A5038548013- Aeolian processes and effects
- Atmospheric chemistry and aerosols
- Atmospheric aerosols and clouds
- Soil erosion and sediment transport
- Ecology and Vegetation Dynamics Studies
- Geology and Paleoclimatology Research
- Occupational and environmental lung diseases
- Geotechnical and construction materials studies
- Marine and environmental studies
- Coastal and Marine Management
- Atmospheric and Environmental Gas Dynamics
- Air Quality and Health Impacts
- Grouting, Rheology, and Soil Mechanics
- Arctic and Russian Policy Studies
- Engineering and Material Science Research
- Tree Root and Stability Studies
- African Botany and Ecology Studies
- Rangeland Management and Livestock Ecology
- Burn Injury Management and Outcomes
- International Maritime Law Issues
- Landfill Environmental Impact Studies
- Radiation Dose and Imaging
- Aquatic Ecosystems and Phytoplankton Dynamics
- Marine and coastal ecosystems
- Plant and animal studies
International Geographical Union
2016-2024
University of Cape Town
2013-2024
NSW Department of Planning and Environment
2023
Texas A&M University System
2006
Establishing mineral dust impacts on Earth's systems requires numerical models of the cycle. Differences between optical depth (DOD) measurements and modelling cycle emission, atmospheric transport, deposition indicate large model uncertainty due partially to unrealistic assumptions about emission frequency. Calibrating DOD typically in North Africa, are routinely used reduce magnitude. This calibration forces modelled emissions match but may hide correct magnitude frequency events at...
Mine dust has been linked to the development of pneumoconiotic diseases such as silicosis and coal workers' pneumoconiosis. Currently, it is understood that physicochemical mineralogical characteristics drive toxic nature particles; however, remains unclear which parameter(s) account for differential toxicity dust. This study aims address this issue by demonstrating use partial least squares regression (PLSR) machine learning approach compare influence D50 sub 10 μm particle against markers...
Abstract Modeled estimates of eolian dust emission can vary by an order magnitude due to the spatiotemporal heterogeneity emissions. To better constrain location and emissions, a surface erodibility factor is typically employed in models. Several landscape‐scale schemes representing potential for use models have recently been proposed, but validation such has only attempted indirectly with medium‐resolution remote sensing mineral aerosol loadings high‐resolution land mapping. In this study,...
In an effort to construct roads more quickly, high-plasticity index soils stabilized with lime are now routinely compacted the day after mixing. With this practice has come increasing number of heaves due soluble sulfates reacting form ettringite. Soils sulfate concentrations below 7,000 8,000 parts per million (ppm) can generally be treated lime. This research was performed identify stabilizers that used above 10,000 ppm. The effectiveness determined by measurement three-dimensional (3-D)...
This paper serves as a brief review and overview of the surface geology geomorphology around obabeb in entral amib esert. It introduces major lithologies associated with amara rogen Precambrian ambrian age, followed by ertiary sandstones conglomerates uaternary uiseb valley conglomerates, silts gravels. To celebrate 50th anniversary research station recent designation ea world heritage site, we are presenting map to inform guide future educational activities obabeb. The contrast between an...
Previous remote sensing studies (2005–2008) have identified Namibia's Kuiseb as the dustiest river in southern Africa. The purpose of this study was to extend dust event record through 2014, and examine nature surfaces from which satellite imagery indicates these plumes originate. new 10-year confirms delta geomorphological unit (54% plumes), followed by gravel plain (28%) then (8%). No originated Namib Sand Sea dunes or interdunes. Field observations provided detail about sedimentological...
Abstract Determining the controls on aeolian dust emissions from major sources is necessary for reliable quantification of atmospheric aerosol concentrations and fluxes. However, ground‐based measurements at‐source are rare generally short duration, failing to capture annual cycle. Here, we provide new insights into dynamics by measuring meteorological conditions a full year (July 2015–June 2016) at Etosha Pan, Namibia, globally significant source. Surface deployed field instrumentation...
Abstract South Africa has vigorously embraced the concept of ‘blue economy’ and is aggressively pursuing a blue growth strategy to expand ocean economy, create jobs, alleviate poverty. However, many these initiatives’ are leading conflicts amongst various stakeholders with different histories, relationships resources areas, worldviews, values. Investment in economy being prioritized by government planning, environmental assessment, decision-making processes fast-tracked. Consequently,...
Although heuweltjies (19–32 m diameter) dominate the surface of much southwestern Cape South Africa, their origins, distribution and age remain controversial. Current hypotheses are that (1) constructed by excavation mounding habits burrowing animals; (2) result erosion water areas between patches protected from fluvial action denser vegetation or (3) product localised aeolian sediment accumulation beneath associated with termitaria. At a site where quartz-containing gravels occur on soil in...
The Free State has been identified as the region with most dust sources in South Africa. These can be linked large, heavily cultivated cropland areas this province, which leaves fields vulnerable to wind erosion after harvest winter. For study, focus was on factors that influence emission from bare, flat surfaces agricultural lands region. Portable In-Situ Wind Erosion Laboratory (PI-SWERL) used measure flux adjacent crusted and loose surfaces, combined shear strength, moisture, soil texture...
Dust models are essential for understanding the impact of mineral dust on Earth's systems, human health, and global economies, but emission modelling has large uncertainties. Satellite observations point sources (DPS) provide a valuable dichotomous inventory regional emissions. We develop framework evaluating model performance using existing DPS data before routine calibration models. To illustrate this framework's utility arising insights, we evaluated albedo-based (AEM) with its areal...
In an effort to construct roads more quickly, high-plasticity index soils stabilized with lime are now routinely compacted the day after mixing. With this practice has come increasing number of heaves due soluble sulfates reacting form ettringite. Soils sulfate concentrations below 7,000 8,000 parts per million (ppm) can generally be treated lime. This research was performed identify stabilizers that used above 10,000 ppm. The effectiveness determined by measurement three-dimensional (3-D)...
Exposure to coal dust from mining-related activities has historically been linked several preventable but incurable respiratory diseases. Although the findings of numerous biological studies have determined that physicochemical and mineralogical aspects particles greatly influence both cytotoxic proinflammatory pathways, robust datasets which quantitatively define these characteristics remain limited. This study aims develop a characterisation routine applicable for real-world dust, using an...
The genesis of regularly spaced mounded landscapes worldwide remain mysterious. Mima-like heuweltjies (Afrikaans for small mound, ca 30 m diameter, 1 high) South Africa have been suggested to arise from 1) faunal accumulation sediment, 2) aeolian deposition around termite mounds and/or vegetation patches, or 3) differential erosion sediment between patches. We adopted nabkhas as a model system and hypothesised that retain at least some the morphological, spacing characteristics nabkhas....