Groundwater resource assessment for development and use in Jozini, KwaZulu-Natal
| dc.contributor.advisor | Gomo, M. | |
| dc.contributor.author | Mofokeng, Setjhaba Seromo Ignatius | |
| dc.date.accessioned | 2018-09-20T08:29:28Z | |
| dc.date.available | 2018-09-20T08:29:28Z | |
| dc.date.issued | 2017-12 | |
| dc.description.abstract | English: Due to a shortage of surface water, coupled with the current drought situation that has befallen South Africa, groundwater plays an important role in the water supply for domestic users; mostly for the rural communities in South Africa. Groundwater resource assessment aims to obtain significant data and information required to describe the hydraulic and chemical parameters for the estimation of the available groundwater resource suitable for human consumption. A study was undertaken for groundwater resource assessment for the rural town of Jozini in Northern KwaZulu-Natal, South Africa. The field investigations included the use of geophysical methods, and for this study magnetic (G5 Proton magnetometer), together with electromagnetic methods (Geonics EM 34-3 system) were chosen as the preferred methods. The reason for the magnetic method was because it is easy to operate, analyse and interpret the anomalies from a possible structure such as a dolerite intrusion. On the other hand, the electromagnetic method was chosen, because it determines the resistivity of the rock, and the resistivity of variations with depth and lateral extent of geological structures, whereupon these variations are then interpreted to identify the drilling targets. Based on the results of the geophysics, drilling targets were sited, and seven boreholes were drilled using rotary percussion air drilling. Blow yields for the newly drilled boreholes ranged between 0.14-2.28 l/s, which is an indication of low yielding to moderately yielding boreholes. An aquifer pumping test was conducted on all newly drilled boreholes and existing four boreholes, for the duration of between 9 hours and 22 hours. Pumping test for the existing boreholes was conducted by another external consulting company, during their refurbishment. The aquifer parameters were estimated using the Cooper-Jacob (1946) method and the Theis recovery (Theis, 1935) method. The general groundwater flow in the study area is from both the fractures and from the matrix, as seen from other boreholes. The combined yield of 0.95l/s (0.0821 ML/d) was estimated from all eleven boreholes (seven newly drilled and the four existing boreholes). These sustainable yields are very low and cannot sustain the requirement in the study area. The groundwater quality assessment reveals that there are two dominant water types in the study area namely: the NaCl water type (42%) and the Na-HCO3- water type (28%), other samples show a mix of water types. The conclusion was therefore made that although the area is characterised by low yielding boreholes, the municipality with the help of the DWS should drill more boreholes which will supplement the existing and newly drilled boreholes. It is then recommended that when drilling boreholes for water supply in the study area, the host rock (rhyolite) or the intrusion should be targeted as these areas have shown to have a bit higher yields than the boreholes which were drilled targeting the contact between the host rock and the intrusion. | en_ZA |
| dc.description.abstract | Afrikaans: As gevolg van 'n tekort van oppervlak water, tesame met die huidige droogte situasie wat Suid-Afrika, het speel grondwater 'n belangrike rol in die watervoorsiening vir huishoudelike gebruikers; meestal vir die landelike gemeenskappe in Suid-Afrika. Grondwater en grondwaterbronne poog betekenisvolle data en inligting wat vereis word om te beskryf die hidroliese en chemiese parameters vir die skatting van die beskikbare grondwater bronne wat geskik is vir menslike verbruik te bekom. 'N studie is onderneem vir grondwater grondwaterbronne vir die landelike dorp van Jozini in noordelike KwaZulu-Natal, Suid-Afrika. Die veld ondersoeke sluit in die gebruik van Geofisiese metodes, en vir hierdie studie magnetiese (G5 Proton magnetometer), tesame met elektromagnetiese metodes (Geonics EM 34-3 stelsel) is gekies as die verkose metodes. Die rede vir die magnetiese metode was, want dit is maklik om te bedryf, ontleed en interpreteer die anomalieë uit 'n moontlike struktuur soos 'n dolerite indringing. Aan die ander kant, die elektromagnetiese metode is gekies, want dit bepaal die resistivity van die rots, en die resistivity van variasies met diepte en laterale omvang van geologiese strukture, waar hierdie variasies word dan geïnterpreteer identifiseer die boor teikens. Gebaseer op die resultate van die verlengde, boor teikens was geplaas, en sewe boorgate geboor was gebruik roterende percussion lug boor. Blaas opbrengste vir die nuut geboor boorgate gewissel tussen 0.14-2.28 l/s, wat 'n aanduiding van lae opbrengs te matig opbrengs van boorgate. 'N waterdraer pomp toets is gedoen op alle nuut geboor boorgate en bestaande vier boorgate, vir die duur van tussen nege ure en twee en twintig ure. Die bestaande boorgate is egter pomp getoets en word deur 'n ander eksterne konsultasie maatskappy, terwyl hulle hulle opknapping was. Die waterdraer parameters was na raming gebruik die Cooper-Jacob (1946) metode en die Theis herstel (Theis, 1935) metode. Die algemene grondwater vloei in die studiegebied is van beide die frakture en uit die matriks, soos gesien vanaf ander boorgate. Die gesamentlike opbrengs van 0.95 l/s (0.0821 ML/d) was na raming van al elf boorgate (sewe nuut geboor en die vier bestaande boorgate). Hierdie volhoubare opbrengste is baie laag en die vereiste in die studiegebied te kan onderhou. Die grondwater kwaliteit assessering onthul dat daar is twee dominante water tipes in die studiegebied naamlik: die NaCl water tipe (42%) en die Na-HCO3-water tipe (28%), ander monsters wys 'n mengsel van water tipes. Die slotsom wat bereik is dat alhoewel die gebied gekarakteriseer is deur boorgate wat ñ lae obrengs lewer, the munisipaliteit, met die hulp van Departement van Water & Sanitasie (DWS)meer boorgate moet boor wat die bestaande & nuwe boorgate sal aanvul. Dit word dan aanbeveel dat wanner boorgate in die omgewing geboor word, die gasheer rots (rioliet) of dat die inmenging geteiken sal word omdat hierdie areas bewys het dat dit ñ hoër opbrengs lewer as die boorgate wat geboor was tussen die gasheer rots & die inmenging. | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11660/9324 | |
| dc.language.iso | en | en_ZA |
| dc.publisher | University of the Free State | en_ZA |
| dc.rights.holder | University of the Free State | en_ZA |
| dc.subject | Groundwater occurrence | en_ZA |
| dc.subject | Aquifer hydraulic | en_ZA |
| dc.subject | Borehole sustainable yields | en_ZA |
| dc.subject | Hydrogeochemical processes | en_ZA |
| dc.subject | Groundwater quality | en_ZA |
| dc.subject | Dissertation (M.Sc. (Institute for Groundwater Studies))--University of the Free State, 2017 | en_ZA |
| dc.title | Groundwater resource assessment for development and use in Jozini, KwaZulu-Natal | en_ZA |
| dc.type | Dissertation | en_ZA |