A Fuzzy Multi-Criteria Group Decision-Making Model Based on Weighted Borda Scoring Method for Watershed Ecological Risk Management: a Case Study of Three Gorges Reservoir Area of China

In watershed ecological risk management, a series of alternatives will be analyzed in terms of multiple complex criteria, and different stakeholders with conflicting risk attitudes will be involved, which means that ecological risk management decision-making is a process surrounded by a wide range of uncertainties derived from scarcity of data, lack of knowledge, deficiency of assumptions and lexical vagueness. Based on modified Borda scoring method, this paper discusses how to apply a fuzzy multi-criteria group decision-making (FMCGDM) model into such a process. Then, a two-stage, 12-step MCDM methodology is proposed to obtain the optimal alternative decided by multiple decision-makers (DMs) from a given alternatives set. Firstly, all DMs make their own independent choice respectively, then, all the independent conclusions are integrated by using their subjective/objective weights. A modified Borda method is followed to rate and rank the weighted alternatives; in which the one with the highest score will be selected as the final preferable option. This model is demonstrated to be applicable and reliable by an application in the ecological risk decision making process of Three Gorges Reservoir area located in the upper reaches of Yangtze River in China. Of course, this method can also be applied in other research fields of environmental management.