Zonasi Rawan Longsor Daerah Muara Sungai Bone Kota Gorontalo

Abstract

In Gorontalo City, there have been 11 landslides in 2017 which are spread in 3 sub-districts namely Hulonthalangi, Kota Barat, and Dumbo Raya. While in 2018 there was a landslide in Tenda village which claimed two lives. The research site is in coordinate 00°29'00 "- 00°31’51" NL and 123°3'00" - 123°5'27"  EL with the wide of area 2.529 Ha consisting of 1.788 Ha of the mainland and 741 Ha of the sea. Administratively, the area is in Dumbo Raya Sub-district, Gorontalo City, Gorontalo province. The purpose of this study was to determine the lithology of the study area constituents, determine the level of landslide proneness in the study area, and make zonation maps prone to landslides. This research method is site survey and GIS analysis in for of scoring and overlay. The parameters which influence the landslide are lithology, precipitation, slope, lineament density, type of soil, and the land use. The lithology of the research site consists of 6 rock units, which are granite, granodiorite unit, volcanic breccia, reef limestones, coastal sediment unit, and alluvial unit. Based on the analysis of landslide proneness, the level of proneness in the research site consists of 3 classes; low, moderate, and high. The low class of landslide proneness has the area of 217.46 ha, the moderate class of landslide proneness has the area of 338.93 Ha with the biggest spread is in Leato Selatan village, 102.68 Ha. The high class of landslide proneness has the area of 1188.70 Ha with the biggest spread in Leato Selatan Village, 288.66 Ha.