The Water Environmental Capacity Research In Liangshan State

The calculation of water environmental capacity is a significant technical measure of water environmental management, and it is the foundation of ensuring the safety of the river basin and the sustainable development of regional economy and society. The research of calculating the water environmental capacity is always the focus and frontier of the water environment management subject.Based on the national water environmental capacity check and ratification guide by the Chinese environmental planning institute,2003, this paper studied and calculated the water environmental capacity of3108.72kilometers flow path of four main watercourse systems including Jingsha river and Yalong river in Liangshan state, offering scientific basis to the water quality management of the river system in the state.In this paper, first, we systematically analyzed the architectural feature of the river systems in Liangshan state, and then we studied the watercourse related hydrology parameters such as flux, flow rate, river width and sloping etc. Based on that, we generalized the space-time distribution of the pollution source within the river way and the basin perimeter. We used the capacity computation model and technical parameters that is determined by the analogy analysis method and is suitable to local water environmental feature to analyze and compute the main streams and tributaries’ water environmental capacity of the four main river systems consists of Jingsha river, Yalong river, Anning river, and Dadu river. In the process of volumetric analysis and computation, we paid full attention to the feature and maneuverability of the water environment management. A public administration district is divided as a calculation and control unit. The concentration value of the control unit entrance section is seted according to the water body function condition to analyze and calculate the water environmental capacity in each control unit. The environmental capacity calculated by this measure is more safe and beneficial to control and manage the water environmental quality of the basin for administrative departments.In this paper, we employed a two dimension calculation model to calculate the water environment capacity of the main streams of Jingsha river, Yalong river, Anning river, and Dadu river to satisfy the hydrodynamics state condition of real river way. For the tributaries that have smaller water surfaces, one-dimension calculation model is adopted and it basically satisfies the computational accuracy requirement.The result of our work showed the water environmental capacity distribution of the four main water systems and the corresponding water systems capacity distribution map is drawn. The analysis of water environment capacity indicates that in Liangshan state, the available COD ideal water environment capacity is234600ton per year, and the ammonia nitrogen water environment capacity is12900ton per year.