A Variable Fuzzy Set Assessment Model for Water Shortage Risk: Two Case Studies from China

Water shortage risk assessment is full of uncertainty. Hence a water shortage assessment model was developed based on the variable fuzzy set, which reasonably identifies the relative membership degree and function of simple index and standard interval of each level. The model is used to assess water shortage risks in the Yangtze River Delta (which comprises the cities of Shanghai and Nanjing) and in the Capital-area of China (including the cities of Beijing and Tianjin). Results show that the proposed model rationally determines the membership grade in the range of rankings for all related indicators. More importantly, the proposed model is flexible and adaptable for diagnosing water shortage risks for different ecological conditions.