A REMOTE SENSING AND GIS SCHEME FOR RANGELAND QUALITY ASSESSMENT AND MANAGEMENT IN THE NORTH WEST PROVINCE, SOUTH AFRICA NAHOM GUDETA FAJJI A thesis submitted in fulfillment of the requirement for the degree of Philisophiae Doctor in Environmental Sciences at Mafikeng Campus of the North-West University SUPERVISER: Prof. L.G. Palamuleni CO-SUPERVISOR: Prof. V. Mlambo November 2015 I | P a g e AUTHOR'S DECLARATION I hereby declare that the research work presented in this thesis has never been submitted in its fullness or in part to any other university for a degree. Therefore, it represents my own original work except where proper acknowledgements are made. Nahom Gudeta Fajji November 3rd 2015 I | P a g e Dedication In memory of my parents To my wife Grace, daughter Ruhammah and son Ammi II | P a g e ACKNOWLEDGEMENTS I would like to express my deepest gratitude to all those who have made this research work possible. I am, particularly indebted to the LORD GOD who strengthened me and gave me inner peace, and courage and provided me with everything that I needed during this work. I would like to express my gratefulness to Prof. L.G. Palamuleni who was my main supervisor and Prof. V. Mlambo who was my co-supervisor for your expert scientific guidance, encouragement, continued dedication and commitment to this research work. I would like to express my sincere appreciation to Dr. A. Abebe from Physics Department, and Dr. S. Mulugeta from School of Agricultural Sciences for the guidance and continued support during this research work and valuable comments and editing this thesis. I am also grateful to my friends Mr. G. Mekennen and Mr. G. Ayanne who are both physics PhD students for making me feel home at the North West University. I also appreciate the support that was offered by Mr. L. Keelley for his assistance with field data collection. I am greatly indebted to Prof. C. Munyati from the Department of Geography and Environmental Sciences for guiding me to develop the proposal and assisting me to design the skeletal framework of this research. May I also extend my appreciation to Mr. L. Sethlamo of the North-West Province Tourism and Parks Boards and Mr. K.B. of the North-West Province Department of Agriculture for providing me with critical datasets for this work. I would like to thank my colleagues at Setumo High School, particularly Mrs. M. Seshabela for assisting me financially when I needed it most during this work, Setumo High School principal Mrs. S. Motshegwa for her valuable moral support and creating a favorable condition to pursue my study and staffs of Setumo High School for creating a friendly atmosphere. I am deeply indebted to my entire family for their moral support and prayers. I treasure the unwavering support of my wife Grace, daughter, Ruhammah and Son, Ammi during my studies. III | P a g e Contents CHAPTER ONE 1 1. BACKGROUND TO RANGELAND MANAGEMENT 1 1.1 Introduction 1 1.2. Problem statement 2 1.3 Study area 3 1.3.1 Climatic conditions 4 1.3.2 Soils and vegetation 4 Source: The South African Weather Service 5 3.1.3 Land usese in the North-West province 5 1.4. Specific study areas 6 1.4.1 Low rainfall zone 6 1.4.2 Medium rainfall zone 8 1.4.3 The high rainfall zone 9 1.5 Justification of the study 10 1.6 Research aim and objectives 11 1.6.1 Aim 11 1.7 Research hypotheses 12 1.8 Provisional division of chapters in the thesis 12 CHAPTER TWO 15 2. LITERATURE REVIEW 15 2.1. Introduction 15 2.2 Rangeland models 15 2.2.1 The Range succession model 15 2.2.2 The State-and-Transition model 16 2.3.3 The Sustainable Range Management strategy 16 2.3 Theoretical framework 16 2.3.1 Area and percentage of rangeland with a significant change in bare ground 17 2.3.2 Rangeland area by plant community 17 2.3.3 Above-ground biomass 17 2.3.4 Area and percent of rangeland with accelerated soil erosion by water or wind 17 2.3.5 Fragmentation of rangelands 18 2.3.6 Proportion of available rangeland grazed by livestock 18 2.3.7 Intensity of human uses 18 2.4 Knowledge gaps identified 18 2.5 Characteristics of dryland ecosystems 19 2.6 Importance of rangelands in South Africa 20 2.6.1 Conditions of rangelands in South Africa 20 IV | P a g e 2.7 Characteristics of remote sensing 22 2.7.1 Satellite Pour l’Observation de la Terre (SPOT) 23 2.7.2 Rangeland management and remotely sensed data 23 2.8 Remote sensing and above ground giomass estimation 26 2.9 Determining rangeland livestock carrying capacity 29 2.10 Integration of GIS and remote sensing for rangeland management 30 2.11 Conclusion 33 CHAPTER THREE 34 3. RANGELAND PRODUCTIVITY ASSESSMENT IN RELATION TO GROUND BASED DATA, RAINFALL, TEMPERATURE AND MANAGEMENT STRATEGIES 34 3.1 Introduction 34 3.2 Materials and methods 35 3.2.1 Data types and sources 35 3.3.2 Data analysis 39 3.4 Results and discussion 40 3.4.1 Effects of rainfall and temperature on AGB productivity 40 3.4.2 Impacts of rangeland management systems on AGB productivity 44 3.5 Conclusion 48 CHAPTER FOUR 50 4. APPLICATIONS OF SPOT IMAGERY FOR LANDCOVER MAPPING AND ASSESSING INDICATORS OF EROSION AND PROPORTIONS OF BARE GROUND IN ARID AND SEMI ARID AREAS 50 4.1 Introduction 50 4.2 Materials and methods 52 4.2.1 Data types and sources 52 4.2.2 Analysis of SPOT 5 data 53 4.2.3 Relationship between proportion of bare ground and rainfall 56 4.3 Results 56 4.3.1 Land use/Land cover statistics 56 4.3.2 Accuracy assessment 62 4.4.4 Impact of rainfall distribution and management regimes on the proportion of bare ground 67 4.4.5 Conclusion 70 CHAPTER FIVE 72 5. EVALUATING THE ABILITY OF DERIVED VEGETATION INDICES AND COVER FRACTION IN ESTIMATING RANGELAND ABOVEGROUND BIOMASS IN SEMI-ARID ENVIRONMENTS 72 5.1 Introduction 72 5.2 Materials and methods 75 5.2.1 Data types and sources 75 V | P a g e 5.2.2 Data analysis 76 5.3 RESULTS 82 5.3.1 Relationship between vegetation indices (NDVI and SAVI) and vegetation fraction (SMA) and AGB 82 5.4 Discussion 87 5.5 Conclusion 91 CHAPTER SIX 93 6. FORAGE ASSESSMENT AND DETERMINATION OF RANGELAND CARRYING CAPACITY 93 6.1 Background 93 6.2 Materials and methods 95 6.2.1 Satellite data 95 6.2.3 Data analysis 100 6.3 Results and discussion 105 6.3.1 Effects of slope and watering points on the available forage 105 6.3.2 Impact of rainfall distribution on forage production 110 6.3.3 Impact of watering point distances on accessing allowable forage 111 6.3.4 Gross and available forage production 112 6.3.5 Carrying capacity (ha AUˉ¹ 6 monthsˉ¹) of the study sites 118 6.4 Conclusion 122 CHAPTER SEVEN 125 7. CONCLUSION AND RECOMMENDATIONS 125 7.1 Conclusion 125 7.2 Limitations of the study 12 7.3 Recommendations 127 REFERENCES 129 ANNEXURE 180 VI | P a g e List of Figures Figure 1: Map of the North-West province and the locations of the study sites ........................................ 3 Figure 2: Average annual rainfall and temperature in the low rainfall zones of the North West province 6 Figure 3: Average annual rainfall and temperature in the medium rainfall zones of the North-West province ...................................................................................................................................................... 8 Figure 4: Average annual rainfall and temperature in the high rainfall zones of the North-West province .................................................................................................................................................................. 10 Figure 5: A flow chart of the field data collection process....................................................................... 37 Figure 6: Sample points from the study sites - high grazing intensity and low grazing intensity ............ 38 Figure 7: Aboveground biomass production in relation to distribution of rainfall ................................... 40 Figure 8: Relationship between rainfall distribution and above ground biomass production .................. 41 Figure 9: Relationship between rainfall and temperature in the study area ............................................. 42 Figure 10: Relationship between temperature and aboveground biomass ............................................... 43 Figure 11: AGB production in the low rainfall zones .............................................................................. 46 Figure 12: Distribution of land cover classes and proportion of bare ground in Onderstepoort private ranch ......................................................................................................................................................... 59 Figure 13: Distribution of land use/land cover classes and proportion of bare ground ............................ 60 Figure 14: Relationship between rainfall distribution and proportion of bare ground ............................. 67 Figure 15: Relationship between rainfall distribution and proportion of bare ground across the study sites in the North West Province ...................................................................................................................... 68 Figure 16: Field measurement during the field data collection from Disaneng communal rangeland: February 28, 2014 ..................................................................................................................................... 76 Figure 17: Flow chart showing major steps of the study .......................................................................... 81 Figure 18: Regression coefficient of the grass AGB and the NDVI in the low rainfall area; showing the combined (HGI and LGI) samples