IDENTIFICATION AND ANALYSIS OF LANDSLIDE SOIL VULNERABILITY AS THE BASIS OF DISASTER MITIGATION WITH GEODETIC MEASUREMENT METHODS AND QUANTITATIVE DESCRIPTION

Abstract

Karanganyar Regency is one of the regencies/cities in Central Java Province, most located around Mount Lawu. The rock structure is sedimentary or has not been lithified. Based on these geological conditions, the area around Mount Lawu is vulnerable to hydrometeorological disasters such as landslides supported by several factors other than soil conditions, namely high rainfall, slopes, overburdening plants, or symptoms of geological structures. One of the villages affected by the hydrometeorological disaster was Jambon Village, Jenawi District, Karanganyar Regency. The natural disaster that hit Jambon Hamlet in 2014 caused soil cracks and damage to houses. As a form of disaster analysis and mitigation, this study assessed landslide susceptibility through deformation parameters using a GNSS (Global Satellite Positioning System) measuring instrument to determine the magnitude and direction of landslide movement. The deformation analysis results based on the GNSS measuring instrument show that the measurement results still meet the threshold, or there is no deformation of the soil structure at the 7 sample points measured. This caused an anomaly because the landslide happens conditions were very severe except for one area, including one church and 13 houses. Therefore, it is necessary to study further to prove the cause of landslides through other parameters such as geological structure symptoms and time. The results of this study are expected to provide recommendations for safe areas around landslides to be maintained or not.