中文摘要：

以2006年6月至2007年4月野外观测的8场降雨径流事件中TN、TP、COD与SS含量和流量数据为基础,分析了紫色土丘陵区农村集镇的降雨径流污染物来源、形态与输出负荷及初期冲刷效应,研究了农村集镇降雨径流污染特征.结果表明,农村集镇降雨径流中TN、TP、COD与SS的事件平均浓度（EMC）均值分别为25.52、3.63、714、2396mg·L^-1,年污染负荷分别为39.21、5.57、993、3335kg·hm^-2.农村集镇降雨径流污染物浓度峰值出现在流量峰值之前,两者间隔时间为3-45min.近40%的TN、TP、COD与SS污染负荷由占总径流量30%的初期径流所运移,降雨径流污染物具有中等的初期冲刷效应.可溶性氮、颗粒态磷分别是农村集镇降雨径流污染中氮、磷素输出的主要形态.可溶性氮输出量受最大雨强影响较大（r=-0.825,p〈0.05）,而颗粒态磷输出量较为稳定,受降雨特征影响较小.不透水地面源污染与沟道累积污染是农村集镇降雨径流的主要污染源,透水地（林地、旱坡地）的水土流失则加剧其污染.

英文摘要：

A small catchment of the Linshan township（area 2.32 hm^2）in Yangting county,Sichuan basin was selected to examine runoff discharge and content of total nitrogen（TN）,dissolved nitrogen（DN）,total phosphorus（TP）,dissolved phosphorus（DP）,chemical oxygen demand（COD）and suspended solids（SS）.Data was collected from the stormwater of 8 rainfall events from June 2006 to April 2007.Results showed that the averages of event mean concentration（EMC）for TN,TP,COD and SS were 25.52,3.63,714 and 2396 mg · L^-1,respectively.And the annual loads for TN,TP,COD and SS were 39.21,5.57,993,and 3335 kg · hm^-2,respectively.The peak pollutant concentrations in the storm water occurred 3-45 min before the peak concentrations appeared in the runoff.TN,TP,COD and SS showed medium mass first flushes,in which nearly 40% of the total pollutant loads were transported by the early runoff,comprising 30% of the total flow volume.Soluble nitrogen and particle-bound phosphorus were the main forms of nitrogen and phosphorus output.Soluble nitrogen was negatively related to the maximum rainfall intensity（r=-0.825,p〈0.05）,while particle-bound phosphorus was not related to rainfall parameters.The rainfall-runoff pollution of Linshan township was characterized by both non-point pollution from impervious areas and accumulative point pollution in the drainage ditches.Soil erosion and runoff from pervious forestland and slopeland intensified the runoff pollution.