Research on the Drought Deduction and Drought Resistance Plan Regulation in Pishihang Irrigation District.

The drought of water resources is the key factor that limits the sustainable development of irrigation areas. In order to improve the ability of drought prevention and control of irrigation area and make it play a better role in water saving and disaster reduction, Pishihang Irrigation District is taken as the study area. By dividing the sub-units of water resources allocation and setting up regulation and storage nodes, the optimal fairness and the minimum water supply shortage rate is used as the objective function, total quantity control, water supply capacity and different quality water supply as constraints, the non-dominant genetic algorithm based on elite strategy is adopted to solve the problem, and the regional General Water Allocation and Simulation Model(GWAS) is constructed. With 2022 as the base year and combined with 2023 planning year, it is divided into two categories: continuous drought and discontinuous drought. Based on the regulation idea of "three times balance of emergency drought" of water resources in irrigated areas, and on the basis of analyzing water shortage in irrigated areas under different drought scenarios, the drought resistance allocation of water resources in irrigation area is studied. The supply and demand balance of water resources under different drought relief schemes is deduced and analyzed. The results show that in the continuous drought year and the 2023 planning year of irrigation district, under the water inflow frequency of scenario I (P=90%) and scenario II (P= 80%), there are different degrees of water shortage in each township allocation unit, and the total regional water shortage rates are 35.1% and 20.8%, respectively. In the discontinuous drought years, in the 2023 planning year, under the water frequency of scenario III (P= 50%), the benchmark water allocation of the model can basically meet the water demand of villages and towns in the region, and the total water shortage rate of the region is 5.9%. After the optimal allocation of water replenishment at the tail pumping station of different drought relief schemes, adjustment of crop planting structure and external water transfer, the total water shortage rate in the three scenarios is finally reduced to 0%. After optimization, the water supply improvement effect of each configuration unit is significant. The research results can provide a technical support for the reasonable adjustment of water resources under different drought types in Pishihang Irrigation District in the future, and provide a theoretical basis for realizing unified water resources management and unified allocation of water resources in this region. [ABSTRACT FROM AUTHOR]