Information Entropy Study On Precipitation Distribution In Time And Space

Some fundamental concepts, for example, information, total-information and information entropy, are introduced. The paper reviews minutely principle of maximum entropy and principle of information transmission and their application to derivation of distributions, parameter estimation, design of hydrological networks, water quality assessment and optimization etc., and discusses some different methods about calculating information entropy.The concept of information field is raised in hydrology and water resources. The principle of information transmission on based information field is studied, the principle contains information transmission function, mean information distance and information plane which are used to measure the strength of information transmission. The paper also extends the method of fuzzy information measured by entropy, explores a uncertainty phenomenon including random as well as fuzzy, which infers compound entropy.Using the principle of information transmission, the paper researches a question on precipitation distribution in time and space on the basis of precipitation data of 99 gauging stations in the Huaihe River valley from 1953 to 1987. Through the study about distribution situation and moving law of time information entropy in space, the following conclusions are drawn: (1) ITF decreases progressively as distance increasing; (2) the rate of decreasing is faster in the direction south-north than east-west; (3) the capability of information transmission of stations in southeast of the valley is stronger than ones in northwest of the valley. Correspondingly, this paper studies distribution situation and moving law of space information entropy of 99 stations in time. The space information entropy's distribution in time(year) is found to be no obvious regularity to be imitated, so space information entropy(year) has no more values on precipitation distribution. But information transmission of precipitation in Huaihe River valley presents clear cyclical fluctuation for quarterly and monthly.