Mixed Zero-Inflation Method and Probability Distribution in Fitting Daily Rainfall Data

  • Kwanchai Pakoksung Kochi University of Technology
  • Masataka Takagi Kochi University of Technology

PDF Downloads

Download data is not yet available.


In hydrological processes, rainfall is one of the important components of water supply for human life. We considered how well the statistical distribution simulates rainfall intensity. We propose an asymmetric statistical probability distribution joined by zero-inflated to fit the daily continuous record of rainfall data in Thailand. The candidate statistical probabilities are General Pareto, Exponential, Beta, Gamma, Generalize extreme value, Extreme Value, Normal, Lognormal, Weibull and Rayleigh distribution. The daily data from 123 rain gauges in Thailand collected and removed in a given year, using the null value. The statistical distributions estimated on the statistical coefficient, using the maximum likelihood estimation (MLE) method and resulted in a cumulative density function (CDF). The CDF compared to the CDF of observed data that estimated, using Kaplan-Meier algorithm. The comparisons were evaluated by Goodness of fit (GOF) in 3 null hypothesis tests (Kolmogorov-Smirnov, Anderson-Darling and Chi-Square test). The best fit distribution was identified by minimum residual (R) index and maximum correlation (Cor) index based on difference value between the estimated and observed data. The Weibull distribution matched to the 118 rain gauges while 5 rain gauges were best fitted by the Gamma distribution.

Author Biographies
Kwanchai Pakoksung

Kochi University of Technology, Tosayamada, Kami, Kochi, 782-0003, Japan

Masataka Takagi

Kochi University of Technology, Tosayamada, Kami, Kochi, 782-0003, Japan

Thailand, rainfall statistical modelling, rainfall probability distribution, zero-inflation, goodness of fit Regional climate.

Authors who publish with Engineering Journal agree to transfer all copyright rights in and to the above work to the Engineering Journal (EJ)'s Editorial Board so that EJ's Editorial Board shall have the right to publish the work for nonprofit use in any media or form. In return, authors retain: (1) all proprietary rights other than copyright; (2) re-use of all or part of the above paper in their other work; (3) right to reproduce or authorize others to reproduce the above paper for authors' personal use or for company use if the source and EJ's copyright notice is indicated, and if the reproduction is not made for the purpose of sale.

Article Statistics
Total PDF downloads: 220