Temporal-Spatial Patterns and Incentives Analysis on Urban Land Expansion of Wuhan City

The temporal-spatial patterns and incentives of the urban land expansion are studied, taking Wuhan city as a case. The construction land data was captured according to land use database standard of CAS from Landsat TAT images of 1995, 2000 and 2005 respectively. With the Supermap GIS software platform, the spatial analysis of construction land was made during two periods of 1995-2000 and 2000-2005. Based on the land use data we captured and the authoritative statistical data, the temporal-spatial characteristics of the urban land expansion as well as structure evolution was analyzed applying several indices, such as expansion intensity, population flexibility and land-use structure proportion. The result shows that there are quite different characteristics of urban land expansion in the two periods. The expansion intensity index is 0.1948 during the period of 1995-2000 while it is 0.4894 during the period of 2000-2005. And the expansion pattern has experienced a conversion from the simplified external expansion to the combination of external expansion and internal fill, or from continuous expansion in the shapes of axes or ribbon to non-continuous counterpart centered on a growth polar or grown as conglomeration. Related analysis shows that the expansion of Wuhan city has been driven by the integration of multiple impetuses, such as the increase of population, economic development and traffic infrastructure improvement, together with periodic industrial policies.