The genesis and current reshaping of dunes at the eastern margin of the northern Namib Desert (Hartmann Valley, NW Namibia) Modelled wind-flow patterns, multi-temporal aerial photograph analysis and anthropogenic morphodynamics
Hartmann, Kerstin; Brunotte, Ernst
published: Sep 1, 2008
ArtNo. ESP023105202001, Price: 29.00 €
This research was carried out in the framework of the Collaborative Research Centre for "Arid Climate Adaptation and Cultural Innovation in Africa" (ACACIA/SFB 389) at the University of Cologne. The research centre was financed by the German Science Foundation (DFG) and included the study of landscape formation in north-western Namibia.One focus of our research was on the transitional area between the Namib Desert and the dry savannah in the Marienfluss Valley - HartmannValley region. When the research project was initiated, this region with a total area of approx. 5600 km2 was 'terra incognita' from a geomorphological point of view. For this reason the entire recent Quaternary development of relief including current morphodynamics was studied.In the context of the issue of 'shifting desert margins', dune fields at the eastern margin of the Namib Desert in NW Namibia south of the Angolan border were studied during several years of field observation using geomorphological relief analysis in the field, aerial photographs and pictures taken when flying over the area. In the absence of meteorological stations, the genesis of the dunes has been inferred on the basis of calculated wind-flow patterns. In this way it was possible to show that the distribution of dunes in the study area is determined by a change in wind direction over the South Atlantic.The changes in dune forms since 1964 were identified by means of multi-temporal analysis of aerial photographs; reshaping by man through the beginnings of tourism in recent years could be observed directly. The transformation of dunes in heavy thunderstorms is also described.