Monitoring the evolution of coastline in Sicily by aerial photos and high resolution satellite imagery

Abstract

Italy is one of the country more exposed to coasts erosion: about 1200 km of coasts on about 8350 km are moved back of about 25 m in the last 50 years. Particularly Sicily have about 300 km of coasts moved back. There are various reasons of this phenomenon: natural factor (climatic or physical-oceanographic) with environmental and economic effects. The paper reviews the activity of the Dipartimento di Rappresentazione of University of Palermo in cooperation with the Regional Agency of Environmental Protection (ARPA) about the coastline evolution in Sicily. The research is carried out on selected physiographic units marked out by important erosive phenomena. The coastline trend are reconstructed by the elaboration of aerial photos and high resolution imagery. Particularly were used the aerial photos of the years 1954-55 (scale 1:33.000), 1987 (scale 1:10000) and 1997 (scale 1:20.000). Besides were used QuickBird high resolution satellite imagery of the year 2006. The aerial photos and the QuickBird imagery have been oriented with planimetric accuracy of ± 2 m. The Ground Control Points were collected by static GPS surveys. The comparison with orthophotos allowed to estimate the real coastline trend in the last 50 years.