减少面源污染的农田排水工程设计标准与管理措施

Design standards and management measures for farmland drainage systems to mitigate non-point source pollution

以控制排水量和减少污染物的流失量,并提高水、肥利用率为目标,探讨了具有环境和资源效应的排水工程设计标准和管理措施:采用灌溉与排水系统结合、减少暗管的埋深等新技术,可以有效防止过度排水,并降低排水中硝态氮和盐分的浓度;实施地下水位管理,不仅能够减少排水量,而且可以提高灌溉水的利用率,同时降低污染物的流失量.这些方法和措施适合在湿润地区推广,在干旱和半干旱地区要防止控制排水产生盐碱化,当土壤中的磷富集时,地下水位上升可能导致排水中磷的浓度升高.应用结果表明:这些技术和方法改善了水环境并提高了水资源的利用率.

The design standards and management measures for drainage systems with environmental and resource effects were discussed by regarding the control of the total drainage flow,the reduction of the contaminant load and the improvement of irrigation and fertilization efficiency as the goal.The new techniques of the combination of controlled drainage and sub-irrigation systems and the reduction of installation depth of lateral pipes would effectively prevent excessive drainage and mitigate nitrate and salt concentrations in drainage flow.The management of water table position would reduce the drainage flow and contaminant load and improve the irrigation efficiency.The above measures would be applicable to humid areas.When applied in arid and semi-arid areas,the soil salinity should be avoided.When the phosphorus in the soil was rich and the concentration of phosphorus in the drainage flow might be raised by the increase of the water table.The results show that these new techniques and methods for drainage systems can improve the efficiency of water resources.