INCORPORATING LANDSLIDE SUSCEPTIBILITY IN LAND REHABILITATION (A Case Study: In Middle Part of Kodil Watershed, Central Java, Indonesia)

AGUNG RUSDIYATMOKO, Prof. Dr. rer. nat. Junun Sartohadi, M.Sc.

2013 | Tesis | S2 Geo-Informasi untuk Manajemen Bencana

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Lack of hazard information will influence determination of land rehabilitation priority and kind of action to reduce a hazard. Landslides are commonly distributed on sloping area mainly in mountainous and hilly. Landslide characteristic knowledge is required before developing landslide susceptibility assessment. The appropriate method is needed to construct landslide susceptibility in Kodil Watershed in which data availability is categorized poor and limited. The main objective of this research is to develop better method for determining land rehabilitation priority by using land cover and landslide susceptibility analysis. Rainfall is needed to support landslide assessment. Condition rainfall data which is poor is illustrated by a lot of blank data and inconsistency data. TRMM data can be used to estimate blank data. Evaluation TRMM data which is illustrated by SNE, R², PBIAS, and RSR are categorized have equality to observed data (rainfall data in rainfall station). Soil depth is essential data in landslide study can be generated by compiling between landform and slope data. The result of soil depth is described that soil depth is identical with landform. Road network is anthropogenic causes landslide where built by cut the slope and passed by overload. The research area is dominated by moderate level of landslide susceptibility. Most of landslide event was distributed in moderate landslide susceptibility. Landslide event occurred is categorized as deep seated landslide where distributed in thick soil depth. Land management is also influencing landslide event with heterogeneity type of vegetation and road network. Land cover condition in research area is extracted from ASTER 2003 and 2012. Numerically, built up area is increasing twice with additional area reached 531.80 Ha in which 50 events landslide occurred. Extent of wooden broad leaves coverage is slightly decreased with 141.22 Ha. Number of landslide event in wooden broad leaves is 85 events when plotted on ASTER 2012. To map priority area of land rehabilitation, coverage vegetation and landslide susceptibility are incorporated. Middle part of Kodil Watershed is categorized in priority level (5,188.17 Ha). Forest farmers as stakeholder in land rehabilitation activity who directly playing a role in land management are giving agree response to protect area in landslide prone area. Invasive vegetation should be reduced and changed in to indigenous vegetation to protect area from landslide event.

Kata Kunci : Landslide susceptibility, ASTER, TRMM, Land Cover, Land Rehabilitation