南水北调中线工程引入密云水库水质变化趋势分析

Analysis on the change trend of water quality of Miyun reservoir introduced from the middle route of South-to-North water transfer Project

随着2015年9月南水北调中线工程引入的“南水”陆续进入密云水库.密云水库的蓄水量有了明显提升。密云水库是北京市唯一的地表饮用水源地,担负着首都城市供水的重任,密云水库的水质安全尤为重要。水体富营养化是密云水库目前面临的主要水质威胁.为了掌握南水北调中线工程引入水源(南水)入库对密云水库水质的影响,通过分析汛期中(5—10月)一些与水体富营养化相关的指标参数:TN、NH3一N、TP、DO、CODMn、Chla、水温等对南水进入密云水库前后的水质状况进行分析,掌握水质变化趋势。得出深水区水质稳定,基本没有发生水华趋势;浅水区部分营养指标小幅升高,随着密云水库蓄水量的增加水华发生压力有所缓解,用以预测密云水库水质发展趋势。

The water storage capacity of Miyun Reservoir has been significantly improved since September of 2015,due to the water introduced from the middle route of South-to-North water transfer project.Miyun reservoir,as the only source of surface drinking water supplying for Beijing,is responsible for the water supply of capital city,and its water quality is particularly important.The eutrophication of reservoir is a main threat in the water quality currently faced by Miyun reservoir.To grasp the impact of the introduction on the water quality of Miyun reservoir,the paper analyzes some indicators related to eutrophication in the flood season (May-October),such as total nitrogen (TN),ammonia nitrogen (NH^+4-N),total phosphorus (TP),dissolved oxygen (DO),permanganate index (CODMn),chlorophyll a (Chla),water temperature (T)The paper analyzes the water quality before and after "South Water"enters Miyun reservoir,and grasps the change trend of water quality.The paper ultimately concludes that:the water storage capacity is obviously increased after the introduction of "South Water";the water quality in the deep water area is stable with no trend of water bloom;some nutrient indicators in the shallow water area increase slightly, which needs further observion to analyze the causes.In general,water bloom of Miyun reservoir has been alleviated after the water introduction from the middle route of South-to-North water transfer project,whichcan be used to forecast the change trend of water quality in this reservior.