1. INTRODUCTION
One of the main tasks in Geographic Information Systems (GIS) is making decisions using information from different layers. In conventional decision-making process, a common type of operation is the threshold model. In the threshold model, low and high threshold values limit the exact boundaries of criteria. For each criterion the study area is classified into two subregions describing whether a property value of a specific location is in the defined limits or not. Then maps produced for each criterion are overlaid using logical connectives (i.e.,Boolean overlay). Such models can cause problems since theyare inherently rigid. On the other hand, FuzzyCell (Yanar and Akyürek, 2006) can be used to make decisions capturing uncertain information using fuzzy set methodologies.