Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1016/j.rse.2013.07.011 |
Toward structural assessment of semi-arid African savannahs and woodlands: The potential of multitemporal polarimetric RADARSAT-2 fine beam images | |
Mathieu, Renaud1; Naidoo, Laven1; Cho, Moses A.1; Leblon, Brigitte2; Main, Russell1; Wessels, Konrad3,4; Asner, Gregory P.5; Buckley, Joseph6; Van Aardt, Jan7; Erasmus, Barend F. N.8; Smit, Izak P. J.9 | |
通讯作者 | Mathieu, Renaud |
来源期刊 | REMOTE SENSING OF ENVIRONMENT
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ISSN | 0034-4257 |
EISSN | 1879-0704 |
出版年 | 2013 |
卷号 | 138页码:215-231 |
英文摘要 | Woody vegetation structure affects wildlife habitat selection and species diversity for a wide range of taxa, and at a variety of scales. Indicators of woody structure can indicate the spatio-temporal variability of biodiversity, species occurrence and assemblages. Woody cover is the simplest and most widely used structural metric. Combined with the vegetation height, it provides a volumetric indicator, which is more informative, and is simple to calculate. We therefore assessed the utility of multitemporal polarimetric RADARSAT-2 C-band imagery to map measures of woody volumetric indices in Lowveld savannahs, in the vicinity of the Kruger National Park, South Africa. RADARSAT-2 Quad-Pol fine beam images were acquired at three key phenological stages of the seasonal savannah cycle: i) wet (summer), ii) dry (winter), and iii) end of wet (autumn). Multi-polarized band intensities (C-HH, C-HV, and C-VV, with V = vertical and H = horizontal) and polarimetric decomposition variables (Freeman-Durden, Cloude-Pottier, and Van Zyl) were derived from the SAR images and used to predict structural metrics (woody canopy cover, cylindrical woody volume, and woody canopy volume, see definition in Section 3.3) derived from 1.1 m LiDAR strips acquired across the study area, and coinciding with 12% of the SAR dataset. The best single relationship (R-2 = 0.66) was obtained between the cross-polarized HV intensity band and the total canopy volume (TCV). In terms of the seasonality, the best results were obtained using the SAR imagery from the dry season when most woody plants have lost their leaves and the grass-soil layer was dry. Validation outputs of best predictive models for TCV, at the individual season level, yielded an R-2 of 0.67, a Standard Error of Prediction (SEP) of 39%, and consisted of the SAR parameters: C-HH, C-HV, C-VV, and Freeman-Durden decomposition parameters. At the multi-seasonal level, the best predictive models for TCV yielded an R-2 of 0.75, a SEP of 35%, and comprised of the same variables but for all three seasons. The C-band SAR data thus,provided encouraging results in open, semi-arid savannahs and hint at larger area structural assessments than is possible with LiDAR sensors alone. The combined use of C-band and L-band (ALOS-Palsar 2) should also be investigated. (C) 2013 Elsevier Inc. All rights reserved. |
英文关键词 | Polarimetry SAR LIDAR Savannah Structure |
类型 | Article |
语种 | 英语 |
国家 | South Africa ; Canada ; USA |
收录类别 | SCI-E |
WOS记录号 | WOS:000326767300019 |
WOS关键词 | WOODY VEGETATION STRUCTURE ; SYNTHETIC-APERTURE RADAR ; DISCRETE-RETURN LIDAR ; FOREST BIOMASS ; ABOVEGROUND BIOMASS ; SPECIES-DIVERSITY ; CANOPY STRUCTURE ; AIRBORNE LIDAR ; BASAL AREA ; C-BAND |
WOS类目 | Environmental Sciences ; Remote Sensing ; Imaging Science & Photographic Technology |
WOS研究方向 | Environmental Sciences & Ecology ; Remote Sensing ; Imaging Science & Photographic Technology |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/179741 |
作者单位 | 1.CSIR, ZA-0001 Pretoria, South Africa; 2.Univ New Brunswick, Fac Forestry & Environm Management, Fredericton, NB, Canada; 3.CSIR, Meraka Inst, Remote Sensing Res Unit, ZA-0001 Pretoria, South Africa; 4.Univ Pretoria, Ctr Geoinformat Sci, Dept Geog Geoinformat & Meteorol, ZA-0002 Pretoria, South Africa; 5.Carnegie Inst Sci, Dept Global Ecol, Stanford, CA USA; 6.Royal Mil Coll Canada, Dept Phys, Kingston, ON, Canada; 7.Rochester Inst Technol, Ctr Imaging Sci, Rochester, NY 14623 USA; 8.Univ Witwatersrand, Sch Anim Plant & Environm Sci, Ctr African Ecol, Johannesburg, South Africa; 9.South Africa Natl Pk, Sci Serv, Skukuza, South Africa |
推荐引用方式 GB/T 7714 | Mathieu, Renaud,Naidoo, Laven,Cho, Moses A.,et al. Toward structural assessment of semi-arid African savannahs and woodlands: The potential of multitemporal polarimetric RADARSAT-2 fine beam images[J],2013,138:215-231. |
APA | Mathieu, Renaud.,Naidoo, Laven.,Cho, Moses A..,Leblon, Brigitte.,Main, Russell.,...&Smit, Izak P. J..(2013).Toward structural assessment of semi-arid African savannahs and woodlands: The potential of multitemporal polarimetric RADARSAT-2 fine beam images.REMOTE SENSING OF ENVIRONMENT,138,215-231. |
MLA | Mathieu, Renaud,et al."Toward structural assessment of semi-arid African savannahs and woodlands: The potential of multitemporal polarimetric RADARSAT-2 fine beam images".REMOTE SENSING OF ENVIRONMENT 138(2013):215-231. |
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