Coastal erosion is the loss of landmass into the sea due to natural processes such as waves, winds and tides, or even due to human interference. Large storm-generated waves can cause coastal erosion. Erosion can be the result of long term processes, individual events, or a combination of both.
Historical coastline changes are calculated using a variety of methods, such as:
- Collection of historical coastlines from ortho rectified aerial photographyor satellite images
- Collection of coastline from Lidar data that is taken on at least two different occasions
- Beach profiling with survey transects
- Beach Profiling with GPS
- Analysis of historical maps
Coastal change rates derived from a consideration of past changes in the coastline do not necessarily reflect seasonal, episodic, or sudden but unusual changes. They give an indication of coastal vulnerability. Even coastal vulnerability may change as sediment sources become exhausted or new ones appear.