太湖水质评价计算方法及近年来水质变化分析

以2000~2005年太湖水质监测资料为基础,结合算术平均法、算术平均法与湖区面积加权综合运用、监测点代表面积与湖区面积加权综合运用等3种不同的湖区水质评价计算方法,对太湖水质状况及其近年来的变化趋势进行了分析。分析了这3种计算太湖水质指标方法的特点和存在问题,并选用监测点代表面积与湖区面积加权综合运用的方法,对太湖水质状况进行评价分析,避免由于个别测站水质状况有较大的差异而影响湖区评价结果。评价结果表明,太湖污染严重区域为北部梅梁湖、竺山湖和五里湖,但水质恶化趋势在2003年后总体上得到了有效的遏制,近年来太湖湖体水质总体稳定,太湖东部沿岸区、东太湖和南部沿岸区水体水质满足饮用水水源地水质标准。

Evaluation method for water quality of Taihu Lake and its variation in recent years

Using data from 2000 to 2005, the water quality of Taihu Lake in recent years is analyzed with three different water quality evaluation methods： the arithmetic average method, the method of weighted arithmetic averages of the acreage of each lake section, and the method of weighted arithmetic averages of the representative acreage of each station. Considering the characteristics and shortcomings of each method, and excluding unreasonable results caused by distinct variation of water quality at some water quality stations, the third method was used to evaluate the water quality of Taihu lake. The results show that Meiliang Lake, Zhushan Lake and Wuli Lake are seriously polluted, the trend of deterioration of the water quality of Taihu Lake reversed in 2003 and water quality has been stable in recent years, and the water quality in East Taihu Lake and in the waters along the bank of the southem and eastern part of Taihu Lake has reached the water quality standard for a drinking water source area.