High Resolution Satellite Images to Reconstruct Recent Evolution of Domitian Coastline

Abstract

In the last decades, combinations of natural and humanfactors have resulted in extensive morphological changes to our coastlines andin many cases have amplified erosion. In order to limit these changes and theirimpact on coastal zone, it is important toplan specific actions; for this purpose detailed cognizance of coastal zone isnecessary. Different and heterogeneous data such as historical and recent maps,remotely sensed images and topographic survey result very useful to reconstructtemporal shoreline changes. In this study the attention is focalized onDomitian coastal zone (Italy), which is one of the most emblematic examples ofcoastal erosion in Europe. Study of the shoreline evolution in this areabetween 1876 and 2005 was used as the starting point of the present paper that investigatesover a span of seven years (2005 to 2012), by using remotely sensed data. Theaim is to adapt and integrate geomatics techniques to transform very highresolution satellite images in powerful tools to analyse coastline changes. So,in order to identify eroded and added areas, IKONOS-2 (2005), GeoEye-1 (2011)and WorldView-2 (2012) imageries are compared. These data-sets were re-georeferredto improve the positional accuracy. More over Normalized Difference Water Index(NDWI) was applied to pan-sharpened multispectral images to facilitatecoastline vectorising at the same geometric resolution of panchromatic data. Inaddition, variance propagation was considered to establish the accuracy of thereconstruction of coastal evolution. Added and eroded areas were defined andrelated to the impact of the defence structures that were built in this zone in2011.