Reduction of Tsunami Inundation Energy by the Modification of Coastal Topography Based on Local Wisdom

Local wisdoms such as a tradition, land-use system and etc. had sometimes mitigated tsunami damages in Indonesia. The effective use of those local wisdoms is strongly desired especially in developing countries, because it is quite difficult for those countries to allocate enough budgets for constructing hard type countermeasures against tsunami. Among local wisdoms against tsunami hazard, this study evaluates the efficiency of a hollow topography which can be seen on the beach along Lampon village in Indonesia. Artificial hollows are arrayed on the beach as one of the local wisdoms in Lampon village to reduce the intensity of inundated tsunami flow. Hollow topography means a low ground that is locally dug by residential people as one of the countermeasures based on the local wisdom. The numerical simulation of tsunami inundation is conducted to evaluate the efficiency of this hollow topography. Furthermore, this study evaluates the efficiency of some contrivances, such a combination of vegetation area and a multiple-use of hollow and embankment topography, in order to enhance the performance of countermeasure based on the local wisdom. This study is also described the GIS analysis for spatial planning based on the result of numerical simulation.