Longshore propagation erosion of beach in the vicinity of tsunami-induced concave shoreline

Collapse of Sand Spit at the Kalu River Mouth in Kalutara, Sri Lanka

“…The intrusion of sand spit to inland direction was mainly because of the deepening of the water depth at the river mouth due to the tsunami waves and its return flow. This phenomenon was also commonly observed at many river mouths in Japan after the 2011 tsunami 11) . Although the breaching was not observed along Calido Beach during the 2004 tsunami due to the effectiveness of the dense vegetation on the sand spit at that time, but tsunami waves have broken the equilibrium state that obtained in the Period 2 in this area.…”

“…The decreasing trend of the area A 3 after 2015 suggested that the significant reduction of sediment supply from the northern part to this area. Hoang et al 11) have indicated that the concave shoreline was commonly observed at the river mouth area due to the erosion of sand spit barrier under the tsunami impacts. During the recovery process, the erorional area was extended along the beach.…”

“…5(c), is used to determine the erosion propagation distance (x e ) in this study. Hoang et al 11) have shown that the distance of erosion propagation increases in proportion to the square root of elapsed time based on analyzed date from various river mouths after the 2011 tsunami. Based on the analytical solutions of the one-line model, the relationship between the erosion propagation distance and elapsed time can be expressed as follows;…”

Morphology Recovery and Convergence of Topographic Evolution in the Natori River Mouth after the 2011 Tohoku Tsunami

“…Monecke et al [11] simulated the cross-shore profile change under the prevailing hydrodynamic conditions to investigate the recovery process, while Martínez et al [12] applied a more complicated sediment transport model (Delft3D) in conjunction with morphology and topography data analysis to discuss the erosive behavior of the microtidal Tubul-Raqui wetland in south-central Chile. In Japan, more thorough and multidisciplinary research of the coastal and riverine damage and recovery after the tsunami was conducted using the sufficient availability of both pre-and post-tsunami data [13][14][15][16][17][18][19][20][21].…”

“…Based on past research, the recovery was rather fast in barrier breaches and straight coasts with minor changes [8][9][10]18]. In the river mouths and tidal inlets, the recovery is more complicated and reliant on the hydrodynamic conditions and the availability of sediment supply in the littoral zone.…”