官厅水库入库断面水质多指标评价与演变特征分析

水体质量状况及其污染特征是流域水污染防治规划和治理措施制定的前提和基础。采用主成分分析和层次聚类分析等多元统计分析方法,选取溶解氧、高锰酸盐指数、化学需氧量等10个不同类型的监测指标,综合评价了官厅水库入库断面八号桥2006—2017年丰水期和枯水期水质年际变化特征,识别了不同阶段关键污染指标。结果表明:各年份丰水期(9月)大多数水质指标均优于枯水期(5月),特别是粪大肠菌群和氨氮,但总磷和高锰酸盐指数的差异较小。根据水质指标年际变化情况,可将研究期分为污染严重阶段(2006—2007年)、污染改善阶段(2008—2015年)和污染全面好转阶段(2016—2017年)。大部分水质指标呈现逐年好转的趋势,特别是粪大肠菌群、氨氮和五日生化需氧量,但总磷仍是官厅水库入库河流的重要污染指标。

Multi-index Evaluation and Evolution Characteristic Analysis of Water Quality at Inlet Section of Guanting Reservoir

Assessment of water quality and analysis of pollution characteristics are the premise and basis of water pollution prevention planning and control measures. In this paper,10 monitoring indicators,such as dissolved oxygen,permanganate index and chemical oxygen demand,were selected as evaluation indicators by combining principal component analysis and hierarchical clustering analysis. The interannual variation characteristics of water quality of Bahaoqiao section in Guanting reservoir entrance during the dry season(May) and floodseason(September) from 2006 to 2017 were comprehensively evaluated,and key pollution indicators at different stages were identified. The results showed that most water quality indicators in flood season were better than those in dry season,especially fecal coliform bacteria and ammonia nitrogen,but the difference of total phosphorus and permanganate index was small. According to the annual variation of water quality indicators,the research period can be divided into three stages:serious pollution stage (2006-2007),pollution improvement stage (2008-2015) and comprehensive improvement stage (2016-2017). Most water quality indicators showed a trend of improvement year by year,especially fecal coliform bacteria,ammonia nitrogen and five-day biochemical oxygen demand,but total phosphorus was still important pollution indicators of Guanting reservoir inflow river.