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.

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 Analysis of water use by gated communities in South Africa

Water SA ◽  
2018 ◽  
Vol 44 (1 January) ◽  
Author(s):  
Jacques JL Du Plessis ◽  
Heinz E Jacobs
Keyword(s):  
South Africa ◽  
Water Use ◽  
Summer Rainfall ◽  
Gated Communities ◽  
Winter Rainfall ◽  
Telecommunication Services ◽  
Homeowners Associations ◽  
Annual Water ◽  
Study Sites ◽  
Rainfall Region

Gated communities (hereafter GCs) are popular in many countries, including South Africa, because added security and lifestyle improvements are offered relative to homes built on freestanding properties. One of the key factors for the popularity of GCs is the availability of amenities to support the demands of the residents, such as gymnasia, walkways, golf courses, play parks and polo fields. Further benefits include the improved management of infrastructure such as telecommunication services, roads, water, sewer, electrical and stormwater assets. GCs are often governed by trustees or homeowners’ associations, responsible for the operation and the maintenance functions of the infrastructure, as well as implementing and adhering to legislation that pertains to the GC. As part of this study, the monthly water-use records of 2 888 GCs in 3 different South African cities were analysed. Water use was evaluated for each GC as a whole, and also per household in each case. The average number of homes per GC was 33 households/GC, with the smallest GC in the study sample containing 3 houses and the largest 524 houses. One of the study sites was in the winter rainfall region, while 2 sites were in the summer rainfall region. The average annual water use of individual households in each GC was plotted against current guidelines and was found to be relatively low. The average annual daily demands of all properties in the winter rainfall region was 0.63 kL/d, compared to 0.66 kL/d and 0.49 kL/d for the two study sites in the summer rainfall region. The results highlighted peculiarities in the water use of GCs that have not been reported on before, in particular the relatively low water use and the differences between GC homes’ water use in the various rainfall regions.

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

Late Quaternary micromammals and the precipitation history of the southern Cape, South Africa

2018 ◽  
Vol 91 (2) ◽  
pp. 848-860 ◽  
Author(s):  
J. Tyler Faith ◽  
Brian M. Chase ◽  
D. Margaret Avery
Keyword(s):  
South Africa ◽  
Late Quaternary ◽  
Regional Climate ◽  
Summer Rainfall ◽  
Tyto Alba ◽  
Winter Rainfall ◽  
Rainfall Seasonality ◽  
Barn Owls ◽  
History Of ◽  
The Last Glacial

AbstractThe southern Cape of South Africa is important to understanding regional climate because it straddles the transition between the winter and summer rainfall zones. We examine late Quaternary changes in rainfall seasonality and aridity through analysis of micromammal assemblages from three sites: Boomplaas Cave and Nelson Bay Cave in the aseasonal rainfall zone and Byneskranskop 1 in the winter rainfall zone. Our interpretation is based on analysis of 123 modern micromammal assemblages accumulated by barn owls (Tyto alba), which empirically links species composition to climate. The Pleistocene record (∼65 to 12 ka) from Boomplaas Cave, together with the last glacial maximum (LGM) samples from Nelson Bay Cave, indicates enhanced winter rainfall, especially during the LGM. Boomplaas Cave documents progressive aridification from the LGM to the earliest Holocene, followed by a return to moderately humid conditions through the Holocene. Byneskranskop 1 indicates a dominance of winter rains over the last 17 ka and a shift from an arid middle Holocene to a humid later Holocene. Agreement between the micromammal record and other local and regional proxies reinforces the potential of southern African micromammal assemblages as paleoclimate indicators.

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
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