Vol. 13, Special Issue 1: 34th EARSeL Symposium, 76-81, 2014

Forest damage assessment using SAR and optical data: Evaluating the potential for rapid mapping in mountains
Ruben Remelgado, Claudia Notarnicola, and Ruth Sonnenschein

Abstract
In mountain ecosystems, forest damages are of high importance and a challenge for forest management and conservation. However, a quick assessment of these changes is difficult in complex terrain. In response to this constraint, rapid mapping using earth observation data has become an attractive solution. In particular, Synthetic Aperture Radar (SAR) offers a unique opportunity for forest management applications due to its independence of weather conditions. In this study, the potential of X-band COSMO-SkyMed Stripmap SAR images for forest change detection in mountainous environments is evaluated. A forested area in the Southern Alps (South Tyrol) is chosen which was affected by a storm event in June 2011. We mapped the forest changes using a statistical approach (Principal Component Analysis (PCA)). To evaluate the potential of radar relatively to optical data, two RapidEye images were obtained and forest changes by thresholding image differences between both years were mapped. The results show that optical data showed higher forest change accuracies than the SAR images. Using RapidEye imagery we accurately captured changes with a minimum area of 0.1 ha while the minimum detectable area was 0.5 ha with COSMO-SkyMed. The difference in results is explained by the high level of speckle noise introduced by the SAR resolution and by the high Local Incidence Angles (LIAs) within the study area (55° to 95°). The combination of these two effects introduced an increase in false alarm changes. The advantage of using SAR data is the capability of a quick assessment of changes especially in difficult weather conditions. However, the use of radar for rapid mapping of forest damages in mountains can be limited depending on the acquisition geometry. Thus, the acquisition geometry should be carefully chosen with respect to the topography to reduce layover and shadowing effects.

View Full Text (pdf file, 1.2 MB) previous page
DOI: 10.12760/02-2014-1-14

History
Submitted: 01 Apr 2014
Revised: 22 Oct 2014
Accepted: 29 Oct 2014
Published: 11 Nov 2014
Responsible editor: Bogdan Zagajewski

Citation
Remelgado R, C Notarnicola & R Sonnenschein, 2014. Forest damage assessment using SAR and optical data: Evaluating the potential for rapid mapping in mountains. EARSeL eProceedings, 13(S1): 76-81
EARSeL-logo

EARSeL European Association of Remote Sensing Laboratories, Strasbourg, France

   
BIS-logo

BIS-Verlag
BIS Library and Information System, Carl von Ossietzky University of Oldenburg

   
Scopus-logo

Indexed in Scopus

   
DOAJ logo

DOAJ
Directory of Open Access Journals

   
SPERPA/RoMEO logo

SHERPA/RoMEO
Opening access to research

Creative Commons License

ISSN 1729-3782