基于水质-污染源响应关系的抚仙湖水环境承载力计算研究

Study on environmental carrying capacity of Fuxian Lake based on the response of water quality to pollution load

抚仙湖是中国最大的深水型淡水湖泊。随着流域入湖污染负荷的增加,其整体水质呈下降趋势,水污染呈自北向南和自沿岸向湖心推进的分布特征。本文依据水质-污染源响应关系,建立了基于湖泊水动力水质模型的水环境承载力计算方法;在对湖泊水动力和水质模型率定验证的基础上,计算得到了抚仙湖在规划水质目标(I类)下,CODMn、TN和TP这三类主要污染物的水环境承载力分别为20065.7 t/a、821.9 t/a和115.8 t/a;并根据抚仙湖环湖入湖河流及排污口分布特征,进一步提出了环湖分片主要污染物容许入湖负荷及污染物总量控制指标。

Fuxian Lake,the largest deep freshwater lake in China,is confronted with the challenge from the pollution.The water quality of this lake has been badly affected by pollution inlet.Based on response relationship between water quality and pollution loadings,the water environmental carrying capacity of CODMn,TN and TP in Fuxian Lake were calculated using a 2-D coupled model of water hydrodynamics and water quality in the paper.The numerical calculation results indicate that water environment carrying capacity of CODMn,TN and TP is 20065.7 t/a、821.9 t/a and 115.8 t/a respectively.In addition,the target reduction amounts of different pollutants in the different planning periods and different region were determined under the environment carrying capacity.