辽河流域清河水环境容量计算方法探究

Discussion on the water environmental capacity of Qinghe River in Liaohe River basin

以辽河流域铁岭段一级支流清河为例,按照全河段水质达标的考核方法,重新划定河段水质目标,采用一维水质模型计算在水功能区划水质目标约束条件下清河的CODCr和NH4-N的水环境容量。计算结果表明:研究河段枯、丰两种水文条件下CODCr的水环境容量为2 012、4 111 t/a,氨氮的水环境容量为46、80 t/a。由流域点源及非点源污染负荷现状确定研究区域所需污染削减量的取值范围,CODCr月削减699～874 t、NH4-N月削减406～441 t,即可满足水功能区水质要求。

Taking Qinghe river which is a tributary of the Liaohe River basin for example,according to the water quality standards achieved by every section of the water body,the paper redefined the water quality objectives of every segment.Using one-dimensional water quality model,the water environmental capacity of CODCr and NH4-N were 2012 and 46 t/a in dry season,4111 and 80 t/a in wet season.Finally,according to the pollution loads status of the point source and non-point source in the study area,the amount range of pollution reduction required was defined.Reduced capacity of 699 ~ 874 t CODCr and 406 ~ 441 t NH4-N monthly can satisfy the water quality objectives.