生态清洁小流域污染物总量及水环境容量研究——以上海市华漕镇为例

Study on total pollutants and water environment capacity in ecological clean small watershed:case of Huacao Town in Shanghai City

上海市生态清洁小流域建设以治水为核心,以小流域水质作为关键指标。要从根本上实现小流域水质达标,需要先对污染源及水环境容量进行测算,根据测算结果才能制定更有针对性的整治思路及治理措施。以上海市华漕镇生态清洁小流域建设为例,根据污染源调查现状,结合水质目标、水文水动力条件、污染排放类型及空间布局等因素,测算现状华漕镇流域污染源总量及水环境容量。结果表明:依据量化数据分析比较,2019年华漕镇生态清洁小流域水环境余量COD_(Cr)为84.91 t/a,NH_(3)-N为-13.69 t/a,TP为-5.85 t/a,氨氮及总磷是流域主要污染因子,该结果与同期水质监测结果基本吻合,说明本次测算结果合理。依据上述主要污染物类型及排放量,从地表径流控制、生活污水排放控制、水生态修复治理、农业面源污染4个方面提出了整治实施方案。研究结果可为上海市全面开展生态清洁小流域建设提供参考。

The construction of ecological clean small watershed in Shanghai City takes the water treatment as core and the water quality as key indicator.In order to fundamentally achieve the water quality standard of small watershed,it is necessary to calculate the pollution source and water environment capacity,and then formulate more targeted remediation ideas and measures based on the calculation results.Taking the construction of ecological clean small watershed in Huacao Town,Shanghai City as an example,the total amount of pollution sources and water environmental capacity of Huacao Town watershed were calculated according to the pollutant investigation,water quality targets,hydrological and hydrodynamic conditions,pollution discharge types and spatial distribution.The results showed that in 2019 the water environment margin of the COD_(Cr) in Huacao Town was 84.91 t/a,the NH_(3)-N was-13.69 t/a,TP was-5.85 t/a,showing that ammonia nitrogen and total phosphorus were the main pollution factors in the watershed.The results are basically consistent with the water quality monitoring results in the same period,indicating that the calculation results are reasonable.According to the above-mentioned main pollutant types and emissions,targeted implementation plans are put forward from four aspects:surface runoff control,domestic sewage discharge control,water ecological restoration and control,agricultural non-point source control.The research results can provide a reference for the comprehensive development of ecological clean small watershed construction in Shanghai City.