干旱区生态环境知识资源中心(Arid): Assessment of Aeolian Activity in the Bodele Depression, Chad: A Dense Spatiotemporal Time Series From Landsat-8 and Sentinel-2 Data

Arid

DOI	10.3389/fenvs.2021.808802
	Assessment of Aeolian Activity in the Bodele Depression, Chad: A Dense Spatiotemporal Time Series From Landsat-8 and Sentinel-2 Data
	Ali, Eslam; Xu, Wenbin; Xie, Lei; Ding, Xiaoli
通讯作者	Xu, WB (corresponding author)，Cent South Univ, Sch Geosci & Info Phys, Changsha, Peoples R China.
来源期刊	FRONTIERS IN ENVIRONMENTAL SCIENCE
EISSN	2296-665X
出版年	2022
卷号	9
英文摘要	There are several hotspots of dust production in the central Sahara, the Bodele Depression (BD) in northern Chad is considered the largest source of aerosol dust worldwide, with the fastest Barchan dunes that migrate southwesterly. Less is known about the complex patterns of dune movement in the BD, especially on a short time scale. Time-series inversion of optical image cross-correlation (TSI-OICC) proved to be a valuable method for monitoring historical movements with low uncertainties, high spatial coverage, and dense temporal coverage. We leveraged similar to 8 years of Landsat-8 and similar to 6 years of Sentinel-2 data to capture the dune migration patterns at BD. We used TSI-OICC, creating four independent networks of offset maps from Landsat-8 and Sentinel-2 images, and forming three networks by fusing data from the two sensors. We depended on the multi spatial coherence estimated from Sentinel-1 interferograms to automatically discriminate between the active and stagnant regions, which is important for the postprocessing steps. We combined the data from the two sensors in areas of overlap to assess the performance of the fusion between two sensors in increasing the temporal scale of the observations. Our results suggest that dune migration at BD is subject to seasonal and multiyear variations that differed spatially across the dune field. Seasonal variations were observed with migration slowing during the summer months. We estimated the median for velocities belonging to the same season and calculated the seasonal sliding coefficient (SSC) representing the ratio between seasonal velocities. The median SSC reached a maximum value of similar to 2 for winter/summer, while the ratios were similar to 1.10 and similar to 1.35 for winter/spring and winter/autumn, respectively. The seasonal variability of the temporal patterns was strongly supported by the wind observations. Between (1984-1998 and 1998-2007) and (1998-2007 and 2013-2021), decelerations in dune velocities were observed with percentages of similar to 4 and similar to 28%, respectively, and these decelerations were supported by a deceleration in wind velocities. Inversion of time series provides dense spatiotemporal monitoring of the dune activity. The fusion between two sensors allows condensing the temporal sampling up to a weekly scale especially for locations exposed to contamination of high cloud cover or dust.
英文关键词	Bodele depression dune migration COSI-Corr image matching time series inversion
类型	Article
语种	英语
开放获取类型	gold
收录类别	SCI-E
WOS记录号	WOS:000752618300001
WOS关键词	SINAI SAND SEA ; WESTERN DESERT ; DUSTIEST PLACE ; IMAGERY ; DUNES ; CONFIGURATION ; VELOCITIES ; ALGORITHM ; INVERSION ; MIGRATION
WOS类目	Environmental Sciences
WOS研究方向	Environmental Sciences & Ecology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/376526
作者单位	[Ali, Eslam; Xie, Lei; Ding, Xiaoli] Hong Kong Polytech Univ, Dept Land Surveying & Geoinformat, Hong Kong, Peoples R China; [Xu, Wenbin] Cent South Univ, Sch Geosci & Info Phys, Changsha, Peoples R China
推荐引用方式 GB/T 7714	Ali, Eslam,Xu, Wenbin,Xie, Lei,et al. Assessment of Aeolian Activity in the Bodele Depression, Chad: A Dense Spatiotemporal Time Series From Landsat-8 and Sentinel-2 Data[J],2022,9.
APA	Ali, Eslam,Xu, Wenbin,Xie, Lei,&Ding, Xiaoli.(2022).Assessment of Aeolian Activity in the Bodele Depression, Chad: A Dense Spatiotemporal Time Series From Landsat-8 and Sentinel-2 Data.FRONTIERS IN ENVIRONMENTAL SCIENCE,9.
MLA	Ali, Eslam,et al."Assessment of Aeolian Activity in the Bodele Depression, Chad: A Dense Spatiotemporal Time Series From Landsat-8 and Sentinel-2 Data".FRONTIERS IN ENVIRONMENTAL SCIENCE 9(2022).