ABSTRACT
Ecological vulnerability evaluation has been fast developed in recent years. The previous studies have developed many methods, such as the comprehensive evaluation method (Goda and Matsuoka, 1986; Gowrie, 2003), the artificial neural-network evaluation method (Dzeroski, 2001; Park et al., 2004), the osculation value method (Xue et al., 2003), and the Principal Component Analysis (PCA) method (Li et al., 2006). Considering that the river ecological vulnerability assessment is a fuzzy concept with multiple indicators and classes, the fuzzy comprehensive evaluation method, which has been proved effective in solving problems of fuzzy boundaries, has been studied for the eco-environment assessment and other fields in recent years (Enea and Salemi, 2001; Li et al., 2009; Wang et al., 2012; Samani and Shahbodaghlou, 2012). However, by using the Maximum Membership Principle in fuzzy comprehensive assessment method, contradictions arise when any of the critical parameters incline extremely to different strengths of the evaluated status. The improved fuzzy comprehensive assessment developed weighted average principle by applying assessment coefficients (Liu et al., 2001).
