Frequency Analysis of Rainfall Data Using Probability Distribution Models

Analysis of daily maximum rainfall of different return periods is a basic tool for safe and economical planning and design of small dams, bridges, culverts, irrigation and drainage work etc. Though the nature of rainfall is erratic and varies with time and space, yet it is possible to predict design rainfall fairly accurately for certain return periods using various probability distributions (Upadhaya and Singh, 1998). Probability analysis can be used for predicting the occurrence of future events of rainfall from the available data with the help of statistical methods (Kumar and Kumar, 1989). Anaya Kalita et al., (2017) worked on frequency analysis of daily rainfall data of 24 years to determine the annual one day maximum rainfall and discharge of Ukiam (Brahmaputra River). Weibull’s plotting position Gumbel, Log Pearson and Log normal probability distribution functions were fitted. For determination of goodness of fit chi square test was carried out. The results found showed that the Log Pearson and Log Normal were the best fit probability distribution. Esberto (2018) determined the best fit frequency distribution of rainfall patterns for event forecasting in order to address potential International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 8 Number 06 (2019) Journal homepage: http://www.ijcmas.com