South African Hydrostratigraphy: A conceptual framework

2019 ◽  
Vol 122 (3) ◽  
pp. 269-282
Author(s):  
R. E. Diamond ◽  
M.A. Dippenaar ◽  
S. Adams
Keyword(s):  
South African ◽  
Hydrological Cycle ◽  
Abiotic Factors ◽  
Fold Belt ◽  
Kalahari Desert ◽  
Ground Conditions ◽  
Standard Terminology ◽  
Coastal Deposits ◽  
Cape Fold Belt ◽  
Moisture Conditions

Abstract South African geology, geomorphology and climate are distinctly variable, resulting in a complex hydrological cycle superimposed on equally complex ground conditions. With fractured and karstic systems dominating the hydrogeology, thick vadose zones comprising soil and rock and at highly variable moisture conditions contribute to complex hydrostratigraphic systems comprising various confining and hydraulically connected units. This paper proposed standard terminology for basic concepts pertaining to the description of ground and water in the subsurface to eventually propose a hydrostratigraphic classification based on abiotic factors fairly constant over short periods of time (geology, geomorphology and climate), as well as those temporally highly variable (climate) and those introduced by human involvement (society). Ten major hydrostratigraphic units are eventually described, namely the Cape Fold Belt, Kalahari Desert, Witwatersrand Supergroup, Malmani Subgroup, Cenozoic Coastal Deposits, Saldanian Basement, Karoo Main Basin, Namaqua-Natal Metamorphics, Waterberg Group, and Archaean Granitoids.

scholarly journals Soil and Water Conservation in Rainfed Vineyards with Common Sainfoin and Spontaneous Vegetation under Different Ground Conditions

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1058 ◽  
Author(s):  
Nahed Ben-Salem ◽  
Sara Álvarez ◽  
Manuel López-Vicente
Keyword(s):  
Water Conservation ◽  
Cover Crop ◽  
Sediment Traps ◽  
Sediment Yields ◽  
Rainfall Depth ◽  
Ephemeral Gullies ◽  
Ground Conditions ◽  
Spontaneous Vegetation ◽  
The Mean ◽  
Moisture Conditions

Soil erosion seriously affects vineyards. In this study, the influence of two vegetation covers on topsoil moisture and the effect of different physiographic conditions on runoff and sediment yields were evaluated in a rainfed vineyard formed by four fields (NE Spain) during 15 months. One field had spontaneous vegetation in the inter-row areas, and three fields had a cover crop of common sainfoin. Moisture conditions were dry and stable in the vineyards’ rows, wet and very variable in the inter-row areas and wet and very stable in the corridors. Topsoil moisture in the areas with common sainfoin was much higher than in the rows (62–70%), whereas this difference was lower with spontaneous vegetation (40%). Two runoff and sediment traps (STs) were installed in two ephemeral gullies, and 26 time-integrated surveys (TIS) were done. The mean runoff yields were 9.8 and 13.5 L TIS−1 in ST2 and ST3. Rainfall depth (12 mm) and erosivity (5.2 MJ mm ha−1 h−1) thresholds for runoff initiation were assessed. The mean turbidity was 333 (ST2) and 19 (ST3) g L−1. Changes in the canopy covers (grapevines and vegetation covers), topography and rainfall parameters explained the runoff and sediment dynamics.

scholarly journals Continued professional development of teachers to facilitate language used in numeracy and mathematics

2012 ◽  
Vol 59 (1) ◽  
Author(s):  
Anna-Maria Wium ◽  
Brenda Louw
Keyword(s):  
Professional Development ◽  
South African ◽  
Language Use ◽  
Learning And Teaching ◽  
Rural And Urban ◽  
Mathematical Problems ◽  
Standard Terminology ◽  
Urban Contexts ◽  
And Mathematics ◽  
Performance Teachers

Learners in South African schools have been found to perform poorly in mathematics because they do not understand the language used in solving mathematical problems. In order to improve academic performance teachers need to be made aware of the importance of language in the development of numeracy. A continued professional development (CPD) programme addressed this need. The purpose of the research was to understand how the participants implemented the strategies developed during the programme and how they perceived the support provided by the programme. The research was conducted over 2 years in semi-rural and urban contexts. As part of a more comprehensive mixed method study, the qualitative data referred to in this article were obtained through open-ended questions in questionnaires, focus groups, reflections in portfolios, and a research diary. Results showed that numeracy terminology was often used by learners that differed from standard terminology prescribed by the curriculum. The participants themselves did not necessarily understand the numeracy terminology and thus found it a challenge to implement curriculum outcomes. Issues related to language use of the participants in teaching numeracy were associated with the lack of resources available in the language of learning and teaching  (LoLT). Some of the participants taught numeracy in English, rather than LoLT. The results indicated low teacher expectations of the learners. The CPD programme was considered valuable and effective. SLPs in schools need to be expand their role to provide CPD opportunities for teachers.

Biomes, geology and past climate drive speciation of laminate-toothed rats on South African mountains (Murinae: Otomys)

2019 ◽  
Vol 189 (3) ◽  
pp. 1046-1066
Author(s):  
Peter John Taylor ◽  
Teresa Kearney ◽  
Desire Lee Dalton ◽  
Gamuchirai Chakona ◽  
Christopher M R Kelly ◽  
...  
Keyword(s):  
South African ◽  
Dna Sequences ◽  
Mountain Range ◽  
Western Cape ◽  
Eastern Cape ◽  
Species Complexes ◽  
Craniometric Analysis ◽  
Cape Fold Belt ◽  
Great Escarpment ◽  
Geological Formations

Abstract Mitochondrial DNA sequences (1137 bp) of the cytochrome b gene and craniodental and craniometric data were used to investigate the evolutionary relationships of six putative rodent taxa of Otomys (family Muridae: subfamily Murinae: tribe Otomyini) co-occurring in the Western Cape and Eastern Cape provinces of South Africa. Phylogenetic analysis of 20 new sequences together with craniodental and craniometric characters of 94 adult skulls reveal the existence of a unique lineage of Otomys cf. karoensis (named herein Otomys willani sp. nov.) from the Sneeuberg Centre of Floristic Endemism in the southern Drakensberg Mountain Range. Craniometric analysis distinguished O. karoensis from O. willani and identified a further four localities in the range of the latter species. We document southern range extensions of both Sloggett’s ice rat, Otomys sloggetti, and the vlei rat Otomys auratus to the Sneeuberg Mountain Range, in addition to appreciable genetic divergence between Sneeuberg and southern and central Drakensberg populations of O. sloggetti. Our results demonstrate parallel patterns of cryptic speciation in two co-occurring species complexes (Otomys irroratus s.l. and O. karoensis s.l.) associated closely with the boundaries of biomes (fynbos vs. grassland biomes) and geological formations (Cape Fold Belt vs. Great Escarpment).

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