Abstract:

Calculation of water environmental capacity is an important basis in distribution of water environmental capacity,relating to the reachability of water quality target in river basin.It is very important for making distribution plan of water environmental capacity to calculate water environmental capacity based on control units,which are the basic implementation units in water environmental management of river basin.As a case study of the Jinjiang River basin,Jiangxi province,the water environmental capacities of COD and NH+4N were both calculated in each control unit according to the calculation methods of water environmental capacity,pollution situation, water quality status and water environmental function division in the river basin.Results showed that water environmental capacities of control unit was closely related to the distribution of drain outlet and water quality target in the function area; the capacity of COD in Gaoan control unit was the largest 21 811 t/a,followed by Shangyin control unit 21 168 t/a,Xinfeng control unit 14 493 t/a and Wanzai control unit  7 607 t/a.The distribution characteristics of NH+4N capacity in each control unit were slightly different from that of COD capacity,and Shangyi control unit had the largest capacity 790 t/a,followed by Gaoan control unit 664 t/a,Xinfeng control unit 462 t/a and Wanzai control unit 303 t/a