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The investigation of groundwater potential zones in the Neotectonic area of Ntabankulu Local Municipality, Eastern Cape Province, South Africa

  • Authors: Nonkula, Zenande https://orcid.org/0000-0002-3858-7703
  • Date: 2021-09
  • Subjects: Groundwater , Water-supply , Neotectonics
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10353/22875 , vital:53068
  • Description: Ntabankulu extends from latitude 30° 51' 09"S to 31° 09' 10" S and from longitude 29° 06' 51"E to 29° 23' 49"E in the Eastern Cape Province of South Africa. Ntabankulu Local Municipality has 141 villages with 125 976 population size. About 36% of villages do not have water sources, 38% have partial functional water sources, 6% have non-functional water sources, and 20 % have reliable water sources, primarily rivers (Mnceba, Caba and Mzimvubu). Water is scarce in this area, especially in the dry season when perennial rivers and springs become dry. This research investigates groundwater potential zones and identifies suitable aquifers that can be developed to augment the water resources. The study involved: literature review, remote sensing, borehole and springs data, geological, petrographic and geophysical (gravity, magnetic and electrical resistivity) analyses. Each method has its purpose in finding the potential groundwater zones. Ntabankulu Local Municipality is located on the Karoo Supergroup in Ecca and Beaufort Group, Adelaide Subgroup and Balfour Formation. During field analysis, it was observed that this area consists of sandstone, shale and dolerite sills, dykes and complex rings. Fining up sequences, massive bedding, concretions, and spheroidal weathering were observed in sandstone, shale, and dolerite, respectively. Groundwater seepages are found within these structures. Sandstones are yellow due to the presence of limonite because of the continuous seepage. Red coloured laminated shale reflects that the rock has an iron oxidation state with hematite (Fe2O3) on the sediments. The Geographical Information Systems (GIS) method was used to extract lineaments. Lineaments dominate Ntabankulu with an NW-SE direction. Some of the lineaments are due to Karoo igneous intrusions, and others are due to neotectonic activities. Ntabankulu is located on the eastern and northern neotectonic belts. Geological maps and lineament maps were compared; it was observed that sandstones and shales are found on high liinament density areas. High yielding boreholes and springs coincide with lineaments, and some lineaments are faults. Hence areas that have high lineaments density could be groundwater potential zones. There are geological structures (faults, joints, and fractures) that are present. Systematic and non-systematic joints are found on sandstones which are due to extensional stress. These joints have been reactivated and acted as strike-slip faults. All these geological structures increase the porosity and permeability of the rocks. It was observed that the area of Ntabankulu consists of coarse-grained and medium-grained sandstone with quartz and orthoclase minerals. Dolerite consists of labradorite, clinopyroxene, olivine, oxide minerals with twinning formed during cooling and magma crystallisation. The gravity and magnetic methods were used to study the subsurface rock density contrasts and susceptibilities, respectively. The gravity and magnetic maps were generated in Geosoft Oasis 8.3 software. High gravity zones coincide with some of the mapped Karoo intrusions. Unmapped dolerite intrusions, lineaments and faults were inferred. The magnetic method delineated the subsurface structures (lineaments and faults), which are known to control groundwater accumulation. These structures and inferred dolerite intrusions helped in identifying groundwater potential zones. Groundwater potential zones were inferred in sedimentary rocks between dolerite intrusions and areas where sills and dykes intersect. A total of six vertical electrical soundings (VES) were conducted at Mzalwaneni and Tabankulu town areas using the Schlumberger configuration array with a maximum penetration depth of about 25- 33 m. The VES data were modelled in Winresist and Surfer 9 software to obtain 1D models and geoelectric sections, respectively. These 1D models have three layers with response curves of H-type. The top layer is about 0.4 - 0.7 m thick, with resistivity values from 12.3 – 1885.9 Ωm and is topsoil (sand and clay). The second layer of thickness 5.2 – 13.3 m has low resistivity values from 23.1- 44.9 Ωm. This layer is interpreted to be fractured shales and sandstones possibly containing water. The third layer of high resistivity values of 145.9 – 727.4 Ωm is inferred to be sandstone. The simultaneous interpretation of resistivity and normalised chargeability revealed that groundwater potential zones are characterised by low resistivity values and low normalised chargeability values for layers from 0.7 - 13.3 m depth. The groundwatwer in the area of Ntabankulu can be found on unconfined aquifers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
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  • Date Issued: 2021-09

Vulnerability assessment of wetland ecosystems to water demand, climate variability and land-use/cover change: The case of Die Vlei wetland, Eastern Cape province, South Africa

  • Authors: Gwena, Kudzanai Rosebud https://orcid.org/0000-0002-1032-8937
  • Date: 2021-09
  • Subjects: Water-supply , Climate change mitigation
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10353/22688 , vital:52656
  • Description: Water scarcity is a major challenge in many different countries, particularly arid and or semi-arid like South Africa. Wetlands are one of the freshwater ecosystems that may assist in alleviating water scarcity because they are valuable not only as a water source for humans but also as an ecosystem of animals and plant species. However, wetlands have been experiencing rapid rates of vulnerability/risk due to alterations by population growth leading to enhanced water demand, climate variability, and human activities leading to land cover/land-use changes. Geographical Information Systems (GIS) and Remote Sensing (RS) are less financially taxing methods useful in studying water scarcity, as shown in this study. The study begins with a literature review presentation based on a desk study from predominantly academic publications and additional municipal and consultancy reports on the wetland ecosystem’s vulnerability/risk and focuses on applying GIS & RS in related studies. After that, the study conducts a vulnerability assessment using the Ramsar Convention’s wetland vulnerability assessment using the theoretical framework stages using GIS and RS technologies. The study hypothesizes that water demand, climate variability, and land-use/cover changes (LULC) are the tri-factor responsible for wetland vulnerability. It begins the assessment by first quantifying wetland water demand using the wetland water budget, ecosystem services and the Penman-Montheith-FAO (ETo) evapotranspiration index. Secondly, objectively representing climate variability on wetland vulnerability using trend analysis to measure rainfall and temperature variability. Thirdly, reconstructing LULC changes from multi-date remotely sensed SPOT imagery over ten years from 2007 to 2017 to identify and monitor impacts of trends. The vulnerability was assessed through a Principle Component Analysis (PCA) that identified relevant variables and Multi-Criteria Evaluation (MCE) to evaluate the wetland’s exposure. The study concludes that there is evidence of a possible increase in water demand whilst climate variability, which is estimated to have a 39% contribution to the wetland dynamics, is characterised by a decrease in precipitation and an increase in temperatures. Lastly, LULC trends showed a marked increase in domestic and commercial farming, and farming has been identified as a wetland stressor of note. , Thesis (MPhil) -- Faculty of Science and Agriculture, 2021
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  • Date Issued: 2021-09

An assessment of service delivery challenges: Intsika Yethu Municipality

  • Authors: Shasha, Zamuxolo
  • Date: 2012
  • Subjects: Government productivity -- South Africa -- Eastern Cape -- Evaluation , Municipal services -- South Africa -- Eastern Cape , Water-supply
  • Language: English
  • Type: Thesis , Masters , MPA
  • Identifier: vital:8272 , http://hdl.handle.net/10948/d1015965
  • Description: This study assesses service delivery challenges in Intsika Yethu Municipality with reference to water and electricity. This report presents the findings of a study conducted to identify the service delivery challenges related to the provision of basic services such as water and electricity, together with the recommendations on how these challenges can be resolved. This study was prompted by the huge number of backlogs experienced regarding water and electricity as well as complaints of non-service delivery and little understanding of the programme and plans within Intsika Yethu Municipality. The results of this study show that the communities do not fully participate in their development planning processes and they do not understand the purpose and existence of IDP document. The researcher hopes that this study will sensitise the community to participate in the affairs of their development that will change the quality of their lives. Intsika Yethu Municipality should improve their strategies and consultation structures in the implementation of water and electricity projects as well as the IDP processes.
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  • Date Issued: 2012

Investigation of local institutions for the application of the in-field rain water harvesting technology in rural areas: the case of Guquka and Khayaletu in Nkonkobe Municipality in central Eastern Cape

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