降雨特征和下垫面特征对径流污染的影响分析

Effect of Rainfall and Underlying Surface Characteristics of Runoff Pollution

对深圳光明新区典型下垫面的径流雨水水质和水量进行了监测分析,采用Pearson相关系数法研究了降雨特征和下垫面参数对径流污染物的平均浓度（event mean concentrations,EMCs）的影响。结果表明：（1）降雨特征和下垫面特征共同影响着污染物EMCs,而且污染物EMCs随雨前干旱天数、平均雨强和车流量的增加而上升,随着降雨量、降雨历时、最大雨强和汇流面的增加而下降。（2）雨前干旱天数、降雨量、降雨历时和车流量是影响研究区域降雨径流污染的主要参数。（3）污染物的冲刷规律存在一个临界雨强,当降雨强度小于临界雨强时,污染物以冲刷和溶解为主,污染物浓度随着雨强的增加而升高;当大于临界雨强时,污染物以稀释为主,随着雨强的增加,污染物浓度有所降低;公园植被浅沟中SS的累积和冲刷规律的临界雨强（或范围）介于0.15-0.49 mm/min。该研究结果旨在为研究区域降雨径流污染的评价和控制方案的设计、优化提供基础数据。

Pearson correlation coefficient method was used to analyze the effect of rainfall characteristics and land surface parameters on runoff pollution. Results showed that rainfall characteristics and surface characteristics affected pollutant EMCs. The pollutant EMCs increased as the increase of dry days, average rainfall intensity and traffic volume, and decreased as the increase of rainfall depth, rainfall duration, maximum rainfall intensity and catchment area. Dry days, rainfall, rainfall duration and traffic flow were the main factors of rainfall runoff pollution. There existed a critical rainfall intensity or range. When the rainfall intensity was less than the critical rainfall intensity, the pollutants were washed and dissolved, and the pollutant concentration increased with the increase of rainfall intensity. When the rainfall intensity was greater than the critical rainfall intensity, the pollutant was diluted and the pollutant concentration decreased with the increase of rainfall intensity. The critical rainfall intensity of the grass swales in the park was 0.15-0.49 mm/min. The study would provide basis for the optimization of design, evaluation of regional rainfall runoff pollution and control scheme.