Application Of Set Pair Analysis And Rough Set Theory To Hydrology And Water Resources

As an open large-scale system, much information in water environment has some uncertainty. data in hydrology and water resources was influenced by many factors, such as astronomical,geographical and artificial activities and so on. So data in hydrology and water resources has characteristics such as nonlinear,multi-changes and great randomicity and so on, Meanwhile, it has periodicity and tendency changed with years.These problems can not be solved by conventional linear model; It will bring big errors to the main results of the problems if the uncertainty of the information is neglected.Therefore, to solve the complex problems and processing various uncertainty data in hydrology and water resources, set pair analysis and rough set theory are used. Through MATLAB computer language programming, establishing mathematical model, applying in the production practice, and get a good result.Set pair analysis and rough set theory can both be used for treatment of certain and un-certain problems; The former uses Same-Indefinite-Contrary connection degree as a tool, uncertainty and rough set degree are expressed by upper and lower approximation sets in rough set theory. Set pair analysis can solve comprehensive uncertain problems that caused by stochastic fuzzy unknown medium and emergent and so on, which conventional evaluation method can not do. The characteristic of Rough set theory reflects great advantages in processing data in hydrology and water resources.Main result as follows:1. Based on application of set pair analysis to hydrology and water resources, generalization of set pair analysis and Same-Indefinite-Contrary connection number as four-element connection number and five-element connection number, and then pluralistic connection number. Five-element connection number is used in evaluation of eutrophication lakes,water quality assessment and soil environmental quality assessment, all got a good result.2. Rough set theory is a tool of new treatment for uncertainty knowledge, But conventional rough set theory has to do data discretization first, numerical attribute reduction based on neighborhood granulation and rough approximation are used in this paper, and its application to evaluation system on the sustainable utilization of regional water resource, Conventional evaluation index have attribute reduction. With reduction index evaluation, the evaluation results are consistent with the results of SP model. It shows that the reduction results comparatively accurate, the result is satisfying. It provides rapid and practical method for water resources assessmentBased on establishment of the models above, In dissertation, rational combination of the theory and practice were made. The results can not only make contribution to treatment methods of uncertain data in hydrology and water resources, it provides new methods and thoughts, At the same time, it propagate the scope of application for set pair analysis and rough set theory; Moreover, relevant improvements of theory were made, so as to better apply in hydrology and water resources field.