山美水库水质指标特征分析和生态调控效果评价

Analysis of water quality index characteristics and evaluation of ecological control ef fect of shanmei reservoir

本文以山美水库以渔治水生态调控前(2019年)和实施一年后(2020年)的水质监测结果为依据,从时间、空间比对库区水质指标pH值、总氮(TN)、总磷(TP)、高锰酸盐指数(COD_(Mn))、叶绿素a(CHL.a)、透明度(SD)、综合营养状态指数、藻密度的变化趋势,分析评价水库进库、出库区域水质指标时空变化特征和综合营养状态;比对分析前后两年国控点实时监测的pH值和人工监测库面6个点位的藻密度、叶绿素a(CHL.a),评价以渔治水生态调控的效果,以期为水库生态环境评价、恢复和建设提供参考依据。结果表明:(1)时间上,夏季初秋时期为表层pH值高位即藻华风险期,该时期应加强监测预警。(2)空间上,TN进库和年均值两年都为劣Ⅴ类,TP进库浓度Ⅲ-Ⅳ类,主要污染源由上游支流带入,水库受上游污染的形势依旧严峻。(3)TLI和pH值、TN、TP、COD_(Mn)、CHL.a呈正相关变化特征,和SD呈负相关变化特征。这两年水库TLI均值在31.2~45.3,水库处于中营养状态。(4)比对分析藻密度、CHL.a和国控点表层pH值实时数据,说明通过以渔治水调控藻类、促进水体酸碱平衡初见成效。

This paper is based on the water quality monitoring results before fishery ecological control(2019)and one year after implementation(2020),from the change trend of time and spatial comparison,pH value,total nitrogen(TN),total phosphorus(TP),permanganate index(COD_(Mn)),chlorophyll a(CHL.a),transparency(SD),comprehensive nutritional state index,and algal density,Analyze and evaluate the spatial and temporal change characteristics and comprehensive nutritional status of the water quality indicators in the inlet and exit areas of the reservoir;pH value with real-time monitoring of national control points in two years before and after the analysis and algae density and chlorophyll a(CHL.a at 6 points before and after the manual monitoring library surface),to evaluate the effect of ecological regulation by fishing and water control,in order to provide a reference basis for the reservoir ecological environment evaluation,restoration and construction,The results show that:(1)In terms of time,summer early autumn is the surface pH value is the algae risk period,monitoring and early warning should be strengthened.(2)Spatially of space,TN inflow and annual average are inferior class V in two years,and TP inflow concentration-class.The main pollution sources are brought by upstream tributaries,and the situation of reservoir caused by upstream pollution is still grim.(3)TLI and pH value,TN,TP,COD_(Mn),CHL.a are characterized by positive correlation changes and negative correlation changes in SD.The mean TLI of the reservoir is in 31.2-45.3,and the reservoir is in medium nutrition.(4)Alignment analysis of real-time data of algae density,CHL.a and surface pH value of national control points shows that initial results in regulating algae and promoting water acid and base balance.