Mapping fire scars in global boreal forests using imaging radar data

Abstract

This study is an extension of earlier research which demonstrated the utility of ERS SAR data for detection and monitoring of re-disturbed boreal forests of Alaska. Fire scars were mappable in Alaska due to the ecological changes that occur post-burn including increased soil moisture. High soil moisture caused a characteristic enhanced backscatter signal to be received by the ERS sensor from burned forests. Since regional ecological di V erences in the global boreal biome may have an e V ect on post-re ecosystem changes, it may also a V ect how re scars appear in C-band SAR imagery. In the current study we evaluate the use of C-band SAR data to detect, map and monitor boreal re scars globally. Study sites include four regions of Canada and an area in central Russia. Fire boundaries were mapped from SAR data without a priori knowledge of re scar locations. SAR-derived maps were validated with re service records and eld checks. Based on results from test areas in Northwest Territories, Ontario, southeastern Quebec, and central Russia, C-band SAR data have high potential for use in detecting and mapping re scars globally.

A Review of Swidden Agriculture in Southeast Asia

“…However, the historical footprint data were extremely underutilized and very few research studies have so far explored the remote sensing techniques for swidden identification and mapping. Literature shows that a diverse number of remotely sensed algorithms or models have been applied in the fields of fire ignition probabilities, burnt area and burn severity in the boreal forest region and Mediterranean climate zone [104,109]. By contrast, swidden-related burned area mapping techniques used in the subtropical and tropical regions were not adequately investigated.…”

“…Besides, Synthetic Aperture Radar (SAR) data also has unique capabilities for fire scars and burnt area monitoring because microwave energy can penetrate clouds [109,110]. This feature is particularly critical for mapping fire scars in tropical forest.…”

The contribution of remote sensing to the assessment of drought effects in forest ecosystems

“…These studies have been using C-band data (ERS, Radarsat) and have been carried out in boreal regions, in North America [8,32,47,57] and in Siberia [77], in the Mediterranean region [34,35], and in tropical regions [62,90]. Burnt scar mapping has been found possible, which has generally been explained by changes in soil humidity [47].…”

Land Cover Mapping and Change Detection Analysis over Nanggroe Aceh (NAD) Province after Tsunami

“…The purpose of conducting change detection is to compare spatial representation of two points in time by measuring changes caused by differences in the variables of interest and controlling all variables caused by differences in variables that are not of interest (Green et al, 1994). Normally, change detection involves the utilization of multi-temporal satellite (Lunetta et al, 2002;Read and Lam, 2002;Weng, 2002) 2. forest or vegetation change (Woodcock et al, 2001;Lu et al, 2002) 3. forest mortality, defoliation and damage assessment (Rigina et al, 1999) 4. deforestation, regeneration and selective logging (Asner et al, 2002;Wilson and Sader, 2002) 5. wetland change (Munyati, 2000) 6. forest fire (Bourgeau-Chavez et al, 2002) 7. landscape change (Taylor et al, 2000) 8. urban change 9. environmental change (Kimura and Yamaguchi, 2000) 10. other application such as crop monitoring (Engeset et al, 2002) A good and successful change detection research should provide the following information:…”