Temporal-spatial evolution of water quality in Lake Dongting,China

Abstract

根据洞庭湖湖区的1983-2004年的水质监测数据,参照GB3838-2002中Ⅲ类水质标准,运用内梅罗水污染指数法进行水质评价,分析了洞庭湖湖区22年来的水质时空变化.结果表明:洞庭湖湖区水质污染在时间上呈有升有降的波动变化.洞庭湖湖区丰水期和洪水期的水质较差,但是从2002年以后,丰水期的水质逐渐好于平水期.污染空间变化表现为入湖河道的污染程度高于湖体,湖体污染呈西洞庭湖的污染较为严重,南洞庭湖其次,东洞庭湖的水质仍较好的格局.;According to Basic Analytical Methods of Environmental Quality Standards for surface water, GB3838-2002,we used the 1983-2004 monitoring data to evaluate and characterize water quality condition and to analyzewater quality temporal-spatial evolution trend of Lake Dongting, based on the application of comprehensive indexmethods such as Nemerow Index. The results showed that Water quality changed in Lake Dongting which fluctuatedbetween up and down temporally. In 1983-1985,water quality was clean in Lake Dongting. From then on, waterquality had been polluted seriously in 1988 and graduated in light pollution after 199 f,and then ran down in 1999and dropped to light pollution in 2001 again, as well as had begun to aggravate in 2004. The main pollutant was to-tal phosphorus (TP) in Lake Dongting. Water quality was worse in the flood water season than in the other waterseasons, but after 2002,water quality was worse in the flood water season had been better than in the normal water season.The water pollution could be more~in the entering riverways than in the lake bodies of Lake Dongting spatially. Water quality in Lake Weat Dongting was worst, in lake South Dongting was worse, and in Lake East Dongtingwas not polluted badly.