杭州市城区不同土地利用类型降雨径流污染特征

城市土地利用方式是影响城区流域水质的主要因素，与水体水质之间存在相关关系，这种关系受到土地利用类型及其空间分布的影响。以杭州市为例，对不同土地利用类型的地表径流水质进行了监测，并对地表雨水径流污染物的出流规律，污染物的事件平均质量浓度（EMC），以及污染物负荷量进行了探讨。研究结果表明，在径流初期5～20min，地表径流污染物质量浓度大多达到较高值，随着降雨历时的延续，污染物质量浓度呈波浪状降低，直至趋于平稳，具有明显的初期冲刷效应；污染物年负荷量在不同用地类型之间的高低顺序为：交通区、工业区、商业区、居民区。

Pollution characteristics of runoff in different function areas of Hangzhou city

The urban land use is a major factor affecting water quality in the urban watershed, which has the correlation with water quality, i. e. , this relationship is affected by the types of land use and the spatial distribution. The surface runoff in different function areas of Hangzhou was monitored after typical rainfall to investigate the variations of pollutants concentration, event mean concentrations （ EMCs ） and the pollutant load of runoff caused by rainfall water. Results showed that the pollutant concentration is up to the higher value in the first 5-20 min and then descended to a stable value in a wavy pattern, which indicates an obvious scouring effect in the early step of rainfall. Furthermore, the pollution load in different types of land use from high to low is traffic area, industrial area, commercial area and residential area.