Application Study Of Principle Of Maximum Entropy In Hydrology Frequency Analysis

It's necessary to provide different hydrologic design values for various kinds of hydraulic works through hydrologic frequency analysis in order to determine the scale, investment and benefit of the project. The main purpose of the thesis is to study parameter estimation method for Pearson-III distribution based on the principle of maximum entropy (POME).On the basis of the systematic summary of the study progress in hydrologic frequency analysis in China and abroad, and brief introduction of current application situation of the principle of maximum entropy in hydrologic frequency analysis. A new parameter estimation method (POMELM) based on POME and L-moment is proposed in the thesis. Considering that the actual two parameter estimation methods (POMEMOM and POMEFIT) may not utilize historical flood information, so a series of formula with considering historical flood information for POMELM. POMEMOM and POMEFIT are also proposed. Through the comparison by Monte-Carlo experiment, the results show that the new method POMELM is much better than POMEMOM and POMEFIT both in bias or effectiveness of quantiles and parameters. It also shows that the formula considering historical flood proposed are effective and feasible by Monte-Carlo method. In order to understand further the statistic performance of the new method POMELM, the comparison with conventional estimation methods, such as method of Moments, method of Weighted Function Moments, method of L-Moments and Curve-Fitting method has been done by Monte-Carlo experiment too. The results show that POMELM is obvious match better than Method of Moments, and it's almost equal to the method of L-Moments, but in majority of experiment schemes, it leans toward to be a little bit better than method of L-Moments, especially in the effectiveness of quantiles.