A distance variable to simulate the urban population

摘要

The urban population density declines from Central Business District (CBD) to city edge. Some studies have explored several mathematical forms to describe the relationship between population density and location. But these models assume that the city is single center and the urban population decline with concentric circle format. It is difficult to satisfy this requirement in actual cities. A distance variable, city edge distance, has been developed to solve the problem in this paper. Using city edge distance can express multi-centered city situation. The irregular city is easily transformed into a virtual concentric circle city. Then the Clark model and power exponential model are transformed into new format based on the city edge distance. A case study indicates that the transformed formats could successfully simulate the urban population density. But more applications are needed in different city types to validate and improve this distance variable.