改进的模糊综合评价法在洱海水质评价中的应用

针对单因子评价法评价结果未能较好地反映近年来洱海水环境治理效果这一问题,本文系统收集了洱海1992—2015年的水质监测数据,采用层次分析和熵权法组合赋权的模糊综合评价法,选用多个水质指标,从水质和湖泊富营养化两个方面出发,对洱海水环境变化趋势进行评价,并与单因子评价结果进行对比。结果表明:从年际变化来看, 1992—2003年期间洱海水质逐渐变差,2003年之后逐渐好转,并趋于稳定;从年内变化来看,洱海水质非汛期好于汛期(6—10月),湖中心区水质好于南部和北部。整体而言,洱海富营养化水平由贫营养逐渐向中营养转变。与单因子评价结果相比,采用改进的模糊综合评价法能更好地反映洱海近20年水质的动态变化特征。

Application of improved fuzzy comprehensive method to water quality assessment in Erhai

The results of water quality aeessment in Erhai using single factor evaluation, do not well re-flect the effect of water environment management in recent years. This paper collects the monitoring data of water quality of Erhai systematically in 1992-2016. Based on the improved fuzzy comprehensive evaluation method and several water quality indexes, the trend of water environmental change in Erhai was evaluated from the aspects of surface water quality standard and lake eutrophication, and the results were compared with those obtained by the single factor evaluation method. The results show that the surface water quality in Erhai gradually deteriorated between 1992 and 2003, since 2003, and the water quality of Erhai has been improved year by year and tends to be stable. The quality of Erhai in non-flood season is better than that in flood season (during June to October) during the year, and the water quality in the center of the lake is better than in the south and north. Overall, the eutrophication level of Erhai has gradually changed from oligotrophic to medium nutrition. Compared with the single factor evaluation method, the improved fuzzy comprehensive evaluation method can better reflect the dynamic change characteristics of water quality in Erhai in recent 20 years.