Reach On The Modeling Of Water Environmental Capacity In Plain River Network Areas

The water environmental capacity means that the maximum of pollutants carried by waters under certain water quality standard. It is a basic theoretical problem in the field of water environmental research. It is also an important application technology in the water environmental managements and the basic theory of controlling the total pollutants drained into the waters.This paper is focused on the water carrying capacity at plain river network area. After the comparison of present numerical models for water carrying capacity, a model for water environmental capacity based on the coupled model of river network hydrodynamic model and water quality model was developed which indicates the characteristics of tidal river network areas and applies to the project planning of flood control Integrated planning of water resources in Kunshan City.The main contents studied in this paper are as follows:(1) A water environmental capacity model was founded that can be used in the plain of river network areas. The model is based on the method of water environmental capacity definition. It is on the assumption that there is no pollution discharged into water functional districts. In accord with the result of the coupled model of river network hydrodynamic model and water quality model, we simulate the water self-purification capacity and dilution capacity of each water functional districts with method of water environmental capacity definition. Then, the water environmental capacity could be calculated.(2) The water evironmental capacity model of the rivers network has been made up base on the Kunshan project to control the flood and plan water resource, and we can use this model to forecast the water carrying capacity in the fuctional districts in each planned year. The corresponding measures for pollutant discharge decreasing were proposed according to the water evironmental capacity and different pollution levels, so that the total pollutant amount controlling was carried out and the water resouce can be protected.