中文摘要：

选择太湖上游典型城镇，在不同临前降雨条件下，对城镇地表径流系统地进行空间采样，分析采样样本的统计分布特征。结果显示，受城镇复杂人类活动的影响，城镇地表径流面源污染输出具有较大的空间差异，针对典型城镇整体的空间采样样本符合对数正态分布，基于样本频率分布特征，统计城镇地表径流的面源污染浓度，其中COD为7．729（7．299，8．184）mg·L^-1．TN和11P分别为1．790（1．752，1．829）mg·L^-1和0．117（0．107，0．129）mg·L^-1。对不同临前降雨条件下、不同用地类型的样本分别进行统计，获得不同临前降雨条件、不同城镇用地类型的地表径流面源污染浓度统计特征，证实了临前降雨条件、城镇用地类型对城镇地表径流面源污染输出有较大影响。

英文摘要：

Many researches have proved non-point pollution to be one of main factors causing water pollution. In recent years, there are many studies about non-point pollution load assessment of agriculture land use in watershed scale, but the non-point load from town are rarely studied. In order to assess non-point source pollution from town in Taihu basin, a surface runoff monitoring in typical town was carried out in different antecedent rainfall conditions. A total 74 runoff samples were collected and three constituent concentrations, including COD, total N and total P, were measured for all runoff samples. The results showed that the pollutant concentration varied largely due to different sampling locations, land use and antecedent rainfall conditions. The statistical tests for spatial differences proved that the constituent concentration of runoff samples accorded with logarithm normal distribution. Geometrical mean, less affected by extreme observations than arithmetical mean, was considered a more appropriate index for assessing representative concentration of town runoff. The averaged concentrations of COD, total N and total P in runoff for whole town were 7.729 mg· L^- 1 （7.299-8.184 mg· L^- 1 ）, 1.790 mg· L^- 1 （1.752- 1.829 mg· L^- 1 ） and 0.117 mg· L^- 1 （0.107-0.129 mg· L^- 1 ）, respectively, in different five-day antecedent rainfall conditions, the variation rates of concentration of COD, TN and TP were about 1.453, 1.820 and 2.111 times respectively. Pollutant concentrations of surface runoff varied with different land uses in town. The runoff concentrations of COD, total N and total P were 8.392 mg· L^- 1 , 1.943 mg· L^- 1 , and 0.145v for town residence land, respectively, and 8.669 mg· L^- 1 , 2.008 mg· L^- 1 , 0.097 mg· L^- 1 for industrial and commercial land, and 9.117 mg· L^- 1 , 2.768 mg· L^- 1 , 0.175 mg· L^- 1 for suburb residence land, and 9.338 mg· L^- 1, 1.957 mg· L^- 1, 0.139mg· L^- 1 for transportation land.