“…Over the past 20 years, many studies in the field of geographic information systems (GIS) and spatial database domains have focused on models of fuzzy geographical objects and their relationships, because the shapes of many spatial objects are inherently vague (e.g. residential centers, polluted rivers, forests) (Bloch, ; Dilo, ; Du et al, ; Guo, & Cui, ; Liu & Shi, ; Schneider, ; Schneider, ; Wang, Du, Feng, Zhang, & Zhang, ; Zhan, ). Molenaar () introduced three definition levels of fuzzy objects, and extensional uncertainty plays a dominant role in the spatial representation of fuzzy objects.…”