The Research Of The Nansha River Basin Water Environmental Capacity

Water is the vital resource, which is the important and indispensable natural resource for human survival and economic development. In recent years, the water environment has been severely damaged with the rapid development of the domestic economy. Water shortage and pollution has become a major constraining factor of social and economic development. One of the reasons for the damage of water environmental is unreasonable development and utilization of its capacity. How to develop and utilize the existing capacity of the water environment, which is become an urgent problem in today’s society.Nansha River is belong to Liaohe River that originates in Qianshan Scenic Area and cross the north of Anshan. Nansha River carries the industrial wastewater and municipal sewage of the city. In recent years, industrial wastewater and domestic sewage have increased with the development of industrial production and urban population increasing. Large amounts of untreated sewage directly discharged into Nansha River, so that the suspended solids, COD and other pollutants exceeded and the river quality deteriorated, the smell thick, presenting black turbid state, the basic biological disappeared and water environmental deteriorated extremely.In this paper, it conducts a detailed analysis of the investigation for the water quality status and1996-2009Calendar year the water quality change of the Nanshahe River, The nansha river basin water quality in of present situation is bad V class, can not reach the function requirements, the main pollution type is good oxygen type and nutrient pollution type, the major pollutants are ammonia nitrogen and oxygen to chemical class. During1996-2009the nansha river water quality in the monitoring section was bad V class. All of them did not reach the water environment function requirements. The pollutants discharged exceed the standards mainly focused in the periods of normal flow and low flow In this paper, it also conducts a analysis of the investigation for pollution sources of the Nanshahe River, determine the Nanshahe River pollution caused by the main reason is point source, Just for point source, urban life the contribution of pollution is the largest, COD and ammonia nitrogen accounted for79.75%of the total emissions and96.03%;Industrial pollution sources of COD and ammonia nitrogen accounted for1.38%of the total emissions and1.66%.In this paper, comparison to usable range of zero dimension, one dimensional and2d water quality model, according to model selection principle and the actual situation of Nanshahe River, it should choose1dimension steady state water quality model to calculate water environmental capacity in the Nanshahe River for COD and Ammonia-nitrogen; According to the measured hydrological station flow, establish flow and other hydrology of the relationship between the parameters; According to different water conditions the degradation of pollutants range, determine COD and ammonia nitrogen degradation coefficient; River water environment in the functional zoning requirements to determine each river section water quality target;90%of the lowest flow over the years was chosen as desgin flow;With section function division of pollutant concentration and the background required concentration the difference as constraint concentration, for programming solver, to obtain the result:COD capacity for2634.20t/a, Ammonia nitrogen capacity for:134.97t/a. On the basis of calculation results, choosing capacity utilization rate, population, cultivated land, GDP and status quo load as evaluation indexes of total amount allocation, using experts scoring method to determine the weight coefficient, with the principle of the furthest environmental capacity utilization and total amount allocation rationality index, giving consideration to efficiency and fairness, it distributed water environmental capacity, and put forward reasonable allocation plan.