干旱区生态环境知识资源中心(Arid): Analyses of Namibian Seasonal Salt Pan Crust Dynamics and Climatic Drivers Using Landsat 8 Time-Series and Ground Data

Arid

DOI	10.3390/rs12030474
	Analyses of Namibian Seasonal Salt Pan Crust Dynamics and Climatic Drivers Using Landsat 8 Time-Series and Ground Data
	Milewski, Robert 1; Chabrillat, Sabine 1; Bookhagen, Bodo 2
通讯作者	Milewski, Robert
来源期刊	REMOTE SENSING
EISSN	2072-4292
出版年	2020
卷号	12 期号:3
英文摘要	Salt pans are highly dynamic environments that are difficult to study by in situ methods because of their harsh climatic conditions and large spatial areas. Remote sensing can help to elucidate their environmental dynamics and provide important constraints regarding their sedimentological, mineralogical, and hydrological evolution. This study utilizes spaceborne multitemporal multispectral optical data combined with spectral endmembers to document spatial distribution of surface crust types over time on the Omongwa pan located in the Namibian Kalahari. For this purpose, 49 surface samples were collected for spectral and mineralogical characterization during three field campaigns (2014-2016) reflecting different seasons and surface conditions of the salt pan. An approach was developed to allow the spatiotemporal analysis of the salt pan crust dynamics in a dense time-series consisting of 77 Landsat 8 cloud-free scenes between 2014 and 2017, covering at least three major wet-dry cycles. The established spectral analysis technique Sequential Maximum Angle Convex Cone (SMACC) extraction method was used to derive image endmembers from the Landsat time-series stack. Evaluation of the extracted endmember set revealed that the multispectral data allowed the differentiation of four endmembers associated with mineralogical mixtures of the crust's composition in dry conditions and three endmembers associated with flooded or muddy pan conditions. The dry crust endmember spectra have been identified in relation to visible, near infrared, and short-wave infrared (VNIR-SWIR) spectroscopy and X-ray diffraction (XRD) analyses of the collected surface samples. According these results, the spectral endmembers are interpreted as efflorescent halite crust, mixed halite-gypsum crust, mixed calcite quartz sepiolite crust, and gypsum crust. For each Landsat scene the spatial distribution of these crust types was mapped with the Spectral Angle Mapper (SAM) method and significant spatiotemporal dynamics of the major surface crust types were observed. Further, the surface crust dynamics were analyzed in comparison with the pan's moisture regime and other climatic parameters. The results show that the crust dynamics are mainly driven by flooding events in the wet season, but are also influenced by temperature and aeolian activity in the dry season. The approach utilized in this study combines the advantages of multitemporal satellite data for temporal event characterization with advantages from hyperspectral methods for the image and ground data analyses that allow improved mineralogical differentiation and characterization.
英文关键词	salt pan playa spectral analysis crust saline pan cycle evaporites time-series mapping
类型	Article
语种	英语
国家	Germany
开放获取类型	Green Submitted, Green Published, gold
收录类别	SCI-E
WOS记录号	WOS:000515393800133
WOS关键词	PLAYA EVAPORITE MINERALS ; DIFFERENCE WATER INDEX ; ARAL SEA BASIN ; DUST EMISSIONS ; DEATH-VALLEY ; HYPERSPECTRAL DATA ; SOUTHERN-AFRICA ; MOJAVE DESERT ; SALINE LAKE ; SOIL
WOS类目	Environmental Sciences ; Geosciences, Multidisciplinary ; Remote Sensing ; Imaging Science & Photographic Technology
WOS研究方向	Environmental Sciences & Ecology ; Geology ; 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/2XILL650/315419
作者单位	1.Helmholtz Ctr Potsdam, GFZ German Res Ctr Geosci, Sect Remote Sensing & Geoinformat 1 4, D-14473 Potsdam, Germany; 2.Univ Potsdam, Inst Geosci, Karl Liebknecht Str 24-25, D-14476 Potsdam, Germany
推荐引用方式 GB/T 7714	Milewski, Robert,Chabrillat, Sabine,Bookhagen, Bodo. Analyses of Namibian Seasonal Salt Pan Crust Dynamics and Climatic Drivers Using Landsat 8 Time-Series and Ground Data[J],2020,12(3).
APA	Milewski, Robert,Chabrillat, Sabine,&Bookhagen, Bodo.(2020).Analyses of Namibian Seasonal Salt Pan Crust Dynamics and Climatic Drivers Using Landsat 8 Time-Series and Ground Data.REMOTE SENSING,12(3).
MLA	Milewski, Robert,et al."Analyses of Namibian Seasonal Salt Pan Crust Dynamics and Climatic Drivers Using Landsat 8 Time-Series and Ground Data".REMOTE SENSING 12.3(2020).