Study On Total Amount Control Of Pollutant In Hanjiang River (Shaanxi Section)

In order to alleviate the pollution and poor quality of the ecological environment of upper reaches of the Hanjiang River tributaries,protecting the important water source area of Middle route of South to North Water Transfer Project, the total amount control of pollutant based on water ecological carrying capacity of the Hanjiang River (Shaanxi section) was researchd;Firstly,Taking water ecosystem and economic society coordinated development as the goal, combined with the concept of sustainable development, the research on the water ecological carrying capacity was conducted. Secondly, based on the theory of water environmental capacity, the water environmental capacity of river upper reaches of Hanjiang River was calculated by the model of mathematics;Finally, carrying water ecological comprehensive consideration of the natural property and social property, Total pollutant allocation based on water ecological carrying capacity ,Acccss to pollutant emissions and reductions in watersheds. The main research contents are as follows:(1)Based on the concept of sustainable development and the existing research results, the theoretical research on the bearing capacity of basin water ecological was discussed,water ecological carrying capacity index system based on "driving force-pressure-state-impact-response"(D-P-S-I-R) of Hanjiang River (Shaanxi section) was established ,using AHP to determine the weight of each index.(2)After testing the effectiveness of the system dynamics model, the system dynamics model of Hanjiang River (Shaanxi section) water ecological carrying capacity was established,evaluating the water ecological carrying capacity combined with the membership method quantitative assessmenl;through the simulation analysis on the bearing capacity of the 5 control schemes. the comprehensive control scheme which consists of moderate speed of economic development and the population growth rate, water saving and pollution control,increase investment in environmental protection docs well to water ecological carrying capacity significantly.(3)The sewage situation within the basin from 2016 to 2020 was forccasted,Based on the investigation of hydrology, water quality, pollutant emission; the water quality in the basin is simulated with one-dimensional hydrodynamic water quality model; based on the control section to amount to mark ,water environmental capacity model was established and water environmental capacity of COD was quantitative analysed.(4)Through the theoretical study of total pollutant control,considering the natural attribute and social attribute of water ecological carrying capacity,a method is proposed,based on the ecological carrying capacity of water resources in the basin, allowable pollutant emission was received.On this basis, the reduction and reduction ratio of pollutants was determined. And the corresponding total control measures was put forward.