用于农田非点源污染控制的生态拦截型沟渠系统及其效果

针对太湖流域农田非点源污染严重的现状，结合当地实际情况提出了一种新的生态工程学解决方法——生态拦截型沟渠系统，它主要由工程部分和植物部分组成，能减缓水速，促进流水携带颗粒物质的沉淀，有利于构建植物对沟壁、水体和沟底中逸出养分的立体式吸收和拦截，从而实现对农田排出养分的控制。试验区沟渠植物具有一定的经济价值，且景观效果良好。沟渠系统对农田径流中总氮、总磷的去除效果分别达到48．36％和40．53％。此外，该生态工程的另一个显著优点就是不另外占用土地，符合平原水网地区农田沟渠的实际，具有很好的推广应用潜力。

Ecological ditch system with interception function and its effects on controlling farmland non-point pollution

Aiming at the severity of farmland non-point pollution and the fact of more population with less arable land in Taihu Lake basin, this paper set forward a new ecological engineering solution, ecological ditch system with interception function, which consisted of project part and plant part. This system could decrease flow rate, promote the sedimentation of particulate materials carried by paddy runoff, enhance the plant absorption and removal of the nutrients from ditch wall, water body and sediments, and thus, effectively prevent the runoff nutrients from paddy fields entering into adjacent water bodies. The plants in the ditch system could bring back definite economic returns and gave good aesthetic sights, and the removal rate of runoff total-N and total-P by the ditch system was 48.36 % and 40.53 %, respectively. Another distinct character of the solution was no additional land costs, which accorded with the reality of the farmland ditches in plain region with water nets, possessing a good practical prospect.