Irrigation projects often result in many far-reaching environmental changes. This paper considers the case of the Hetao Irrigation District, the largest irrigation project along the Yellow River in China, and studies the impacts of agricultural water management on the hydrology and the environment. Long-term data (1954–2013) concerning irrigation, drainage, soil salinity, groundwater, and the environment of Wuliangsuhai Wetland, the lake that receives the drainage water, were collected and analyzed. The findings show that uncontrolled irrigation and the absence of effective drainage initially resulted in a rising groundwater table, worsening soil salinization, and the expansion of the lake, which is an important internationally recognized wetland. The completion of an artificial drainage system and the implementation of water-saving practices have had promising effects on lowering the groundwater table and controlling soil salinity. However, the risk of soil salinity is still threatening the irrigation system because salt is continuously accumulating within it and the total dissolved salts (TDS) in the groundwater are increasing. For better soil salinity control, more effective drainage is necessary to drain more salt and lower the water table, but this may harm the natural vegetation and the eco-environment of the Wuliangsuhai Lake because the non-point-source pollution from agricultural drainage has resulted in a serious eco-crisis in the Wuliangsuhai Lake. The results show that it is important to ensure there is a certain amount of low-TDS drainage water to protect the Wuliangsuhai Lake environment. Therefore, a balance must be achieved among soil salinity control, groundwater quality, favorable conditions for natural vegetation, and wetland protection. Further research is needed to develop optimal agricultural water management strategies, especially in the context of the ongoing water-saving renovation program.

灌溉项目常常导致许多深远的环境变化。本文以黄河沿岸最大的灌溉工程河套灌区为例，研究了农业用水管理对水文和环境的影响。收集并分析了有关灌溉，排水，土壤盐分，地下水和无水苏海湿地（接收排水的湖泊）的环境的长期数据（1954-2013年）。研究结果表明，不受控制的灌溉和缺乏有效的排水系统最初导致地下水位上升，土壤盐碱化加剧以及湖泊扩张，而湖泊是国际上公认的重要湿地。人工排水系统的完成和节水措施的实施对降低地下水位和控制土壤盐分具有令人鼓舞的效果。但是，土壤盐分的风险仍然威胁着灌溉系统，因为盐在其中不断累积，并且地下水中的总溶解盐（TDS）不断增加。为了更好地控制土壤盐分，有必要进行更有效的排水，以排泄更多的盐分并降低地下水位，但这可能会损害五粮苏海的自然植被和生态环境，因为这导致了农业排水的面源污染。在五粮素海发生严重的生态危机。结果表明，重要的是要确保有一定量的低TDS排水，以保护五粮苏海湖的环境。因此，必须在土壤盐分控制，地下水质量，天然植被的有利条件和湿地保护之间取得平衡。需要进一步研究以制定最佳的农业用水管理策略，尤其是在正在进行的节水改造计划的背景下。