河流水质模拟及污染源归因分析

针对大连市登沙河流域水环境质量问题，采用输出系数法估算流域内工业点源、农村生活、畜禽养殖、农业种植的氨氮和总磷入河污染负荷，基于QUAL2K水质模型模拟污染物的迁移转化规律，解析各污染源在不同时、空尺度下对河流中、下游水质考核断面的污染负荷贡献.结果表明：畜禽养殖是研究区氨氮污染的主要来源，分别占中游和下游断面氨氮总负荷的56.5%和43.2%；农业种植是总磷污染的主要来源，分别占中游和下游断面总磷总负荷的50.4%和59.1%.此外，由于天然降水及人类活动的季节性特征，各污染源的负荷贡献亦呈现年内变化.基于以上分析，进一步因地制宜地提出研究区水环境治理措施建议，研究可为我国农村地区中小河流水质改善及水环境管理提供示范参考和决策依据.

Water quality simulation and multi-source attribution analysis

Facing with the water quality deterioration in the Dengsha river watershed in Dalian, China, the pollutant loads of ammonia nitrogen and total phosphorus generated by various pollution sources were estimated, including industries, rural households, animal feedlots and agricultural planting. The QUAL2K water quality model was then applied to capture the migration and transformation of ammonia nitrogen and total phosphorus in the main river, and the contribution of each source to the total pollutant load was quantified at different temporal and spatial scales. Results indicated that animal feedlot was the major contributor of ammonia nitrogen load, accounting for 56.5% and 43.2% at the middle and downstream sections, respectively. The majority of total phosphorus load was contributed by agricultural planting, accounting for 50.4% and 59.1% at the middle and downstream sections, respectively. Moreover, contribution of pollutant sources also exhibited intra-annual variations due to the seasonality of natural rainfall and human activities. Based on these analyses, this study further proposed suggestions for water quality improvement and governance in the study region, which can therefore be a reference example for other small and medium-sized polluted watersheds.