| Soil salinization is a significant factor limiting the sustainable development of agriculture in the Hetao irrigation district. Improving irrigation and drainage management plays a crucial role in the prevention and control of soil salinization in the region. Using typical irrigation and drainage units in the Hetao irrigation district as examples, this study simulated and predicted the dynamic changes in soil salinization in both cultivated land and wasteland over the next 10 years under different irrigation and drainage management scenarios, based on the validated SahysMod model. Results indicated that under the current conditions, soil salinity in cultivated land exhibited a slow increase during the early stage of the forecast (2021—2025) and a more pronounced rise in the later stage (2026—2030). In contrast, soil salinity in wasteland increased gradually during the early stage of the prediction and remained relatively stable in the later stage. These scenarios were based on the validated SahysMod model. Compared to wasteland, the reduction in total water diversion had a greater impact on soil salinity changes in cultivated land. As the irrigation quota decreased, soil salinity in cultivated land increased significantly. However, as the irrigation quota increased, the rate of reduction in soil salinity accumulation was not as pronounced. Increasing the irrigation quota continues to play an important role in soil salt leaching and in maintaining the effectiveness of drainage and salt removal in the study area. From the perspective of salt accumulation in cultivated land versus wasteland, the most significant salt control effect is achieved by increasing the current drainage ditch depth from 1.5 meters to 1.8 meters. |