Soil salinization seriously threats the sustainability of agriculture in irrigation districts in arid and semi-arid regions. Unreasonable land consolidation aimed to increase cultivated land by developing uncultivated land makes soil salinization more serious in irrigation districts in the northwest of China. The uncultivated land serves as the salt discharge area, which is necessary for cultivated land with reasonable area, excavation depth, and spatial allocation. Therefore, this study aims to optimize the allocation of salt discharge areas based on soil water and salt movements simulated by SahysMod, choosing Yinchuan North Irrigation District as a case study in the northwest of China. Results showed that SahysMod was an effective tool to simulate soil water and salt movements between cultivated land and salt discharge areas. The parameters of optimum allocations, including excavation depths of salt discharge areas and area ratios of cultivated land to salt discharge areas, indicated the negative and positive effects of power functions on soil salinity of cultivated land, respectively. In this case study, an excavation depth of 0.3 m, the area ratio of 1.5, and salt discharge areas located in the southwest and northeast were more conducive and cost effective in terms of removing soil salinity of cultivated land. Moreover, the average soil salinity of cultivated land by optimum allocation was reduced to 1.2 dS/m compared with 2.7 dS/m by original allocation in 2027. It proved that the reasonable allocation of salt discharge areas was very important to address soil salinization of cultivated land and ensure its sustainable utilization, which provided a theoretical basis and technical guide for the allocation of salt discharge areas in land consolidation in the arid irrigation districts.

土壤盐渍化严重威胁干旱和半干旱地区灌区农业的可持续性。通过开垦荒地增加耕地的不合理土地整治，使西北灌区土壤盐渍化更加严重。荒地作为排盐区，是合理面积、开挖深度和空间配置的耕地所必需的。因此，本研究以银川北灌区为例，基于SahysMod模拟的土壤水盐运动，优化排盐区配置。结果表明，SahysMod 是模拟耕地和排盐区之间土壤水盐运动的有效工具。排盐区开挖深度、排盐区面积比等优​​化配置参数分别表明幂函数对耕地土壤盐分的正负效应。本案例开挖深度为0.3 m，面积比为1.5，排盐区位于西南和东北，在去除耕地土壤盐分方面更有利于和成本效益。此外，优化分配的耕地平均土壤盐度从2027年原分配的2.7 dS/m降低到1.2 dS/m，证明排盐区的合理分配对于解决耕地土壤盐渍化问题非常重要。土地并确保其可持续利用，