中国湖库水环境质量现状调查分析

Status Quo of Aquatic Environmental Quality of China's Lakes and Reservoirs:Investigation and Analysis

湖库是人类赖以生存的重要资源,也是我国最为重要的饮用水来源。随着经济发展和污染负荷入湖库量持续增加,我国湖库水环境质量不断下降。以2005-2007年我国大陆地区各省(自治区、直辖市)183个湖泊、531个水库25项水质指标的调查资料为基础,采用单项指标评价和综合评价方法,分析了我国湖库主要的污染状况。结果表明,我国湖库污染的形势十分严峻,Ⅰ类水比例极低,而Ⅴ类和劣Ⅴ类水质比例过高。有机污染仍然是我国湖库主要的污染问题之一,超标因子主要有化学需氧量、石油类、五日生化需氧量、高锰酸盐指数和粪大肠菌群;同时重金属和其它有毒有害物质的超标问题也十分严重,超标因子主要为汞、镉、砷、铅和氰化物。我国达到集中式饮用水水质标准(Ⅰ类、Ⅱ类和Ⅲ类)的湖泊比例仅有20.9%,水库比例稍高,但也仅为53.5%。

Surveys were conducted for investigating environmental quality of the main lakes and reservoirs in China,involving 183 lakes and 531 reservoirs.The water quality data consisted of 25 indexes in the national water quality standard for surface water body,covering the period from 2005 to 2007.This paper reported the analysis of the status-quo water quality by the single index method and comprehensive method based on the data collected during the surveys.Result of the surveys showed that in general the water quality of lakes and reservoirs investigated has become worse with very small number of lakes are of good quality water-Class I in the national standard.Organic pollution identified as COD,BOD and permanganate index,as well as fecal coliform are the main problem;at the same time heavy metal and other toxic contaminants including Hg,Cd,As,Pb and CN also pose risks to public health especially regarding the drinking water sources.Compared with lakes,the situation in reservoirs as a whole is little bit better in terms of drinking water source.