Study On Water Environmental Capacity Of The Chuanzi River In ChangDe Hunan Province

Water environment as part of the system environment, its importance and scarcity have gradually attracted attention. With the worldwide water resources dwindling and water pollution increasing, environmental capacity of river water is imperative. It can be used as theoretical basis to judge whether the river water environment and economic development along the river area are in coordination of integrated and response.This article first discussed the basic theory of environmental capacity of river water and some basic environmental capacity types, and then introduced the result of Chuanzi River functional zoning, while through a comprehensive analysis of Chuanzi River water quality to find out the main pollution parameters, namely Water environmental capacity of the pollutant index. The one dimensional water quality model and two-dimensional water quality model that were used to comprehensively analyze the water environmental capacity were compared and analyzed. Finally we calculated the amount of pollution reduction in Chuanzi River and reached pollution control program based on the analysis of the results of Chuanzi River. Main results of the paper are as follows:1) via the river basin water quality monitoring data by Changde Municipal Environmental Protection Bureau on Chuanzi River in 2001 and 2009, water quality assessment of 8 sections of Chuanzi River results showed that the overall water quality of Chuanzi River is inferior V water quality, pollution was serious. At the same time in selected water quality evaluation process, BOD5, COD, ammonia nitrogen, these three kinds of representative pollutants as a factor for this calculation.(2) One and two dimensional models were used to calculate the Chuanzi River water environmental capacity, and under these two methods are two kinds of water environmental capacity results were:â‘ the result of the one dimensional model:BOD5:238.77t/a, COD:454.48t/a, ammonia nitrogen:53.54t/a.â‘¡the result of the second dimensional model:BOD5:178.90t/a, COD: 298.80t/a, ammonia nitrogen:33.40t/a.(3) Through the comparative analysis of one-dimensional and two-dimensional results, it showed that it was theoretically possible to use one and two dimensional methods to calculate on Chuanzi River environment capacity; either one dimensional or two-dimensional calculations results showed the pollutants discharged into the Chuanzi River was beyond the river water environment capacity; using one-dimensional model, the calculated water environmental capacity of three pollutant index values were greater than the value of two-dimensional model, which showed one-dimensional calculation of the water environmental capacity constrained on the capacity of water environment capacity less than the two-dimensional calculation.(4) Through the establishment of water quality model, simulation, of Chuanzi River water quality, based on the principle of corresponding cuts, combined with Chuanzi River water environment capacity, total amount of pollutants were reduced, so that each Chuanzi River water quality functional divisions reached the discharge standards, (â…£water) demands.According to two-dimensional water environment capacity calculation, the total Chuanzi River pollution reduction results are as followsBOD5 total discharge 359.88t/a,water environment capacity 178.90t/a,total reduction 180.98t/a, total reduction rate 50.29%.COD total discharge 748.28t/,water environment capacity 298.80t/,total reduction 449.48t/a, total reduction rate 60.07%.ammonia nitrogen total discharge 108.04t/a,water environment capacity 33.40t/a,total reduction 74.64t/a, total reduction rate 69.09.