Waves and tsunamis

Abstract

▪ Coasts are some of the most rapidly changing places on earth. Understanding the natural adjustments that occur between coastal landforms and the processes that influence them is essential for the better management of coastal resources, reducing catastrophic scenarios in these urban areas.

▪ Energetic sea actions (waves, tides and currents) play a major role in the natural dynamic of coastal zones. These dynamic processes can lead to local or more widespread coastal erosion, with land loss, that can be critical along some frontages, especially in a medium to long term (Figure 1).

▪ Human intervention can reduce the severity and/or extent of coastal erosion, for example by coastal protection measures, but can also increase erosion, e.g. down-drift of obstructions to long-shore drift along the shoreline. Increased urbanization at the coast increases risks of loss due to wave actions generated by storms (including cyclones and hurricanes) or by tsunami (Figure 2).