No abstract

No abstract

No abstract

This paper may be of particular interest to the readers as it provides a new environmental risk assessment system for phosphogypsum tailing dams. In this paper, we studied the phosphogypsum tailing dams which include characteristics of the pollution source, environmental risk characteristics and evaluation requirements to identify the applicable environmental risk assessment methods. Two analytical methods, that is, the analytic hierarchy process (AHP) and fuzzy logic, were used to handle the complexity of the environmental and nonquantitative data. Using our assessment method, different risk factors can be ranked according to their contributions to the environmental risk, thereby allowing the calculation of their relative priorities during decision making. Thus, environmental decision-makers can use this approach to develop alternative management strategies for proposed, ongoing, and completed PG tailing dams.

Taking an abandoned quarry located in Chengang town of Zhoushan city as an example and on the basis of investigating into vegetation and soil condition, the physicochemical properties of soil and plant community characteristics are analyzed. The results indicate: the physicochemical properties of the four types of the disused lands of the quarry are very poor; the nutrient condition of abandoned quarry area is also poor, they are the main limiting factor to ecological restoration. The main types of vegetation in this area are grassland. The woody species are rather singular with only 5 families, 7 genera and 7species, but the herb communities are much more abundant with 5 families, 24 genera and 27species in total. The changes of α diversity indexes to four types of the abandoned lands of quarry are quite different, the order of the species richness indexes to different types of the abandat quarry from big to small was spoil mound, stone-soil stack, worked-out area and terrace for crush. While the species diversity and species richness indexes are worked-out area, stone-soil stack, spoil mound and terrace for crush.