Inundation and topographic Change due to the 2004 Indian Ocean Tsunami at the Kirinda port, Sri Lanka

Abstract

Tsunami can yield extensive topographic change, which causes secondary damages such as collapse of coastal structures. Therefore, it is important to analyze the topographic change due to the tsunami. In this study, we investigated spatial variation of sedimentation and erosion due to the 2004 Indian Ocean tsunami at the Kirinda port, Sri Lanka by using the bathymetric data before (Nov, 2004) and after (Feb, 2005) the tsunami. We also conducted numerical analysis of tsunami propagation and sediment transport. The results show that the tsunami caused approximately 5m erosion or deposition, and the shoreline was moved approx. 100m toward the offshore. Morever, backwash that was redirected by coastal structures played a main role of significant erosion around the wave breaker.

Numerical Simulations of Sediment Transport Induced by the 2004 Indian Ocean Tsunami Near Kirinda Port in Sri Lanka

“…On land, SRTM bathymetry data sets are used. The median diameter of the bed material is 0.12 mm, as reported by Nishihata et al (2006) and Takahashi et al (2008).…”

“…In the present study, numerical simulations of sediment transport induced by the 2004 Indian Ocean tsunami near Kirinda port in southeastern Sri Lanka are carried out, to investigate the characteristics of tsunami-induced sediment transport in actual coastal areas. This case has already been studied by two-dimensional simulations by Nishihata et al (2006) and Takahashi et al (2008). Furthermore, we discuss the relationships between the tsunami-induced flow and sediment transport.…”

Remarkable bathymetric change in the nearshore zone by the 2004 Indian Ocean tsunami: Kirinda Harbor, Sri Lanka

“…We adopted the tsunami source model that well explains the tidal record and field observations at Sri Lanka (Takahashi et al, 2008). The validity of that model will be evaluated in Section 5.1.…”

“…6), the sediment was likely to have been transported by the tsunami run-up wave from the offshore shallow sea bottom outside the studied region. In fact, preliminary numerical modeling for sediment transport using measured grain size data shows that great amount of the sediment was transported shoreward from the shallow sea bottom by the first run-up wave (Takahashi et al, 2008).…”

“…(a) Location map of the studied area with the tsunami source model proposed byTakahashi et al (2008). The initial water level is shown in gray scale.…”