Identification of Landslides Controlling and Triggering Factors by Using the Analytical Hierarchy Process Method in Dermasuci Village, Pangkah District, Tegal Regency, Central Java - Indonesia Brenanto Tsaqofa Widodo (a*), Hendy Setiawan (b*), I Wayan Warmada (b**)
a) Master Program in Geological Engineering, Gadjah Mada University
Grafika Bulaksumur No.2, Senolowo, Sinduadi, Mlati District, Sleman Regency, Daerah Istimewa Yogyakarta 55284, Indonesia
*brenanto.tsa1999[at]mail.ugm.ac.id
b) Department of Geological Engineering, Gadjah Mada University
Grafika Bulaksumur No.2, Senolowo, Sinduadi, Mlati District, Sleman Regency, Daerah Istimewa Yogyakarta 55284, Indonesia
*hendy.setiawan[at]ugm.ac.id
**warmada[at]ugm.ac.id
Abstract
The National Disaster Management Agency (BNPB) stated that in 2022 around 545 landslides occurred in Indonesia. One of the regions in Indonesia that experienced landslide disasters is located in Dermasuci Village, Pangkah District, Tegal Regency, Central Java Province. The landslide disasters occurred on February 5, 2022, and the subsequent movement occurred on February 10, 2022. Based on the Tegal Meteorological Station, the highest rainfall intensity before the landslide disasters happened was recorded at 39.7 mm/day on February 3, 2022, and 33.5 mm/day on February 9, 2022. The landslide disasters caused damage to 61 residents^ houses and four roads. The objective of this study is to identify the controlling and triggering factors that mainly contributed to the landslide event. These two factors are determined based on the order of their static and dynamic properties using the Analytical Hierarchy Process method. Controlling and triggering factors of the landslide in the study area are determined based on geological and geotechnical conditions which were obtained from surface mapping results. The controlling factors obtained are the dip of the rock layers, the geological structure in the form of faults, the slope angle, the engineering properties of soil and rock, the land use, and the groundwater table. The triggering factors that are known and commonly occur are rainfall in the form of antecedents and intensity, and earthquakes that are able to induce landslides.
Keywords: Landslide- Controlling and triggering factors- Analytical hierarchy process method- Tegal regency
