Land use planning for settlements area considering flood and landslide hazards in Bagelen Sub-district, Purworejo Regency, Central Java, Indonesia

MEI, Estuning Tyas Wulan, Dr. H.A. Sudibyakto, MS

2008 | Tesis | S2 Magister Geo Informasi dan Penataan Ruang dan M

Located in the denudational hills in the eastern part and in flood plain in the western part, the Centre of Bagelen Sub-district faces flood and landslide hazards problems. Since the present land use plan for settlement in Bagelen, Bugel, Krendetan, and Bapangsari Villages has not yet visualized spatially, it is needed for this study to highlight that involving the natural hazard and non hazard criteria to analyse the settlement suitability in geographic information system becomes important to find out the suitable area for development purpose. The main objective in this research is focused on the determining alternative land use planning for settlement development which includes natural hazard susceptibility. Data and information were obtained from interviewing the respondents using questioner, participatory GIS, direct-observation in the field, laboratory analysis for soil sample and secondary data. The flood hazard map was generated by means of GIS interpolation techniques; flood depth map for the largest flood in the year 2004 was created. The landslide map was made using GIS overlay methods for each criterion which are slope; land use; geology; texture; soil depth; shrink-swell value. The settlement suitability analysis was done by weighting overlay method of natural hazard criteria, flood and landslide, and non hazard criteria, slope, road, availability of infrastructure, land capability, and existing land use. Area with high hazard of flood located in the flood plain and back swamp, administratively in Bugel, Bagelen and Bapangsari Villages. The area with high landslide hazard is located in the hilly area in the eastern part of the area of study. The result of overlaying two hazard maps, flood and landslide, indicates that the area which considered has less hazard both flood and landslide is located in the colluvial plain. Mitigation strategy of flood and landslide comprises of structural and nonstructural mitigation done by the community and government. The result of suitability analysis including hazard criteria and based on the people perception shows that the suitable area (329.1 Ha) is mostly located in Bagelen and Krendetan Villages. The result of suitability analysis of the non-hazard criteria shows the suitable area (435.84 Ha) is mostly located in Bagelen Village and Krendetan Villages with 338.1 Ha of existing settlement. The moderately suitable area (557.9 Ha) is dispersedly located in the study area with 28.9 Ha of existing settlement. The results of suitability analysis considering flood and landslide hazards show 21 unit areas. Considering the natural hazard limitation, the S1 – F unit area is decided as the most suitable for settlement area, because it has low flood hazard and landslide hazard. Other suitable areas can be used as settlement area, but has to consider about the natural hazard limitations by take in to account the mitigation strategies.

Kata Kunci : Permukiman,Perencanaan Penggunaan Lahan,Bahaya Alam,Suitability, Settlement, Land use Planning, Natural Hazard