Dune mobility and vegetation cover in the Southwest Kalahari desert

Giles F.S. Wiggs, David S.G. Thomas, Joanna E. Bullard, Ian Livingstone

    Research output: Contribution to Book/ReportChapter

    Abstract

    As part of a wider project investigating the palaeoenvironmental significance of partially vegetated linear dunes in the southwest Kalahari, data collected in the latter part of 1992 concerning dune movement and vegetation cover suggest that sediment transport is occurring on some dune surfaces, and that the majority of surface activity occurs on the crests and upper slopes of the dunes. The data suggest that the limiting variables on surface sediment movement vary on different parts of a dune. On interdunes and lower dune slopes the primary limiting variable is available wind energy, while on dune crests and upper slopes it is vegetation cover. Ground cover by litter has much greater importance in protecting the surface sediment from erosion than rooted vegetation, From individual data points, no evidence is found to support a threshold vegetation cover below which sediment movement occurs, Rather, a gradient of activity is suggested whereby a reduction in vegetation cover increases the potential for sediment movement and surface change. However, dunes with differing amounts of mean vegetation cover display differing degrees of surface activity, and at this scale, a vegetation cover threshold in the region of 14 per cent may be recognized.
    Original languageEnglish
    Title of host publicationEarth Surface Processes and Landforms
    Pages515-529
    Number of pages15
    DOIs
    Publication statusPublished - 1995

    Publication series

    NameEarth Surface Processes and Landforms
    Volume20

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    Keywords

    • Kalahari Desert
    • dune movement
    • linear dunes
    • sediment transport
    • vegetation cover

    Cite this

    Wiggs, G. F. S., Thomas, D. S. G., Bullard, J. E., & Livingstone, I. (1995). Dune mobility and vegetation cover in the Southwest Kalahari desert. In Earth Surface Processes and Landforms (pp. 515-529). (Earth Surface Processes and Landforms; Vol. 20). https://doi.org/10.1002/esp.3290200604