The Swartland region in the Western Cape of South Africa is situated in a Mediterranean climate z... more The Swartland region in the Western Cape of South Africa is situated in a Mediterranean climate zone, aff ected by large gullies that are widespread in occurrence on commercial farms. Despite gully erosion being recognized as a major land degradation process, especially in Mediterranean climates, these large gully scars in the Swartland are believed to be inactive remnants of the past. Due to this belief, gully erosion research in the Swartland is a topic that has long been ignored. To address this research shortfall, a fi eld-based case study of a classic, discontinuous gully system in the Swartland was done. Sediment movement was measured at hillslope scale and discussed in the context of rainfall data and fi eld observations of gully activity. The results showed that the gully system was an active sediment source, but also a conduit for sediment from hillslopes. Notably, ploughed contour banks, a measure introduced to curb gully erosion, are causing the expansion of the gully net...
Renewable energy and clean energy have been on the global agenda for energy transition for quite ... more Renewable energy and clean energy have been on the global agenda for energy transition for quite a long time but recently gained strong momentum, especially with the anticipated depletion of fossil fuels alongside increasing environmental degradation from their exploitation and the changing climate caused by their excessive carbon emissions. Despite this, Africa’s pursuit to transition to a green economy using renewable energy resources still faces constraints that hamper further development and commercialization. These may include socio-economic, technical, political, financial, and institutional policy framework barriers. Although hydrogen demand is still low in Southern Africa, the region can meet the global demands for green hydrogen as a major supplier because of its enormous renewable energy resource-base. This article reviews existing renewable energy resources and hydrogen energy policies in the Southern African Development Community (SADC). The significance of this review i...
There has been a conspicuous increase in malaria cases since 2016/2017 over the three malaria-end... more There has been a conspicuous increase in malaria cases since 2016/2017 over the three malaria-endemic provinces of South Africa. This increase has been linked to climatic and environmental factors. In the absence of adequate traditional environmental/climatic data covering ideal spatial and temporal extent for a reliable warning system, remotely sensed data are useful for the investigation of the relationship with, and the prediction of, malaria cases. Monthly environmental variables such as the normalised difference vegetation index (NDVI), the enhanced vegetation index (EVI), the normalised difference water index (NDWI), the land surface temperature for night (LSTN) and day (LSTD), and rainfall were derived and evaluated using seasonal autoregressive integrated moving average (SARIMA) models with different lag periods. Predictions were made for the last 56 months of the time series and were compared to the observed malaria cases from January 2013 to August 2017. All these factors ...
ABSTRACT Abstract in English. Thesis (PhD Natural and Agricultural Sciences (Zoology))-University... more ABSTRACT Abstract in English. Thesis (PhD Natural and Agricultural Sciences (Zoology))-University of Pretoria, 2005. Includes bibliographical references.
CSIR 3rd Biennial Conference 2010. Science Real and Relevant. CSIR International Convention Centr... more CSIR 3rd Biennial Conference 2010. Science Real and Relevant. CSIR International Convention Centre, Pretoria, South Africa, 30 August – 01 September 2010 A South African Pedestrian Environment Assessment Tool has been created and piloted as a first step towards a holistic approach to improve the pedestrian environment
Onderstepoort Journal of Veterinary Research, 2007
The suitability of present and future climates for 30 Rhipicephalus species in Africa are predict... more The suitability of present and future climates for 30 Rhipicephalus species in Africa are predicted using a simple climate envelope model as well as a Division of Atmospheric Research Limited-Area Model (DARLAM). DARLAM's predictions are compared with the mean outcome from two global circulation models. East Africa and South Africa are considered the most vulnerable regions on the continent to climate-induced changes in tick distributions and tick-borne diseases. More than 50% of the species examined show potential range expansion and more than 70% of this range expansion is found in economically important tick species. More than 20% of the species experienced range shifts of between 50 and 100%. There is also an increase in tick species richness in the south-western regions of the sub-continent. Actual range alterations due to climate change may be even greater since factors like land degradation and human population increase have not been included in this modelling process. Ho...
ABSTRACT The Intergovernmental Panel on Climate Change (IPCC) released its latest report on March... more ABSTRACT The Intergovernmental Panel on Climate Change (IPCC) released its latest report on March 31, 2014. This report was the second instalment of the Fifth Assessment Report, prepared by Working Group 2, on impacts, vulnerability, and adaptation to climate change. In this Comment, we, as contributors to the chapter on human health, explain how the IPCC report was prepared and highlight important findings.
The Swartland region in the Western Cape of South Africa is situated in a Mediterranean climate z... more The Swartland region in the Western Cape of South Africa is situated in a Mediterranean climate zone, aff ected by large gullies that are widespread in occurrence on commercial farms. Despite gully erosion being recognized as a major land degradation process, especially in Mediterranean climates, these large gully scars in the Swartland are believed to be inactive remnants of the past. Due to this belief, gully erosion research in the Swartland is a topic that has long been ignored. To address this research shortfall, a fi eld-based case study of a classic, discontinuous gully system in the Swartland was done. Sediment movement was measured at hillslope scale and discussed in the context of rainfall data and fi eld observations of gully activity. The results showed that the gully system was an active sediment source, but also a conduit for sediment from hillslopes. Notably, ploughed contour banks, a measure introduced to curb gully erosion, are causing the expansion of the gully net...
Renewable energy and clean energy have been on the global agenda for energy transition for quite ... more Renewable energy and clean energy have been on the global agenda for energy transition for quite a long time but recently gained strong momentum, especially with the anticipated depletion of fossil fuels alongside increasing environmental degradation from their exploitation and the changing climate caused by their excessive carbon emissions. Despite this, Africa’s pursuit to transition to a green economy using renewable energy resources still faces constraints that hamper further development and commercialization. These may include socio-economic, technical, political, financial, and institutional policy framework barriers. Although hydrogen demand is still low in Southern Africa, the region can meet the global demands for green hydrogen as a major supplier because of its enormous renewable energy resource-base. This article reviews existing renewable energy resources and hydrogen energy policies in the Southern African Development Community (SADC). The significance of this review i...
There has been a conspicuous increase in malaria cases since 2016/2017 over the three malaria-end... more There has been a conspicuous increase in malaria cases since 2016/2017 over the three malaria-endemic provinces of South Africa. This increase has been linked to climatic and environmental factors. In the absence of adequate traditional environmental/climatic data covering ideal spatial and temporal extent for a reliable warning system, remotely sensed data are useful for the investigation of the relationship with, and the prediction of, malaria cases. Monthly environmental variables such as the normalised difference vegetation index (NDVI), the enhanced vegetation index (EVI), the normalised difference water index (NDWI), the land surface temperature for night (LSTN) and day (LSTD), and rainfall were derived and evaluated using seasonal autoregressive integrated moving average (SARIMA) models with different lag periods. Predictions were made for the last 56 months of the time series and were compared to the observed malaria cases from January 2013 to August 2017. All these factors ...
ABSTRACT Abstract in English. Thesis (PhD Natural and Agricultural Sciences (Zoology))-University... more ABSTRACT Abstract in English. Thesis (PhD Natural and Agricultural Sciences (Zoology))-University of Pretoria, 2005. Includes bibliographical references.
CSIR 3rd Biennial Conference 2010. Science Real and Relevant. CSIR International Convention Centr... more CSIR 3rd Biennial Conference 2010. Science Real and Relevant. CSIR International Convention Centre, Pretoria, South Africa, 30 August – 01 September 2010 A South African Pedestrian Environment Assessment Tool has been created and piloted as a first step towards a holistic approach to improve the pedestrian environment
Onderstepoort Journal of Veterinary Research, 2007
The suitability of present and future climates for 30 Rhipicephalus species in Africa are predict... more The suitability of present and future climates for 30 Rhipicephalus species in Africa are predicted using a simple climate envelope model as well as a Division of Atmospheric Research Limited-Area Model (DARLAM). DARLAM's predictions are compared with the mean outcome from two global circulation models. East Africa and South Africa are considered the most vulnerable regions on the continent to climate-induced changes in tick distributions and tick-borne diseases. More than 50% of the species examined show potential range expansion and more than 70% of this range expansion is found in economically important tick species. More than 20% of the species experienced range shifts of between 50 and 100%. There is also an increase in tick species richness in the south-western regions of the sub-continent. Actual range alterations due to climate change may be even greater since factors like land degradation and human population increase have not been included in this modelling process. Ho...
ABSTRACT The Intergovernmental Panel on Climate Change (IPCC) released its latest report on March... more ABSTRACT The Intergovernmental Panel on Climate Change (IPCC) released its latest report on March 31, 2014. This report was the second instalment of the Fifth Assessment Report, prepared by Working Group 2, on impacts, vulnerability, and adaptation to climate change. In this Comment, we, as contributors to the chapter on human health, explain how the IPCC report was prepared and highlight important findings.
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Papers by Jane Olwoch