Cluster method in regional rainfall frequency analysis : a case study in the Central and Highland region

Abstract

Regional rainfall frequency analysis is increasingly used in hydrology because this approach allows us to make sample size bigger for each station in the area and thus increases the certainty of statistics probability. However, in order to apply this approach, the homogeneous sampling is required. The fact that when analysis uses sample area data of a large quantity of gauged rainfall and a large area, it is often difficult to have a homogeneous sample. Therefore, it is necessary to divide the study area into several sub-regions so that the sample of each sub-region can be homogeneous. The study presents two cluster methods in regional rainfall frequency analysis and is initially applied to 75 gauged rainfalls for the central and the highland The results form a basis for development of the extreme rainfall map for this region.