Conclusions
(1)
With the fast economic development, urban expansion of Guangzhou City, China is accelerated, as the built-up urban area achieves a net increase of 325.5 km2 in the 23 years period between 1979 and 2002, and the built-up urban area in 2002 is increased by nearly 4.5 times of that in 1979, with an annual average increase of 14.2 km2, and an annual change rate of 19.7%.
(2)
The model of urban expansion of Guangzhou City, China basically takes the form of radiation centered around the old downtown, consisting of layer-by-layer outward extension and extension along major traffic routes, which results in a spatial development pattern as characterized by three groups plus two routes; The rate of expansion is different in different periods, with the eastward urban expansion being the most remarkable in all stages.
(3)
Economic growth is the major driving force for expansion of the built-up urban area, population growth and resident income increase are the two most direct driving forces for urban land expansion, while city infrastructure construction, city planning and policy control to considerable extent the macroscopic pattern and development rate of urban expansion, natural geographic environment and topography constrains to a certain degree the spatial development of a city.
(4)
Dynamic monitoring of urban expansion, in terms of area, orientation and rate, by means of multi-temporal remote sensing images, is a highly efficient and feasible technique, which can provide scientific criteria for reasonable planning and decision-making for macroscopic management of a city.