新安江水库近10年水质演变趋势及与水文气象因子的相关分析

Water quality trends in recent 10 years and correlation with hydro-meteorological factors in Xin'anjiang Reservoir

根据2003—2012年水质逐月监测数据和水文气象资料,对新安江水库水质和营养状态变化进行分析,探讨了新安江水库水质演变规律及其与水文气象因子之间的关系.结果表明,近10年间新安江水库总磷、总氮、生化需氧量和p H存在显著的年际变化.叶绿素a浓度上升趋势明显.综合营养状态指数显示水库营养状态由贫营养逐步向中营养转变.营养盐和叶绿素a浓度存在显著空间差异性,河流区高于过渡区和湖泊区,且丰水期高于枯水期,说明水库营养盐主要来自面源污染.年均气温及水温呈下降趋势,降雨量、出入库流量则呈上升趋势,相关分析表明水文气象因子对水质指标影响较大.

Based on the monthly water quality monitoring data and hydro-meteorological data from 2003 to 2012,this study analyzed water quality and nutritional status in Xin' anjiang reservoir and investigated the relationship between water quality change and hydro-meteorological factors. The results showed that the interannual variability of total phosphorus,total nitrogen,BOD and p H value were significant in the past 10 years in Xin' anjiang Reservoir. Chlorophyll a concentration increased in recent 10 years. Comprehensive nutrition state index showed that the reservoir trophic status was improved gradually from oligotrophic to mesotrophic. Nutrient and chlorophyll a was higher in riverine zone than transitional and lacustrine zone and in flooding season than dry season,which indicated that reservoir nutrients came mainly from non-point source pollution. The mean annual air temperature and water temperature decreased,while rainfall,out flow and in flow increased. The correlation analysis showed that hydro-meteorological factors had significant impacts on water quality index.