Simulation and Optimization Coupling Model for Soil Salinization and Waterlogging Control in the Urad Irrigation Area, North China

How to rationally optimize the allocation of surface water and groundwater resources in saline-alkali areas is a difficult problem in current model optimization. Based on an interval two-stage stochastic programming (ITSP) method, this paper considers the system risk involved in saline-alkali land treatment, follows a robust optimization method, and constructs an interval two-stage data-driven subrobust optimization (ITDRO) model, which can optimize the distribution of groundwater and surface water for different crops and realize the combination of wells and canals through the joint dispatch of surface water and groundwater. This paper takes the Urad Irrigation Area as the research object, and the obtained results provide water distribution objectives under situations of multiple sources of water, multiple crops, and different robust coefficients. After the successful calibration and verification of the SaltMod model, the water distribution target is taken as the main input parameter and substituted into the simulation model based on the principle of water and salt balance. The output includes soil salinity, drainage salinity, groundwater salinity (GWS), groundwater table (GWT) depth, and drainage. The results show that the integrated ITDRO and SaltMod model can control the groundwater level below the critical depth under the premise of satisfying crop irrigation, reducing the groundwater level by approximately 0.75 metres and the GWS in the irrigation area by approximately 0.68 g/L, which can provide a reference for the prevention and control of soil salinization and waterlogging. This approach is suitable for arid and semiarid regions that face similar problems.