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dc.contributor.advisorDennis, S. R.
dc.contributor.authorBaker, Kathleen Victoria
dc.date.accessioned2018-04-18T07:32:16Z
dc.date.available2018-04-18T07:32:16Z
dc.date.issued2011
dc.identifier.urihttp://hdl.handle.net/11660/8206
dc.description.abstractEnglish: This Masters thesis forms the capacity development component of the Water Research Commission (WRC) project number KS/1763, entitled "The identification and delineation of high-yielding well-field areas in Karoo aquifers as future water supply options to local authorities". The project was initiated due to the need to place the significant knowledge on groundwater of the Karoo Basin within the realms of water resource planning. The ever growing issues related to water resource planning include not only the challenge of finding groundwater resources, but quantifying the supply of this resource in terms that are readily understood by hydrogeologists and related professions. In an attempt to address these issues, a method by which groundwater resources can be identified as well as quantified is described in this thesis, which incorporates the concept of assurance of supply. This method involves the use of a number of tools, some of which are existing and are readily available to the public, others may be available in the specific area of interest (e.g. aeromagnetic imagery), and the remaining have been developed as part of the WRC project, and critically reviewed in this thesis. The development of the Transmissivity Map in this thesis took both existing borehole yields and geology into account, and provides a range of possible transmissivity values presented both in tables and maps. The ranges are provided for each hydrogeological domain (based on lithologies and in some cases, sub-divided lithologies), dole rite dykes and sills, fractured margins of sills and areas of thick alluvium. Woodford's method was used, which can be found in Dondo et al., 2010, which was then extrapolated across the Main Karoo Basin. This map is the most detailed map produced of the Main Karoo Basin and from the case studies presented appears to provide a reasonable estimate of transmissivity values. The Aquifer Assured Yield Model (AAYM) was run for a large number of quaternary catchments spread across the Karoo Basin to test the model's credibility, as well as to propose parameter values to be used per region or drainage basin. The AAYM compared well with other databases, namely the HP and GRAII AGEP. The work appears to be the first documented approach to quantifying groundwater with levels of assurance, and thus should be considered "work-in-progress", as is it requires an iterative process of development, testing, modifying and re-testing. The Wellfield Model was successfully developed on the basis of the Cooper-Jacob equation (Cooper & Jacob, 1946). Through the testing of the model, relationships of borehole spacing with transmissivity values were investigated in an attempt to provide a guideline on the design of a wellfield with certain borehole interference limitations. In addition to this, the distinct nature of groundwater flow in dykes was considered by referring to the Boonstra- Boehmer equation (Kruseman & de Ridder, 1992) whereby a certain increase in borehole spacing is required when a borehole is sited on a dyke. This model enables the designing and manipulation of a wellfield and the effect of groundwater abstraction on drawdown can be evaluated thereby aiding in the most optimum design. The methodology applied to case studies demonstrates the practical application of these tools and models described above. The purpose of the case studies was to apply the groundwater yield assessment methods in areas with known aquifer parameters and yields. The yield assessment methods were evaluated in terms of their accuracy and practicality by comparing the results with other existing yield assessment tools and with field data. The case studies showed that the newly produced geological maps and the Transmissivity Map can be easily used with satellite imagery to identify new potential borehole and wellfield areas. Overall, this thesis provides a step by step methodology to identify and delineate high groundwater potential areas in the Main Karoo Basin, and quantify the groundwater that is available in these areas. In order for groundwater resources to be accurately quantified, it must be presented with levels of assurance of supply and from these rates a wellfield can be developed whereby guidelines should be followed to obtain an optimum design in order to avoid over abstraction. Recommendations have been provided regarding further work and expansion to be undertaken in each of these tools and models.en_ZA
dc.description.abstractAfrikaans: Hierdie Meesters tesis vorm die ontwikkelings komponent van die Waternavorsingskommisie (WNK) projek nommer KS/1763, getiteld "Die identifisering en afbakening van hoë-lewerings grondwater produksieveld gebiede in Karoo akwifere as toekomstige opsies vir water voorsiening aan plaaslike owerhede". Die projek is begin as gevolg van die behoefte om die aansienlike kennis van die grondwater van die Karoo Kom binne die grense van water hulpbron beplanning te plaas. Die steeds groeiende kwessies in verband met water hulpbronbeplanning sluit nie net die uitdaging om die grondwater hulpbronne te vind nie, maar ook die kwantifisering van hierdie hulpbron in terme wat maklik verstaanbaar is deur hidrogeoloeë asook ander verwante beroepe. In 'n poging om hierdie kwessies aan te spreek, word 'n metode om grondwater hulpbronne te kan identifiseer asook te kwantifiseer in hierdie tesis beskryf en word die konsep van versekering van lewering van water ook ingesluit. Hierdie metode behels die gebruik van verskeie hulpbronne, sommige is reeds bestaande en geredelik aan die publiek beskikbaar, ander mag slegs beskikbaar wees in die spesifieke area van belangstelling (bv. aeromagnetiese beelde), en die res is ontwikkel as deel van die WNK-projek en word krities hersien in hierdie tesis. Die ontwikkeling van die Grondwater Geleidings Kaart in hierdie tesis het beide bestaande boorgat lewerings asook die geologie in ag geneem, en bied 'n reeks van moontlike grondwater geleidings waardes in beide tabel vorm asook op kaarte. Die reekse is vir elke hidrogeologiese eenheid (gebaseer op litologieë en in sommige gevalle, onderverdeelde litilogieë) doleriet gange en plate, gefraktuurde kantlyne van plate en gebiede van dik alluvium. Woodford se metode was gebruik, gevind in Dondo et aI., 2010; wat dan geëkstrapoleer is oor die Hoof Karoo Kom. Hierdie kaart is die mees gedetaileerde kaart van die Hoof Karoo Kom en, afgelei uit die gevallestudies wat voorgelê is, blyk dit asof 'n redelike raming van grondwater geleidings waardes voorgelê word. Die "Aquifer Assured Yield Model" (AAYM) was vir 'n groot aantal kwaternêre opvangsgebiede, verspreid oor die Karoo Kom, gehardloop om die model se geloofwaardigheid te toets, asook om parameter waardes voor te stel wat per area of dreinerings-kom gebruik kan word. Die AAYM het goed vergelyk met ander databasisse, naamlik die HP en GRAII AGEP. Dit kom voor asof hierdie werk die eerste gedokumenteerde benadering tot grondwater kwantifisering met vlakke van versekering is en moet dus as In "werk-in-ontwikkeling" gesien word omdat dit 'n herhalende proses van ontwikkeling, toetsing, verandering en her-toetsing vereis. Die Grondwater Produksie Veld Model was suksesvolop die basis van die Cocper-Jacob vergelyking (Cooper & Jacob, 1946) ontwikkel. Deur die toetsing van die model is die verhoudings van boorgat spasiëring met grondwater geleidings waardes ondersoek in In poging om In riglyn vir die ontwerp van In grondwater produksie veld met sekere boorgat interferensie beperkings te vind. Benewens hierdie, is die duidelike aard van grondwater vloei in gange oorweeg deur te verwys na die Boonstra-Boehmer vergelyking (Kruseman & de Ridder, 1992), waarvolgens In sekere toename in boorgat spasiëring vereis word wanneer 'n boorgat op In gang geleë is. Hierdie model kan mens in staat stelom die ontwerp en manipulasie van In grondwater produksie veld voor te stel en die effek van grondwater onttrekking op grondwater aftrekking kan ge-evalueer word en daardeur kan die model help om die mees optimale grondwater produksie veld te ontwerp. Die metodologie wat toegepas is op di gevallestudies demonstreer die praktiese toepassing van die hulpbronne en modelle soos hierbo beskryf. Die doel van die gevallestudies was om die grondwater lewerings assesserings metodes toe te pas op areas met bekende akwifeer parameters en lewerings. Die lewering assesserings metodes was in terme van hul akkuraatheid en praktiese sin ge-evalueer en die resultate is met ander bestaande lewerings assesserings hulpbronne en veld data vergelyk. Die gevallestudies het gewys dat die nuut geproduseerde geologiese kaarte en die Watergeleidings Kaart baie maklik in samewerking met satellietbeelde gebruik kan word om nuwe potensiële boorgate en grondwater produksie velde te identifiseer. In die algeheel bied hierdie tesis In stap vir stap metodologie om hoë grondwater potensiaal gebiede in die Hoof Karoo Kom te identifiseer en af te baken, en om die grondwater wat beskikbaar is in hierdie areas te kwantifiseer. Ten einde die grondwater hulpbronne akkuraat te kwantifiseer, moet dit voorgestel word met vlakke van versekering van lewering en van hierdie lewerings kan 'n grondwater produksie veld ontwikkel word waarby riglyne gevolg moet word om optimale ontwerp te verseker wat die oor-onttrekking van grondwater uit die grondwater produksie velde te voorkom. Aanbevelings is ten opsigte van verdere werk en die uitbreidings wat onderneem moet word in elkeen van hierdie hulpbronne en modelle.en_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectAquifers -- South Africa -- Karooen_ZA
dc.subjectGroundwater -- South Africa -- Karooen_ZA
dc.subjectWellhead protection -- South Africa -- Karooen_ZA
dc.subjectWater table -- South Africa -- Karooen_ZA
dc.subjectHydrologyen_ZA
dc.subjectDissertation (M.Sc. (Institute for Groundwater Studies))--University of the Free State, 2011en_ZA
dc.titleThe identification and delineation of high-yielding wellfield areas in Karoo Aquifers as future water supply options to local authoritiesen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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