There are a number of reasons for protecting the coast. Coastlines tend to be very heavily populated. They are areas of high economic value due to tourism. Coastlines are particularly prone to flooding. Finally, they are fragile ecosystems which take a long time to recover if they are destroyed.
Techniques for managing the physical processes of coastal erosion, transportation and deposition can be divided into hard engineering options (such as building sea walls and groynes) and soft engineering options (such as beach nourishment and managed retreat).