城区地表径流面源污染和河道水环境治理的研究

Nonpoint Source Pollution from Urban Runoff and Pollution Abatement in Urban Waterways

河流为人类提供了多样的生态服务功能,然而城市化对河流生态系统健康状况造成严重的影响。随着点源污染的有效管理控制,非点源污染降雨径流己成为造成城市地表水环境污染的主要原因。为了改善河道水质,引调清水激活城市内河水体,提高河道的水环境自净能力,有效改善城市水环境。文章以南京河西水系为例,利用Saint-Venant方程组对水系建立一维水动力模型,并通过汇流结点水位法对方程组进行数值求解;对WASP5水质模型进行二次开发用于水质模拟;建立水质模型和一维河网水动力模型的耦合模型,将水动力模型计算所得到的水动力参数耦合到WSAP5水质模型中,模拟降雨过程以及引调清水过程的河网各河段的水质变量浓度,得出降雨径流对河流的污染程度以及引清冲污措施对河流水质改善的效果并优化调水过程。

To improve self-purification capacity of rivers coping with the increasing non-point source pollution, this paper highlights developing a one-dimensional hydrodynamic model based on Saint-Venant equations and a modified WASP5 model to simulate water quality of the river waterways in the west part of Nanjing City. Values of river water quality in terms of pollutant concentrations during either raining or clean-water diversion were obtained by coupling the hydrodynamic model into WASP5 water quality model, which indicated the seriousness of pollution due to urban rainfall run-off and the positive environmental effect of diverting clean water into the river system with pollutants being flushed out.