Abstract

The purpose of this study was to analyze this characteristics of rainfall in the Lower Central part of Thailand. The Procedures of this study was to collect the available daily rainfall data from 1952 to 1982 of 87 stations which were recorded by the computer at Royal Irregation Department. The rainfall data were analyzed for the rainfall distribution pattern, the month of the highest rain, annual coefficient of variation, probability of heavy rain per day, the frequency of dry soil, probability of dry spell, and probability of return period of annual maximum rainfall in 24 hours.

The results of study revealed as following :

The average of annual rainfall was between 919.3-1,943.9 millimeters. The area which had highest rain was on the eastern, and the lowest rain was on the western part.

The maximum rainfall occured in September, October or August

The variation coefficients of rain were greater on the western part and lesser on the eastern part of the region. The probability of heavy rain per day was between 6.9-22.8 percents.

The frequencies of dry spell in rainy season were greater on the western part and lesser on the eastern part.

The probability of dry spell highly occured in June and July The Probability of return period of annual maximum rainfall in 24 hours was increasing in accordance with the lenght of time.