Integrated satellite remote sensing and geospatial analysis for tsunami risk assessment

Tsunami risk is defined as a combination of the danger posed by tsunami hazard, the vulnerability of people to an event (exposure), and the probability of destructive tsunami or likelihood of the tsunami occurring. Tsunami risk is also defined as the mathematical calculation of tsunami vulnerability and tsunami hazard, and it can be assessed using a spatial multi-criteria. The study applied the combination of the element at risk to assess tsunami risk area along the coastal area of East Java Indonesia off the Indian Ocean. Remote sensing approach followed by geospatial analysis into tsunami risk assessment along with the existing perspective evolving the role of Geographical Information System. The existing physical vulnerability parameter was analyzed and evaluated. All parameters in both tsunami vulnerability and tsunami risk assessment were analyzed through weighted overlay in geospatial analysis, in which the criteria's weight was calculated through Analytical Hierarchy Process. The results were provided as thematic maps of tsunami vulnerability and tsunami risk. Tsunami risk map described five classes of risk from very low to very high based on the geospatial analysis. It described that coastal area with low elevation identified as high risks to the tsunami. The coastal area with high density of vegetation described a low level of tsunami risk. The existence of river and another water canals along coastal area were also identified as important parameters in generating tsunami risk map. Risk map highlights the coastal areas with a strong need for evacuation capacities, including evacuation route and evacuation building.