The pressure of population and its demands for fuel, for heating or industrial usage, causes destruction of the natural environment. One of the clearest examples for the accelerated degradation of changes in the forest area and coastline is in the Kilyos-Karaburun coastline located in the northern part of Istanbul metropolitan city. The open-pit mining activities in the region are threatening the balances of both sea and land ecosystems, and cause degradation of forest areas and changes along the coastline. In this paper, the changes are examined with multisensor satellite data such as Landsat Thematic Mapper (TM), SPOT Panchromatic (P), and RADARSAT images by using different image-processing techniques. The degrees of changes in coastline length and coastal region area were calculated, and the effectiveness of the use of different image data sets was outlined for coastal environments.