Application and establishment model of non-point source pollution based on statistical data

The study on non-point source pollution is an important aspect in the research on water environment pollution. the non-point source pollution, featured by extensive coverage, dynamic complexity and difficult quantification of accurate spatial location and discharge volume, is a key and difficult issue for the study of water environment pollution. In this paper, an improved export coefficient method is proposed to estimate non-point source pollution load in watersheds, samely considering the influences of rainfall and the reduction of pollutant in the process of transport. Taking Jinghe River in Shaanxi province as example, through combination with the statistical data information of total nitrogen nutrition resources from 2002 to 2007 and using the export coefficient model, the average non-point source load of total nitrogen above Zhangjiashan for many years is 6014.5986 t, and in 2003 and 2007, the amounts are 21171.130 t and 5163.882 t respectively and for other years, the average amount is 2432.0347 t. The amounts of precipitation and runoff are large in wet years of 2003 and 2007, so the non-point source pollution loads generated are large too;in other years, the non-point source pollution loads are less because of less rainfall in normal-water years.