| Summary: | Pleret sub-district is one of the earthquake prone area. The high vulnerability of this region is often associated with the presence of Opak fault system in the eastern part of this sub-district, which is oriented southwest-northeast. Proved, in the event of May 27, 2006 Yogyakarta earthquake, areas along this Opak fault was badly damaged. This research was conducted to determine the earthquake risk condition through identification of hazard characteristic, residential building vulnerability, and social capacity. The method used in this research was integration between remote sensing, geographic information system, and field observation. Hazard assessment in this research is combination between geological information obtained from ASTER sattelite imagery intepretation with the value of seismic index on each lithological unit. Building vulnerability assessment was conducted by field observation using rapid visual screening of building for potential sesimic hazard procedure developed by FEMA. Social capacity assessment in this research are using semi-qualitative method toward awareness and preparedness variables which are obtained from intervew processes. Seismic index value on each lithologycal unit in study area are highly dependent on surface material type. The compact material of surface type tend to have low seismic index value. Based on the result, it can conclude that lithology unit of recent Merapi material deposit have high seismic index ranged from 7.0 - 13.8. Aluvial deposits from denudation material of Semilir and Nglanggran Formation have moderate seismic index ranged from 2.1 - 3.8. Semilir and Nglanggran Formation which are solid rock have low seismic index i.e not more than 1. Building structure in the Pleret sub-district are dominated by Reinforced masonry buildings with rigid floor and roof diaphragms (RM2) which have low level of vulnerability i.e. above the value of 1.75 which is defined as the limit of vulnerability by FEMA. The social capacity of Pleret sub-district are still low due to lack of preparedness to cope with eartquake hazard. This condition lead the level of risk in building unit become mostly moderate. Risk reduction effort which is emphasize on rising the capacity particularly on preparedness aspect could effectively reduce the earthquake risk that might be occurred.
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