MapAsia, Bangkok 2006
Irvan Sophian* and Dicky Muslim*
Abstract
In Indonesia, West Java Province is well known for the most frequent landslide occurrence from time to time. Physically destructed land by geological hazard such as landslide could widely affect people and infrastructures. In the eastern part of West Java landslide frequently occurs on the Citanduy River catchment area. This phenomenon is approached through slope stability analysis.
Quantitative analysis of slope stability (SF) and plotting of previous landslides occurrences on Geological map are carried out to produce slope stability map. Conditions of geomorphology, hydrogeology, soil types and distribution and also current landuse are considered as supported data.
Result of analyses shows that there are 3 zones of slope stability on the study area. SF more than 1.25 is stable zone. SF 1.25 to 1.1 is critical to stable zone. SF 1.1 to 1.0 is critical zone. SF less than 1.0 means unstable slope where landslide occurs. Stable zone is characterized by plain area on thin soil, coarse grain soil. Critical to stable zone is of hilly to mountainous land, fine grain thick soil of sedimentary or volcanic rocks. Critical zone is of swelling-shrinking type of thick soil on high-angle slope, high density of geological structures, high run-off caused by drainage on the top of slope (ponds, paddy fields, etc).
Keywords: Landslide, Slope Stability, Citanduy River, Safety Factor