Scenarios of Urban Growth in Kenya Using Regionalised Cellular Automata based on Multi temporal Landsat Satellite Data Dissertation Zur Erlangung des Doktorgrades (Dr. rer. nat.) der Mathematisch-Naturwissenschaftlichen Fakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn Vorgelegt von Kenneth Wagia MUBEA Aus Nairobi, Kenia Bonn, 2014 Angefertigt mit Genehmigung der Mathematisch-Naturwissenschaftlichen Fakultät der Rheinischen Friedrich-Wilhelms-Universität Bonn 1. Referent: Prof. Dr. Gunter Menz 2. Referent: Prof. Dr. Klaus Greve Tag der Promotion: 15 April 2014 Erscheinungsjahr: 2014 Diese Dissertation ist auf dem Hochschulschriftenserver der ULB Bonn http://hss.ulb.uni-bonn.de/diss_online elektronisch publiziert ii TABLE OF CONTENTS ACKNOWLEDGEMENTS ................................................................................................... VI ABSTRACT ...................................................................................................................... VIII ZUSAMMENFASSUNG ....................................................................................................... X ACRONYMS ...................................................................................................................... XII LIST OF FIGURES ............................................................................................................. XIII LIST OF TABLES ............................................................................................................... XV LIST OF PAPERS .............................................................................................................. XVI 1 INTRODUCTION .................................................................................................. 1 1.1 Purpose of the Research .................................................................................... 1 1.2 Statement of the problem ................................................................................. 4 1.3 Research Questions ............................................................................................ 5 1.4 Research objectives ............................................................................................ 5 1.5 Outline of the research ...................................................................................... 6 2 URBAN GROWTH MODELLING AND CELLULAR AUTOMATA ............................. 9 2.1 Introduction........................................................................................................ 9 2.2 Urban modelling ............................................................................................... 10 2.2.1 Models .............................................................................................................. 10 2.2.2 Types of Models ............................................................................................... 11 2.2.3 Challenges ........................................................................................................ 12 2.2.4 Model uncertainty ............................................................................................ 15 2.3 Modelling urban growth .................................................................................. 18 2.3.1 Background ....................................................................................................... 18 2.3.2 Modelling approaches ...................................................................................... 19 2.3.3 Current practices in urban land-use modelling ................................................ 22 2.3.4 Complexity of Urban Growth ........................................................................... 24 2.3.5 Role of GIS and remote sensing in urban growth modelling ........................... 26 2.4 Cellular automata modelling ............................................................................ 28 2.4.1 Introduction...................................................................................................... 28 2.4.2 Elements of Cellular Automata ........................................................................ 30 2.4.3 Cellular automata models ................................................................................ 34 2.4.4 Advantages of CA urban models ...................................................................... 38 2.4.5 Limitations of CA urban models ....................................................................... 38 2.4.6 Developments in CA models ............................................................................ 39 2.4.7 Cellular automata in urban growth modelling ................................................. 41 iii 3 URBAN GROWTH IN AFRICAN CITIES ............................................................... 43 3.1 Introduction...................................................................................................... 43 3.2 Sustainable growth and characteristics of African cities ................................. 45 3.3 Prosperity of cities ............................................................................................ 47 3.4 Factors influencing urban growth .................................................................... 49 3.5 Nairobi .............................................................................................................. 51 3.5.1 Research area ................................................................................................... 51 3.5.2 Background ....................................................................................................... 53 3.5.3 Physical characteristics..................................................................................... 55 3.5.4 Urban growth in Nairobi .................................................................................. 56 3.6 Nakuru .............................................................................................................. 58 3.6.1 Research area ................................................................................................... 58 3.6.2 Background ....................................................................................................... 59 3.6.3 Physical characteristics..................................................................................... 62 3.6.4 Urban growth in Nakuru .................................................................................. 63 4 MONITORING LAND-USE CHANGES ................................................................. 64 4.1 Introduction...................................................................................................... 64 4.2 Utility of multi-sensor satellite data ................................................................ 66 4.3 Land-use change analysis in Nakuru ................................................................ 70 4.3.1 Data .................................................................................................................. 70 4.3.2 Land-use classification ..................................................................................... 71 4.3.3 Results and Discussion ..................................................................................... 75 4.3.4 Factors influencing land-use changes and urban growth ................................ 86 4.3.5 Consequences of Nakuru’s urban growth ........................................................ 89 4.4 Land-use change analysis in Nairobi ................................................................ 90 4.4.1 Data .................................................................................................................. 90 4.4.2 Land-use classification ..................................................................................... 91 4.4.3 Results and discussion ...................................................................................... 92 4.4.4 Factors influencing land-use changes and urban growth ................................ 95 4.4.5 Consequences of Nairobi’s urban growth ........................................................ 98 5 MODELLING URBAN GROWTH ....................................................................... 100 5.1 Introduction.................................................................................................... 100 5.2 The modelling framework (XULU) .................................................................. 103 5.3 Model Parameters and Growth Types ........................................................... 105 5.4 Model calibration ........................................................................................... 109 5.5 Model validation ............................................................................................ 109 5.6 Scenarios of urban growth ............................................................................. 112 iv 5.7 Scenarios of urban growth in Nakuru ............................................................ 114 5.7.1 Data ................................................................................................................ 114 5.7.2 Modelling of urban growth in Nakuru ........................................................... 117 5.8 Scenarios of urban process in Nairobi ........................................................... 130 5.8.1 Data ................................................................................................................ 130 5.8.2 Modelling of urban growth in Nairobi ..........................................................