An index of equilibrium of urban land-use structure and information dimension of urban form

To characterize the equilibrium extent of structure of urban land use, an index formula based on information entropy is advanced as follows: J=-∑NiP i log P i/ log N In the formula,P i=A i/A=A i/∑NiA i,where A is the area of urbanized area of a city, A i is the land area of a certain function type,and N is the number of land function types Correspondingly, the difference of an index is defined as I=1-J,which can be used to reflect the inequality of urban land use When information entropy is generalized to describe the spatial morphology of urban land use by means of making ‘nets’ on maps,information dimension as one of the fractal dimensions can be computed to qualify the spatial patterns of urban land use .