scholarly journals Can CHIRPS fill the gap left by the decline in the availability of rainfall stations in Southern Africa?

Water SA ◽  
2021 ◽  
Vol 47 (2 April) ◽  
Author(s):  
WV Pitman ◽  
AK Bailey
Keyword(s):  
South Africa ◽  
Time Series ◽  
Water Resources ◽  
Hydrological Model ◽  
Mean Annual Precipitation ◽  
Winter Rainfall ◽  
Important Input ◽  
The Difference ◽  
Rainfall Region ◽  
Larger Sample

Rainfall is the most important input to any hydrological or water resources study. The decline in the number of suitable rainfall stations since the 1970s is a cause for concern, plus there is an additional complication in that – for a number of catchments – mean annual precipitation (MAP), as derived from a recent study by Pegram, differs substantially from those adopted by the Water Resources of South Africa, 2012 study (WR2012) (mostly as derived by Dent). Rainfall data sourced by the Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) satellite database was selected as a basis for comparison, both for catchment MAP and time series of monthly rainfall as used for input to the Pitman hydrological model (WRSM/Pitman, previously called WRSM2000). The analyses revealed that the WR2012 method of constructing the time series yielded the best results overall, but the difference was not marked, except in the winter rainfall region, where CHIRPS (and to a lesser extent, Pegram) performed poorly. It is concluded that CHIRPS will have a role to play in future water resources studies. It is recommended that the study be extended to cover a larger sample of catchments with up-to-date rainfall and that the possibility of CHIRPS data being recalibrated for the winter rainfall area be investigated.

scholarly journals Probabilistic assessment of the rainwater harvesting potential of schools in South Africa

2014 ◽  
Vol 364 ◽  
pp. 435-440 ◽  
Author(s):  
J. G. Ndiritu ◽  
S. McCarthy ◽  
N. Tshirangwana
Keyword(s):  
South Africa ◽  
Rural Areas ◽  
Storage Capacity ◽  
Rainwater Harvesting ◽  
Summer Rainfall ◽  
Mean Annual Precipitation ◽  
Expected Number ◽  
Time Step ◽  
Winter Rainfall ◽  
Rainfall Region

Abstract. In comparison to other sources of water supply, rainwater harvesting (RWH) has the typical advantages of being cheaper and easier to operate and maintain. This study aimed at assessing the hydrologic rainwater harvesting potential of rural schools in South Africa by obtaining RWH storage capacity (level of supply) reliability relationships of representative schools. Thirty-two schools located in three rural areas that have varied rainfall characteristics were selected for the analysis. For each school, a daily time-step behaviour analysis of the rainwater harvesting system with a specified storage was carried out for a period of 101 years (over which rainfall data was available) and the number of days that the school’s daily water demand was met in each year obtained. Using the Weibull plotting position formula, the expected number of days that the demand can be met per year was then obtained for 85, 90 and 95 % reliability. For the two summer rainfall regions where a large proportion of rain falls during school holidays, the expected number of days of supply per year improved up to a storage capacity of 25 m3. For the winter rainfall region where the rainfall periods and school learning times have more co-incidence, a tank volume of 5 m3 obtained similar supply levels as larger capacities. At 90 % reliability, the supply levels for different schools in the summer rainfall area with a mean annual precipitation (MAP) of 800–1000 mm/year ranged from 60 to 120 days per year, while the summer rainfall region with a lower MAP (500–600 mm) gave supply levels ranging from 40 to 70 days per year. The winter rainfall area had a MAP of 500–600 mm and obtained supply levels ranging from 60 to 80 days at 90 % reliability.

Occurrence of putatively resistant plantago in the winter rainfall region of South Africa: a survey

2021 ◽  
Vol 38 (5) ◽  
pp. 411-415
Author(s):  
Vhuthu Ndou ◽  
Ethel E Phiri ◽  
Frederik H Eksteen ◽  
Petrus J Pieterse
Keyword(s):  
South Africa ◽  
Winter Rainfall ◽  
Rainfall Region

scholarly journals An assessment of the skill of downscaled GCM outputs in simulating historical patterns of rainfall variability in South Africa

2013 ◽  
Vol 45 (1) ◽  
pp. 134-147 ◽  
Author(s):  
D. A. Hughes ◽  
S. Mantel ◽  
T. Mohobane
Keyword(s):  
South Africa ◽  
Water Resources ◽  
General Circulation ◽  
Hydrological Model ◽  
Rainfall Variability ◽  
General Circulation Models ◽  
Local Scale ◽  
Coastal Areas ◽  
General Applicability ◽  
Modelling Studies

Uncertainties associated with General Circulation Models (GCMs) and the downscaling methods used for regional or local scale hydrological modelling can result in substantial differences in estimates of future water resources availability. This paper assesses the skill of nine statistically downscaled GCMs in reproducing historical climate for 15 catchments in five regions of South Africa. The identification of skilled GCMs may reduce the uncertainty in future predictions and the focus is on rainfall skill as the GCMs show very similar patterns of change in temperature. The skill tests were designed to assess whether the GCMs are able to realistically reproduce precipitation distribution statistics and patterns of seasonality, persistence and extremes. Some models are consistently less skilful for the regions assessed, while some are generally more skilful with some regionally specific exceptions. There are differences in the GCMs skill across the different regions and in the skill ranking between coastal areas and inland regions. However, only a limited reduction in uncertainty is achieved when using only the downscaled GCM outputs identified as being skilled in a hydrological model for one of the regions. Further modelling studies are required to determine the general applicability of this observation.

Bradyrhizobium sp. ( Lupinus ) in the winter rainfall region of South Africa

2002 ◽  
Vol 36 (5) ◽  
pp. 335-343 ◽  
Author(s):  
Wilhelm Botha ◽  
Jacomina Bloem ◽  
Ian Law
Keyword(s):  
South Africa ◽  
Winter Rainfall ◽  
Bradyrhizobium Sp ◽  
Rainfall Region

A Taxonomic Revision of the Othonna bulbosa Group (Asteraceae: Senecioneae: Othonninae)

2019 ◽  
Vol 104 (4) ◽  
pp. 515-562 ◽  
Author(s):  
Simon L. Magoswana ◽  
James S. Boatwright ◽  
Anthony R. Magee ◽  
John C. Manning
Keyword(s):  
South Africa ◽  
South African ◽  
Geographical Distribution ◽  
Taxonomic Revision ◽  
Cape Floristic Region ◽  
The South ◽  
Winter Rainfall ◽  
African Species ◽  
Taxonomic Treatment ◽  
Rainfall Region

Othonna L. (Asteraceae: Senecioneae: Othonninae) is a genus of some 120 species concentrated in the Greater Cape Floristic Region (GCFR) of South Africa, with a few species extending into southern Namibia, Angola, and Zimbabwe. The South African species of Othonna were last revised more than a century ago, and many species, particularly from the southern African winter rainfall region, remain poorly understood. This study focused on the geophytic species comprising the O. bulbosa group, distinguished by their tuberous rootstock and annual, leafy, aerial stems. A comprehensive taxonomic treatment is presented, including descriptions, complete nomenclature and typification, illustrations, and geographical distribution. Twenty-five species are recognized, of which four are newly described (O. lilacina Magoswana & J. C. Manning, O. nigromontana Magoswana & J. C. Manning, O. revoluta Magoswana & J. C. Manning, and O. sinuata Magoswana & J. C. Manning), and 18 names are reduced to synonymy. The species differ in habit, shape and incision of foliage, capitulum type (radiate vs. disciform), number of involucral bracts, pappus length, and cypselae (myxogenic vs. nonmyxogenic). We place the species into four morphologically diagnosable series (series Heterophyllae Magoswana & J. C. Manning, series Disciformes Magoswana & J. C. Manning, series Perfoliatae Magoswana & J. C. Manning, and series Undulosae Magoswana & J. C. Manning) based on habit and capitulum type.

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