Field measurements and numerical simulations of the 2004 tsunami impact on the south coast of Sri Lanka

This paper examines the factors that have contributed to the significant spatial variability of the impact of the December 2004 tsunami in the southern province of Sri Lanka. Documented observations of the evidence left behind by the 2004 tsunami together with numerical simulation of tsunami propagation have been utilized for this purpose. The field data examined in the present analysis comprise the maximum water levels, the horizontal inundation distances and the number of housing and other buildings damaged as a result of the 2004 tsunami whilst the numerical results considered include the distribution of the amplitude of the tsunami. The present model results confirm that source directivity controls the distribution of tsunami amplitudes farther offshore whilst large-scale bathymetric features significantly influence the tsunami propagating over the shelf. Our analyses of field data also show the dominant influence of coastal geomorphology and topography on the extent of tsunami inundation.