Generating reliable database for loss estimation and mitigation planning of tsunami effects :: Case study Cilacap City Indonesia

SIHOMBING, Rahmat Ganda Pandapotan, Dr. rer.nat. Djati Mardiatno, MSi

2010 | Tesis | S2 Geo Informasi untuk Manajemen Bencana

This research was intended to formulate efficient and effective methods in developing reliable database for loss estimation and mitigation planning of tsunami effects. The existing maps are usually not sufficient for loss estimation and mitigation planning purposes in terms of geometrical aspect. New maps can be generated utilizing high spatial resolution satellite imagery. For loss estimation and mitigation planning in the basis of individual buildings, the positional accuracy of the imagery must be improved through geometrical correction. In accordance with the sub-meter pixel size, the GCPs to be used in the rectification process are highly recommended to have horizontal precision of sub-meter also. Differential GPS measurement must be conducted to provide GCPs of the expected horizontal precision. The corrected imagery and the spatial arrangements of the features in the existing maps are combined to develop new maps for the database of elements at risk. A good database can be used as the basis for accurate loss estimation and effective mitigation planning. Ideally, a complete identification of all elements at risk exposed to certain hazards must be established for loss estimation and mitigation planning. This study will focus on the population and buildings where the community live and do their activities. Land parcels will also be taken into account because mitigation planning is usually arranged in the basis of individual building or individual land parcel. A site-specific study on the vulnerability of elements at risk will result more accurate loss estimation and more effective mitigation planning. For this reason, the vulnerability curves of buildings constructed by the 2006 South Java tsunami reconnaissance survey team are used for this study. The behavior of a building under the effects of certain hazards will determine whether the people in the building might be injured or killed. Therefore, the vulnerability of people inside or nearby a building is determined based on the vulnerability of individual building. Dynamic distribution of population is estimated based on architectural space requirements and several reasonable assumptions. Loss estimation and mitigation planning were conducted two times, based on the original imagery and the corrected imagery. Comparison of the final results of the works will show whether or not geometrical correction applied upon the imagery changes the estimated loss significantly. Furthermore, the comparison will show whether or not the proposed methods for developing the database of elements at risk are useful for loss estimation and mitigation planning.

Kata Kunci : Mitigation planning,Tsunami effects,Database for loss estimation