Historical Shoreline Change of the Sele Plain (Southern Italy): The 1870–2009 Time Window

In the Mediterranean, the coastal population was estimated at 146 miUion in 1990 and the urban coastal population alone is projected to rise to 176 million by 2025, with an addition of 350 million of tourists per year. In coastal zones, forecasting shoreline location and changes in time is a basic tool for decisional making regarding land management and future planning. Historical maps, aerial photography, topographic maps and a beach survey were used as data sources to detect the shorelines of the Sele Plain coastline between the towns of Salerno and Agropoli (southern Italy) and define its change from 1870 to 2009. By using the potential of ArcGIS release 8.3 software and its extension digital shoreline analysis system, we followed two main stages. The first required identification of the shorelines, reducing to a minimum the errors associated to the suitability of source material, distortion of the photographs, residuals in georeferencing, and seasonal shoreline variation. The second was to define the shoreline variations along 170 transects spaced every 200 m. This systematic analysis showed that in the Sele River plain the highest rates of erosion, generally localized at river mouths (Picentino River, mean value = 0.4 m/y; Sele River, mean value = 1.3 m/y), have decreased in the last 20 years, revealing that the beach system is acquiring new coastal stability