An integrated evaluation of landscape change using remote sensing and landscape metrics: a case study of Panyu, Guangzhou

The 'reform and openness' policy applied in China since the late 1970s has shaped the landscape of the country, and has resulted in various environmental and ecological impacts. However, very few investigations of land use changes from a landscape perspective have been conducted so far. In this paper, remote sensing data and landscape metrics are used to investigate the changes in land use and landscape pattern in Panyu, Guangzhou over a study period from 1988 to 2002. Landsat Thematic Mapper (TM) images are processed using ERDAS IMAGINE, and landscape metrics are calculated at landscape and class levels using FRAGSTATS. A land use transition matrix shows that land use patterns in Panyu have been undergoing rapid changes over the past two decades. Changes were mostly due to the conversion of cultivated land and orchard to urban built up area, which in 2002 had increased by more than three times that in 1988. All integrated evaluation of landscape pattern based on landscape metrics analysis indicates that a mixture of cultivated land and orchard could serve as a matrix in 1988. Due to rapid economic development and urbanization, the landscape became more fragmented and heterogeneous from 1988 to 1998. Since 1998, the landscape had been dominated by a mixture of urban and cultivated land, and became more homogenous and aggregated in 2002. This study highlights that a landscape matrix should also be synchronously investigated when landscape matrix change is of concern, especially in a rapidly developing area. The study demonstrates that landscape metrics can be a useful indicator in land use change analysis and are vital for integrated landscape evaluation.