Urban heat islands in South Africa: A case study of Cape Town (by) Lukas Robin Nigel Beuster Thesis presented in partial fulfilment of the requirements for the degree of Master of Urban and Regional Science in the Faculty of Arts and Social Sciences at Stellenbosch University. Supervisor: D du Plessis April 2019 i Stellenbosch University https://scholar.sun.ac.za Declaration By submitting this thesis electronically, I declare that the entirety of the work contained therein is my own, original work, that I am the sole author thereof (save to the extent explicitly otherwise stated), that reproduction and publication thereof by Stellenbosch University will not infringe any third party rights and that I have not previously in its entirety or in part submitted it for obtaining any qualification Date: 13th November 2018 Copyright © 2019 Stellenbosch University All rights reserved ii Stellenbosch University https://scholar.sun.ac.za ACKNOWLEDGEMENTS I would like to express my great appreciation to Danie du Plessis for his insights, useful critiques, comments and enthusiasm on the topic of this thesis. Further, I would also like to thank the German Academic Exchange Service who made this degree possible, financing not one but two years of studying abroad. Finally, I wish to thank Tegan Snyman for her support during the preparation of this report. iii Stellenbosch University https://scholar.sun.ac.za ABBREVIATIONS AUHI Atmospheric Urban Heat Island CE Cooling Efficiency CoCT City of Cape Town CTMSDF Cape Town Municipal Spatial Development Framework GHG Greenhouse gases GTI GeoTerraImage ICC International Code Council ISA Impervious Surface Area IUDF Integrated Urban Development Framework LC Land Cover LST Land Surface Temperature MSDF Municipal Spatial Development Framework NDP National Development Plan SUHI Surface Urban Heat Island SUHII Surface Urban Heat Island Intensity SDF Spatial Development Framework UCI Urban Cool Island UHI Urban Heat Island UHII Urban Heat Island Intensity iv Stellenbosch University https://scholar.sun.ac.za CONTENTS [INHOUD] Chapter 1 Introduction ........................................................................................................... 1 1.1 Problem statement ...................................................................................................... 2 1.2 Research Questions: ................................................................................................... 4 1.3 Aim and objectives ...................................................................................................... 4 1.3.1 Aim........................................................................................................................ 4 1.3.2 Objectives ............................................................................................................. 4 Chapter 2 Literature review ................................................................................................... 5 2.1 Background ................................................................................................................. 5 2.2 Urban heat islands ....................................................................................................... 6 2.2.1 Overview ............................................................................................................... 6 2.2.2 The field of Urban Climatology .............................................................................. 7 2.2.3 Measuring UHI in the present ................................................................................ 7 2.2.4 Causes of urban heat islands ................................................................................ 8 2.2.5 Effects and mitigation of UHI ............................................................................... 12 2.2.6 Current and future mitigation and adaptation strategies ...................................... 16 2.2.7 UHI in Africa ........................................................................................................ 23 2.2.8 Research going forward ...................................................................................... 23 2.3 Legislation ................................................................................................................. 24 2.3.1 International ........................................................................................................ 24 2.3.2 Regional .............................................................................................................. 28 2.3.3 National ............................................................................................................... 29 2.4 Application of UHI mitigation strategies worldwide ..................................................... 39 2.4.1 Chicago ............................................................................................................... 39 2.4.2 Los Angeles ........................................................................................................ 40 2.4.3 Toronto ............................................................................................................... 40 2.4.4 UHI-mitigation going forward ............................................................................... 41 2.5 Literature review summary conclusion ....................................................................... 41 v Stellenbosch University https://scholar.sun.ac.za Chapter 3 Methodology ....................................................................................................... 44 3.1 study area .................................................................................................................. 44 3.2 Deriving Land Surface Temperature .......................................................................... 46 3.2.1 Deriving land surface temperatures ..................................................................... 47 3.3 Land cover mapping .................................................................................................. 48 3.4 Spatial Analysis ......................................................................................................... 49 Chapter 4 Results ............................................................................................................... 50 4.1 Land Surface Temperature ........................................................................................ 50 4.2 Hot and Cold Spots (Getis-Ord GI*) ........................................................................... 53 4.2.1 Cluster and outlier analysis ................................................................................. 58 4.3 Land Cover and LST – consistent hot spots and regression ...................................... 60 4.3.1 Overall analysis ................................................................................................... 60 4.3.2 Differences between LC Categories .................................................................... 61 4.3.3 Consistent hot and cold spots ............................................................................. 64 4.3.4 Regression analysis ............................................................................................ 71 Chapter 5 Summary and conclusions .................................................................................. 77 5.1 Main trends ................................................................................................................ 77 5.2 A question of policy and legislation? .......................................................................... 78 5.3 Urban Heat Islands in the City of Cape Town ............................................................ 81 5.3.1 Poverty, informality and heat ............................................................................... 81 5.3.2 Green spaces for UHI mitigation within the urban edge ....................................... 83 5.3.3 Agriculture and heat stress .................................................................................. 84 5.3.4 Cool surfaces ...................................................................................................... 85 5.4 Possible recommendations ........................................................................................ 87 5.5 Potential limitations and further research recommendations ...................................... 90 5.6 Conclusions ............................................................................................................... 92 Chapter 6 Bibliography ........................................................................................................ 94 vi Stellenbosch University https://scholar.sun.ac.za TABLES [TABELLE] Table 4.1 LST recorded throughout 2014 ............................................................................ 50 FIGURES [FIGURE] Figure 3.1 Overview CoCT - study area .............................................................................. 45 Figure 4.1 Raw LST data throughout the year 2014. a.) January, b.) April, c.) July, d.) October, e.) November ...................................................................................................................... 51 Figure 4.2 Hot spot analysis within the urban edge a.) January, b.) April, c.) July, d.) October, e.) November 2014 ............................................................................................................. 54 Figure 4.3 Hot and cold spots July (left) and November