Estimation and Allocation Water Environmental Capacity of Dadu River of Luding Segment

Environmental capacity of the water basin was often used as the basis of total amount control of pollutants, which was concerned by environmental workers for a long time. However, with the governance of the on point source pollution, the non-point source (NPS) pollution drew people´s close attention day by day. This article was selected to the main non-point source pollution of Dadu River of Luding Segment. Through the existed results of water quality monitoring and drainage area´s pollution load estimated by means of export coefficient method, then established a calculation model of water environmental capacity (WEC), and finally classified the distribution of the remaining water environmental capacity. The results showed that the water of Dadu River of Luding Segment would be made full use of on the premise that the water quality of this area could reach the goal of environmental management, thus ease the water environmental pressure of this segment.