北京温榆河流域水污染控制情景模拟与分析

温榆河的水环境状况已成为制约该流域乃至北京市经济、社会和环境协调发展的重要因素。本研究以控制水污染为目标,从点源控制和非点源控制两个方面出发设计了不同的情景方案,应用SWAT（Soil and Water AssessmentTool）模型进行温榆河流域的水污染控制情景模拟计算和分析。结果表明：控制点污染源的达标排放是减少温榆河入河污染负荷量和改善水体环境的有效措施,总氮和总磷负荷的削减率分别达到66.2%和80.5%;改变农田施肥量和施肥方式、坡耕地的退耕还林和减少城镇区不透水面积等措施对减少流域的非点源污染负荷产出都有较好的效果,且各种不同的污染控制措施对总氮、总磷的削减效果不同,总氮削减率为1.2%～32.3%,总磷削减率为3.7%～49.9%。模拟结果还显示,只有将点源控制和非点源控制相结合、浓度控制和总量控制相结合,并辅以适当的河道治理工程,才能彻底实现温榆河水质还清的目标。模拟分析结果可为该流域的水污染控制和治理规划提供参考。

Scenario analysis of water pollution control in Wenyu River basin in Beijing

Poor water quality of the Wenyu River has become a bottleneck for the coordinate development of economic,society and environment in the local region,even in the whole Beijing city.This study evaluates water pollution control measures and provides helpful information for water quality improvement of this river.Measures of point and nonpoint pollution control were proposed,and scenario analysis method and SWAT model were adopted to evaluate the effects of these measures on water quality improvement.The results show that the most effective measure is to control the concentration of waste water discharge from point pollution sources below the standard level,which reduces total nitrogen and total phosphorus of the study area by 66.2% and 80.5%,respectively.Second measure is to reduce agricultural fertilizer use and adopt scientific method for the use to control non-point sources.On the other hand,returning hillslope farmland to woodland and decreasing the urban area or the impermeable urban area also have good effects on non-point source control,an reduction of 1.2%~32.3% in total nitrogen and 3.7%~49.9% in total phosphorus.The simulation indicates that to restore a clear Wenyu,nothing can be done but a combinative control over the point sources and non-point sources and over the concentration and total amount,supplemented with certain pollution control engineering.These results provide a support for planning of water environment protection.