晋江流域污染负荷空间分布及关键源区识别

提出了利用水文和水质同步监测资料计算流域污染负荷空间分布的一般程序,并探讨了采用污染负荷贡献与集水区面积占比关系识别流域污染关键源区的方法,并在晋江流域进行了实例应用.结果表明:晋江下游取水口金鸡断面污染负荷主要来自东溪和西溪,枯水期CODMn、NH3-N和TP负荷分别是226.8、27.1和17.1g/s,占丰、平水期的18%~67%.丰、枯水期东溪和西溪对金鸡断面污染负荷贡献基本相当,而平水期西溪贡献显著大于东溪.晋江流域污染关键源区分别为蓬壶-长厅桥区间、长厅桥-港龙区间、横口-园美区间等5个断面区间,该关键源区识别方法不仅较好反映了污染物浓度和污染负荷在流域内的空间分布,同时还指出了主要污染物及敏感时期,可为后期的污染治理提供依据.本研究提出的污染负荷贡献计算程序以及关键源区识别方法具有较好的普适性,可为其他流域提供借鉴.

Spatial distribution of pollution load and critical source area identification in the Jinjiang River Basin

Based on the monitoring data on water quantity and quality at different river cross sections, a procedure on calculating the spatial distribution of pollutant loads was suggested. A method for identifying critical source area based on the relationship between pollutant loads and catchment areas in sub-areas was further proposed. The procedure and method had been taken into practice in the Jinjiang River Basin, an important drinking water source area. The results showed that the output pollutant loads of the Jinjiang River Basin (Jinji water intake section) mainly derived from East stream (EStm) and West stream (WStm). In low river flow periods, the output pollutant loads of CODMn, NH3-N (ammonia nitrogen) and TP (total phosphorus) were 226.8, 27.1 and 17.1g/s, which accounted for 18%~67% of high and normal flow periods. In high and low flow periods, EStm (Honglai section above) and WStm (Yuanmei section above) had almost same contribution in pollutant loads to the total outputs, but in normal flow period WStm generated significantly greater pollutant loads than EStm. Five critical source areas were indentified using the above method, including Penghu-Changtingqiao, Changtingqiao-Ganglong and Hengkou-Yuanmei section, etc. The identification method can not only mirror spatial distribution of pollutant concentrations and loads, but also define key pollutants and sensitive flow periods, which is beneficial to pollution control. The proposed procedure and method in this paper can be widely used in the other river basins in China.