Ditch wetlands reduce agricultural nonpoint source pollution and protect the water environment in drainage areas. One effective management option is controlled drainage. However, for ditch wetlands receiving salt-laden drainage water in arid or semi-arid irrigation areas, controlled drainage may lead to eventual build up of salinity to critical levels that are detrimental to the ecological services and agricultural production of wetland systems. In order to evaluate the positive and negative impacts of agricultural practice of using controlled drainage to manage ditch wetlands water quality in arid or semi-arid irrigation area, based on the principle of water-salt balance we constructed an analysis model. A ditch wetland as a case example in semi-arid irrigation area was then used to display model predictions of salinity variations over time under different watertable control depths. The ditch wetland area to farmland area ratio is 0.091, and the input sources of water and salt are not unique. The results showed that the model established by considering various inflows and outflows has higher simulation accuracy. The water stored in the wetland is key to affecting the salt concentration of the wetland, and the amount of water can be regulated by controlled drainage. Controlled drainage changes the hydrological process of farmland and ditch wetlands, reduces drainage output and damage by high concentrations of salt. But this management measure also increases the risk of medium salt concentrations that may cause an increase in salt output. Considering agricultural production and environmental protection of ditch wetlands, the drainage water table controlled at 1.2 m is a suitable drainage management measure in this irrigation area. The results provide the underlying insights needed to guide the design of drainage management practices in ditch wetlands that receive drainage discharge in semi-arid regions that can be sustained to the maximum benefit of the agricultural system and the environment.

沟渠湿地减少了农业面源污染并保护了流域的水环境。一种有效的管理方案是控制排水。但是，对于在干旱或半干旱灌溉区接受含盐排水的沟渠湿地，控制排水可能最终导致盐分积累到临界水平，这不利于湿地系统的生态服务和农业生产。为了评估干旱或半干旱灌溉区使用控制排水管理沟渠湿地水质的农业实践的正面和负面影响，基于水盐平衡的原理，我们构建了一个分析模型。然后以半干旱灌溉区的沟渠湿地为例，显示在不同水位控制深度下盐度随时间变化的模型预测。沟湿地面积与耕地面积之比为0.091，水和盐的输入来源不是唯一的。结果表明，考虑各种流入和流出量建立的模型具有较高的仿真精度。储存在湿地中的水是影响湿地盐分浓度的关键，并且可以通过控制排水来调节水量。受控的排水改变了农田和沟渠湿地的水文过程，减少了排水量并因高浓度盐分而受到破坏。但是，这种管理措施还增加了中等盐浓度的风险，这可能导致盐产量增加。考虑到农业生产和沟渠湿地的环境保护，将排水水位控制在1.2 m是该灌区的一种合适的排水管理措施。结果为指导在半干旱地区接受排水排放的沟渠湿地的排水管理实践设计提供了潜在的见识，这些干旱可以持续到农业系统和环境的最大利益。