Research Outputs (Geography, Archaeology and Environmental Studies)

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    The Victoria west: Earliest prepared core technology in the acheulean at canteen kopje and implications for the cognitive evolution of early hominids
    (Royal Society, 2017-06) Li, H.; Kuman, K.; Lotter, M.G.; Leader, G.M.; Gibbon, R.J.
    Prepared core technology illustrates in-depth planning and the presence of a mental template during the core reduction process. This technology is, therefore, a significant indicator in studying the evolution of abstract thought and the cognitive abilities of hominids. Here, we report on Victoria West cores excavated from the Canteen Kopje site in central South Africa, with a preliminary age estimate of approximately 1Ma (million years ago) for these cores. Technological analysis shows that the VictoriaWest cores bear similarities to the ‘Volumetric Concept’ as defined for the Levallois, a popular and widely distributed prepared core technology from at least 200 ka (thousand years ago). Although these similarities are present, several notable differences also occur that make the Victoria West a unique and distinctive prepared core technology; these are: elongated and convergent core shapes, consistent blow directions for flake removal, a predominance of large side-struck flakes, and the use of these flakes to make Acheulean large cutting tools. This innovative core reduction strategy at Canteen Kopje extends the roots of prepared core technology to the latter part of the Early Acheulean and clearly demonstrates an increase in the cognitive abilities and complexities of hominids in this time period.
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    High and medium resolution satellite imagery to evaluate late holocene human-environment interactions in arid lands: A case study from the Central Sahara.
    (MDPI, 2017-04) Biagetti, S.; Merlo, S.; Adam, E.; Lobo, A.; Conesa, F.C.; Knight, J.; Bekrani, H.; Crema, E.R.; Alcaina-Mateos, J.; Madella, M.
    We present preliminary results of an Earth observation approach for the study of past human occupation and landscape reconstruction in the Central Sahara. This region includes a variety of geomorphological features such as palaeo-oases, dried river beds, alluvial fans and upland plateaux whose geomorphological characteristics, in combination with climate changes, have influenced patterns of human dispersal and sociocultural activities during the late Holocene. In this paper, we discuss the use of medium- and high-resolution remotely sensed data for the mapping of anthropogenic features and paleo- and contemporary hydrology and vegetation. In the absence of field inspection in this inaccessible region, we use different remote sensing methods to first identify and classify archaeological features, and then explore the geomorphological factors that might have influenced their spatial distribution.
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    Modeling the risk of transmission of schistosomiasis in Akure North Local Government Area of Ondo State, Nigeria using satellite derived environmental data
    (Public Library of Science, 2017-07) Ajakaye, O.G.; Adedeji, O.I.; Ajayi, P.O.
    Schistosomiasis is a parasitic disease and its distribution, in space and time, can be influenced by environmental factors such as rivers, elevation, slope, land surface temperature, land use/cover and rainfall. The aim of this study is to identify the areas with suitable conditions for schistosomiasis transmission on the basis of physical and environmental factors derived from satellite imagery and spatial analysis for Akure North Local Government Area (LGA) of Ondo State. Nigeria. This was done through methodology multicriteria evaluation (MCE) using Saaty’s analytical hierarchy process (AHP). AHP is a multi-criteria decision method that uses hierarchical structures to represent a problem and makes decisions based on priority scales. In this research AHP was used to obtain the mapping weight or importance of each individual schistosomiasis risk factor. For the purpose of identifying areas of schistosomiasis risk, this study focused on temperature, drainage, elevation, rainfall, slope and land use/land cover as the factors controlling schistosomiasis incidence in the study area. It is by reclassifying and overlaying these factors that areas vulnerable to schistosomiasis were identified. The weighted overlay analysis was done after each factor was given the appropriate weight derived through the analytical hierarchical process. The prevalence of urinary schistosomiasis in the study area was also determined by parasitological analysis of urine samples collected through random sampling. The results showed varying risk of schistosomiasis with a larger portion of the area (82%) falling under the high and very high risk category. The study also showed that one community (Oba Ile) had the lowest risk of schistosomiasis while the risk increased in the four remaining communities (Iju, Igoba, Ita Ogbolu and Ogbese). The predictions made by the model correlated strongly with observations from field study. The high risk zones corresponded to known endemic communities. This study revealed that environmental factors can be used in identifying and predicting the transmission of schistosomiasis as well as effective monitoring of disease risk in newly established rural and agricultural communities.
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    Comments on 'the age of fossil stw573 ('little foot'): An alternative interpretation of 26al/10be burial data'.
    (Academy of Science of South Africa (ASSAf), 2017-05) Stratford, D.; Granger, D.E.; Bruxelles, L.; Clarke, R.J.; Kuman, K.; Gibbon, R.J.
    No abstract available.
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    Issues of water quality in stormwater harvesting
    (Academy of Science of South Africa (ASSAf), 2017-05) Knight, J.
    No abstract available
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    Wind speed characteristics and implications for: Wind power generation: Cape regions, South Africa
    (Academy of Science of South Africa (ASSAf), 2017-07) Grab, S.W.; Wright, M.A.
    Spatio-temporal dynamics of near-surface wind speeds were examined across the Northern, Western and Eastern Cape regions of South Africa. The regions assessed were geographically subdivided into three zones: coastal, coastal hinterland and inland. Wind speed data (10 m) were evaluated at monthly, seasonal, annual and zonal resolutions, with the aim to establish wind speed attributes and trends. Data from 19 weather stations with high-resolution wind records between 1995 and 2014 were evaluated. The majority of stations (79%) recorded a decrease in mean annual wind speed over the study period. The mean rate of decrease across all stations over the 20-year period equates to-1.25%, quantifying to an annual decrease of-0.002 m/s/year (-0.06% pa). The largest seasonal decline of-0.006 m/s/year (-0.15% pa) was recorded in summer. Statistically significant declines in mean annual wind speed are somewhat more pronounced for the coastal zone (-0.003 m/s/year,-0.08% pa) than over interior regions (-0.002 m/s/year,-0.06% pa) for the study period. The largest decrease (-0.08% pa) was recorded for the coastal zone, followed by the inland zone (-0.06% pa), equating to an annual reduction in available energy of 0.18% pa and 0.09% pa, respectively. When considering all stations over the study period, the mean inter-annual variability is 3.11%. Despite such decreases in wind speed, the variance identified in this study would not have posed any risk to power generation from wind across the assessed stations, based on the period 1995 to 2014.
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    Opposite polarities of ENSO drive distinct patterns of coral bleaching potentials in the southeast Indian Ocean
    (Nature Publishing Group, 2017) Zhang, N.; Feng, M.; Hendon, H.H.; Hobday, A.J.; Zinke, J.
    Episodic anomalously warm sea surface temperature (SST) extremes, or marine heatwaves (MHWs), amplify ocean warming effects and may lead to severe impacts on marine ecosystems. MHW-induced coral bleaching events have been observed frequently in recent decades in the southeast Indian Ocean (SEIO), a region traditionally regarded to have resilience to global warming. In this study, we assess the contribution of El Niño-Southern Oscillation (ENSO) to MHWs across the mostly understudied reefs in the SEIO. We find that in extended summer months, the MHWs at tropical and subtropical reefs (divided at ∼20°S) are driven by opposite ENSO polarities: MHWs are more likely to occur at the tropical reefs during eastern Pacific El Niño, driven by enhanced solar radiation and weaker Australian Monsoon, some likely alleviated by positive Indian Ocean Dipole events, and at the subtropical reefs during central Pacific La Niña, mainly caused by increased horizontal heat transport, and in some cases reinforced by local air-sea interactions. Madden-Julian Oscillations (MJO) also modulate the MHW occurrences. Projected future increases in ENSO and MJO intensity with greenhouse warming will enhance thermal stress across the SEIO. Implementing forecasting systems of MHWs can be used to anticipate future coral bleaching patterns and prepare management responses.
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    Anthropological contributions to historical ecology: 50 questions, infinite prospects
    (Public Library of Science, 2017-02) Armstrong, C.G.; Shoemaker, A.C.; McKechnie, I.; Ekblom, A.; Szabó, P.; Lane, P.J.; McAlvay, A.C.; Boles, O.J.; Walshaw, S.; Petek, N.; Gibbons, K.S.; Morales, E.Q.; Anderson, E.N.; Ibragimow, A.; Podruczny, G.; Vamosi, J.C.; Marks-Block, T.; LeCompte, J.K.; Awâsis, S.; Nabess, C.; Sinclair, P.; Crumley, C.L.
    This paper presents the results of a consensus-driven process identifying 50 priority research questions for historical ecology obtained through crowdsourcing, literature reviews, and in-person workshopping. A deliberative approach was designed to maximize discussion and debate with defined outcomes. Two in-person workshops (in Sweden and Canada) over the course of two years and online discussions were peer facilitated to define specific key questions for historical ecology from anthropological and archaeological perspectives. The aim of this research is to showcase the variety of questions that reflect the broad scope for historical-ecological research trajectories across scientific disciplines. Historical ecology encompasses research concerned with decadal, centennial, and millennial human-environmental interactions, and the consequences that those relationships have in the formation of contemporary landscapes. Six interrelated themes arose from our consensus-building workshop model: (1) climate and environmental change and variability; (2) multi-scalar, multi-disciplinary; (3) biodiversity and community ecology; (4) resource and environmental management and governance; (5) methods and applications; and (6) communication and policy. The 50 questions represented by these themes highlight meaningful trends in historical ecology that distill the field down to three explicit findings. First, historical ecology is fundamentally an applied research program. Second, this program seeks to understand longterm human-environment interactions with a focus on avoiding, mitigating, and reversing adverse ecological effects. Third, historical ecology is part of convergent trends toward transdisciplinary research science, which erodes scientific boundaries between the cultural and natural.
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    Development of census output areas with AZTool in South Africa.
    (Academy of Science of South Africa (ASSAf), 2016-07) Mokhele, T.; Mutanga, O.; Ahmed, F.
    The use of a single geographical unit to both collect and disseminate census data is common in many countries across the world, especially in developing countries. In South Africa this approach poses some challenges, as the design of small geographical units called enumeration areas to facilitate data collection differs considerably from the design of units that aid data analysis and interpretation. We aimed to create optimised census output areas using the Automated Zone-design Tool (AZTool) program, using the 2001 census enumeration areas as building blocks at various spatial levels, for both rural and urban settings in two South African provinces. The results were consistent and stable. The primary criterion of the confidentiality limit of 500 people was respected at all geographical levels or regions, in both urban and rural settings, for newly created optimised output areas. For the second criterion, lower intra-area correlation values at lower geographical levels for both rural and urban areas showed that higher geographical levels produced more homogeneous output areas than did lower geographical levels or regions. Our obtained intra-area correlation of 0.62 for the two provinces combined indicated that the selected homogeneity variables were good indicators of social homogeneity for creating optimised output areas in South Africa. We conclude that the AZTool software can be used to effectively and objectively create optimised output areas for South African data. Further research on the comparison of the newly created output areas with existing output areas in South Africa should be explored.
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    Climate change threats to two low-lying South African coastal towns: Risks and perceptions.
    (Academy of Science of South Africa (ASSAf), 2016-05) Fitchett, J.M.; Grant, B.; Hoogendoom, G.
    Climate change poses a considerable threat to low-lying coastal towns. Possible risks include flooding induced by sea-level rise, increased discomfort from changes in temperature and precipitation, more frequent extreme events, biodiversity shifts, and water shortages. For coastal towns that attract many tourists, these threats can have far-reaching economic effects and may compromise the continued viability of the tourism sector. A growing number of studies are being published on the inter-relationship between climate change and tourism in the global North. As yet, little equivalent research has been conducted in developing countries with economically significant tourism sectors. This paper presents a mixed-method pilot study on two adjacent coastal towns, St Francis Bay and Cape St Francis, in the Eastern Cape Province of South Africa. We explored the climate change threats in this region, and perceptions of these threats within the tourism sector. The tourism climate index results showed that the towns are climatically well suited to tourism, but a decrease in these index scores between 1978 and 2014 suggests that climate change experienced in recent decades has detrimentally affected tourist comfort. A digital elevation model sea-level projection for the towns indicated a high risk of sea-level induced flooding by 2050, particularly for properties along the coastline. Interviews with tourism establishment respondents showed that people are aware of climate change threats, yet little adaptation is forthcoming. Rather the government is deemed responsible for adaptation, despite its limited capacity. A disjuncture therefore exists between the perceived severity of risk and the risk that is evident from scientific analyses. This gap results in poor planning for the costs associated with adaptation.
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    A multi-disciplinary review of late Quaternary palaeoclimates and environments for Lesotho
    (2016-07) Fitchett, J.M.; Grab, S.W; Bamford, M.K.; Mackay, A.W.
    Lesotho provides a unique context for palaeoclimatic research. The small country is entirely landlocked by South Africa, yet has considerable variation in topography, climate, and associated vegetation over an approximate east–west transect. The region has been of archaeological interest for over a century, and hosts many Early to Late Stone Age sites with occupation preceding 80 000 years before present. The eastern Lesotho highlands are of interest to periglacial and glacial geomorphologists because of their well-preserved relict landforms and contentious evidence for permafrost and niche glaciation during the late Quaternary. However, continuous proxy records for palaeoenvironmental reconstructions for Lesotho are scarce and hampered by a range of methodological shortfalls. These challenges include uncertain ages, poor sampling resolution, and proxies extracted from archaeological excavations for which there may be bias in selection. Inferences on palaeoclimates are thus based predominantly on archaeological and palaeogeomorphological evidence for discrete periods during the late Quaternary. This review paper presents a more detailed multidisciplinary synthesis of late Quaternary conditions in Lesotho. We simultaneously considered the varying data that contribute to the under-studied palaeoenvironmental record for southern Africa. The collective palaeoenvironmental data for eastern Lesotho were shown to be relatively contradictory, with considerable variations in contemporaneous palaeoclimatic conditions within the study area. We argue that although methodological challenges may contribute to this variation, the marked changes in topography result in contrasting late Quaternary palaeoenvironments. Such environments are characterised by similar contrasting microclimates and niche ecologies as are witnessed in the contemporary landscape. These spatial variations within a relatively small landlocked country are of importance in understanding broader southern African palaeoenvironmental change.
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    Changing boundaries: Overcoming modifiable areal unit problems related to unemployment data in South Africa.
    (Academy of Science of South Africa (ASSAf), 2016-03) Weir-Smith, G
    The longitudinal comparison of census data in spatial format is often problematic because of changes in administrative boundaries. Such shifting boundaries are referred to as the modifiable areal unit problem (MAUP). This article utilises unemployment data between 1991 and 2007 in South Africa to illustrate the challenge and proposes ways to overcome it. Various censuses in South Africa use different reporting geographies. Unemployment data for magisterial districts of census 1991 and 1996 were re-modelled to the 2005 municipal boundaries. This article showed that areal interpolation to a common administrative boundary could overcome these reporting obstacles. The results confirmed more accurate interpolations in rural areas with standard errors below 3300. Conversely, the largest errors were recorded in the metropolitan areas. Huge increases in unemployment between 1996 and 2001 statistics were also evident, especially in the metropolitan areas. Although such areas are more complex in nature, making it more difficult to accurately calculate census data, the increase in unemployment could also be the result of census taking methods. The article concludes that socio-economic data should be available at the smallest possible geographic area to ensure more accurate results in interpolation. It also recommends that new output areas be conceptualised to create a seamless database of census data from 1991 to 2011 in South Africa.
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    An Acheulean handaxe from Gladysvale Cave site, Gauteng, South Africa.
    (Academy of Science of South Africa (ASSAf), 2006-03) Hall, G.; Pickering, R.; Lacruz, R.; Hancox, J.; Berger, L.R.; Schmid, P.
    WE DESCRIBE A SINGLE HANDAXE FROM fossiliferous breccias at Gladysvale Cave, South Africa. The artefact is the only known tool so far discovered during the controlled excavations conducted at this site over the last decade, and was recovered from decalcified sediments near the stratigraphic interface of two breccia units, making it difficult to assign it with confidence to either. The morphology of the handaxe indicates a middle-late Acheulean industry, and preliminary electron spin resonance and palaeomagnetic dating suggest an age of greater than 780 000 years.
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    Projections of rapidly rising surface temperatures over Africa under low mitigation.
    (Institute of Physics Publishing, 2015-08) Engelbrecht, F.; Adegoke, J.; Bopape, M.-J.; Naidoo, M.; Garland, R.; Thatcher, M.; McGregor, J.; Katzfey, J.; Werner, M.; Ichoku, C.; Gatebe, C.
    An analysis of observed trends in African annual-average near-surface temperatures over the last five decades reveals drastic increases, particularly over parts of the subtropics and central tropical Africa. Over these regions, temperatures have been rising at more than twice the global rate of temperature increase. An ensemble of high-resolution downscalings, obtained using a single regional climate model forced with the sea-surface temperatures and sea-ice fields of an ensemble of global circulation model (GCM) simulations, is shown to realistically represent the relatively strong temperature increases observed in subtropical southern and northern Africa. The amplitudes of warming are generally underestimated, however. Further warming is projected to occur during the 21st century, with plausible increases of 4-6 °C over the subtropics and 3-5 °C over the tropics by the end of the century relative to present-day climate under the A2 (a low mitigation) scenario of the Special Report on Emission Scenarios. High impact climate events such as heat-wave days and high fire-danger days are consistently projected to increase drastically in their frequency of occurrence. General decreases in soil-moisture availability are projected, even for regions where increases in rainfall are plausible, due to enhanced levels of evaporation. The regional dowscalings presented here, and recent GCM projections obtained for Africa, indicate that African annual-averaged temperatures may plausibly rise at about 1.5 times the global rate of temperature increase in the subtropics, and at a somewhat lower rate in the tropics. These projected increases although drastic, may be conservative given the model underestimations of observed temperature trends. The relatively strong rate of warming over Africa, in combination with the associated increases in extreme temperature events, may be key factors to consider when interpreting the suitability of global mitigation targets in terms of African climate change and climate change adaptation in Africa.
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    A matter of ephemerality: The study of Kel Tadrart Tuareg (southwest Libya) campsites via quantitative spatial analysis.
    (Resilience Alliance, 2016) Biagetti, S.; Alcaina-Mateos, J.; Crema, E.R.
    We examined the settlement structure from the Kel Tadrart Tuareg, a small pastoral society from southwest Libya. Our objective was to apply spatial analysis to establish the statistical significance of specific patterns in the settlement layout. In particular, we examined whether there is a separation between domestic and livestock spaces, and whether particular residential features dedicated to guests are spatially isolated. We used both established statistical techniques and newly developed bespoke analyses to test our hypotheses, and then discuss the results in the light of possible applications to other case studies.
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    Resilience of small-scale societies: a view from drylands.
    (Resilience Alliance, 2016) Gomez-Baggethun, E.; Salpeteur, M.; Puy, A.; Biagetti, S.; Scheffran, J.; Balbo, A.L.
    To gain insights on long-term social-ecological resilience, we examined adaptive responses of small-scale societies to dryland-related hazards in different regions and chronological periods, spanning from the mid-Holocene to the present. Based on evidence from Africa (Sahara and Sahel), Asia (south margin of the Thar desert), and Europe (South Spain), we discuss key traits and coping practices of small-scale societies that are potentially relevant for building resilience. The selected case studies illustrate four main coping mechanisms: mobility and migration, storage, commoning, and collective action driven by religious beliefs. Ultimately, the study of resilience in the context of drylands emphasizes the importance of adaptive traits and practices that are distinctive of small-scale societies: a strong social-ecological coupling, a solid body of traditional ecological knowledge, and a high degree of internal cohesion and self-organization.
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    Disjunct perceptions? Climate change threats in two-low lying South African coastal towns.
    (Nicolaus Copernicus University Press, 2016-03) Hoogendoorn, G.; Grant, B.; Fitchett, J.M.
    Coastal towns rely heavily on the quality and expanse of their beaches to attract tourists. Climate is an important tourism determinant, controlling the length and timing of peak arrivals. South African tourism is particularly reliant on these factors. Perceptions of tourists and tourist accommodation establishment regarding climate change threats to tourism are explored for the towns of St Francis Bay and Cape St Francis. Tourism accommodation establishments were predominantly concerned with day-to-day changes in weather, investing in small-scale infrastructural changes to improve the comfort of their guests. By contrast, tourists demonstrated greater concern for the risk of flooding, sea-level rise and the degeneration of the beaches. This reflects concerning disjunctures between perceptions of tourists and accommodation establishments regarding climate change threats. This may portray to tourists insufficient investment in adaptation at accommodation establishments, resulting in decreased tourist visitations in the short-term in favour of destinations perceived as better prepared.
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    Medical tourism by Indian-South Africans to India: An exploratory investigation
    (Nicolaus Copernicus University Press, 2015-09) Dangor, F.; Hoogendoorn, G.; Moolla, R.
    Medical tourism is a well-established sector in developing countries, and attracts a significant number of tourists from developed countries. Medical tourism is a strong driver of economic growth, but some argue that this kind of tourism promotes inequality in terms of access to healthcare facilities in both developing and developed countries. Whilst research has been conducted on medical tourists travelling to South Africa, no research has focused on the geography of South Africans travelling abroad for medical tourist activities. This study therefore sought to obtain first-hand information from Indian-South African citizens who have partaken in medical tourism in India. Data was gathered through personal, semi-structured interviews conducted with 54 individuals. It was ascertained that the majority of the individuals interviewed in this study travelled to India primarily for medical treatment, while tourist activities were a secondary objective. A smaller proportion of interviewees travelled to India for vacation, with medical care being a secondary motivation, or an impulse due to the low cost of treatment and convenience. Medical tourism by Indian-South Africans travelling to India highlights various shortfalls in South African medical care, including a lack of treatment availability, a poorer quality of service, medical expertise abroad, and the higher cost incurred locally.
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    Evidence for climate-induced range shift in Brachystegia (miombo) woodland.
    (Academy of Science of South Africa (ASSAf), 2015-07) Pienaar, B.; Thompson, D.I.; Erasmus, B.F.N.; Hill, T.R.; Witkowski, E.T.F.
    Brachystegia spiciformis Benth. is the dominant component of miombo, the sub-tropical woodlands which cover 2.7 million km2 of south-central Africa and which is coincident with the largest regional centre of endemism in Africa. However, pollen records from the genus Brachystegia suggest that miombo has experienced rapid range retraction (∼450 km) from its southernmost distributional limit over the past 6000 years. This abrupt biological response created an isolated (by ∼200 km) and incomparable relict at the trailing population edge in northeast South Africa. These changes in miombo population dynamics may have been triggered by minor natural shifts in temperature and moisture regimes. If so, B. spiciformis is likely to be especially responsive to present and future anthropogenic climate change. This rare situation offers a unique opportunity to investigate climatic determinants of range shift at the trailing edge of a savanna species. A niche modelling approach was used to produce present-day and select future B. spiciformis woodland ecological niche models. In keeping with recent historical range shifts, further ecological niche retraction of between 30.6% and 47.3% of the continuous miombo woodland in Zimbabwe and southern Mozambique is predicted by 2050. Persistence of the existing relict under future climate change is plausible, but range expansion to fragmented refugia in northeast South Africa is unlikely. As Brachystegia woodland and associated biota form crucial socio-economic and biodiversity components of savannas in southern Africa, their predicted further range retraction is of concern.
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    Exploring the Stone-Walled Structures of the Suikerbosrand: a Study on Location, Visibility and Political Rankings
    (2015-03-24) O'Malley, Caitlin
    The Suikerbosrand Nature Reserve has a number of Iron Age stone-walled structures situated in the landscape. The most recent stone-walled structures – the Group II stone-walled structures – date between the 17th and 19th Centuries, and have the highest potential for political stratification. This study aimed to identify political and social structures in the Suikerbosrand Group II sites, using Geographic Information Systems (GIS) and visibility analyses to establish an index for social and political rank. Links were identified between socially constructed landscapes, political hierarchies, economic control of resources and trade, and the interactions between site formation and visibility. A complex construction of social and political indices was identified, and a number of observations on social and political interactions were concluded.