Regional Water Resource Security in China Based on a New Fuzzy Method with Combination Weighting

As one of the important natural resources, water resources are related to the future survival and development of human beings. In recent years, the problem of water resources security has become more and more prominent, and it is urgent to study water resources security. Taking 30 provinces and cities in China as an example, this paper constructs a water resources security index system from three aspects of resource supply, social economy and ecological environment, and innovatively proposes a new evaluation method. Specifically, considering the influence of subjective and objective factors on the weighting of indicators, the best–worst method (BWM) and the criteria importance through intercriteria correlation (CRITIC) method are used to determine the subjective and objective weights of each indicator, and the two weights are unified in combination with the principle of maximizing variance. After that, the combined weight was applied to the technique for order preference by similarity to ideal solution (TOPSIS) method, and a new fuzzy multiple criteria decision-making (MCDM) method of combined weighting was finally developed to evaluate the water security status in China. This avoids the error of the traditional single-weight method evaluation to a certain extent, and also conducts other relevant empirical analysis. The research method developed in this paper provides a new idea for dealing with multi-criteria optimization problems in complex systems, and the research results provide a theoretical basis for ensuring regional water resources security and promoting coordinated development among regions.