东北地区春季融雪期非点源污染负荷估算方法及应用

针对我国东北地区春季融雪期非点源污染的形成特点,提出了基于现场监测的径流浓度法估算春季融雪期非点源污染。该方法主要包括监测频次确定、监测点位布设、现场监测、融雪径流计算、非点源污染产生量估算、典型子流域入河系数估算和非点源污染入河量估算等7个过程。其中,监测点布设于不同土地利用类型的平均坡度与该种土地利用类型的主要土壤类型重合的区域,监测频次通过分析融雪过程和融雪径流特征确定。将该方法应用于东北地区的阿什河流域,计算出春季融雪期阿什河流域非点源污染COD的产生量为1 637.03 t,入河量为151.11 t。

Study and Application of Estimation Method for Spring Non-point Source Pollution in Northeast China

Non-point source pollution(NSP) can be caused by spring snowmelt runoff in mid-latitude climatic regions(30°~60°),including Northeast China.In view of the NSP formation characteristics in the spring snowmelt period in the Northeast China,the study proposed an estimation method to calculate the NSP output loads based on field-monitoring and calculate the export loads based on the ratio of export loads in the period.This method had seven processes including monitoring frequency determination,monitoring site arrangement,in-situ monitoring,snowmelt runoff simulation,NSP output load estimation,export coefficient estimation of the typical sub-watershed and the estimation of NSP export loads.In the implementation of the method,the monitoring sites of different land use types were located in the overlapped areas of the main soil type and the average slope.The monitoring frequency was determined by the analysis of snowmelt process and the characteristics of snowmelt runoff.Runoff in spring was calculated by mechanism model.The ratio of export loads was the quotient,dividing output loads by export loads of NSP in typical sub-watershed.Based on the application of this method in the Ashihe watershed in Northeast China,the NSP output loads of COD was 1 637.03 t and the NSP export loads of COD was 151.11 t during the snowmelt period in spring.