Changing of return periods of extreme rainfall using satellite observation in Java Island

Abstract

As a flood-prone area and a centre of activity in Indonesia, the high intensity of rainfall needs to be watched out for. Excessive rainfall can lead to disastrous outcomes like floods and landslides. Analyzing the frequency of extreme rainfall events, calculated by a statistical approach involving employing probability distribution models and generalized extreme value distributions. Return levels are defined as the maximum value that will be exceeded once in a given time period. This study aims to map changes in maximum rainfall that have occurred repeatedly on the island of Java in the last 40 years. Changes in the rainfall return period are detected using CHIRPS rainfall estimates, by calculating every 20 years. The calculation results show high rainfall intensity in the south of Java Island for all return periods and there is an increase in rainfall in the north of Jakarta. The southern region of West Java and Central Java has also experienced a relatively high increase in rainfall intensity, especially over a 20-year period. Meanwhile in East Java Province, increased rainfall occurred in the easternmost part of the province.