Green Cover (Tree) Analysis of Chennai Metropolitan Area Using High Resolution Satellite Imagery

Abstract

Sustainable urban environment addresses the issues associated with the urban development due to the increase in land use/land cover (LU/LC) and decrease in forest and agricultural areas. As vegetation plays a major role in ecological, social, health, and economic benefits to the inhabitants of a city, urban greeneries should be monitored through the remotely sensed data with high resolution imagery for a sustainable urban development. The present study investigates the green cover (tree) change of Chennai Metropolitan Area (CMA) through the satellite data of Resourcesat-1 LISS IV and Resourcesat-2 LISS IV. CMA consists of approximately 426 km 2 of urban area and 774 km 2 of sub-urban area with many LU/LC categories like settlements, vegetation and open spaces. Green cover mapping with the accuracy assessment was carried out by using both digital image processing technique and on-screen visual interpretation (Google Earth imagery). Vegetation indices and texture analysis were employed to extract the green cover for 2005 and 2012, to which the change detection was applied. The results reveal that the green cover area of CMA administrative boundary decreased approximately by 1.18% for 2005-2012 and the actual green cover for 2012 reduced by 8.62%. This analysis will be useful to the policy makers of urban development in planning infrastructure development projects and administrators of metropolitan cities, especially Chennai.