A comparison of Landsat ETM+ and high-resolution aerial orthophotos to map urban/suburban forest cover in Massachusetts, USA

Abstract

This article examines the extent to which L(ow)-spatial resolution Landsat Enhanced Thematic Mapper Plus (ETM+) imagery can be used to map urban/suburban forest cover in comparison with H(igh)-spatial resolution (less than 1 m) digital aerial orthophotos from the same study area and time period. This research has practical implications for resource managers, government agencies and forestry researchers interested in mapping large-area urban/suburban forests because Landsat imagery is more accessible, has an extensive historical archive, has broader spatial and temporal coverage and is more cost efficient than H-resolution aerial orthophotos. Classification tree results suggest that Landsat ETM+ imagery is adequate for mapping larger, contiguous patches of forest (i.e. small forest patches greater than 2 acres) in urban/suburban settings, but its spatial resolution is too coarse to accurately map spatially complex residential areas in urban/suburban landscapes.

Acknowledgements

The United States' National Science Foundation (NSF) supported this work via the following programmes: Long Term Ecological Research via grants OCE-0423565 and OCE-1026859 for the Plum Island Ecosystems, Coupled Natural Human Systems via grant BCS-0709685 and Research Experiences for Undergraduates via grant SES-0849985. Any opinions, findings, conclusions or recommendations expressed in this article are those of the authors and do not necessarily reflect those of the funders. Anonymous reviewers supplied constructive feedback that helped to improve this article.