1. Introduction
This chapter aims to introduce an application of remote sensing to recent tsunami
disasters. In the past, acquiring tsunami damage information was limited to only field
surveys and/or using aerial photographs. In the last decade, remote sensing was applied
in many tsunami researches, such as tsunami damage detection. Satellite remote sensing
can help us survey tsunami damage in many ways. In general, the application of remote
sensing for tsunami disasters can be classified into three stages depending on time and
disaster-related information. In the first stage, general damage information, such as
tsunami inundation limits, can be obtained promptly using an analysis combined with
ground truth information in GIS. The tsunami inundation area is one of the most
important types of information in the immediate aftermath of a tsunami because it helps
estimate the scale of the tsunami’s impact. Travel to a tsunami-affected area for field
surveys takes a lot of time, given the presence of damaged roads and bridges, with much
debris as obstacles. In the second stage, detailed damage interpretation can be analysed;
i.e., classification of the building damage level. Recently, the quality of commercial
satellite images has improved. These images help us clarify, i.e., whether a house was
washed away or survived; they can even classify more damage levels. The third stage
combines the damage and hazard information obtained from a numerical simulation, such
as the tsunami inundation depth. The damage data are compiled with the tsunami hazard
data via GIS. Finally, a tsunami vulnerability function can be developed. This function is a
necessary tool for assessing future tsunami risk.
The contents of this chapter are arranged in three sections:
- Satellite image analysis for detecting tsunami-affected areas
- Tsunami damage level classification by visual interpretation and image analysis
- Development of a tsunami vulnerability function by applying a numerical model