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The December 26, 2004 tsunami has caused extensive damage in the Union Territory of Andaman & Nicobar Islands, India, affecting 115.36 km of coastline. In order to identify the impacts of tsunami in South Andaman of the Andaman Islands, the study has been carried out using satellite data for pre-tsunami (Feb. 2003) and post-tsunami (March 2005). This paper provides an assessment of damages caused by tsunami and suitable resettlement places for the people using remote sensing and GIS technology. Assessment of tsunami inflicted damage to island ecosystems assumes greater importance owing to their life-sustaining and livelihood support abilities. Apart from the reparation caused to life and property, significant damage has afflicted the ecosystem, which will have long lasting effects. The tsunami-induced damage to coastal ecosystems was studied based on coastal landuse, geomorphology and coastal critical habitat for South Andaman Island using remote sensing and GIS. An area of 3,366 ha of land area was affected by tsunami. Within the coastal ecosystem, coral reef and mangrove were also severely affected. The study of landforms shows that the land is submerged. The severity of damages and their consequences suggest the need for a definite restoration ecology programme.

Open coast storm surge water levels consist of a wind shear forcing component generally referred to as a wind setup; a wave setup component caused by wind induced waves transferring momentum to the water column; an atmospheric pressure head component due to the atmospheric pressure deficit over the spatial extent of the storm system; a Coriolis forced component due to the effects of the rotation of the earth acting on the wind driven alongshore current at the coast; and, if astronomical tides are present, an astronomical tide component (although the tide is not really a direct part of the meteorological driven component of storm surge). Typically, the most important component of a storm surge is the wind setup component, especially on the East Coast of the US and in the Gulf of Mexico. The importance of bathymetry to this wind setup storm surge component is considered herein with special reference to the coastline of Florida where eight Florida transects consisting of a cross-section of bathymetric data perpendicular to the shoreline were investigated. Effects of Coriolis, wave setup, atmospheric pressure head, and astronomical tide are not considered herein but will be addressed in future papers. The present study findings show that the wind setup component can vary over an order of magnitude for the same wind speed depending on the bathymetry leading up to the coast.

The proposed formula for modeling sedimentation is based on a concept of hydrodynamic equilibrium in sediment transport. Hydrodynamic equilibrium occurs when the sediment transport is in a form of grain jumps with the distance traveled $dx$ smaller than the one established in the numerical modeling. A first-order upwind scheme FDM is applied. It provides the solution to equations describing changes in bathymetry in time and space coupled with simultaneous changes of bed sediment distribution. A clear-cut division of sediment transport into those during wave crest and wave trough is proposed. The results of bathymetry modeling coincided satisfactorily with the laboratory data. Moreover, the longer the experiments run, the more the results of measurements are compliant with the calculations. A certain time is needed for sediment transport to reach the hydrodynamic equilibrium, especially when the suspended load is significant. It is reached after going through the initial stages of bed level changes coupled with simultaneous changes of grain size distribution. The application of the model to field conditions shows its ability to predict sedimentation of dredged channels. Furthermore, the calculations show a good agreement with measured bed grain size distributions of sediment samples taken from the sites within the navigational channel of Łeba Port in Poland.

Two SPOT images were used to derive the surface wave spectra for mapping water depths in the coast zone. By the general dispersion relation of water wave, the surface wave changes its wavelength over varying water depth. The estimated depths from this wave spectrum bathymetric (WSB) method were further corrected to water depths relative to the mean lower low tide. The average error of this image-derived water depth is about 10% from the measured water depths. This WSB method takes advantages of the remote sensing technology to obtain the synoptical bathymetry of coastal waters safely, economically and quickly. It is especially suitable for the coastal zone west of Taiwan where the bathymetry changes yearly near some river mouths, the bottom slope is gentle enough, satisfying the requirement of WSB method, and the non-uniformity of water quality incapacitate the application of optical bathymetry method.

Many beaches in Penang island were severely inundated by the 26 December 2004 Indian Ocean mega tsunami with 57 deaths recorded. It is anticipated that the next big tsunami will cause even more damages to beaches in Penang. Hence, developing community resilience against the risks of the next tsunami is essential. Resilience entails many interlinked components, beginning with a good understanding of the inundation scenarios critical to community evacuation and resilience preparation. Inundation scenarios are developed from tsunami simulations involving all three phases of tsunami generation, propagation and run-up. Accurate and high-resolution bathymetric–topographic maps are essential for simulations of tsunami wave inundation along beaches. Bathymetric maps contain information on the depths of landforms below sea level while topographic maps reveal the elevation of landforms above sea level. Bathymetric and topographic datasets for Malaysia are, however, currently not integrated and are available separately and in different formats, not suitable for inundation simulations. Bathymetric data are controlled by the National Hydrographic Centre (NHC) of the Royal Malaysian Navy while topographic data are serviced by the Department of Survey and Mapping Malaysia (JUPEM). It is highly desirable to have seamless integration of high-resolution bathymetric and topographic data for tsunami simulations and for other scientific studies. In this paper, we develop a robust method for integrating the NHC bathymetric and JUPEM topographic data into a regularly-spaced grid system essential for tsunami simulation. A primary objective of this paper is to develop the best Digital Elevation and Bathymetry Model (DEBM) for Penang based upon the most suitable and accurate interpolation method for integrating bathymetric and topographic data with minimal interpolation errors. We analyze four commonly used interpolation methods for generating gridded topographic and bathymetric surfaces, namely (i) Kriging, (ii) Multiquadric (MQ), (iii) Thin Plate Spline (TPS) and (iv) Inverse Distance to Power (IDP). The study illustrated that the Kriging interpolation method produces an integrated bathymetric and topographic surface that best approximates the admiralty nautical chart of Penang essential for tsunami run-up and inundation simulations. Tsunami inundation scenarios critical to risk analysis and mitigation could then be developed using this DEBM for various earthquake scenarios, as presented in this paper for the 2004 Indian Ocean Tsunami.