Landslide vulnerability assessment using gis and remote sensing techniques: a case study from Garut – Tasikmalaya road

Abstract

Road constructions, especially in mountainous topographical features, have been noted responsible for the significant increase of landslide occurrences. In the Garut – Tasikmalaya Road, numerous landslides have been recorded causing enormous losses. This road has a very important role as the main transportation connector between two regencies in West Java; those are Garut and Tasikmalaya Regency. To deal and control such problems, spatial distributions of landslide vulnerability need to be analyzed. The aim of this study was to assess the widespread landslide vulnerability zones along the Garut – Tasikmalaya Road. The landslide triggering factors, i.e. topographic slope, land use, lithology, distance to geological structure and distance to stream, were spatially evaluated and integrated using Analytical Hierarchy Process (AHP) and simple numerical rating method to determine the landslide vulnerability zones. The data of landslide triggering factors were derived from remote sensing data and processed using GIS technology. The data integration produced landslide vulnerability map along the Garut – Tasikmalaya Road, which delineates the research area into three zones of landslide vulnerability (high, moderate, and low). The landslide vulnerability map was validated using landslide inventory. The high vulnerability zones of landslide, that will affect the Garut – Tasikmalaya Road, are mainly located in the Salawu District.