructed, and the candidate solution feasible region and the infeasible boundary are generated, so that the water supply reliability in the key window period and the allowable spillage level become detectable criteria, and the spillway trigger condition is synchronously associated, so as to exclude combinations that cannot meet the window demand or have systemic oversupply risk in advance, and reduce the uncertainty of subsequent engineering iteration and review.

[0028] In the candidate solution feasible region, the service domain mapping is prioritized, and the pool site and pool capacity are determined according to the shortest delivery path and the minimum effective water head, so that the combination of pool site-pool capacity-service domain is optimal in both dynamics and geometry, and the calculation of the minimum nominal pool capacity avoids the virtual high of the nominal storage capacity, improves the self-flowing proportion, and reduces the energy consumption and pipeline maintenance risk.

[0029] The lower limit and the upper limit of the target water level of the seasonal rule curve are derived from the service domain demand summary and the inflow characteristics, and the pre-discharge water-carrying strategy is developed accordingly, so that the operation side has a clear time sequence control boundary, can supply back in advance to suppress spillage at the upper limit in the wet period, and can guarantee the available water quantity at the lower limit in the key window period, and forms an executable field instruction with the spillway trigger condition, the monitoring point and the compliance residual error.

[0030] The pre-sedimentation scheme demand index is constructed by the proportion of inflow connectivity indication quantity and effective storage capacity, and is landed together with the lining scheme, so that the high connectivity inflow channel is configured with targeted sand blocking and seepage prevention, the storage capacity attenuation is delayed, the time sequence supply capacity of effective irrigable water is stabilized, the operation and maintenance burden of dredging and water quality treatment is reduced, and the continuous accessibility of seasonal regular curve is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 A flowchart of a slope farmland catchment pool layout optimization method based on irrigation and storage matching constraints is provided. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0033] Please refer to Figure 1 The present application provides a slope farmland catchment pool layout optimization method based on irrigation and storage matching constraints, comprising,

[0034] In step one, the time period water demand curve and the event storage sequence are unified to the same time resolution and dimension, and the effective irrigable water is defined on the same data object level. Whether the minimum effective water head is reachable is determined from the terrain elevation data and the irrigated land block elevation, so as to provide the basis input which can be directly called and has consistent name for the subsequent solution of pool position-pool capacity-service domain.

[0035] To this end, taking the land block index and the pool body index as the main line, the time period water demand curve with key window period memory is first constructed on the demand side, then the event storage sequence is generated on the supply side according to the confluence time delay structure, then the effective irrigable water is defined in the explicit loss manner, and the reachability criterion of the minimum effective water head is given by the terrain elevation data and the irrigated land block elevation.

[0036] In step one, the time period water demand curve, the event storage sequence and the effective irrigable water are constructed on the same time axis and dimension, and the reachability of the minimum effective water head is determined, so as to form the basis data required for the solution of the pool position-pool capacity-service domain.

[0037] The windowing of the demand side and the pulsing of the supply side are the essential conflicts of the water resources redistribution of the slope farmland. If the two are not modeled in the design side, any subsequent constraints will lack a common reference object. Therefore, the time period water demand curve is generated in the unit of land, and the event storage sequence is generated in the unit of pool in the same time resolution, so that they can be compared and measured by time, thereby providing a solid premise for the subsequent definition of effective irrigable water and minimum effective water head determination.

[0038] First, the time period water demand curve is constructed by convoluting the reference evapotranspiration and the crop coefficient with the key window weight check. Then, the event storage sequence is obtained by time delay transformation of the difference between rainfall and infiltration with the flow concentration time distribution. Both of them are expressed in the same time step and immediately registered with the index to ensure that they can be directly aligned and called.

[0039] To avoid breaking down the key window period information into several static coefficients, the key window weight kernel is introduced at the land scale, so that the product of the reference evapotranspiration and the crop coefficient is windowed and smoothed in time, thereby obtaining a time period water demand curve that reflects the window superposition effect. This processing replaces the empirical segmented weight list with a window kernel, reduces the stacking of adjustment factors, and maintains continuous response to growth progress and meteorological fluctuations, so it can be directly compared with the event storage sequence in time, where: ; The time period water demand curve : Land index of the demand side timing, ; Crop reference evapotranspiration : Land index of the reference evapotranspiration timing, , providing atmospheric evapotranspiration driving; crop coefficient : Land index of the time variable coefficient, ; Key window weight kernel : Land index of the window kernel, , satisfying , weighted sampling and smoothing in time on the neighborhood of the key window period.

[0040] The time period water demand curve expresses the impact of the key window period with continuous convolution, so it has a sensitive response to short-term evapotranspiration peaks caused by concentrated heat and wind field, thereby enabling subsequent constraints to accurately target the window period; the convolution structure in the same time resolution reduces the artificial segmented weight, avoids misjudgment caused by unclear parameter reference, and is conducive to embedding the demand side directly into the generation of the feasible region of the candidate solution.

[0041] Instead of approximating with a single runoff coefficient, the supply side describes the migration and convergence of slopes and channels using the confluence time distribution, thus expressing the time delay and diffusion of event generation and confluence without introducing redundant adjustment factors. At the pool scale, the difference between rainfall intensity and infiltration intensity is used as the source term, and a convolution transformation is performed through the confluence time distribution to form the event ingestion sequence for the pool, where:

[0042] In the formula: the sequence of events entered into the database. Pool Index The order of entry into the warehouse Rainfall intensity Regional-scale rainfall time series Infiltration intensity Pool Index infiltration timing, Reduce supply-side runoff, affected by soil layer and previous water content; positive part operator Operators that take zero for negative values ​​are guaranteed to be physically nonnegative;

[0043] Convergence Time Distribution Pool Index Time distribution, ,satisfy This expresses the time delay and diffusion of the confluence path.

[0044] When used, the event sequence stored in the database has the ability to distinguish rainfall duration, peak interval and upstream infiltration changes, avoiding the compression of diverse rainfall patterns into a single event quantity, improving the timing accuracy of matching. The normalization condition of the confluence time distribution ensures that it is comparable in dimensionality to the water demand curve generated by the demand side convolution, paving the way for subsequent hourly difference and integral calculations.

[0045] After achieving a unified representation of both the demand and supply sides, if the reduction in effective storage capacity caused by evaporation, leakage, and siltation is not directly incorporated into the same object, any subsequent constraints may be based on nominal inflows and nominal storage capacity, leading to a disconnect between design and operation. Therefore, defining the effective irrigation volume within a unified time step and determining whether the minimum effective head is achievable using topographic elevation data and the elevation of the irrigated plot ensures that physical accessibility and dimensionally unified available quantity are established at the same level.

[0046] First, the effective irrigable water capacity is defined by explicit loss reduction, and then the topographic equipotential difference is used to construct the accessibility criterion of minimum effective water head. The outputs of the two will be used as the only object and necessary condition for constructing constraints. To avoid post-loss as an empirical correction, the effective storage capacity reduction caused by evaporation, seepage and sedimentation is explicitly displayed on the time axis, and the effective irrigable water capacity is defined in the integral form of uniform time step, making it the only measurement object of subsequent constraints. This definition naturally accommodates the pulse nature of the event storage sequence and the window nature of the period water demand curve, thereby achieving consistency in dimension and time.

[0047] ; In the formula: effective irrigable water capacity : pool index The available volume at time step , ; Dynamic sedimentation effective coefficient : effective storage capacity coefficient of pool index , ; Time step : uniform calculation step, Convert instantaneous flow to time step volume; evaporation loss : evaporation flux of pool index , ; Seepage loss : seepage flux of pool index , , deduct the bottom and lateral seepage; event storage sequence : storage timing of pool index , ;

[0048] When used, the effective irrigable water capacity directly binds the supply end and the loss process into a single object, and all subsequent constraints only need to face this object, without the need to convert between multiple objects. The time step integral form makes the contribution of pulse storage to window demand comparable on the same scale, thereby avoiding unit inconsistency when constructing constraints. The introduction of dynamic sedimentation effective coefficient does not depend on external empirical adjustment, but as a physical proportion quantity into the expression, which is convenient for updating with monitoring points in the operation period.

[0049] To screen out physically inaccessible pool maps at the early stage of design, construct the equipotential difference with topographic elevation data and the elevation of irrigated land, and use the minimum effective water head as the criterion to generate accessibility indicator. This process can give preliminary screening results after aerial survey or surveying and mapping without relying on complex energy loss models, saving search cost for subsequent pool-site-pool-capacity-service-domain solution, wherein:

[0050] ; ; In the formula: topographic equipotential difference : pool index relative block index isopotential difference; pool body water surface elevation : pool body index water surface elevation; irrigated block elevation : block index surface elevation; accessibility indicator : binary indicator, whether the minimum effective water head is met; minimum effective water head : criterion threshold, ensuring the minimum water head required for gravity flow and end-of-line conditions;

[0051] In use, the accessibility indicator establishes clear feasibility boundaries for pool-ground mapping in space, enabling direct exclusion of infeasible mappings when constructing constraints subsequently. The static calculation of isopotential difference has a low threshold for data availability, naturally coupled with topographic elevation data and irrigated block elevation, facilitating rapid formation of judgments after reconnaissance. After being stored alongside the effective irrigable water volume, the minimum effective water head can be used in conjunction with the critical window period water supply reliability and the allowable level of spillage to act on the same object when constructing constraints, reducing the uncertainty of cross-object coupling.

[0052] Step two, constraint the period water demand curve and event storage sequence on the object of effective irrigable water volume, and generate candidate solution feasible region and infeasible boundary accordingly, to ensure that the subsequent pool-site-pool-capacity-service-domain solution is executed under a unified criterion.

[0053] The period water demand curve and event storage sequence have been established within a unified time step, but if the critical window period water supply reliability and the allowable level of spillage are not translated into hard criteria for effective irrigable water volume, then obviously unusable combinations cannot be eliminated in the design phase. Therefore, on the basis of the same-domain expression of the demand side and the supply side, the reliability constraint and the spillage constraint with effective irrigable water volume as the only object are constructed, so that "whether the demand can be met in the critical window period" and "whether excessive spillage is caused in the wet season" are implemented as conditions that can be checked, thereby providing a quantitative cornerstone for the candidate solution feasible region.

[0054] First, the critical window period water supply reliability is integrated through the period water demand curve and the effective irrigable water volume, and second, the allowable level of spillage measures the acceptable mismatch when the system is in excess supply; both are defined by integrating a unified time step and keeping synchronization with the accessibility indicator, so that the subsequent set construction does not involve object migration.

[0055] To avoid simplifying reliability as a statistical proportion within the year and losing the time structure of the critical window period, the critical window period water supply reliability at the block level is directly defined on the critical window period set in a time-by-time comparison manner.

[0056] Specifically, accessible land plots that cannot be mapped by gravity flow are removed, and only the effective irrigation capacity corresponding to those that can be mapped by gravity flow is summarized. This is then compared with the water demand curve for each time step, and the water supply reliability during the critical window is obtained in the form of time proportion.

[0057] Where: Water supply reliability during critical window period Land Parcel Index The percentage of time periods that meet the requirements. Key Window Set Land Parcel Index The key window of time is a time set; set measure : Duration of the critical window period Normalized denominator; indicator function Numerical representation of logical decisions Transform time-sequential satisfaction into integrable objects;

[0058] Accessibility indicator Pool Index To index the land parcel Reachability markers, Supply is only counted when the minimum effective head is met; effective irrigable water volume Pool Index At time step Available volume; water demand curve for different time periods Land Parcel Index Water demand per unit time; time step : Standardize the calculation step size Dimensional transformation and integral window.

[0059] When in use, the reliability of water supply during critical windows is based on hourly satisfaction, avoiding the averaging that masks short-term water shortages; therefore, it is possible to identify window-sensitive combinations during the design phase, and through the filtering of accessibility indicators, only allow the supply that meets the minimum effective head to enter the judgment, thereby ensuring the physical feasibility of reliability.

[0060] To avoid defining water diversion as a single-pool overflow project and losing the system-level supply and demand perspective, this paper summarizes the effective irrigation capacity of all pools and the time-limited water demand curves of all plots within a unified time step. This defines the potential excess supply at the system level, and its proportion in the total supply characterizes the permissible water diversion level. This definition does not rely on undetermined pool capacity curves nor introduces additional adjustment factors, providing a constraint reference before layout solutions are implemented.

[0061] Where: allowable flow diversion level Potential oversupply ratio Evaluation time domain The time set during the design period is the time set; positive part operator For operators that take zero for negative values, the value is non-negative, and only the oversupply portion is accumulated;

[0062] In practice, the allowable diversion level measures oversupply from a system perspective, enabling early screening without relying on individual reservoir capacity details. This accelerates the construction of the feasible region for candidate solutions. Defined within the same domain as the water supply reliability during critical windows, it facilitates joint constraint application on the same object, reducing boundary ambiguity caused by inconsistent criteria. Treating oversupply as a recalibration of effective irrigation capacity helps align with engineering records of overflow triggering conditions, ensuring consistent standards in subsequent boundary labeling. After establishing quantitative criteria for reliability and diversion, the spatial accessibility caused by the minimum effective head and the engineering-level overflow triggering conditions need to be incorporated into the set expression. This ensures that the feasible region of candidate solutions not only has temporal criteria but also spatial and engineering constraints. Only by unifying these constraints at the set level can subsequent reservoir location-capacity-service domain solutions be searched within clearly defined boundaries, avoiding unrealizable combinations.

[0063] First, construct a set of reachable maps that satisfy the minimum effective head. Then, define the feasible and infeasible boundaries of candidate solutions in a set manner, so that reliability, flow abandonment and reachability are combined under the same expression and conditions are imposed on the pool location-pool capacity-service domain triplet.

[0064] To ensure that spatial reachability is explicitly defined at the set level, the pool-land pairs corresponding to the reachability indicators are converged into a set of reachable maps, which serves as the upper bound set of optional edges in the service domain. This process avoids repeatedly determining the minimum effective head in subsequent solutions, ensuring that the combinatorial space of the service domain is pruned by the physical boundary before entering optimization: where:

[0065] In the formula: the set of reachable mappings : The set of allowed pooled mapping pairs, which is a finite set; reachability indicator Same as above, the determination of whether the minimum effective head is satisfied.

[0066] When used, the determination of the minimum effective head is moved from line-by-line inspection to the set construction stage, thereby reducing the search space and computational cost of subsequent solutions. The reachable mapping set provides a natural edge set for the graph structure of the service domain, so that the spatial constraints of the feasible domain of the candidate solution have a clear and fixed carrier, which does not conflict with the time constraints of water supply reliability and allowable flow abandonment level during the critical window period, thus achieving orthogonal integration of time and space constraints.

[0067] To ensure that constraints can be uniformly verified at the pool location-pool capacity-service domain triplet level, a feasible region for candidate solutions is defined using a set approach, and infeasible boundaries are defined using constraint saturation conditions. Specifically, a solution space element containing the pool location-pool capacity-service domain triplet is constructed, requiring it to satisfy the lower limit of water supply reliability during the critical window, the upper limit of allowable flow diversion, and the service domain inclusion relationship, thus forming the feasible region of candidate solutions. Infeasible boundaries are then labeled with conditions indicating that reliability has reached its lowest point or flow diversion has reached its highest point, where: ; In the formula: the feasible region of the candidate solution The set of triples that satisfy all constraints; triples Pool slot-pool capacity-service domain triple, a Cartesian product, an abstract representation of a single solution; pool slot set One of the ternary components, representing a set of spatial coordinates or indices, is used to locate the position of the pool body; this formula implicitly contains... Pool volume vector One of the ternary components, encompassing the volume of each pool. The vector, Depicting the scale of the pool; this formula implicitly contains ;

[0068] Service domain mapping One of the ternary components, is A subset is defined to determine the water supply relationship of the pool area. In this formula, the explicit constraint is... Lower limit of water supply reliability during critical window period Land Parcel Index The reliability threshold, Upper limit of allowable flow level The maximum allowed percentage of data to be discarded. Limit oversupply; infeasible boundaries : The set of boundary conditions that are constrained to saturation, denoted as a set, with boundary states labeled for engineering verification; closure A closure in the topological sense of a set is a set that guarantees the completeness of its boundary definition.

[0069] When used, time constraints, space constraints, and proportional constraints are unified into a pool position-pool capacity-service domain triple in a set manner, realizing the one-time construction of the feasible domain; the explicit expression of the infeasible boundary allows engineers to specifically review solutions close to the boundary, improving the certainty and interpretability of solution review; the coupling between set-triple-threshold provides a clear calling interface for subsequent progressive solutions, reducing the object mapping cost across steps.

[0070] First, the priority decision of service domain mapping is used to resolve the huge uncertainty of space combination, and then the common criterion of minimum effective water head and shortest delivery path is used to determine the pool position and pool capacity under the premise of maintaining the key window period water supply reliability and the satisfaction of the allowable level of flow rejection, so that the pool position-pool capacity-service domain is progressively determined in the same evaluation coordinate system, and the clear mark of the requirement of pre-sedimentation scheme is formed at the high connectivity inflow channel.

[0071] Step three, in the candidate solution feasible region, the pool position-pool capacity-service domain is progressively solved in the sequential manner of service domain first, pool position and pool capacity second, and the constraints of key window period water supply reliability, flow rejection allowable level and minimum effective water head are maintained.

[0072] The candidate solution feasible region has unified the time constraints, spatial accessibility and system over-supply boundary, but without the stable service domain mapping, any optimization of pool position and pool capacity may repeatedly oscillate between large-scale combinations. Therefore, the time alignment of time period water demand curve and effective irrigable water volume is used as the criterion to optimize the service domain in the accessible mapping set, so that the supply source of each irrigated land block is physically accessible, path feasible and window period satisfied; on this basis, the service domain is passed to the pool position and pool capacity determination link as a fixed input, so as to compress the search space from the large Cartesian product of three tuples to a subspace with clear boundary set.

[0073] First, the path impedance is normalized by the head margin, and the service domain is obtained by minimizing the total path impedance in the accessible mapping set; then the local balance of the window period is checked by the time-by-time supply and demand deviation function generated by the service domain, to ensure that the contribution of the service domain to the key window period water supply reliability is not underestimated or overestimated.

[0074] In the accessible mapping set, simply pursuing the shortest delivery path may be biased to the location with low terrain but insufficient head margin, and simply pursuing the head margin may lead to long path.

[0075] Therefore, the head margin is composed of terrain equipotential difference and minimum effective water head, and the shortest delivery path is normalized by the head margin to obtain the path impedance considering dynamic accessibility and path cost; on this basis, the service domain is obtained by set optimization, so that each irrigated land block is covered by several physically accessible pools, and the total path impedance is minimized, wherein:

[0076] ; ; In the formula: head margin : pool index to land block index head surplus; terrain equipotential difference : pool index and land block index : potential difference; minimum effective head : minimum head threshold required at the self-flowing end; service domain mapping : set representation of pool-to-plot water supply relations, which is a subset of , defining which pools supply water to which plots;

[0077] optimal service domain mapping : optimal service domain mapping in the sense of path impedance , providing fixed input for subsequent pool location and pool volume solution; shortest delivery path : pool index to plot index : shortest path length from pool index : take 1 if , otherwise take 0, , activate the selected mapping in summation; reachable mapping set : pool-plot mapping set satisfying minimum effective head, upper bound set of service domain selectable edges.

[0078] In use, the normalization of path impedance to head margin prevents the service domain from sacrificing dynamic reachability due to short paths, thereby improving the proportion of self-flow and water supply stability. The set optimization is completed within the reachable mapping set, ensuring that physical reachability is not destroyed, avoiding repeated backtracking in the subsequent pool location and pool volume optimization phase, and the optimal service domain mapping obtained balances in both geometric and dynamic dimensions, providing a stable and interpretable edge set for the solution of capacity and location.

[0079] Once the service domain is determined, it still needs to be checked whether the microstructure of the supply-demand relationship at each time step within the key window period meets the reliability requirement. For this purpose, a time-varying deviation function is constructed to measure whether the cumulative supply of each plot at any time step under the given service domain is sufficient to cover the demand; by analyzing the sign and duration of the time-varying deviation function, it can be determined whether the marginal contribution of the service domain to the supply reliability of the key window period meets the standard, and accordingly trigger the adjustment of the edge mapping, wherein: ; In the formula: time-varying deviation function : plot index supply-demand difference at time step ;

[0080] member indicator : select supply belonging to the service domain; to prevent individual plots from being covered by any pool due to optimization preferences, an additional coverage constraint should be added to the service domain solution of "minimum path impedance": ; member indicator : take one when , otherwise take zero, with a value range ; effective irrigable water volume : pool index : available volume timing; period demand curve : plot index : water demand per unit time; time step : unified computation step, : dimension bridge between volume and flow.

[0081] When used, the hourly deviation function makes the contribution of the service domain to the critical window period water supply reliability locally quantifiable, thereby fine-tuning the edge set without changing the global threshold, the deviation function is expressed with the effective irrigable area and the domain, avoiding cross-object conversion and reducing misjudgment caused by unit inconsistency. By analyzing the duration of negative values of the deviation function, while maintaining the stability of the optimal service domain mapping , the edges with higher individual path impedance can be replaced to improve the overall robustness.

[0082] Based on the optimal service domain mapping obtained by minimizing the path impedance, supplemented by local review of the hourly deviation function, the service domain not only meets the dynamics of accessibility, but also has provable hourly satisfaction in the critical window period, providing stable and physically compliant input for the solution of pool position and pool capacity. After the stability of the service domain, if the capacity and position are not simultaneously solved in the unified evaluation coordinate system, it is easy to appear the situation of nominal reservoir capacity sufficient but self-flow insufficient, or the path cost too high leading to the rise of energy consumption and maintenance risk.

[0083] Therefore, with the service domain as a fixed input, the minimum nominal pool capacity is defined by the upper bound of cumulative surplus, and the pool position is selected by the combined target of path impedance and inflow connectivity, so that the final solution meets the critical window period water supply reliability and the allowable level of abandoned flow while balancing the engineering cost and operation and maintenance controllability. First, calculate the minimum nominal pool capacity by the upper bound of cumulative surplus reduced by explicit loss, and then use path impedance and inflow connectivity to form the objective function of pool position selection, to complete the solution of the pool position-pool capacity-service domain triple.

[0084] The capacity is not specified by empirical proportion, but by the upper bound of cumulative surplus in all windows under the constraint of the service domain. This process integrates the event entry sequence, period demand curve, and evaporation, leakage, and sedimentation reduction into the integral kernel at one time to obtain a lower bound estimate of the nominal pool capacity; this lower bound has engineering implementability before any operation procedure is determined, and can be directly translated into the target capacity of civil design.

[0085] ; In the formula: minimum nominal pool capacity : pool index : target capacity lower bound, , providing a quantitative index for civil design;

[0086] Evaluation time domain : Set of time for design calculation, for time set, upper bound of integral and interval of integral; start time : Integral start point, for time scalar, reference point of cumulative process; dynamic deposition effective coefficient : Pool index : Effective reservoir capacity ratio, reduce deposition to nominal capacity;

[0087] Event storage sequence : Pool index : Storage timing; period demand curve : Plot index : Unit time water demand; evaporation loss : Pool index : Evaporation flux of pool index ; leakage loss : Pool index : Leakage flux of pool index; time step : Unified calculation step, : Dimensional bridge of volume and flow; positive part operator : Take zero for negative, non-negative, ensure non-negative lower bound of capacity.

[0088] When used, the minimum nominal pool capacity is given by the upper bound of the cumulative surplus, independent of empirical coefficients, ensuring that the capacity setting is consistent with the timing structure of window demand, loss and inflow. This lower bound naturally compatible with service domain mapping, making capacity decision and service object one-to-one correspondence, reducing the subsequent redistribution pressure in the running phase. Explicitly introduce the dynamic deposition effective coefficient into the capacity calculation, so that the civil design has some reservation for the effective reservoir capacity decay from the beginning, reducing the impact of later dredging frequency on water supply stability.

[0089] Pool site selection needs to balance path cost and inflow aggregation. The higher the aggregation, the stronger the need for sand and energy dissipation at the front end. Therefore, under the constraint of optimal service domain mapping, a pool-site-pool-capacity-service-domain triple selection criterion is constructed to obtain the final solution, with the sum of path impedance and inflow connectivity indicator as the target; where the inflow connectivity is characterized by the peak value of the confluence time distribution, which marks the demand for pre-sand schemes corresponding to high connectivity inflow channels, as follows: ; ; In the formula: optimal triple : Optimal combination of pool-site-pool-capacity-service-domain, for triple set

[0090] Candidate solution feasible region : Solution set that meets all constraints, limit search range; shortest delivery path : Path cost

[0091] Terrain equipotential difference : Dynamic upper limit. Minimum effective water head : same as above, power threshold; inflow connectivity indicator : pool index : inflow concentration indicator, : depicts inflow peak concentration; confluence time distribution : pool index : time distribution, : meets normalization;

[0092] : upper bound normalization of data endogenous to path impedance term

[0093] : and : dimensionless synthetic quantity as pool site selection target. Normalized path impedance : dimensionless impedance, value range : acts as aggregation on the same scale as : refers to index : pool body-land parcel ordered pair traversed in reachable mapping set : scan index for forming the denominator of normalization, does not itself add entity quantity.

[0094] : In use, the pool site selection criterion juxtaposes path impedance and inflow connectivity, thereby simultaneously taking into account both the cost of delivery and the front-end protection requirements without introducing redundant factors. The use of confluence time distribution peaks allows high-connectivity channels to be automatically identified and matched with pre-sedimentation program requirement markers, enhancing the engineering feasibility of the program. The mapping of candidate solution feasible region and optimal service domain as hard constraints ensures that the final solution neither violates the key window period water supply reliability nor exceeds the allowable level of flow rejection.

[0095] : After fixing the service domain, the minimum nominal pool capacity and pool site selection are determined under the same target, synchronously aligning capacity and location with service objects and inflow characteristics; the result can directly generate parameter sets for civil and hydraulic calculations, and provide clear boundary conditions for the subsequent derivation of seasonal rule curves.

[0096] Step four, with service domain mapping and minimum nominal pool capacity as input, construct the lower limit of target water level and the upper limit of target water level of seasonal rule curve, and give pre-discharge water carrying strategy and spillway triggering condition, at the same time express the demand of pre-sedimentation program and lining program as identifiable engineering requirements, and take the compliance residual of monitoring points as the running period verification quantity, maintain the same standard with the candidate solution feasible region .

[0097] optimal triple The pool location, pool capacity, and service domain have been defined, but if the "lower limit required for supply guarantee" and "upper limit required for overflow prevention" in the time dimension are not clearly defined in the form of seasonal rule curves, it will be difficult for the operation side to implement the pre-release water carrying strategy; at the same time, the allowable flow diversion level... Inflow connectivity indicator If the water level is not translated into an upper limit buffer, a stable safety margin cannot be formed during the high-water season. Therefore, based on the comparison between accumulated demand and accumulated supply, the water level-storage capacity function is used. The monotonicity of the target volume is translated into the lower limit and upper limit of the target water level, thereby precipitating the time series criteria into a clear operating curve.

[0098] First, the lower limit of the target water level is defined based on the service domain demand. Then, the upper limit of the target water level is defined jointly based on the allowable diversion level and inflow connectivity. Based on this, the pre-discharge water-carrying strategy and the overflow triggering conditions are given. Both share the minimum nominal pool capacity. With water level-reservoir capacity function The monotonic mapping ensures the comparability of units and objects.

[0099] Mapping in service domain Assuming stability, the service domain demand aggregation is defined as the composite temporal sequence of land parcel demand from the perspective of the pool, thereby deriving the target water level lower limit based on "demand excess during the most unfavorable period within the future window." First, the service domain demand aggregation is defined: Then, the most recently viewed window set is used. Using the integration domain, the volume buffer ratio is obtained and mapped to the target water level lower limit: ; Where: cumulative gap size Pool Index In the interval Demand-supply gap, value This serves as the criterion for determining the volume gap within the window;

[0100] Service Domain Requirements Summary :Depend on The pool's perspective requirements, summarized, have a range of values. Unified time step Volume-flow dimensional bridging, value range Effective irrigation capacity Volume per step, range of values Minimum nominal pool capacity Lower bound of capacity, range of values ;

[0101] target water level lower limit : The lower rail of the seasonal regular curve

[0102] Water level-reservoir capacity function , pool index monotonic increasing function, , water level and storage capacity mapping;

[0103] For example, if the pool surface area function at different water levels is obtained:

[0104] where is the pool bottom control elevation. First, fit the "water level-area" relationship (such as polynomials, piecewise cubic spline, etc.), and then integrate according to the above formula to obtain the "water level-storage capacity" continuous function and ensure monotonicity, and the water level-storage capacity function is obtained by integrating the water level-area function.

[0105] Inverse function : monotonic mapping, is to make the "storage capacity→water level" mapping into a monotonic, reversible, and computable function. For example, use the "water level-storage capacity table" to directly construct a piecewise linear inverse function; obtain discrete points and strictly increasing with , first locate the interval on the storage capacity axis, and then according to: the corresponding water level is obtained.

[0106] In use, the lower limit of the target water level is defined as the proportion of the "window most unfavorable demand excess", avoiding the dilution of key window risks by averaging, so as to form a clear water retention bottom line at the operation end, taking the service domain demand aggregation as the core, ensuring consistency with the service domain mapping , reducing the uncertainty of redistribution during operation, and the monotonic mapping of the water level-storage capacity function makes the volume lower limit directly translate into the water level lower limit, which is convenient for on-site water level control without real-time volume calculation.

[0107] In the wet period, the allowable level of spill flow should be combined with the inflow connectivity indicator to determine the upper limit of the target water level, so that the volume retained in the reservoir is below the threshold that will trigger systemic oversupply, and according to this, the pre-discharge water carrying strategy is given, and the buffer ratio is defined as , and the upper limit of the target water level is obtained as follows:

[0108] ; In the formula: the upper limit of the target water level : the upper limit of the water level of the pool index : the upper limit of the buffer ratio of the pool index : the pool index : the upper limit of the buffer ratio of the pool index , to leave a volume buffer for risk avoidance;

[0109] allowable spill level : allowable over-supply ratio upper limit, global risk-avoidance constraint; inflow connectivity indicator : pool index inflow peak concentration of, , risk intensity of short-duration peak;

[0110] with uniform time step : non-dimensionalization

[0111]

[0112] inflow connectivity indicator : non-dimensional peak concentration after : pool-side weight with the role of upper-limit buffer ratio. When used, the target water level upper limit combines the global allowable spill level and the inflow peak characteristics of the pool into a buffer ratio, forming an easy-to-implement upper track control. When the pool water surface elevation exceeds the target water level upper limit, the pre-discharge water-carrying strategy is triggered, and the service area is mapped to the irrigated plots in priority, taking into account the shortest delivery path and the water head margin , thereby unifying risk avoidance and supply preservation into the same operation instruction. After the regular curve in the time dimension is determined, the engineering requirements related to inflow connectivity and reservoir capacity decay still need to be externalized into an implementation list, and the compliance verification quantity in the operation period is given. If the requirements of the pre-sedimentation scheme and the lining scheme are not expressed with unified indicators, the design documents and operation verification will lack a common language; if the water level compliance is not expressed with a measurable residual, the monitoring points will have difficulty in fulfilling the responsibility of criterion verification. Therefore, sedimentation and water level compliance are presented with quantitative indicators, and the layout of monitoring points and compliance criteria are integrated and explained.

[0113] First, the inflow connectivity and the effective reservoir capacity ratio are used to construct the pre-sedimentation scheme requirement index, and then the target water level interval and the measured water level are used to construct the compliance residual for threshold-based alarm and operation correction of monitoring points; both serve the quantification and on-map annotation of implementation requirements.

[0114] The superposition of high-connectivity inflow channels and effective reservoir capacity decay significantly shortens the dredging period, which should be expressed with a unified index to express the demand intensity of the pre-sedimentation scheme at the design end. The demand index is defined as the product of the inflow connectivity indicator and the upper bound of the effective reservoir capacity loss, to realize the ordering of the "peak concentration-decay of reservoir capacity" coupled risk:

[0115]

[0116] ​; in which: the requirement index of the pre-sand scheme : the pool index : the requirement intensity of the pool, : the priority ranking of the pre-sand scheme and the maintenance channel; the indication of inflow connectivity : the peak concentration characterization; the evaluation time domain : the time set of the design period, the interval of the upper bound of the time set; the dynamic accumulation effective coefficient : the pool index : the effective storage capacity ratio of the pool, : the expression of the influence of the accumulation on the storage capacity;

[0117] In use, the requirement index expresses the combined intensity of the two types of risks with a single dimension, facilitating the labeling of the construction drawing with contour lines or levels to form a clear deployment of the pre-sand scheme, without the need to introduce additional factors to be compared with the minimum nominal pool capacity Mapping with the service domain Linkage, guiding the sand pool capacity ratio and the location of the maintenance channel, which can be presented with the flood overflow trigger condition in the same figure, so that the operation and maintenance personnel can prioritize the dredging and facility inspection of high-risk pool bodies before the high water period.

[0118] In order to give a quantitative judgment on the execution of the regular curve by the monitoring point, the compliance residual is constructed with the lower limit of the target water level and the upper limit of the target water level; when the residual is positive, it indicates that the water level is out of bounds, and the pre-discharge with water or the backfill measure needs to be executed, and the effectiveness of the lining scheme is reviewed, wherein: ; in which: the compliance residual : the pool index : the out-of-bound amount of the pool, : the quantitative index that triggers the operation disposal and reviews the effectiveness of the lining scheme; the lower limit of the target water level , the upper limit of the target water level : the interval control water boundary, as above; the pool water surface elevation : the pool index : the measured water level of the monitoring point, the observation quantity of the monitoring point; the positive part operator : the operator that takes zero for negative values, taking non-negative values to ensure that the residual is non-negative.

[0119] In use, the compliance residual links monitoring and control into the same numerical quantity, facilitating the recording in the operation log and the coaxial comparison with the seasonal regular curve, when the residual is continuously positive and the trend is the same as the leakage loss , it can be determined that the lining scheme needs to be upgraded or maintained, forming a clear coupling between "rules-facilities-monitoring", and when the land within the service domain mapping is executed with back supply or limited supply, the pool body that needs to be disposed first can be selected according to the distribution of the compliance residual, improving the configuration efficiency of the operation resources.

[0120] Those skilled in the art can clearly understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0121] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0122] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described device embodiments are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0123] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0124] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for optimizing layout of a hillside field catchment basin based on a matching constraint of irrigation and storage, characterized in that: include, The system generates water demand curves and event entry sequences for different time periods, defines the effective irrigation volume based on evaporation, leakage, and siltation reduction, extracts topographic elevation data and the elevation of irrigated plots, determines whether the minimum effective head is achievable, and forms a unified time resolution basic data for solving the pool location-pool capacity-service domain problem. A family of irrigation-storage matching constraints is formed by the water supply reliability during the critical window period, the allowable level of diversion, and the minimum effective head, which uniformly apply to the effective irrigable water volume; the candidate solution feasible region is generated and the infeasible boundary is marked by comparing the water demand curve of the time period with the event inflow sequence hourly. Within the feasible region of the candidate solution, the pool location-pool capacity-service region is solved progressively: first, the service region mapping is determined based on the water intensity during the critical window period and the adjacency relationship of the land parcels; then, the pool location and pool capacity are determined by combining the minimum effective head and the shortest transmission and distribution path; the minimum nominal pool capacity is calculated and a set of preferred solutions is formed. The seasonal regular curve and pre-release water-carrying strategy are derived from the preferred solution set. The upper and lower limits of the target water level of each pool are determined according to the minimum nominal pool capacity and the water level-storage capacity function. Overflow triggering conditions are set. The pool position-pool capacity-service domain and the seasonal regular curve are combined to form an implementation document. The accessibility of the minimum effective head is determined by the difference between the topographic equipotential difference and the elevation of the irrigated plot. When the equipotential difference between the pool and the plot is not less than the minimum effective head, it is recorded as accessible and a set of accessible mappings is formed. The set of accessible mappings serves as the upper limit edge set for subsequent service domain mappings. The service domain mapping is solved within the reachable mapping set by minimizing the path impedance formed by the head margin and the shortest distribution path, and a coverage constraint is imposed on each irrigated plot being covered by at least one pool; the service domain mapping consists only of pool edges that satisfy the minimum effective head. The selection of the preferred solution set is based on the service domain mapping as a fixed input. Within the feasible domain of the candidate solutions, pool location selection and service domain solution are completed by set optimization: First, the head margin is constructed using the topographic equipotential difference and the minimum effective head, and then normalized to the shortest transport path to obtain the path impedance that takes into account both dynamic reachability and path cost. Then the normalized path impedance total and the inflow connectivity indicator are combined to form a composite objective, and the service domain scheme that covers each catchment block with several physically reachable pools and minimizes the total path impedance is obtained, while the pre-sedimentation scheme requirement notes are generated for the channels with significant inflow time distribution peak, wherein: ; ; wherein: head margin : pool index to block index head surplus; terrain equipotential difference : pool index equipotential difference to block index : minimum effective head : minimum head threshold required for gravity end; service domain mapping : set representation of pool-to-block water supply relationship, which is a subset of , defining which pools supply water to which blocks; Optimal service domain mapping : optimal under path impedance significance , provide fixed input for subsequent pool site and pool capacity solution; shortest delivery path : pool body index to plot index : shortest path length to plot index, geometric quantification of delivery cost; member indicator : if , take 1, otherwise take 0, , activate selected mapping in summation; reachable mapping set : pool plot mapping set satisfying minimum effective water head, upper limit set of service domain optional edge.

2. The method for optimizing the layout of water collection ponds on sloping farmland according to claim 1, characterized in that: The water requirement curves for the specified time period are generated based on crop evapotranspiration and crop coefficient within a uniform time step, and are marked on the growth period using key window options. The event entry sequence is obtained by transforming the distribution of rainfall intensity, infiltration, and runoff time; evaporation, leakage, and siltation are deducted hourly and recorded in correspondence with the effective irrigation water volume.

3. The method for optimizing the layout of water collection ponds on sloping farmland according to claim 2, characterized in that: The water supply reliability during the critical window period is defined by comparing the effective irrigation capacity with the water demand curve of the time period hourly within the critical window period set to determine the percentage of satisfaction. The allowable level of flow diversion is defined as the proportion of the potential oversupply volume in the evaluation time domain to the cumulative volume of the event inbound sequence after deducting losses, and the feasible region of the candidate solution is generated accordingly.

4. The method for optimizing the layout of water collection ponds on sloping farmland according to claim 3, characterized in that: The candidate solution feasible region needs to meet the inclusion relationship of the reachable mapping set and the threshold constraints of the lower limit of the key window period water supply reliability and the upper limit of the spillage tolerance level; And mark the infeasible boundary with reliability bottoming out, spillage topping out or insufficient minimum effective water head, record the failure reason of the corresponding pool land edge.

5. The method according to claim 4, wherein: The minimum nominal pool capacity is calculated according to the cumulative surplus upper bound, and in the evaluation time domain, the event storage sequence is sequentially deducted by the service domain demand, evaporation loss, seepage loss and dynamic accumulation effective coefficient reduced by the service domain mapping, and the upper bound of the non-negative cumulative surplus is taken as the capacity lower bound of each pool.

6. The method according to claim 5, wherein: The lower limit of the target water level of the seasonal rule curve is determined according to the proportion of the cumulative gap of the service domain demand and the effective irrigable water volume in the key window period to the minimum nominal pool capacity, and is inversely calculated into a water level sequence through the water level-storage capacity function, and is used to describe the lower rail of the target water level of each pool.

7. The method according to claim 6, wherein: The upper limit of the target water level is determined by the buffer ratio of the composition of the spillage tolerance level and the inflow connectivity indicator, and the flood overflow trigger condition is set at the upper limit of the target water level; The pre-discharge water-carrying strategy is sequentially directed back to supply according to the service domain mapping and the shortest delivery path when the measured water level exceeds the upper limit of the target water level.

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