Abstract:

An assessment index system is built and it is composed of the hazards of risk source and the sensitivity and resiliency of risk receptors. The dynamic assessment of environmental risk in the Yangtze River basin from 2000 to 2011 was evaluated by using the "vertical-and-horizontal scatter degree" method and the "time ordered weighted averaging operator" method. The results are given in the following. 1)Temporally, the environmental risk of the study area decreased slightly in the initial stage of the study period, followed by an obvious increase consequently. 2)Spatially, great variations in risk value indicate that the Yangtze River basin can be divided into the high, relatively high, medium, and low risk regions with assistance of cluster analysis. The high risk zone includes Shanghai, Jiangsu, and Henan; the relatively high risk zone includes Anhui, Hunan, Hubei, and Zhejiang; the provinces in the central area of the Yangtze River basin, such as Sichuan, Guangxi, Chongqing, Yunnan, and so on, are in the medium risk zone; and the Tibet and Qinghai occupy the low risk zone. The temporal and spatial patterns of environmental risk for the Yangtze River basin provides important scientific basis for the environmental risk management.

Key words: environmental risk at regional scale, dynamic evaluation, hazard of risk source, vulnerability of risk receptor