Climate change and rising sea levels increase the risk of flooding and coastal erosion in most coastal locations. Continuous monitoring, surveillance and assessment of these risks are of paramount importance for coastal scientists and managers and several techniques have been developed to monitor morphological changes in the marine environment. In this literature review we attempt to present up to date literature with regards to coastline changes monitoring techniques with a special emphasis on remote sensing monitoring techniques. Coastal zones in particular are receiving an increasing attention by ocean scientists as they are of major social and economic importance and synonymous with high populations being sited worldwide close to the sea.

The coastal zone, which is usually defined as the zone from 200m above to 200m below sea level (Cracknell 1999), is a highly dynamic environment where many physical and geomorphic processes occur to form unique landscapes. Processes such as erosion, accretion, flooding, sea level changes, deposition and sedimentation continuously modify the coastlines. Human activities including coastal engineering, dredging, pollution etc. are also displacing the shorelines. Coastal erosion in particular has negative impacts on marine environment, since the waters that surround the shorelines are breeding grounds for a number of marine species, and also on human populations residing in coastal areas leading to devastating economic losses secondary to population and businesses displacement. Attempting to map shoreline changes and predict future shoreline positions is critical for coastal planning and management (Moore et al 2000), coastal environmental protection and safe navigation. Mapping and monitoring coastline changes has therefore become of paramount importance to maritime and government authorities worldwide, as they have the responsibility to predict shoreline changes before these occur. Application of surveying techniques in coastal zones is however extremely difficult since a large part of the zone consists of water and hence a systematic approach monitoring both sea and land is required. Shoreline dynamics have been traditionally investigated and studied with conventional techniques such as multi-year shoreline mapping ground surveys and aerial photography surveys. Both techniques are often expensive requiring professionals and equipment for data analysis, time consuming and in complex, highly dynamic coasts changes often occur so quickly that the end product of the survey can be outdated by the time it is finished.