117. SHORELINE IDENTFICATION USING SATELLITE IMAGES

Abstract Shoreline identification using satellite images is compared with in situ shoreline measurements in the Yucatan Peninsula to evaluate its potential for studying shoreline changes in places with a paucity of data. This study firstly tests the detection limits of shoreline identification by comparing a SPOT image with ground shoreline measurements, and secondly we showexamples of overlaying satellite -derived shorelines from three different years to assess the ability of the technique to quantify real shoreline changes. The mean (-0.19 m) and the standard deviation(4 m) between the ground and satellite-derived shoreline are much smaller than the pixel size. Shoreline changes of more than 30 mwere measured between images panning severals years 2004( , 2006 and 2008) inareas near to coastal structures and near urban areas without coastal vegetation. Key words: shoreline identification, satellite images, erosion, beach dynamics, shoreline change, Yucatan, Mexico. 1. Introduction