Author:Durrheim, RJ; Dirks, PHGM; Nyblade, AA; Graham, G; Webb, SJ; Jones, MQWDate:Sep 2009AfricaArray (www.africaarray.org) is a long-term programme to build geosciences capacity in Africa in support of the mineral, petroleum, groundwater and environmental sectors. It seeks to do this by establishing effective Africa-based education ...Read more
Author:Kleynhans, W; Salmon, BP; Olivier, JC; Wessels, Konrad J; Van den Bergh, FDate:Jul 2011Human settlement expansion is one of the most pervasive forms of land cover change in the Gauteng province of South Africa. A method for detecting new settlement developments in areas that are typically covered by natural vegetation using ...Read more
Author:Hietkamp, SDate:Jun 2006The highly concentrated CO2 streams currently produced at Sasol are well suited for CO2 sequestration without further processing except for pressurising. The potential in South Africa for biological sequestration is limited compared with many ...Read more
Author:Kleynhans, W; Salmon, BP; Olivier, JC; Wessels, Konrad J; Van den Bergh, FDate:Jul 2011In this paper, a change detection accuracy comparison is made between a recently proposed EKF method and a sliding window. Fast Fourier Transform(FFT) alternative within a spatio-temporal change detection framework. Both methods produce a ...Read more
Author:Robertson, I; Froyd, CA; Walsh, RPD; Newbery, DM; Woodborne, S; Ong, RCDate:Oct 2004In a first step to obtain a proxy record of past climatic events (including the El Ni (n) over tildeo-Southern Oscillation) in the normally a seasonal tropical environment of Sabah, a radial segment from a recently fallen dipterocarp (Shorea ...Read more
Author:Luus, FPS; Van den Bergh, F; Maharaj, BTJDate:Jul 2012QuickBird imagery acquired on separate dates may have significant differences in viewing- and illumination geometries, which can negatively impact across-date settlement type classification accuracy. The effect of cast shadows on classification ...Read more
Author:Durrheim, RJ; Cooper, GRJDate:Jul 1998Measurements of the geomagnetic field can be used to help determine the structure of the Earth, since rocks often contain magnetic minerals. Measurements of the strength of the Earth's gravitational field can also be used, since the more dense ...Read more
Author:Scott, L; Vogel, JCDate:Nov 2000C-13/C-12 ratios in plants depend on factors like temperature, evaporation or seasonal moisture distribution. Fluctuations of C-13/C-12 in Procavia capensis (hyrax) dung samples from different vegetation zones and various ages over the last ...Read more
Author:Adams, S; Titus, R; Pietersen, K; Tredoux, G; Harris, CDate:15 Jan 2001The Western Karoo depends entirely on groundwater for domestic and agricultural use. An understanding of the chemical evolution of the groundwater provides insight into the interaction of water with the environment and contributes to better ...Read more
Author:Kleynhans, W; Olivier, JC; Salmon, BP; Wessels, Konrad J; Van den Bergh, FDate:Jul 2009It is proposed that the NDVI time series derived from MODIS multitemporal remote sensing data can be modelled as a triply (mean, phase and amplitude) modulated cosine function. A non-linear Extended Kalman Filter was developed to estimate the ...Read more
Author:Deadman, AJ; Behnert, ID; Fox, NP; Griffith, DDate:Jul 2011This paper presents the results of the laboratory and field based reflectance panel and radiometer comparisons that took place as part of the CEOS 2010 Key comparison of “techniques and instruments used for the vicarious calibration of Land ...Read more
Author:Clarke, ML; Vogel, JC; Botha, GA; Wintle, AGDate:01 Sep 2003Infrared stimulated luminescence (IRSL) ages have been obtained from a sequence of sandy colluvial deposits in northern Kwazulu-Natal. Comparison of the IRSL ages on sand-sized, potassium-rich feldspars, with radiocarbon dates on A-horizon ...Read more
Author:Talma, AS; Vogel, JCDate:Mar 1992An oxygen isotope temperature record over a large part of the past 30,000 yr has been obtained for the southern Cape Province of South Africa by combining data on the isotopic composition of a stalagmite from a deep cave with that of a confined ...Read more
Author:Linzer, LMDate:Apr 2005The primary objective of this study was to develop a robust MTI method to estimate the moment tensors of clusters of seismic events recorded in the underground environment. To achieve this, three 'hybrid' MTI methods were developed by the ...Read more
Author:Sivakumar, V; Gizaw Mengistu, DT; Botai, OJDate:2009The aim of this work is to construct a model (mean) profile for ozone and water vapor in Southern hemisphere latitude using 14 years (1993-2006) of Halogen Occultation Experiment (HALOE) satellite data and about 10 years (1998-2007) of the ...Read more
Author:Lück-Vogel, Melanie; Strohbach, MDate:Jul 2009Detection and quantification of degradation processes as a first step for understanding and development of prevention and mitigation actions is of international interest as the described processes are observed in semi-arid landscapes globally. ...Read more
Author:Van der Walt, M; Day, M; Rubidge, B; Cooper, Antony K; Netterberg, IDate:Dec 2010The stratigraphic subdivision of the Karoo Supergroup of South Africa has been been addressed for more than a century by various geoscience studies. A lack of good lithostratigraphic markers in the Beaufort Group and the fact that the ...Read more
Author:Waterhouse, JS; Switsur, VR; Barker, AC; Carter, AHC; Hemming, DL; Loader, NJ; Robertson, IDate:Apr 2004In order to predict accurately how elevated atmospheric CO2 concentrations will affect the global carbon cycle, it is necessary to know how trees respond to increasing CO2 concentrations. In this paper, the response is examined over the period ...Read more
Author:Kgathi, DL; Kniveton, D; Ringrose, S; Turton, AR; Van der Post, CHM; Lundqvist, J; Seely, MDate:Apr 2006The Okavango basin comprises the Cuito and Cubango active catchment areas in Angola, in addition to the Kavango-Okavango non-active catchment in northern Namibia and Botswana. The Okavango River water and its ecosystem resources are critically ...Read more