INVESTIGATING THE RELATIONSHIP OF SCALE AND RESILIENCE IN INTEGRATED WATER RESOURCE MANAGEMENT IN THE CROCODILE RIVER, SOUTH AFRICA By NATHAN BARASA WANGUSI A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2013 1 © 2013 Nathan Barasa Wangusi 2 To my parents and family who have nurtured and believed in me through the years and to my Ph.D supervisor Dr. Greg Kiker for his unwavering support, guidance and patience. 3 ACKNOWLEDGEMENTS Funding for this research was generously provided for by the Department of Agricultural and Biological Engineering at the University of Florida and fieldwork studies by the Rotary Foundation. I am grateful to my committee members; Dr. Greg Kiker for giving me academic space to explore different problems and solutions, Dr. Rafael Muñoz-Carpena and Dr. Howard Beck for ensuring I maintained technical depth and rigor in my studies and Dr. Grenville Barnes and Dr. Mark Brown for giving valuable insights on natural resource management. I am indebted to Dr. Jeff Smithers, Dr. Mark Dent, David Clark and Mark Horan of the University of Kwa-Zulu Natal Department of Bioresources Engineering and Environmental Hydrology; Dr. Tally Palmer of the Akili Initiative; Harry Biggs, Dr. Eddie Riddell and Craig Mc Loughlin of the Kruger National Park Service Scientific Services; Steven Mallory of IWR Water Resources; Sharon Pollard of the Association for Water and Rural Development; and Brian Jackson of the Inkomati Catchment Management Agency for their contributions and support during my fieldwork in South Africa. This dissertation reflects their shared knowledge, perspectives and expertise. 4 TABLE OF CONTENTS Page ACKNOWLEDGEMENTS ............................................................................................... 4 LIST OF TABLES ............................................................................................................ 8 LIST OF FIGURES ........................................................................................................ 10 LIST OF OBJECTS ....................................................................................................... 12 LIST OF ABBREVIATIONS ........................................................................................... 13 CHAPTER 1 INTRODUCTION ................................................................................................ 18 Overview of River Modeling in South Africa........................................................ 18 Research Questions, Objectives and Hypothesis ............................................... 19 Background ........................................................................................................ 21 Study Area .................................................................................................. 21 Delineation of Water Management Areas in the Inkomati Catchment ........ 22 Population and Land Use in the Crocodile River Catchment ...................... 23 Water Governance in South Africa ............................................................. 24 2 CONCEPTUAL MODEL FOR INTEGRATING KNOWLEDGE AND INFORMATION FOR THE CROCODILE RIVER CATCHMENT, SOUTH AFRICA .............................................................................................................. 32 Introduction ......................................................................................................... 32 Methodology in the Selection of Research Tools ................................................ 33 A Review of Ecological Complexity and Resilience in the Crocodile River ...................................................................................................... 33 Interactions with Water Resource Institutions ............................................. 38 Research Outcomes ........................................................................................... 42 Development of a Conceptual Map and Integrated System Tools for Estimating Ecological Effects from Flow Regimes in the Crocodile River ...................................................................................................... 42 Akili Forum Results: A General Systems Diagram of the Crocodile River .. 43 The ACRU model as a hydrological model for generating flow regimes for the Crocodile River ........................................................................... 46 Bayesian Network Development for Crocodile River .................................. 47 Discussion .......................................................................................................... 50 5 3 EVALUATING WATERSHED MODEL PERFORMANCE AT TWO SPATIAL SCALES TO AID ADAPTIVE MANAGEMENT IN THE CROCODILE RIVER CATCHMENT, SOUTH AFRICA ........................................................................ 59 Overview of Strategic Adaptive Management in the Crocodile River Catchment ..................................................................................................... 59 Study Area .......................................................................................................... 63 Research Hypothesis and Objectives ................................................................. 65 Methods and Tools ............................................................................................. 67 The Agricultural Catchment Research Unit (ACRU) model ........................ 67 Selection of Model Evaluation Indicators and Testing Criteria .................... 69 Results ............................................................................................................... 74 Evaluation of Model Performance............................................................... 74 Comparison of Results at Quaternary and Quinary Scale .......................... 75 Effects of Uncertainty in Measurement ....................................................... 78 Implications of Model Performance on River Monitoring ............................ 81 Discussion .......................................................................................................... 82 4 MODELING WATER USE DECISIONS FOR STRATEGIC ADAPTIVE MANAGEMENT USING BAYESIAN NETWORKS IN THE CROCODILE RIVER .............................................................................................................. 94 Overview of Bayesian Networks in Adaptive Management ................................ 94 Methodology ....................................................................................................... 96 Bayesian Networks ..................................................................................... 96 Constructing a Bayesian Network............................................................... 99 Problem definition ............................................................................ 99 Model inference ............................................................................. 100 Model validation ............................................................................. 101 Case Study Area Overview .............................................................................. 102 Crocodile River Bayesian Model Development ................................................ 102 Problem Definition .................................................................................... 102 Description of management environment ...................................... 102 Identify management endpoints and zones ................................... 104 Identify management alternatives .................................................. 105 Identify actors and process variables ............................................. 105 Model Inference ........................................................................................ 106 Flow ............................................................................................... 106 Ecostatus ....................................................................................... 106 Validation of Predicted Management Endpoints ....................................... 108 Ecological status ............................................................................ 108 Sectoral economy .......................................................................... 108 Sensitivity Analysis ................................................................................... 109 Application of the Model ................................................................................... 111 Impacts of Management on Assurance of Supply .................................... 111 Cost Benefit of Management Actions ....................................................... 112 Discussion ........................................................................................................ 114 6 5 CONCLUSIONS ............................................................................................... 128 APPENDIX A ACRU DATA FILES .......................................................................................... 132 B BAYESIAN NETWORK MODEL AND CASE FILES ........................................ 133 REFERENCE LIST...................................................................................................... 134 BIOGRAPHICAL SKETCH .......................................................................................... 145 7 LIST OF TABLES Table Page 2-1 Classification of variables for the Bayesian network of the Crocodile