Cape Town International Airport (CTIA) is located along the extreme southern portion of the west coast of South Africa which has the highest frequency of fog in the country. Fog occurs more frequently at CTIA than at any other of the international airports in South Africa. Fog forecasting research in South Africa has largely been neglected and fog forecast verification results show the urgent need for improvement. Accurate fog forecasts are imperative for the aviation industry to prevent costly flight delays and diversions. The main aim of this research is to improve the forecasts of fog at CTIA. The first step towards realising this aim is to provide aviation forecasters with a comprehensive fog climatology that encompasses all aspects of fog: from the seasonal characteristics, to detail regarding the types of fog that frequently occur, synoptic circulations associated with fog and characteristics of the vertical profile of the lower troposphere and boundary layer in which fog forms. Fog types at CTIA are classified by means of an objective hierarchical classification method that takes the formation mechanisms of fog into consideration. Self Organising Maps (SOMs) are used as a synoptic typing method, to determine the synoptic circulations that are most frequently associated with fog at CTIA. Case studies are presented to illustrate the formation mechanisms of 5 different fog types by means of the synoptic circulation, surface observations, satellite imagery and atmospheric soundings. Conclusions drawn from these case studies can assist forecasters with the identification of potential fog events in advance. It is recommended that climatology and case study results be made available to aviation forecasters at CTIA and that similar studies be conducted for all international airports in South Africa that are frequently affected by fog. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Geography, Geoinformatics and Meteorology / unrestricted

Thesis (MA)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The noise produced by aircraft during operations around airports represents a senous social, technical, economic and environmental problem which is only going to get worse as air traffic volumes increase. Rapid urbanisation, development encroachment and poor planning in the past have resulted in noisy airport runways being situated too close to residents' living space. Rapid industrial growth and lack of funding exacerbate noise problems in developing countries. Moreover, developing countries and especially South Africa tend to have moderate climates and open-window living, which makes insulation an ineffective solution to the noise problem. This study aims at employing GIS to establish the potential noise exposure of various sensitive land use categories and population groups in the noise-controlled area at Cape Town International Airport. Firstly, options for the demarcation of a noise-controlled area were evaluated. Thereafter, incompatible land uses and priority areas for land use compatibility projects were identified and recommendations made for urban renewal projects for these areas. Lastly, the noise-exposed population were profiled according to vulnerability characteristics and vulnerable groups identified and located. A recommendation was made that Cape Town International Airport set up an interactive map-based website to disseminate information to the public about noise and any other important issues concerning the airport. An Internet GIS application would empower citizens by providing them with a dynamic and interactive tool for improved public participation and a better understanding of the potential environmental and socio-economic effects of the airport. Noise complaints could also be investigated through the website and prompt feedback given to the communities complaining about aircraft noise. At the local community level where people are being annoyed every day and night resulting in negative health effects, the problem of aircraft noise demands urgent attention, and measures should be put in place to reduce vulnerability to noise and improve the overall quality of life of noiseweary residents. Keywords: aircraft noise, noise mapping, noise-controlled area, noise contours, land use compatibility, noise exposure / AFRIKAANSE OPSOMMING: Die geraas veroorsaak deur vliegtuie by lughawens bied ernstige sosiale, tegniese, ekonomiese en omgewingsprobleme, wat net erger gaan raak namate vlugverkeer toeneem. Snelle verstedeliking, ontwikkelings-oorskryding en swak beplanning in die verlede het veroorsaak dat raserige aanloopbane te nabyaan mense se leefruimte gebou is. Vinnige industriële groei en 'n tekort aan befondsing vererger geraasprobleme in ontwikkelende lande. Bowendien het ontwikkelende lande, en veral Suid Afrika, 'n matige klimaat en oop-venster-leefwyse wat isolering 'n oneffektiewe oplossing maak vir die geraasprobleem. Hierdie studie het ten doelom GIS te gebruik om die potensiële geraas blootstelling van sensitiewe grondgebruike en bevolkingsgroepe in die geraas-kontrole area by Kaapstad Internasionale Lughawe vas te stel. Eerstens is opsies vir die afbakening van die geraas-kontrole area geëvalueer. Daaropvolgend IS onversoenbare grondgebruike en prioriteitsareas VIr grondgebruikversoeningsprojekte geïdentifiseer en aanbevelings gemaak vir stedelike vernuwingsprojekte vir hierdie areas. Laastens is 'n profiel daargestel van die geraas-blootgestelde bevolkings volgens kwesbaarheidskenmerke en kwesbare groepe is geïdentifiseer en hulligging aangedui. 'n Voorstel is gemaak dat Kaapstad Internasionale Lughawe 'n interaktiewe kaart-gebaseerde webwerf in werking moet stelom inligting oor geraas- en ander belangrike probleme in verband met die lughawe beskikbaar te stel vir die publiek en ander belanghebbendes. 'n Internet-GIS toepassing sal mense bemagtig deur hulle te voorsien van 'n dinamiese en interaktiewe meganisme wat sal lei tot beter gemeenskapsdeelname en ook 'n beter begrip van die potensiële omgewings- en sosio-ekonomiese uitwerking van die lughawe. Klagte oor geraas kan ook deur die webwerf hanteer en ondersoek word, en verder hulp verleen word deur vinnige terugvoering aan die gemeenskap wat die klagtes gelê het. Op plaaslike gemeenskapsvlak, waar mense elke dag en nag geïrriteerd raak en waar dit dan kan lei tot negatiewe gesondheidsinvloed, sal die probleem van vliegtuiggeraas dringend aangespreek moet word, en stappe geneem word ten einde kwesbaarheid van inwoners teenoor vliegtuiggeraas te verminder. Dit sal dan lei tot die algehele verbetering van die lewensgehalte van geraas-moeë Inwoners. Sleutelwoorde: vliegtuiggeraas, geraaskartering. geraas-kontrole area, geraaskontoere, grondgebruik versoenbaarheid, geraas blootstelling