Non-point Source Tn Load Research In Weihe Basin Above Lintong Section

The Weihe basin above Lintong Section is the most important zone in Shaanxi Province because there are Baoji, Xianyang, and Xi'an cities in it. Along with the economic and social developments, river N-pollution becomes more and more serious. In which, non-point N pollution is occupied sizeable share. In order to reasonably and effectively control and alleviate Non-point N pollution, it is necessary to make clear the current and future situations of the basin's non-point N pollution loads. For this purpose, the non-point N loads are estimated with various methods in this paper. They are mainly based upon Johnes's export coefficient modeling approach and the correlative method, and some improvements are made. Since these methods can reflect the social and natural influences on nonpoint source pollution, they are more reasonable. On the basis of the definite investigations and researches of the basin's natural and social situations, this paper uses five methods to estimate Non-point TN annual loads of the basin. This paper also carefully and impersonally defines the values of five export coefficients, which include planting area, urban area, natural area, livestock and humans. Finally, this paper reasonably analyzes and forecasts the future annual Non-point TN loads of the researched basin and so on.