Integrating landslide susceptibility into land capability assessment for spatial planning :: A case study in Tawangmangu Sub District Karanganyar Regency Central Java Provinsi Indonesia

WATI, Sri Eka, Prof. Dr. rer.nat. Junun Sartohadi, M.Sc

2010 | Tesis | S2 Geo Informasi untuk Manajemen Bencana

Land capability assessment is one of the important points in spatial planning. The assessment is conducted to divide the land into three land use functions (protected, buffer, and cultivated area) and to manage further land use. The present land capability analysis utilizes scoring method from Ministry of Agriculture. This method considers erosion hazard associated with soil type. Since Tawangmangu Sub District is also prone to landslide hazard, the landslide susceptibility information shall be taken into account in land capability. This research is focused on the integration process of landslide susceptibility in land capability assessment. Landslide susceptibility was analyzed by means of heuristic approach (weighted score method). The parameters were slope, lithology, soil depth, texture, permeability, and land use. The weight was derived from pair wise method and the score was generated from rank method. Those methods are available in ILWIS. A proposed land capability classification was developed based on USDA approach. The susceptibility information was integrated as one additional constraint factor in proposed method. The land capability assessment was developed in general and detailed version. The obtained land capability class was harnessed for dividing land use function and identifying land use deviation. Land capability analysis by means of scoring method was also done in order to compare the obtained result. More than one third of study area (42%) is categorized as high and very high susceptible to landslide while 43% of total area is classified as moderate susceptible area. The rest is categorized as low susceptible area. General land capability classes for study area are class IV, VI, VII, and VIII whereas the detailed land capability class consists of class III, IV, V, VI, VII, and VIII. General land capability class classifies more than a half of study area (58%) as protected area, 31% is assigned as buffer area, and 11% is apportioned as cultivated area. Besides, detailed land capability class allocates 55% of study area as protected area, 37% as buffer area, and 8% as cultivated area. Moreover, the land use deviation in buffer area is higher than protected area and there is no land use inexpediency in cultivated area. On the other side, general version of scoring method assigns 51% of total area as protected area; 31% as buffer area and 18% as cultivated area whereas the proportion of protected, buffer, and cultivated area based on detailed version is 38%, 45% and 17% respectively. Scoring method also identifies that most land use divergence occurs in buffer area rather than protected and cultivated area.

Kata Kunci : Landslide, Land capability, Land use function, Spatial planning