Forest landscape connectivity change analysis in the Yangtze River basin by multi-temporal satellite data

Abstract

This study selected the highly urbanized Wuhan city in the Yangtze River basin as a research area, and used the Landsat 5 TM images from 1990 and the Landsat 7 ETM+ images from 2000 and 2010. These images were combined by using the graph-based integral index of connectivity (IIC), probability of connectivity (PC), and the importance value of the patch to analyze the spatial and temporal dynamic change of the Wuhan urban forest. Results showed the increasing area and the widening Wuhan forest. However, for the past 20 years, their patch structure has been uneven, and composed of several small and super-large patches. The IIC and PC of Wuhan forest tended to increase slightly, whereas the connectivity level of urban forest remained low. The value of the importance of the patch and its range are increasing. Some of its characteristics indicated north is better than south, rural is higher than urban, and the main urban area is lesser than the urban area.