Best Fit Probability Distribution and Development of Isohyetal Maps

A good understanding of the pattern and distribution of rainfall is important for water resource management of a country. Twenty probability distributions such as, Generalized Extreme Value, Exponential(2P & 3P), Beta, chi square(2P & 3P),Gamma(2P & 3P), Gumble (Max & Min),Gen. gamma(3P & 4P), Normal, uniform, weilbull (2P &3P),student¿s t, Johnson SB and lognormal(2P & 3P) distributions, etc. were studied to model the annual rainfall of the study area considered and three goodness-of-fit tests, namely, Kolmogorov-Smirnov, Anderson-Darling and Chi-Squared tests were used to evaluate their fitness. The isohyetal maps generated on the basis of the annual maximum rainfall estimated for the various return periods of Two Years, Five Years, Ten Years ,Twenty Years, Fifty Years, Hundred Years and Two Hundred Years.