In this study, using Landsat-TM Images (1984 and 1992), land-use/land-cover characteristics in Istanbul's Elmali Water Basin Area were analysed and evaluation of thematic and positional accuracy of images was performed. High accuracy raster data were converted to vectorial data and used in Geographic Information Systems. A data base to be used for water basin planning and managing, utilising statistical attribute data covering population, water potential, topographic position, industry and labour force was prepared and overlay analysis was carried out. Finally, comparison between water basin protected areas in 1984 and 1992 using GIS techniques was performed and results were illustrated on three dimensional surface models. (C) 1998 IAWQ Published by Elsevier Science Ltd. All rights reserved.