The Environmental Capacity of the Nitrogen,Phosphorus Pollutants in Guan River Estuary and Adjacent Coastal Area,Northern Jiangsu Province

Under the impact of intensive human activities,discharge of chemical pollutants increasing gradually,Guan River Estuary and adjacent Coastal area(GREC)is suffered serious pollution and eutrophicational problems.Environmental capacity is the basis of pollutants total load control.In order to solve these problems,a three-dimensional water quality model based on FVCOM is constructed to estimate the marine environmental capacity of nitrogen and phosphorus nutrients in GREC,whose simulation results are rational for the area.According to the model,if the target is set to achieve marine functional zoning requirements in Jiangsu Province,the environmental capacity of dissolved inorganic nitrogen(DIN)and soluble reactiv phosphorus(SRP)in one year are approximately 6 000 and 600respectively.Environmental capacity has obvious seasonal variation,which is higher in summer with 2 900 and 260t,and lower in winter and autumn with 1 000 and 90tfor DIN and SRP,respectively.Based on the environmental capacity,the loads of DIN and SRP need to reduce,which accord for 55% and 73% of current nutrients loads in GREC.The research results can provide scientific basis for controlling the land sourced pollutant amount in GREC coastal zone,northern Jiangsu Province.