抚仙湖流域城镇降雨径流污染特征及排放负荷研究

Research on Pollution Characteristics and Emission Load of Urban Rainfall Runoff in the Fuxian Lake Watershed,Yunnan

对澄江县凤麓镇典型降雨事件地表径流污染时空变化特征进行系统分析,并结合气象数据和下垫面面积等资料,运用SCS模型对降雨径流污染负荷进行了精确估算,结果表明:(1)澄江县凤麓镇径流主要污染物为SS、COD、TP及TN,均超出国家地表水环境质量标准Ⅴ类水标准,氮营养盐NH3-N、NO3-N也有不同程度的污染;降雨过程中主要污染物均表现为径流产生初期浓度较高,随着降雨时间的延长以及径流量的减少,各污染物浓度也随之呈现波动下降趋势;强度较大的降雨主要表现出稀释作用,即雨强越大,污染物浓度相对较低。(2)2016年凤麓镇全年径流总量为157.58×104m3,2016年污染物排放负荷以SS和COD为主,分别达到261.85 t/a及166.34 t/a,氮营养盐污染负荷中以NO3-N为主。

This study has analyzed the temporal and spatial variation characteristics of land surface runoff pollution in typical rainfall events in Chengjiang city. The runoff pollution load of chengjiang city was accurately estimated through SCS model. The results showed that the main runoff pollutants in Fenglu town in Chengjiang County were SS, COD, TP and TN, and the concentration of them exceeded the fifth level of the national surface water environmental quality standard. The concentrations of NH 4 ＋-N and NO 3-N also indicated a certain degree of pollution. The main pollutants had high concentrations in the initial rain water. The concentration of each pollutant decreased as time went by. The intensity of rainfall mainly caused dilution effect, which meant that the greater the rain intensity, the lower the pollutant concentration. The total annual runoff volume in Fenglu town was 157.58×10^4m^3 in 2016. The predominant pollutant emission loads were SS and COD, and their quantities reached 261.85 t/a and 166.34 t/a, respectively. NO 3-N was the main pollutants among nitrogen nutrients.