干旱区生态环境知识资源中心(Arid): Uneven surface moisture as a driver of dune formation on ephemeral lake beds under conditions similar to the present day: A model-based assessment from the Makgadikgadi Basin, northern Botswana

Arid

DOI	10.1002/esp.5215
	Uneven surface moisture as a driver of dune formation on ephemeral lake beds under conditions similar to the present day: A model-based assessment from the Makgadikgadi Basin, northern Botswana
	Richards, Jenny; Burrough, Sallie; Wiggs, Giles; Hills, Tiger; Thomas, David; Moseki, Molatlhegi
通讯作者	Richards, J (corresponding author), Univ Oxford, St Johns Coll, Oxford OX1 3JP, England.
来源期刊	EARTH SURFACE PROCESSES AND LANDFORMS
ISSN	0197-9337
EISSN	1096-9837
出版年	2021-10
英文摘要	An association between salt pans or dry lake beds and distinctive crescentic lake-floor sand mounds (1-10 m high, tens to hundreds of metres wide) is commonplace in desert systems. In the Makgadikgadi Basin of northern Botswana, a debate about the formative processes of these landforms has persisted despite numerous morphometric, sedimentary and geochronological analyses, with mound landforms variously inferred to be aeolian dunes, subaqueous dunes, spring mounds or shoreline remnants. We propose a new formative mechanism which draws on the interaction between uneven moisture distribution on the pan surface and mobile aeolian sediments. We use a numerical model (ViSTA), which couples vegetation and aeolian sand transport dynamics, together with optically stimulated luminescence (OSL) dating of a mound in the Makgadikgadi Basin to investigate the feasibility of this 'sticky mound hypothesis'. We find that under a range of modelled environmental conditions, uneven moisture distribution on the pan surface can lead to the development and stabilization of crescentic aeolian dunes, with these dunes growing upwind from the point of initial deposition, corresponding with the chronological data gained from OSL dating of a mound feature. On removal of this moisture, the modelled dunes erode and dissipate. These findings suggest that the formative mechanism of the mounds could be dependent on the interaction between differential drying of the pan surface and the competence of the aeolian sediment transport system across the pan floor.
英文关键词	aeolian sand transport cellular automata drylands lake-bed dunes landscape development paleoenvironment
类型	Article ; Early Access
语种	英语
收录类别	SCI-E ; SSCI
WOS记录号	WOS:000703950700001
WOS关键词	AEOLIAN SAND TRANSPORT ; SEDIMENT TRANSPORT ; CLIMATIC-CHANGE ; ARABIA TERRA ; KALAHARI ; DYNAMICS ; VARIABILITY ; LANDFORMS ; DEPOSITS ; CRATER
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS研究方向	Physical Geography ; Geology
来源机构	University of Oxford
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/362965
作者单位	[Richards, Jenny] Univ Oxford, St Johns Coll, Oxford OX1 3JP, England; [Richards, Jenny; Wiggs, Giles; Hills, Tiger; Thomas, David] Univ Oxford, Sch Geog & Environm, Oxford, England; [Burrough, Sallie] Oxford Univ Ctr Environm, Environm Change Inst, Oxford, England; [Thomas, David] Univ Witwatersrand, Geog Archaeol & Environm Studies, Johannesburg, South Africa; [Moseki, Molatlhegi] Botswana Geosci Inst, Lobatse, Botswana
推荐引用方式 GB/T 7714	Richards, Jenny,Burrough, Sallie,Wiggs, Giles,et al. Uneven surface moisture as a driver of dune formation on ephemeral lake beds under conditions similar to the present day: A model-based assessment from the Makgadikgadi Basin, northern Botswana[J]. University of Oxford,2021.
APA	Richards, Jenny,Burrough, Sallie,Wiggs, Giles,Hills, Tiger,Thomas, David,&Moseki, Molatlhegi.(2021).Uneven surface moisture as a driver of dune formation on ephemeral lake beds under conditions similar to the present day: A model-based assessment from the Makgadikgadi Basin, northern Botswana.EARTH SURFACE PROCESSES AND LANDFORMS.
MLA	Richards, Jenny,et al."Uneven surface moisture as a driver of dune formation on ephemeral lake beds under conditions similar to the present day: A model-based assessment from the Makgadikgadi Basin, northern Botswana".EARTH SURFACE PROCESSES AND LANDFORMS (2021).