3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item Reconstructing the history of urban development in the mining town of Virginia, Free State between 1940 and 2015(2017) Ajayi, Paul OluwanifemiThe nature of urban development experienced by mining towns across the world has been a subject of concern among urban planners because of its transitory nature. Most times mining towns develop gloriously into booming urban centres that create employment, generate wealth and satisfaction. All these fades into oblivion as soon as the mines get depleted. Mining towns often go through a number of urban processes which have been considered an expression of ‘infrastructural violence’ especially in the earlier stage of urban growth, and continually persists throughout the town’s life span. This research sought to reconstruct the history of urban development in the mining town of Virginia, Free State, and to quantify the manifestations of infrastructural violence throughout its timeline using GIS and remote sensing. Hence, land use and land cover maps were produced from aerial photographs, topographical maps and Landsat images through manual on-screen digitizing and classification using supervised support vector machine algorithms. Land use change detection analysis was conducted on the produced images using the cross classification and tabulation tool of QGIS 2.18.4 and the post classification tool of ENVI 5.3. Landscape metrics were employed to calculate the dimensions of growth and change experienced by all the land use classes during the timeline under study. Results obtained from this study confirmed the thoughts and findings of several theories vis a vis the nature of mining towns. Results reveal a rapid growth in the urban formal land use class up until 1995 with urban expansion and sprawl happening in the years between 1986 and 1995 with metrics of CA, NP and ED multiplying to twice their initial values ten years earlier. The urban informal land use class also experienced its subtle growth throughout the timeline of the study with its own urban expansion also happening between 1986 and 1995 with double increase in CA, NP and ED metric values. However, unlike the formal class that experienced decline after this period of urban expansion, the informal class continued to experience growth up until the end of the study period. Infrastructural violence was measured using the fractal dimension index (AWMPFD) of the landscape metrics for the formal and informal LU class. The results reveal continuous fragmentation throughout the period of study but with higher values in the years in which urban development started.Item Assessment of changing urban dynamics in Johannesburg city regions as consequence of re-mining of the tailings dumps using Geographical Information System and remote sensing(2017) Mahao, Tseliso JohnThere is a growing interest in the reclamation of the old gold mines’ tailings dumps in Johannesburg city region driven by the economic value of the remaining gold resource. This reclamation activity is accompanied by various rehabilitation methods to reduce issues such as acid mine drainage and wind pollution. The impact of land use and land cover change (LULCC) can have an enormous impact on land development and planning. Monitoring of LULCC is very important in the planning and decision making processes. Remote sensing (RS) as the source of basic data for monitoring change is very highly recommended as tool to monitor changes occurring in the Johannesburg City Region as a result of rehabilitation and reclamation of the gold mines’ tailings deposits. The main aim of the study is to understand how the reclamation and rehabilitation of the historical tailings dumps in Johannesburg are changing land use patterns of the city and its precincts. The objectives are to quantify the changes in land use and land cover as the results of mining rehabilitation using Landsat earth observation data over a period of 30 years at five years intervals and; to recommend on how the land cleared of waste dumps could be used for looking at the surrounding environment spatially. Various Geographical Information Systems techniques are applied here for change detection analysis and monitoring of potential changes in urban dynamics patterns. The results show rate of rehabilitation and reclamation to be slow, taking several years to see a meaningful change. There is some form of bias towards transforming the reclaimed land into industrial zones as opposed to other activities. The success of tailings dumps rehabilitation through revegetation process is highlighted.