Analisis Ambang Batas Hujan untuk Pengembangan Sistem Peringatan Dini Tanah Longsor Studi Kasus Kecamatan Pejawaran, Kabupaten Banjarnegara, Provinsi Jawa Tengah

Abstract

Landslides are one of the disasters that cause many losses, both materials and fatalities. The need of designing a landslide early warning system in Indonesia is very important because many countries in the world already have this system. A statistical estimation of rainfall data that can trigger landslides is needed as an effort to develop this landslide early warning system. One of the areas in Indonesia that suffered a lot of landslides was Banjarnegara Regency, precisely in Pejawaran Subdistrict which was one of the locations where there were many landslides in this Subdistrict. This study wanted to understand about soil conditions and rainfall when landslides occurred and the threshold of rainfall intensity that could trigger landslides in Pejawaran District using three empirical methods, namely CT Threshold, Threshold ID and Soil Moisture. Those thresholds can be used as a reference for the development of landslide early warning in Pejawaran District. The threshold equation obtained by using the CT Threshold method is P₃ = 138.28 - 0.2874P₁₅ . Whereas, the rain threshold equation using the Threshold ID method is I = 1.6187D^-0.098 .g