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dc.contributor.advisorBotha, J. F.
dc.contributor.authorNel, Jacobus Marthinus
dc.date.accessioned2017-04-07T07:13:49Z
dc.date.available2017-04-07T07:13:49Z
dc.date.issued2001-08
dc.identifier.urihttp://hdl.handle.net/11660/6061
dc.description.abstractEnglish: The importance of groundwater is strongly reflected in the new South African water policy and legislation. All water resources, including groundwater, are now seen as an indivisible asset, with the National Government as its custodian to ensure that the resources are protected, developed and managed properly. Groundwater is the sole source of potable water for the town of Stella in the Lower Vaal Water Management Area of the Northwest Province, but the existing well-field is barely able to supply the present demand. Previous attempts to supply the town with water from groundwater resources have failed, because of the low potential of the aquifers and the poor quality of the groundwater. The proposed resettlement of 2 000 people therefore has to be postponed until sufficient additional water resources can be found for the town. One possible source, not included in previous groundwater explorations of the area, is the granitic aquifer on the farm Middel Kop situated approximately 5 km south-east of Stella. Farmers have used this aquifer extensively since 1990 to irrigate 171 ha of agricultural land. It was consequently decided to investigate this aquifer as a possible additional source of water for Stella. However, farmers have already noticed a continuous decline in the water levels over the years. This meant that the focus of the investigation had to be changed from merely an exploration exercise to an evaluation of the aquifer and the development of a suitable management scheme for the aquifer, as described in this thesis. There are not enough data available to perform a detailed assessment of the aquifer at the moment, a deficiency that should be addressed in future investigations and management of the aquifer. The existing data, however, indicate that the aquifer may be able to sustain a yield of approximately 4 227 m3 d-I in the near future. This volume of water will be able to supply in the needs of the present population and the additional 2 000 resettled people, while allowing 73% of the current irrigated area approximately 8 000 m3 ha-I annually for irrigation. The latter figure can only be achieved if the farmers are allowed to produce one crop per year instead of the two, which is in some cases the practice. This reduction in the water allocated for irrigation may seem harsh, but the decline in the water levels over the last couple of years clearly indicate that the farmers cannot continue with the present practices for much longer. The groundwater quality of the Middel Kop aquifer can be rated as marginal for human consumption. This applies in particular to the relatively high concentrations of fluoride and nitrate in the water, which could affect the health of the population adversely if used untreated for long periods. The conclusion reached in the thesis is that the Middel Kop aquifer can only be used as a source of water for Stella on condition that a detailed monitoring scheme is introduced from the beginning and used to develop a suitable management scheme for the aquifer. This approach will ensure that any impacts on the resource can be properly evaluated and that the quality and quantity of the water can be preserved for future generations.en_ZA
dc.description.abstractAfrikaans: Die belangrikheid van grondwater word sterk beklemtoon in die nuwe Suid Afrikaanse water beleid en wetgewing. Alle waterbronne, insluitende grondwater, word nou as 'n onverdeelbare bate beskou, met die Nasionale Regering as bewaarder, ten einde te verseker dat die bronne beskerm en oordeelkundig benut en bestuur word. Grondwater is tans die enigste bron van drinkbare water vir die dorp Stella in die Laer Vaal Waterbestuursgebied van die Noordwes Provinsie. Die bestaande bron is egter skaars in staat om in die behoeftes van die inwoners te voorsien. Vorige pogings om nuwe bronne vir die dorp te vind het egter almal gefaal, weens die lae potensiaal en swak kwaliteit water in die omliggende bronne. Die voorgestelde hervestiging van ongeveer 2000 mense in Stella moes dus uitgestel word totdat 'n nuwe bron van water vir die dorp gevind kon word. Een bron wat nie vantevore ondersoek is nie, is die granitiese akwifeer op die plaas Middel Kop, wat ongeveer 5 km suidoos van Stella geleë is en reeds sedert 1990 deur boere gebruik word om 171 ha landbougrond te besproei. Gevolglik is daar besluit om op hierdie bron te konsentreer. Boere het egter gevind dat die watervlakke in die bron met die jare kontinue gedaal het. Die fokus van die ondersoek van die bron moes dus verskuif word van 'n blote eksplorasie na die evaluering en bestuur van die bron, wat in hierdie verhandeling bespreek word. Daar is nie voldoende data om die bron op hierdie stadium volledig te evalueer nie, 'n tekortkoming waarmee rekening gehou moet word in toekomstige ondersoeke en bestuur van die bron. Die bestaande data dui egter aan dat die bron in staat behoort te wees om 4 000 m3 d-I in die onmiddellike toekoms te lewer. Hierdie volume water behoort in die behoeftes van die huidige en die 2 000 hervestigde inwoners van Stella te voorsien en ook boere toe te laat om op 73% van die huidige besproeiing oppervlak, 8 000 rrr' ha-I jaarliks vir besproeiing te gebruik. Laasgenoemde syfer beteken egter dat boere slegs een gewas per jaar sal kan produseer, in plaas van die twee soos wat in sommige gevalle gebeur. Die afname in die water wat aan boere vir besproeiing toegeken word, kan moontlik as kras gesien word. Die afname in die watervlakke van die akwifeer oor die afgelope paar jaar, dui egter aan dat boere moeilik hierdie gebruik in die onmiddellike toekoms sal kan volhou. Die grondwater kwaliteit in die Middel Kop akwifeer kan as marginaal beskou word in terme van menslike gebruik. Dit is veral die tloried en nitraat konsentrasies wat relatief hoog is en gesondheidsrisikos vir die gebruikers kan skep indien dit onbehandeld vir lang periodes gebruik word. Monitering van die bron behoort 'n hoë prioriteit te wees in 'n poging om die langtermyn volhoubaarheid van die bron in terme van kwaliteit en kwantiteit te verseker. Die gebruikers van die bron moet toesien dat enige impakte op die bron voldoende geevalueer word en dat voldoende bestuur en beskermingsmaatreëls in plek is om toe te sien dat die bron vir toekomstige geslagte beskikbaar is. Die gevolgtrekking waartoe in die verhandeling gekom word, is dat die Middel Kop akwifeer slegs as waterbron vir Stella gebruik kan word indien die akwifeer van die begin afbehoorlik gemoniteer word en die inligting gebruik word om 'n geskikte bestuursplan vir die akwifeer op te stel. Hierdie benadering sal verseker dat enige impakte op die bron behoorlik ge-evalueer kan word, sodat die kwaliteit en kwantiteit van die water vir toekomstige gebruikers behoue bly.af
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectGroundwater potentialen_ZA
dc.subjectGraniteen_ZA
dc.subjectAquifer delineationen_ZA
dc.subjectRechargeen_ZA
dc.subjectAllocationen_ZA
dc.subjectProtectionen_ZA
dc.subjectResource directed measuresen_ZA
dc.subjectReserveen_ZA
dc.subjectDrasticen_ZA
dc.subjectMonitoringen_ZA
dc.subjectGroundwater -- South Africa -- Stellaen_ZA
dc.subjectAquifers -- South Africa -- Stellaen_ZA
dc.subjectHydrogeology -- South Africa -- Stellaen_ZA
dc.subjectDissertation (M.Sc. (Geohydrology))--University of the Free State, 2001en_ZA
dc.titleAssessment of the groundwater potential of the Middel Kop/Appleby aquifer, Stella District, Northwest Regionen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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