Authors : Khairi Khalid, Mohd Fozi Alib, Nurul Fatin Manc, Nor Faiza Abd Rahmanb, Ahmad Amzari Yaccob, Nur Asmaliza Mohd Noor and Siti Hawa Rosli
Abstract: The selection of the best-fit distribution of the rainfall data is always highlighted by the researchers in the hydrology study and the information is used for planning and designing of various water resource projects. The issue is critical to Malaysia and not excluded to the Langat River Basin since the country is experiencing two distinct monsoon seasons namely Southeast and Northwest Monsoon that brings heavy rainfall and cause floods. The study is attempted to test the goodness-of-fit of the rainfall data and to determine the best-fit distribution to explain the rainfall process in the study area. The reliability of rainfall data was determined using the independence, stationarity and homogeneity tests. Three probability distribution functions were utilized in the study; namely Normal Distributions, Log-Pearson Type 3 and Generalized Extreme Value (GEV) distribution. The parameters of the distributions were estimated by using the method of maximum likelihood. The best-fit distribution to explain the rainfall process is determined by using Chi-squared test. For Langat River Basin, the reliability of rainfall data of all the four rainfall stations is independent, stationary and homogeneous. It was found that GEV distribution is the best-fit distribution to explain the rainfall process in Langat River Basin followed by Log-Pearson Type 3 and normal distribution.
Khairi Khalid, Mohd Fozi Alib, Nurul Fatin Manc, Nor Faiza Abd Rahmanb, Ahmad Amzari Yaccob, Nur Asmaliza Mohd Noor and Siti Hawa Rosli, 2016. Rainfall Data Analysis in Langat River Basin Using Hyfran-Plus. Journal of Engineering and Applied Sciences, 11: 2360-2365.