Detection of Windthrow in Mountainous Regions with Different Remote Sensing Data and Classification Methods
Abstract:After a disastrous storm event, quick and reliable information on the extent of forest damage is required. This study evaluated different remote sensing data and methods to detect windthrown forests in mountainous regions as an alternative to the manual analysis of aerial images or terrestrial methods. To this end, both optical satellite sensors (Landsat-7, Spot-4 and Ikonos) and synthetic aperture radar (SAR) data at various frequencies (X-, L-, P- and C-band) were evaluated, and classifications of the windthrown forests were performed. This study was designed to state the advantages and disadvantages of the investigated data and methods. Classification results were compared with aerial images which were interpreted manually on a stereoscopic base. The study showed that the manual interpretation of Ikonos data revealed the most accurate results, followed by an automatic classification of Spot-4 data. Except for ERS-1/2 data, which are too inaccurate in mountainous regions, and SAR P-band data, all sensors and methods investigated have different advantages, so the choice of a specific sensor and method will depend on the question being answered.
Document Type: Research Article
Affiliations: 1: Swiss Federal Research Institute WSL Cascine di Barico Zürcherstrasse 111 CH-8903 Birmensdorf 2: Sarmap SA. Cascine di Barico CH-6989 Purasca 3: Remote Sensing Laboratories, Department of Geography University of Zurich Winterthurerstrasse 190 CH-8057 Zurich 4: Scherrer Ingenieurbüro AG CH-9650 Nesslau
Publication date: December 1, 2003