How to delineate urban gravitational zones? GIS-based multicriteria decision analysis and Huff’s model in urban hierarchy modeling

Urban gravitational zones (UGZ) are related to cities' functions and population size. In strategic regional territorial planning adequate tools and detailed data are rarely used. This issue is not foreign to Croatia and other countries. How should the UGZ be accurately delineated for each city? A combination of Huff's model and GIS-based multicriteria decision analysis (GIS-MCDA) was used to delineate UGZ. In total, 95 criteria grouped into ten functions were used. The research resulted in a new methodological framework for deriving the urban hierarchy model, a tool that allows automation and simplification of the GIS-MCDA, and an urban hierarchy model of 20 major cities in Croatia.