ETD Collection

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Now showing 1 - 5 of 5
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    The Southward spread of Johannesburg and its impact on precolonial stone walled structures
    (2018) Naidu, Saireeni Latisha
    There are thousands of Stone Walled Structures (SWS) located in the southern half of the Gauteng Province. In the absence of relevant historical documents, these SWS are all the information we have about how pre-colonial societies were organized in this area. Unfortunately, they are threatened by rapid urbanization and development. This research attempts to estimate how many Iron Age SWS have been lost to urban development in Johannesburg South during the last 80 years. I mapped and quantified the SWS and urbanization in four chronological snapshots using remote sensing techniques. Aerial photographs from 1937 and 1961 were used as well as Google Earth satellite images from 2005 and 2015. The data was analyzed on the ESRI software ArcGIS 10.3. The four snapshots show the trend in urban sprawl and destruction of SWS and this information is valuable for mitigation strategies. Fortunately, there are legislations and procedures in place to ensure that not all these sites are lost forever.
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    Using geographical and malaria information systems for enhanced malaria control
    (2009-05-20T13:32:30Z) Coleman, Marlize
    ABSTRACT Introduction The use of information systems to understand the dynamics of malaria disease and inform decisions on control proved valuable to a malaria control programme. Development of simple practical and sustainable information system tools has been slow in coming for many resource-poor environments. This thesis addresses many issues relating to the conceptual development and implementation of simple tools and their integration into operational malaria control to support decision making and advocacy. Methods A basic Microsoft Access malaria data collection and repository tool has been in existence since 1997 focussing mainly on case reporting alone. Better utilization of data and further expansion to include outbreak identification and response, cluster detection and intervention monitoring has been the main focus over time. Eight years of retrospective malaria case data from Mpumalanga Province, South Africa were used to explore disease dynamics including spatial as well as temporal variation in malaria epidemiology. The identification of specific risk areas and the confirmation of the unstable nature of malaria occurrence lead to the conceptualization and development of an outbreak model using binomial statistics. The novel three tier outbreak identification and response system was field tested over a two season period to establish acceptance and the ability to direct resources in times of elevated case loads. Comparison against other existing malaria outbreak systems was conducted. SaTScan freely available software was used to detect spatial and spacetime disease clusters within towns in the highest risk area of the province. A malaria case control study was conducted in seven localities/towns/villages to explore risk and protective characteristics of household structure and practices, including the use of impregnated nets. The micro economic status of households as a determinant of malaria risk was also explored. A spray operations component as part of the malaria information system was developed and implemented during the time to allow for routine monitoring and historical exploration of indoor residual spray activities. Results Retrospective malaria case data analysis identified heterogeneity of malaria risk in the Province and spatial analysis identified significant clusters at small geographical area resolution rejecting the hypothesis that malaria is homogeneously distributed over space and time. The importance of intervention monitoring to identify low coverage areas, over or under application of insecticides, and assessment of the productivity of spray operators was identified. The outbreak identification and response system was successfully implemented, integrated and sustained with a set of response activities developed for implementation at defined threshold levels. The outbreak systems can be considered for utilization in other low transmission settings.Results of the case control study indicated that malaria risk was associated with living in traditional housing and the practice of re-opening windows at night when peak biting behaviour of the main mosquito vector, Anopoheles arabiensis is expected. Higher household socio economic status (SES) profile was associated with a lower risk of malaria. Conclusions The conceptualization, development and implementation of operationally feasible malaria information management tools in a rural African environment proved useful for enhancing malaria control. The novel malaria outbreak identification and response, cluster detection as well as the spray monitoring systems were successfully implemented and adopted as an integral part of the routine malaria control programme monitoring and surveillance system. This research has enabled more informed real-time decision-making for effective programme management.
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    Using spatial rainfall and products from the MODIS sensor to improve an existing maize yield estimation system
    (2008-08-07T13:54:35Z) Frost, Celeste
    Abstract After deregulation of the agricultural markets in South Africa in 1997, the estimated maize crop could no longer be verified against the actual crop, due to the lack of control data from the Maize Control Board. This drove the need to explore remotely sensed data as a supplement to the current crop estimation methodology to improve crop estimations. Input data for the development of a Geographic Information System (GIS)-based model consisted of objective yield point data, Moderate Resolution Imaging Spectroradiometer (MODIS) Normalised Difference Vegetation Index (NDVI) images and rainfall grids. Rainfall grids were interpolated from weather station data. NDVI values were obtained from the MODIS sensor aboard the Terra platform. Objective yield point field survey data for the 2001/2002 growing season were utilised since dry-land or irrigated conditions were recorded for that season. MODIS NDVI values corresponded well with the growing stages and age of the maize plants after being adjusted to reflect the crop’s age rather than the Julian date. Rainfall values were extracted from rainfall grids and also aligned with the age of the maize plants. This is a suggested alternative to the traditional method of using the mean NDVI for several districts in a region over a Julian growing period of 11 months according to Julian dates. South African maize production areas extend over seven (7) provinces with eight (8) different temperature and rainfall zones (du Plessis, 2004). Planting-date zones based on the uniform age of the maize plants were developed from objective yield Global Positioning System (GPS) points for the 2001/2002 growing season and compared with the 2004/2005 growing season (Frost and Kneen, 2006). Planting dates were interpolated from these planting zones for objective yield GPS points which were missing planting dates in the survey database. MODIS imagery is affordable (free) and four (4) images cover the whole of South Africa daily, while one (1) image covers the study area daily. Several recommendations, such as establishing yield equations for a normal, dry, and wet season were made. It is also suggested that dry-land and irrigated areas continue to be evaluated separately in future.
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    Using information and communications technology to improve the efficiency and accuracy of a utility's network data collection business process
    (2007-02-15T11:19:22Z) Van Olst, Rex
    “You can see the computer age everywhere except in the productivity statistics”. This offhand remark by Robert Solow, the Nobel prize-winning economist [1] has stimulated many other economists to conduct more rigorous analyses on the impact of information technology on productivity. The research presented in this dissertation has been conducted on a large telecommunications utility. An important business process of the utility, that of collecting information on its geographically dispersed network assets, was automated using mobile computing and wireless technologies. The research compared this newly developed automated process with the current, manual, process of sourcing the field network asset data using paper-based templates, and capturing the data manually from the templates. The results of the pilot for this automated business process were encouraging and demonstrated an improvement of over 50% in the productivity of the data collection process, and its integrity. An important aspect of the research outlined in this dissertation was to design and implement the mobile computer-based electronic data collection prototype to minimise user obstruction to the technology deployed. The prototype was tested for technology acceptance by the targeted field workers. This test also proved successful. The research demonstrated that an improvement in productivity of over 50% was achievable from a well-considered investment in information technology. The results from the research also pointed the way for the deployment of this data collection solution in other utilities, e.g. electricity distribution, water reticulation, and municipalities. Through user prototype tests and a cultural intervention process on the targeted users (field workers), the research also demonstrated how the automated business process can be geared for use by low-skilled field workers, so important to improve productivity in developing economies such as those in Africa.
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    GIS and Water Utilities: the case of Johannesburg Water
    (2006-11-16T12:47:03Z) Woghiren, Lawrence
    This research report focuses on the implementation of Geographical Information Systems (GIS) in Johannesburg Water, the water utility of the City of Johannesburg Metropolitan Council. The research contributes to a broader debate on the implementation of GIS technology in private and public institutions. While this research field has a long and reasonably strong tradition in the developed world, research on GIS and organisations in the developing world is in its infancy. Based on interviews with a range of personnel in Johannesburg Water the research provides an assessment of the history of GIS implementation in this institution. The history, which begins in the 1980s, examines the development of the technology in Johannesburg Water focusing on the experiences of staff and various software and hardware choices. The research also examines current implementation issues and the impact of GIS in decision-making in this organisation. Finally, the research assesses the implementation of GIS in Johannesburg Water in relation to various theories of, and approaches to, GIS implementation.