Extraction of small biotopes and ecotones from multi-temporal RapidEye data and a high-resolution normalized digital surface model

Abstract

The conservation of habitats and habitat complexes in diverse landscapes is increasingly recognized as a crucial factor in sustaining biodiversity and ecosystems. For the successful management of landscapes, habitat monitoring is necessary, but often small biotopes, e.g. scattered trees, copses, tree rows, hedges, and the transition zones between ecosystems, are ignored. This is important as such small biotopes are recognized as keystone elements in landscape structure for habitat networks. Furthermore, the transition zones between different habitats, often called ecotones, are dynamic and play several functional roles in landscape ecology. This article presents an approach for the extraction of small biotopes and ecotones combining object-based and pixel-based image analysis. Both high-resolution digital elevation data from airborne laser scanning and multi-temporal RapidEye remote-sensing data were used to automatically detect landscape elements and landscape patterns. First, multi-temporal RapidEye images were used to classify the main land-use classes using object-based image analysis. In the second step, a high-resolution digital surface model was integrated with the main classes, and small biotopes and ecotones were delineated by means of pixel-based image analysis. Classification accuracy for main land-use classes is above 92%, and a visual assessment using aerial image and onsite investigation show that the identification results for small biotopes well match reality. The results show the effectiveness of the classification strategy developed and the potential for incorporating the detailed surface mapping in heterogeneous vegetated areas.

Acknowledgements

The airborne laser scanning (ALS) data and aerial photograph from 2005 were supplied from the project of ‘Geographic information networks for cross-border national park region Bohemian-Saxon Switzerland (Dresden University of Technology, Institute of Photogrammetry and Remote Sensing)’. Parts of this article were presented at the 5th RESA Workshop, 20–21 March 2013.

Notes

1. Accessed August 22, 2014. http://www.adv-online.de/Geotopography/ATKIS/