Remote sensing monitoring and driving force analysis of urban expansion in Guangzhou City, China

Based on Landsat remote sensing data and by means of specific extraction and supervised classification of remote sensing information, a dynamic study was carried out on urban expansion of the built-up area of Guangzhou City in different periods. A detailed analysis was made of the area, orientation and rate of variation of urban expansion of Guangzhou City in the period of 23 years lasting from 1979 to 2002, and a model for urban expansion was proposed in this paper. As demonstrated by our research results, urban expansion of Guangzhou City is very fast with high speed development of the economy. In the 23 years period, the built-up area of Guangzhou City attains a net increase of 325.5 km(2), and reaches 397.4 km(2) in 2002, which is nearly 4.5 times of that in 1979 and means an annual average expansion of 14.2 km(2) and an annual growth rate of 19.7%. The model of urban expansion in Guangzhou City is basically characterized by radial expansion centered on the old city town, which takes the form of expansion in rings, in layers and along major traffic routes. Here the rate of urban expansion varies in different periods, and is the most outstanding in various periods in the east of the city. The built-up area of Guangzhou City is highly correlated with the gross domestic product (GDP), total population, urban resident income and urban traffic of the city, which are the dominating driving factors for expansion of the built-up urban area of Guangzhou City. (C) 2009 Elsevier Ltd. All rights reserved.