Wallonia (the region covering southern Belgium) is committed to making a significant increase in its wind-powered electricity production capacity by 2010. Therefore, a decision support system designed to evaluate and map environmental and landscape constraints fundamental to the building of wind farms was developed for the whole Walloon Region (17,000 kM2). This system is a geodatabase using 40 criteria (landscape or environmental) corresponding to three constraint levels (,-xclusion, highly sensitive and sensitive). This geodatabase also has analysis functions developed in the ArcGIS 9 software environmcnt that are used to update the overall constraints map, to analyse sensitivity with respect to constraint criteria-defining parameters as w,ffl as to perform full diagnostic studies on wind farm projects. (c) 2008 Elsevier Ltd. All rights reserved.