长沙湘江枢纽库区蓄水前后水质营养状态变化趋势

The Trend of Water Quality Nutritional Status before and after Water Storage in Xiangjiang Hub Reservoir Area Changsha

为了全面揭示湘江长沙综合枢纽蓄水上游长沙段的水环境参数变化规律,选取判断水体富营养化的重要指标:COD Mn、氨氮、总磷3个参数作为分析对象。选取湘江特大桥前端至三叉矶大桥后端各断面水体为研究对象,对长沙市饮用水水源水质营养状况进行蓄水前后对比分析。根据总体数据分析,高锰酸盐指数、氨氮含量随着湘江上游往下游逐级上升,总磷含量的变化则呈现为上下游高,中游低的趋势。蓄水后水质较蓄水前水质有所改善,部分检测断面对应营养状态等级从“中营养”降为了“贫营养”。

In this paper,in order to reveal the change rule of water environment parameters of Changsha section,which is at the upstream of Xiangjiang River,Changsha Comprehensive Hub,three important indicators of water eutrophication including the permanganate index,the content of ammonia nitrogen and the content of total phosphorus were selected as analysis objects.The water of each river cross section from the front end of Xiangjiang Bridge to the back end of Sanchaji Bridge is selected as research object.They are the source of drinking water in Changsha City.The water quality and nutrient condition was comparatively studied before and after impoundment.The analysis results indicate that the permanganate index and the content of ammonia nitrogen increased from upstream to downstream of the Xiangjiang River,while the content of total phosphorus is higher in upstream and downstream than in midstream along the watershed.And the water quality after impoundment is better than the quality before impoundment,the nutritional status grade in some sampling section changed from"medium nutrition"to"poor nutrition"after impoundment.