Set pair analysis and its application to hydrology and water resources

Set pair analysis(SPA) is a theory for treatment of indeterminate problems.In a certain system,the indeterminateness and determinateness are interrelated and interacted with each other,and sometimes they can interconvert under certain condition.In this paper,the connection degree and its mathematic formula were used for describing various indeterminateness of the system,and thus the assessment of and decision-making for the system were realized.As a case study,a new model for evaluation of regional runoff variation was developed by use of SPA based on the runoff data of the Yellow River and the Yangtze River,and it is verified that the method is of wide scope of application in hydrology and water resources.