基于控制单元的襄河流域容量总量控制及水质达标对策

Pollutant total amount control technique based on environmental capacity and countermeasure proposal to achieve water quality objectives in control unit of Xianghe river basin

采用乡镇行政区划与流域管理相结合的方式,对襄河流域控制单元进行了划分,调查了单元内各污染源污染指标的排放入河情况。根据控制断面的水质目标,计算了各控制区近10年最枯月平均流量下的水环境容量,进而确定各控制单元污染物的削减任务量和具体减排措施。结果表明,流域主要污染源为城镇生活、畜禽养殖和种植业,首要污染物为氨氮、总磷(Total phosphorus,TP)和化学需氧量(Chemical oxygen demand,CODcr)。基于襄河流域3个控制区,9个控制单元的划分方案,各控制单元排污入河量均较大幅度的超过了其水环境容量。近期削减任务量较高为下游C段控制区的襄河镇、六镇镇和十字镇等3个控制单元,为保证襄河入滁河控制断面水质达标,其CODcr、氨氮和总磷的削减比例要分别达到54.6%、82.9%和85.7%。

This study divided control units for Xianghe river basin by combining the county administrative boundary and watershed management. The pollutant discharge amount from multiple sources into the river in each control unit was investigated. The water environmental capacities of each control watershed were calculated under the hydrological condition that average flow of dried-up month at the last 10 years according to the water quality target of control sections. The pollutant reduction amount and emission reduction measures have been pointed out definitely based on control units. The results indicate that the primary pollution sources of Xianghe river basin are urban life source, livestock and poultry source, agricultural source. The dominant pollutants are ammonia nitrogen（NH3-N）, total phosphorus（TP） and chemical oxygen demand（CODcr）. Pollution discharge into the river of each control units greatly exceeds its water environment capacity based on the division of 3 control watersheds and 9 control units. 3 control units that Xianghe town, Liuzhen town and Shizi town in the C section control watershed have higher reduction planning of pollutant in the near future. To achieve the water quality target of river cross section that Xianghe into the Chuhe river Estuarine, reduction rate of CODcr, NH3-N and TP need to reach 54.6%, 82.9% and 85.7%, respectively.