基于多种方法的太湖综合水质评价比较

水污染是太湖主要的水环境问题之一,准确合理地评价太湖水质状况对该地区水环境治理具有至关重要的作用。利用单因子水质标志指数法、综合水质标志指数法、改进的综合水质标志指数法及基于污染物权重的灰色关联分析法对2004—2013年典型断面的水质进行评价,水质单项指标评价表明太湖东部及东南部污染较严重且主要污染物为NH3-N,与该地区水体富营养化现状一致,综合水质评价表明近年来太湖水质呈逐年转好的趋势;对比研究结果表明,综合水质标志指数和改进的综合水质标志指数更接近太湖水质的真实情况,其中改进的综合水质标志指数法考虑了最差污染因子对综合水质的影响,克服了单项指标算术平均带来的误差,能真实反映流域的污染状况,为水环境治理工作提供更可靠的依据。

Comprehensive evaluation of water quality in Taihu Lake based on various methods

Water pollution is one of the important problems of water environment in Taihu Lake basin. To evaluate the water quality of the watershed exactly and reasonably is vital to grasp the characteristic of water pollution and water environmental management. Single-factor identification index was used to evaluate the pollution status of a single element of typical sections. The original and the improved methods of comprehensive identification index and grey incidence analysis based on pollutant weight were used to evaluate the integrated water quality from 2004 to 2013. The analysis results show that the water pollution of east and southeast in Taihu Lake basin was more serious and the main pollutant was NH3-N, which was in accordance with the situation of eutrophication, so the leading management was to reduce the water eutrophication. There were some differences among the results of different water quality evaluation methods, which could reflect the water quality in Taihu Lake basin. The results of comprehensive water quality identification index and grey incidence analysis preferred the lower quality, and those of the improved comprehensive water quality identification index combined with the influence of the worst pollutant preferred the integrated water quality to overcome the error caused by the algebraic average of a single index in order to reflect the pollution of watershed veritably.