河流上下游控制断面非点源污染特征的分析

为了深入研究河流上下游断面非点源污染的特征及其变化,以及同一断面不同年份的非点源污染特征,以渭河的支流沣河上游大峪口断面和中游秦渡镇断面为研究对象,根据两控制断面2009-2011三年的非点源污染水质水量同步实测资料,运用平均浓度法估算非点源污染负荷,并结合河流断面控制流域的土地情况、人类活动等情况,分析了河流上下游控制断面的非点源污染特征。结果表明:非点源污染是沣河的主要污染源,河流上游区域非点源污染负荷所占比重大于下游区域;河流上下游断面非点源浓度基本相当,下游点源浓度大于上游;下游COD、TP和NO2—N的非点源负荷量是上游的10~20倍;人类活动所产生的点源排放对中下游河流水质影响更大。

Analysis of non-point source pollution characteristics in control sections of upstream and downstream river

In order to study the feature of non-point source pollution in control sections of upstream and downstream river,and the characteristics of non-point source pollution in the same section of different years,the paper took Dayukou section of Fenghe river upstream and Qinduzhen section of Fenghe river middle stream which is the tributary of Weihe River as the object of study,and analyzed the feature of non-point source pollution in control sections of upstream and downstream rive according to the synchronous data of water quality and quantity from 2009 to 2011 by using the mean concentration method to estimate the load of non-point source pollution and combining the different basin situations of human activities and land types.The result shows that non-point source pollution is the main pollution of Fenghe River . The load proportion of non-point source pollution in upstream section of river is larger than that in downstream section of river; it is basic equivalent for the non-point source pollution concentration between upstream and downstream sections of the river, but the point source pollution concentration in downstream section is higher than ithat in upstream section; the non-point source load of COD,TP and NO₂-N in downstream section is10-20 times that in upstream section;the point source pollution produced by human activities has greater influence on water quality in middle and downstream sections of river.