大伙房水库控制流域水质变化及污染源识别

为识别大伙房水库控制流域水体水质现状及主要污染因子,通过统计分析2014—2018年大伙房水库控制流域水体的水质数据,采用综合加权指数法和主成分分析方法,开展了大伙房水库控制流域水体水质变化趋势及成因识别研究。结果表明:大伙房水库控制流域水体水质情况总体良好,主要污染因子为总氮和粪大肠菌群。库区水体营养状态整体为中营养,磷限制型,且综合营养状态指数呈逐年下降趋势。水库控制流域水体水质受到地质、气候、农业、畜禽养殖、居民生活等复合影响,主要污染源为农业种植、农村生活及畜禽养殖等农业面源。农业种植源是水体中总氮的主要来源,其贡献总体上先增高再缓慢降低,而农村生活及畜禽养殖源是粪大肠菌群的主要来源,其贡献年际无明显变化。研究表明,大伙房水库控制流域水体中总氮超标严重,主要原因为农业面源污染的氮排放,同时水体中总磷的缺乏限制总氮的去除,加剧了这一现象。

Changes in water quality and identification of the sources of water pollution in the drainage basin of Dahuofang Reservoir

The aim of this study was to assess water quality and identify factors of water pollution in the basin of the Dahuofang Reservoir. We analyzed the water quality data of the basin from 2014 to 2018 using the comprehensive weighted average nutritional status index and principal component analysis methods. Results showed that the major water pollution factors in the basin were total nitrogen(TN)and fecal coliform(FC). Water in the reservoir had the middle nutrient level, limited by phosphorus, and the eutrophication index gradually decreased over years. The sources of water pollution in the basin were primarily agricultural cultivation(for TN), and rural activities and livestock breeding(for FC). The contribution of agricultural cultivation as a source initially increased and sequentially decreased over the years. The contribution of rural activities and livestock breeding remained constant over the years. Therefore, the heavy pollution of total nitrogen in the waters of the basin was attributed to both the continuous emission from agricultural activities and the poor utilization of total nitrogen in waters with a lack of phosphorous.