Today, there are varieties of methods for determining the risk flooding in different areas a catchment. However, use GIS-based weighting is receiving increasing attention among researchers. In early 2019, severe and continuous floods occurred some provinces Iran. Khorramabad was one cities most affected by floods. Regrettably, during construction development city, minimum distance from roads vi...

In this paper,we study the definition of the results for GIS queries. They are based on a graphical representation. Such a representation may introduce some ambiguities depending on the class of queries. We study two different ambiguities due to the aggregate functions and the notion of homogeneity.