ANALISIS TINGKAT KERAWANAN LONGSOR DI KECAMATAN JATIYOSO KABUPATEN KARANGANYAR DENGAN PEMANFAATAN TEKNOLOGI SISTEM INFORMASI GEOGRAFIS

Indonesia is an area that is prone to landslides, including Jatiyoso District which is included in one of the landslide-prone areas, mostly in the form of steep cliffs and hills with high rainfall causing this research area to be prone to landslides. This study has 3 objectives, namely 1) analyzing the distribution of landslide susceptibility levels in Jatiyoso District, Karanganyar Regency. 2) find out the distribution of the location points for landslides in Jatiyoso District, Karanganyar Regency. 3) Analyzing the spatial suitability between the distribution of potential vulnerability and the actual vulnerability of landslides in Jatiyoso District, Karanganyar Regency. This study uses a spatial approach primarily to determine the level of landslide susceptibility in Jatiyoso District. The method used is a survey method with a sampling method, namely Purposive Sampling, namely taking samples with certain characteristics according to the research objectives. The data used are primary data and secondary data which is processed through the rating of each parameter by analyzing through scoring through a quantitative GIS approach. The parameters used in the scoring include rainfall, soil texture, lithology, land use and slope. The analytical method used is through scoring, field surveys and overlays. Based on the results of the analysis of this study, 1) The landslide hazard in Jatiyoso District is divided into 3 classes, namely the non-prone class which includes land units V6 -III -L -T and V6 -I -L -S, the vulnerable class includes land units V3-III- A-H, V3-IV-A-H, V4 -IV -A -H, V5 -IV -L -T, V6 -I -L - P, V6 -II -L -K, V6 -II -L -P, V6 - II -L -S, V6 -II -L -T, V6 -III -L -K, V6 -III -L -S, V6 -IV -A -T, V6 -IV -L -K, V6 -IV - L -S, V6 -IV -L -T and V6 -V -L -T and very vulnerable classes which include land units V3-V-A-H , V4 -V -A -H, V4 -V -A -T, V5 -IV -A -T, V5 -IV -L -P, V5 -V -A -T, V6 -III -L -P, and V6 -IV -L -P. The land unit includes parameters of landform, slope, soil type and land use. The landform consists of the upper slope of a volcano (V3), the middle slope of the volcano (V4), the lower slope of the volcano (V5) and the foot of the volcano (V6). There are 5 grades of slope, namely flat (I), gentle (II), wavy (III), hilly (IV) and steep (V). Soil types include andosol (A) and latosol (L). Land use includes forest (H), dry land (T), gardens (K), settlements (P) and rice fields (S). 2) The distribution of landslide occurrence points which includes 11 points of landslide occurrence and spread in 5 villages of Jatiyoso District, namely Wukirsawit Village, Beruk Village, Wonorejo Village, Wonokeling Village and Jatisawit Village. In general, landslides in the study area occur at the foot of the volcano (V6) with a hilly slope (IV) and the type of soil is latosol and the use of dry land and settlements. 3) The suitability of the distribution of landslide susceptibility to the actual landslide occurrence of landslides has been identified as appropriate, this is indicated by the results of the calculation of the percentage level of conformity of 91%, this indicates that the results of the analysis of the landslide susceptibility map are sufficient in accordance with the field data