Studies On Distribution Of Water Environmental Capacity And Pollutants Discharging Reducation For Jinjiang River Basin

Water pollutant capacity calculation and total amount allocation, the most critical part of basic research on water environment management, is the important measure to guarantee water environmental safety and promote regional sustainable economic and social development. Jin River,as a primary tributary of Gan River,has relatively good ecological environment quality. However, with the rapid development of urban economy, increasing water supply for industrial, agricultural and domestic use causes water shortage, ecological environment damage, and water quality aggravation appears increasing trend year by year as the result of large pollutants emission.Based on domestic and foreign researches on water environmental capacity and total amount control, combining with characteristics of water environment, pollution situation and social-economic factors in Jin River, this research made a study on water capacity allocation method which combines amount control target model of water environmental capacity and fair efficiency. The research content and results are as follows:(1) Through field investigation on pollution sources and the current discharge situation in Jin River, this paper analyzed the main water environmental problems and current situation of water quality, confirmed main pollutnats influencing water quality in Jin river basin is COD and ammonia nitrogen, and divided river basin into several control units;(2) Applying one-dimensional and two dimensional models, combining with river basin hydrological conditions, this paper evaluated water quality goal of each control unit, and analyzed unit environmental capacity. Results show that, the largest water environmental capacity of COD and ammonia nitrogen in Jin River basin is Shangyi and Gao'an control units, followed by Xinfeng and Wanzai.(3) Using goal function and constraint equation to reduce dimension, considering the upper and lower limit condition, though rational assessment, this paper found out optimal solution of main pollutant total amount allocation in each control unit of the Jin river, and on this basis put forward total amount reduction plan of control section in each unit control.