Rainfall Distribution Pattern of Progo Watershed in Observational and Empirical Method

Abstract

Automatic Rainfall Recorder (ARR) has not been widely available in Indonesia, so data of rainfall is available in the form of daily rainfall. To know the pattern of rainfall distribution in a watershed, there are two methods, they are the observational and empirical method. the Observational Method can be done if it has automatic rainfall data minimal hourly-time in a long period. Meanwhile, the empirical method will be used when data is very limited. So in this research, there were two methods to develop the rainfall distribution pattern in Progo Watershed. The data were used by the observational method is from 2013 to 2015. There were two empirical methods which are used namely Alternating Block Method (ABM) and Modified Mononobe Method. The results show that heavy rainfall in Progo watershed is dominated by 7-hourly rainfall distribution. The empirical rainfall distribution pattern that is more suitable with the observation method is Modified Mononobe method than ABM method.