A Comparative Analysis of Environmental Quality Assessment Methods--a Case Study of Heavy Metal-Contaminated Soil

摘要

Four assessment methods (two pollution index and two fuzzy mathematical models) were employed to investigate the environmental quality of eight soils around a heavy metal contaminated site. From the results of analysis, comprehensive index model is more reasonable compared with the single-factor index method; Compared with the pollution index, in fuzzy mathematical methods, membership functions were used to describe the limits between different pollution degrees, and different weights were allocated for the factors according to pollution contribution. In the single-factor deciding model, the dominant factor was given more attention, and the effects of the other factors were weakened. However, in the weighted average model, the contribution of each factor was well taken into account, and the weights were allocated for the factors according to the contribution degree. In fuzzy mathematical methods, membership functions were used to describe the limits between different pollution degrees, and different weights were allocated for the factors according to pollution contribution. Introduction of membership degree and weight of each factor to fuzzy mathematical models made the methods more reasonable in the field of environmental quality assessment.