滇池东岸环湖截污系统农村面源径流量截留率验证

Verification of Rural Non-point Source Runoff Interception Rate in East Bank of Dianchi Lake Basin Interception System

农村面源污染是滇池污染负荷的主要来源之一,环湖截污系统对农村面源径流截留具有重要作用。目前,整个截污系统尤其是东岸部分已基本完善,基于实际运行状态,验证东岸环湖截污系统对农村面源径流的截留功能是否达到设计目标,从而更好地为滇池流域水环境治理提供科学依据。在前期理论论证的基础上,根据现场监测获得的东岸环湖截污系统中沉砂截流井处的实际水量数据,分别就单场降雨以及典型降雨年情况下系统对农村面源径流量截留率进行深入讨论。结果表明,在降雨量分别为43.2和25.9 mm的两场降雨事件中,其对应的农村面源径流量截留率分别为36.98%和70.62%。1995年—2009年期间,农村面源径流量年均截留率最小为42.33%(1998年),最大为69.42%(2000年)。枯水年、平水年和偏丰水年的农村面源径流量平均年截留率分别为61.56%、51.55%和52.31%。因此,滇池环湖截污系统中沉砂截流井的设计能有效实现农村面源径流量截留30%的目标,对评估环湖截污系统效能的发挥具有重要意义。

Rural non-point source pollution is one of the main contamination sources in Dianchi Lake,and wastewater interception systems around the lake play an important role in intercepting rural non-point source runoff.At present,the whole wastewater interception system,especially the east bank part,has been basically completed.Based on actual operation performance,this paper verified whether the interception function of the east bank rural non-point source runoff interception system being reached the design goal,so as to provide a scientific basis for water environment management of Dianchi Lake Basin.On the basis of previous theoretical demonstration,actual water quantity data at settling and intercepting wells in the east bank system were obtained through on-site monitoring,and the interception rates of rural non-point source runoff under the condition of single rainfall and typical rainfall year were discussed deeply.The rural non-point source runoff interception rates were 36.98%and 70.62%in two rainfall events with rainfall of 43.2 mm and 25.9 mm,respectively.During 1995 to 2009,the minimum and maximum annual interception rates of rural non-point source runoff were 42.33%(1998)and 69.42%(2000).The average annual interception rates of rural non-point source runoff in dry years,normal years and partial wet years were 61.56%,51.55%and 52.31%,respectively.In conclusion,the design of settling and intercepting wells in Dianchi Lake wastewater interception system could effectively achieve the goal of intercepting 30%of rural non-point source runoff,which was of great significance to evaluate the performance of the interception systems around the lake.