Regional frequency analysis of rainfall extremes in Gia Lai province

Abstract

     Currently in Vietnam, the rainfall frequency analysis for designing hydraulic works is mainly based on local approach. This approach use limited measured data from a gauge station and use frequency inference to estimate extreme rainfall which have time repeat from 100 to 1000 years. In this paper, the authors introduce a different approach which uses a regional approach and Bayesian inference methods to extend data sample and estimate the reliability of inference. The daily rainfall data of 26 rain gauge station in the Gia Lai province and its neighboring are used. The rainfall disadvantage framework commonly used in designing works are 1, 3, 5 and 7 maximum daily rainfall, will be determined. This approach includes 4 steps: Regional homogeneous test, homogeneous clusters, Distribution selection and regional frequency analysis.