暴雨径流潜流过程及其对分层水库水质的影响

为探究汛期暴雨径流潜入演变过程及其对分层水库水质的影响，以西安金盆水库为研究对象，对2015年6月和2017年10月2次暴雨径流过程中各监测点水温、溶解氧、浊度、总氮、总磷和COD_Mn等水质指标进行持续监测.结果表明：径流量在300~400m³/s时，潜流经历全断面径流-底部潜流-中部潜流3个阶段，最终潜入主库区中部水体.暴雨径流的汇入使水库热分层结构稳定性受到一定破坏，中下部水体溶解氧得到补充.暴雨径流携带的大量泥沙及氮、磷营养盐等污染物质会对水库水质造成较大冲击，2015年6月暴雨径流使水库中层水体总氮、总磷、COD_Mn和浊度从1.60，0.021，3.70mg/L和5NTU增大为2.37，0.100，5.80mg/L和93NTU，水质污染特征为短时高污染负荷.

Impact of stormwater inflow on water quality of stratified source reservoir

To explore the intrusion processes of the density current and its influences on water quality in rainfall events, water temperature, dissolved oxygen, turbidity and related contaminants were monitored in June 2015 and October 2017. 11 monitoring sections were set along the upstream to main basin in Jinpen Reservoir (JPR). The underflow plunged into reservoir undergoes three stages when the inflow was 300~400m³/s:whole-section intrusion with greater water velocity, bottom intrusion with high density and mid-intrusion due to sedimentation of slit. The underflow caused the loss of thermal stability of water column, while the dissolved oxygen in the middle and lower water column were supplemented. Quantities of slit with underflow containing organic matters, nutrients and inorganic substances were transformed into reservoir and the concentration of total nitrogen, total phosphorus, turbidity and other index were resultantly increased in water column. For example, in June 2015, TN, TP, COD_Mn and turbidity were increased from 1.60, 0.021, 3.70mg/L and 5NTU to 2.37, 0.100, 5.80mg/L and 93NTU, respectively.