淮河流域水质污染时空变异特征分析

Analysis of spatial and temporal variation of water quality in Huaihe River Basin

选取淮河流域的82个水质监测站,对各站点的1986—2005年水质监测数据进行统计分析,探讨了全流域内水体污染物浓度变化的时空变异特征,为淮河流域水污染治理、水环境保护以及生态修复提供依据。采用时间序列法分析水体污染物浓度的时间变化规律,应用Mann-Kendall检验法对流域范围内水体污染物浓度变化趋势进行了分析。研究结果表明,淮河流域水质变化主要受到入河排污量、上游来水量、闸坝调控方式以及气候条件等方面因素的影响。蚌埠站的水体污染物浓度多年变化规律表明,1995年是水体污染物浓度变化的转折点,1995年前水体污染物浓度不断恶化,1995年后水体污染物浓度逐渐好转。DO浓度的年内变化主要受到水温的影响,表现为冬季浓度高于夏季浓度;CODMn浓度同时受到闸坝调控方式以及区域来水量的影响,汛期浓度低于非汛期。从全流域的水体污染物浓度变化规律看,有机污染物浓度呈显著上升趋势的河段主要分布在淮北支流上,说明在20世纪90年代后期,虽然流域进入相对丰水期以及进行了大规模的水污染联防工作,淮河流域水质污染得到了一定程度的改善。但在2000年后,随着流域内入河污水量和污染物排放量的增加,淮河流域的水质污染依然严重。

Based on survey data of 82 monitoring stations from 1986 to 2005,the spatial and temporal variation of water quality in the Huaihe River basin were investigated and analyzed to provide scientific basis for water pollution control,water environment protection and ecological restoration. The time series analysis method and Mann-Kendall testing method were adopted to analyze the water pollution status and change trend over the past twenty years. The results show that four main factors influence the change of water quality,including river pollution load,upstream inflow,dam and gate operation,and climatic condition. The water quality of the Huaihe River exhibits a tendency of gradually deteriorated before 1995 and gradual improved after 1995. The change of dissolved oxygen（DO） is affected by water temperature varying in a year,with higher concentration in winter than that in summer. The chemical oxygen demand（CODMn） is affected by operation of dam（gate） and interval inflow simultaneously which is lower in flood season than that in non-flood season. It indicates that significant effects of water pollution control have been obtained throughout the whole watershed in late 1990＇s when it was a relative high flow period for this area. However,tendency analysis shows that significant deterioration of water quality was present on north tributaries of the Huaihe River basin. Following the increase of pollutant discharge and river pollution load after 2000 water quality pollution in Huaihe River basin is still serious.