Spatial Analysis of Rainfall Return Period and Probable Maximum Precipitation over Central Java - Indonesia

Abstract

Most of the lowlands and coastal area in Indonesia are highly affected by flood hazards, particularly Central Java Area. The flood hazards are often associated with extreme precipitation that occur in long duration. This research aims to identify the spatial distribution of extreme precipitations based on daily rain gauge precipitation data over Central Java. Daily precipitation data from 1998-2010 were obtained from rain gauge stations from Indonesian Bureau of Meteorology, Climatology, and Geophysics (BMKG). Extreme precipitation identification taken by precipitation threshold, return period rainfall, and probable maximum precipitation (PMP). The results indicate that extreme precipitation occurs mainly in the lowlands and coastal areas over the northern and southern part of Central Java. The distribution of extreme precipitation could be utilized to map the susceptible area affected by floods, such as Tegal, Pekalongan, Kendal, Semarang, Demak, Purworejo, Kebumen, Kutoarjo, Gombong, and Cilacap.