Detection of Landcover Changes with Rapid Urbanization Using Remotely Sensed Data in and around Chongqing, China

Chongqing, as the central city of inland China, has been subject to especially fast economical development. With increasing population and urban development, various impacts on the surrounding environment, such as deforestation, urbanization and pollution, must be taken into consideration. In particular, decrease in vegetated area and disruption of local ecosystems due to urbanization has emerged as a major issue in recent years. This indicates the necessity of urban landscape management and conservation of environments. In this research, Landsat TM and ETM+ data were employed for landcover classification and to analyze changes in landcover over a 8-year period from 1993 to 2001. The landcover classifications were implemented using the supervised method (Maximum Likelihood), based on accurate ground truth data such as field surveys and aerial photographs. The overall results of classification show that the proportion of forest decreased from 24.0% in 1993 to 21.2% in 2001, and urban area increased from 4.3% in 1993 to 6.7% in 2001. In addition, the topography of Chongqing is mountainous, and the landcover is strongly influenced by topography. The research thus also analyzed landcover status and changes according to elevations and slope. In addition, the landcover status and patterns of change were also correlated with distance from the urban core. By clarifying the status of landcover around Chongqing, and by analysing how these landcover patterns are changing, this research hopes to provide baseline data that will be useful to nature conservation and multifunctional landscape planning as the city continues to grow.