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

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.