Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: In the study, six irrigation schemes based in the Eastern Cape have been
considered and evaluated, according to two levels of supply (LOS) of irrigation
water. The two levels of supply are that of a commercial irrigator and that of a
smallholder irrigator. The irrigation infrastructure for each of the six schemes
was designed, and the associated costs determined, for each level of supply.
The primary objective of the study is to determine the impact of infrastructure
costs and irrigation areas on the target user, either the commercial or the
smallholder irrigator. This is related directly to the assumption that lower water
volumes are used by the smallholder irrigator.
The study addresses the impact of different designs on the amount of water
used, land utilised and resultant costs of the infrastructure.
The initial capital costs and the on-going operational and maintenance costs
(O&M) for each level of supply for each of the schemes have been calculated.
The evaluation of the two LOS has shown that the capital cost for the
commercial LOS is approximately 18 % higher than for the smallholder LOS
and the O&M costs 6 % to 36 % higher.
The schemes that were investigated can be grouped into five general scheme
types. The first type is gravity schemes, which need rehabilitation, while the bulk
supply is in place with no augmentation or rehabilitation required. The second is
pumped scheme which is in need of rehabilitation, while the bulk supply is in
place with no augmentation or rehabilitation required. The third type includes
run-of-river schemes where water is abstracted and pumped directly to the
lands. The fourth type includes run-of-river schemes where water is abstracted
and pumped to storage. The fifth type is the gravity scheme where the bulk
supply needs to be installed as part of the scheme. These types are then
grouped and can be used to give guidance on the anticipated costs dependant
on the scheme type and the required level of service. A further objective of the research is to determine the impact on the smallholder
irrigators who find themselves on a commercial LOS system. This can be either
on a scheme that has already been designed, or on a new system.
The evaluation of the commercial under-utilised LOS and the smallholder LOS
has shown that the commercial capital cost is 18 % higher and the O&M costs
5 % to 29 % higher.
The study further aligns the estimated costs with the farmer typology providing a
broader understanding of the design to be adopted for different levels of supply.
This provides the linkage between farmer types, the design to be implemented
and the anticipated costs thereof. / AFRIKAANSE OPSOMMING: As deel van hierdie narvorsing word ses verskillende besproeiingsskemas in die
Oos-Kaap ten opsigte van twee voorsieningsvlakke ondersoek. Die twee
voorsieningsvlakke ter sprake is vir ‘n kommersiële en kleinboerdery opset. Die
besproeiingsinfrastruktuur is vir elk van die ses besproeiingsskemas ontwerp en
‘n kosteberaming vir elk van voorsieningsvlakke gedoen.
Die hoofdoelwit van hierdie verslag is om te bepaal wat die impak van kostes en
besproeiingsareas op beide kommersiële- en kleinboerderye is. Dit is direk
gebaseer op die aanname dat kleinboerderye minder water gebruik.
Die verslag ondersoek die impak van verskillende ontwerpe op waterverbruik,
besproeiingsoppervlak benodig en die gevolglike infrastruktuurkostes.
Die aanvanklike kapitaalkostes asook bedryfs- en onderhoudsuitgawes (B&O)
vir elk van die voorsieningsvlakke, is vir elk van die besproeiingskemas
bereken. Die resultaat van die ondersoek van die twee voorsieningsvlakke het
aangetoon dat die kapitaalkoste van kommersiële besproeiingskemas 18 %
hoër as die van kleinboerderye is, en bedryfs- en onderhoudsuitgawes 6 tot 36
% hoër.
Die skemas wat ondersoek is, kan in vyf algemene skema tipes verdeel word.
Die eerste is die gravitasieskemas wat rehabilitasie benodig terwyl die
hooftoevoer in plek is met geen uitbreidings- of rehabilitasiebehoeftes. Die
tweede is pompskemas wat rehabilitasie benodig terwyl die hooftoevoer in plek
is met geen uitbreidings- of rehabilitasiebehoeftes. Die derde is rivierskemas
waar besproeiingswater direk uit die rivier na die landerye gepomp word. Die
vierde is rivierskemas waar besproeiingswater direk uit die rivier na a reservoir
gepomp word. Die vyfde skema tipe is die gravitasieskemas waar die
hooftoevoer ook gebou moet word as deel van die skema. Die skema tipes kan
gebruik word om leiding te verskaf ten opsigte van verwagte skema kostes
afhangende van die skema tipe en vereiste voorsieningsvlak. ‘n Verdere doelwit van die studie is om die impak op kleinboere te bepaal wat
op ‘n kommeriële voorsieningsvlak boer. So ‘n stelsel kan ‘n gevestigde of nuwe
stelsel wees.
Die resultaat van die ondersoek van die onderbenutte kommersiële
voorsieningsvlak en die kleinboerdery voorsieningsvlak het gewys dat die
kapitaalkoste van kommersiële besproeiingskemas 18 % hoër as die van
kleinboerderye is, en bedryfs- en onderhoudsuitgawes 5 tot 29 % hoër.
Die verslag vereenselwig die verwagte kostes met die tipe boerdery en verskaf
‘n beter begrip van die tipe ontwerp wat elk van die voorsieningsvlakke benodig.
Dit verskaf dus die verband tussen die tipe boerdery, die ontwerp benodig en
die verwagte projekkostes.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/6501 |
| Date | 03 1900 |
| Creators | Hards, Adrian F. |
| Contributors | Du Plessis, J. A., University of Stellenbosch. Faculty of Engineering. Dept. of Civil Engineering |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | Unknown |
| Type | Thesis |
| Rights | University of Stellenbosch |
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