Browsing by Author "Chuma, Constant"

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    Application of Remote Sensing and Geographical Information Systems in Determining the Groundwater Potential in the Crystalline Basement of Bulawayo Metropolitan Area, Zimbabwe
    (Scientific Research, 2013) Chuma, Constant; Hlatywayo, Dumisani J.; Orimoogunje, Oluwagbenga O.I.; Akinyede, Joseph O.
    This study is concerned with the identification and delineation of aquiferous zones for potential groundwater development across Bulawayo Metropolitan from remotely sensed data and geological inference. Attempts have been made to review literatures on groundwater exploitation in the study area and the constraints to effective and sustainable management of underground water in the study area. Remote Sensing and Geographical Information Systems (GIS) is useful in the recognition and delineation of aquiferous zones for potential groundwater in crystalline basement aquifers. LANDSAT ETM+ image, SRTM data, aeromagnetic data and other ancillary data sets were utilized to extract information on the groundwater storing controlling features of this study area. Six thematic maps were produced from remote sensing data and other ancillary data - Land use/landcover, drainage density, slope map, contact density, lithology and lineament density. GIS modeling technique of the index overlay method was used to produce the groundwater potential map. The study revealed that the regional lineaments correlate with faults, fracture zones, and lithological contrasts along fold belts in the crystalline basement rocks, while the main direction of faulting and jointing is north-north-west to north with several faults oriented, to the north-north-east, parallel to the Great Dyke. Proximity to lineaments is the highest zone of increased porosity and permeability which in turn have a greater chance of accumulating groundwater. The results have shown massive spatial variability of ground water potential ranging from very good to poor. The variability closely followed variations in the structures, geology, topography/slope, drainage density and land use/land cover in the project area. This work is a reconnaissance which needs to be validated by the use of high-resolution terrain data and satellite imagery and the quantitative analysis should be done using geophysical and hydrogeological surveys.
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    A comparison of crystalline basement aquifers and Kalahari aquifers in exploration of groundwater occurrence in Zimbabwe
    (2016-07) Chuma, Constant; Hlatywayo, Dumisani J.; Midzi, Vunganai; Gumbo, Mervyn; Muchingami, Innocent; Mashingaidze, Robin T
    Exploration of groundwater occurrence becomes complex if there is inadequate information to explain the its dynamics. The paper compares the major aquifers found in Zimbabwe in order to maximise the exploration of groundwater in the semi-arid regions. Geophysical and geospatial tools have proved to be useful tools in divining for groundwater in different geological settings. Crystalline basement aquifers are characterised by impervious rock which confines water in the upper layers whilst Kalahari sands provide high yielding unconsolidated aquifers. Transmissivity and conductivity decreases with depth in crystalline whilst the reverse is true for Kalahari sands.
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    Modelling the Subsurface Geology and Groundwater Occurrence of the Matsheumhlope Low Yielding Aquifer in Bulawayo Urban, Zimbabwe
    (Canadian Center of Science and Education, 2013-08) Chuma, Constant; Hlatywayo, Dumisani J.; Zulu, Joseph; Muchingami, Innocent; Mashingaidze, Robin T.; Midzi, Vunganai
    This study is focused on determining the nature, extend and spatial variation of the subsurface and groundwater in the Matsheumhlope low yielding aquifer so as to improve the understanding of groundwater occurrence within Bulawayo Metropolitan area. The abstraction and utilisation of groundwater from crystalline basement complexes have often been hampered by the high rate of borehole failure. For instance, borehole failure in the Matsheumhlope wellfield that characterises the greater part of Bulawayo City, Zimbabwe, is often ascribed to many factors which are yet to be investigated locally and regionally. The electrical resistivity method was used to establish the depth, thickness and sequence of geological units in the low yielding aquifer. Satellite data were used to delineate the lineaments and assess the topographic features of the area. Geological samples obtained from boreholes were correlated with the geophysical pseudo sections to give a better view of the subsurface and groundwater occurrence in the area. Geographic Information Systems (GIS) was used to model the geophysical characteristics of the subsurface giving the potential groundwater occurrence in the area. The study confirmed that the Matsheumhlope aquifer is a heterogeneous unconfined aquifer with a shallow depth to the basement rock in highlands of the study area. The results also showed high spatial variation of subsurface formations and groundwater potential over short distances, thereby indicating the complex nature of mapping basement aquifers. Borehole failure in the area was attributed to the occurrence of shallow depth of the bedrock underlying some parts of the aquifer. Therefore the results of the study recommended that the structural and geodynamic analysis of the fractures of the whole Matsheumhlope aquifer should be done using both structural mapping and geophysical methods.
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    Modelling the subsurface geology and groundwater occurrence of the Matsheumhlope low yielding aquifer in Bulawayo urban, Zimbabwe
    (Canadian Center of Science and Education., 2013-08-19) Chuma, Constant; Hlatywayo, Dumisani J.; Zulu, Joseph; Muchingami, Innocent; Mashingaidze, Robin T.; Midzi, Vunganai
    This study is focused on determining the nature, extend and spatial variation of the subsurface and groundwater in the Matsheumhlope low yielding aquifer so as to improve the understanding of groundwater occurrence within Bulawayo Metropolitan area. The abstraction and utilisation of groundwater from crystalline basement complexes have often been hampered by the high rate of borehole failure. For instance, borehole failure in the Matsheumhlope wellfield that characterises the greater part of Bulawayo City, Zimbabwe, is often ascribed to many factors which are yet to be investigated locally and regionally. The electrical resistivity method was used to establish the depth, thickness and sequence of geological units in the low yielding aquifer. Satellite data were used to delineate the lineaments and assess the topographic features of the area. Geological samples obtained from boreholes were correlated with the geophysical pseudo sections to give a better view of the subsurface and groundwater occurrence in the area. Geographic Information Systems (GIS) was used to model the geophysical characteristics of the subsurface giving the potential groundwater occurrence in the area. The study confirmed that the Matsheumhlope aquifer is a heterogeneous unconfined aquifer with a shallow depth to the basement rock in highlands of the study area. The results also showed high spatial variation of subsurface formations and groundwater potential over short distances, thereby indicating the complex nature of mapping basement aquifers. Borehole failure in the area was attributed to the occurrence of shallow depth of the bedrock underlying some parts of the aquifer. Therefore the results of the study recommended that the structural and geodynamic analysis of the fractures of the whole Matsheumhlope aquifer should be done using both structural mapping and geophysical methods.