Congo Basin Hydrology, Climate, and Biogeochemistry

1 Cover

2 Series Page

3 Title Page

4 Copyright Page

5 List of Contributors

6 Preface REFERENCES

7 1 Congo Basin Research 1.1. INTRODUCTION 1.2. OVERVIEW OF THE CONGO BASIN 1.3. THE HISTORY AND THE FUTURE OF THE CONGO BASIN 1.4. ESTABLISHING A NEW ERA FOR CONGO RESEARCH REFERENCES

8 Part I: Influences on Rainfall 2 Central African Climate 2.1. INTRODUCTION 2.2. RAINBELT MECHANISMS 2.3. CONVECTION 2.4 CLIMATE MODELING 2.5 CONCLUSION REFERENCES 3 The Rainfall and Convective Regime over Equatorial Africa, with Emphasis on the Congo Basin 3.1. INTRODUCTION 3.2. METEOROLOGICAL BACKGROUND 3.3. DATA 3.4. MEAN RAINFALL 3.5. INTERANNUAL VARIABILITY 3.6. CONVECTIVE ACTIVITY 3.7. COMPARISON WITH THE AMAZON 3.8. SUMMARY AND CONCLUSIONS ACKNOWLEDGMENTS REFERENCES 2 Influence of “Slab‐Ocean” Parameterization in a Regional Climate Model (RegCM4) over Central Africa 4.1. INTRODUCTION 4.2. DESCRIPTION OF THE MODEL, EXPERIMENTAL PROTOCOL, DATA, AND METHODOLOGY 4.3. RESULTS AND DISCUSSIONS 4.4. CONCLUSION ACKNOWLEDGMENTS REFERENCES 5 Understanding the Influence of Climate Variability on Surface Water Hydrology in the Congo Basin 5.1. INTRODUCTION 5.2. MATERIALS AND METHOD 5.3. RESULTS 5.4. DISCUSSION AND CONCLUSIONS ACKNOWLEDGMENTS REFERENCES 6 Hydroclimatic Dynamics of Upstream Ubangi River at Mobaye, Central African Republic 6.1. INTRODUCTION 6.2. STUDY AREA: UPPER BASIN OF THE UBANGI RIVER AT MOBAYE 6.3. DATA AND METHODS 6.4. RESULTS 6.5. DISCUSSION 6.6. CONCLUSION ACKNOWLEDGMENTS REFERENCES 7 Evaluation of the Tropical Rainfall Measuring Mission (TRMM) 3B42 and 3B43 Products Relative to Synoptic Weather Station Observations over Cameroon 7.1. INTRODUCTION 7.2. STUDY AREA: AGROCLIMATIC ZONES IN CAMEROON 7.3. DATA 7.4. METHODOLOGY FOR TRMM EVALUATION 7.5. RESULTS 7.6. DISCUSSION 7.7. CONCLUSION ACKNOWLEDGMENTS REFERENCES

9 Part II: Variations in Rainfall and Runoff 8 A New Look at Hydrology in the Congo Basin, Based on the Study of Multi‐Decadal Time Series 8.1. INTRODUCTION 8.2. DATA AND METHODS 8.3. RESULTS AND DISCUSSION 8.4. CONCLUSIONS ACKNOWLEDGMENTS REFERENCES 9 Historical Changes in Rainfall Patterns over the Congo Basin and Impacts on Runoff (1903–2010) 9.1. INTRODUCTION 9.2. MATERIALS AND METHOD 9.3. RESULTS 9.4. DISCUSSION AND CONCLUSION ACKNOWLEDGMENTS REFERENCES 10 Water Budgets and Droughts under Current and Future Conditions in the Congo River Basin 10.1. INTRODUCTION 10.2. BACKGROUND 10.3. METHODS 10.4. RESULTS AND DISCUSSION 10.5. CONCLUSIONS ACKNOWLEDGMENTS REFERENCES 11 Spatiotemporal Variability of Droughts in the Congo River Basin 11.1. INTRODUCTION 11.2. MATERIAL AND METHODS 11.3. RESULTS AND DISCUSSION 11.4. CONCLUSIONS ACKNOWLEDGMENTS REFERENCES

10 Part III: Hydrology and Hydraulics 12 Two Decades of Hydrologic Modeling and Predictions in the Congo River Basin 12.1. INTRODUCTION 12.2. UNDERSTANDING HYDROLOGIC PROCESSES IN THE CONGO RIVER BASIN 12.3. DATA AVAILABILITY 12.4. EVALUATION OF HYDROLOGIC MODEL APPLICATIONS IN THE CONGO BASIN 12.5. APPLICATION CASES: PERFORMANCE OF GW‐PITMAN AND WEAP MODELS IN THE CONGO RIVER BASIN 12.6. CONCLUSIONS AND PROSPECTS FOR FUTURE INVESTIGATIONS ACKNOWLEDGMENTS REFERENCES 13 Sources and Sinks of Water of the Cuvette Centrale Wetlands Using Multiple Remote Sensing Measurements and a Hydrologic Model 13.1. INTRODUCTION 13.2. METHODS 13.3. RESULTS 13.4. DISCUSSION AND CONCLUSIONS REFERENCES 14 Investigating the Role of the Cuvette Centrale in the Hydrology of the Congo River Basin 14.1. INTRODUCTION 14.2. MATERIALS AND METHODS 14.3. RESULTS AND DISCUSSION 14.4. CONCLUSION ACKNOWLEDGMENTS REFERENCES 15 Estimation of Bathymetry for Modeling Multi‐thread Channel Hydraulics 15.1. INTRODUCTION 15.2. DATA AND METHODS 15.3. RESULTS 15.4. DISCUSSION 15.5. CONCLUSIONS REFERENCES 16 Reviewing Applications of Remote Sensing Techniques to Hydrologic Research in Sub‐Saharan Africa, with a Special Focus on the Congo Basin 16.1. INTRODUCTION 16.2. MONITORING THE HYDROLOGICAL CYCLE 16.3. RIVER AND FLOODPLAIN HYDRODYNAMICS 16.4. SYNTHESIS AND CONCLUSION REFERENCES 17 Spatial Hydrology and Applications in the Congo River Basin 17.1. INTRODUCTION 17.2. SPATIAL HYDROLOGY 17.3. THE CONGO BASIN HYDROLOGICAL MONITORING PROJECT 17.4. CONCLUSION REFERENCES 18 Monitoring Hydrological Variables from Remote Sensing and Modeling in the Congo River Basin 18.1. INTRODUCTION 18.2. DATA SETS AND MODEL SET‐UP 18.3. RATING CURVES AND THEIR APPLICABILITY FOR NRT HYDROLOGICAL MONITORING FROM SPACE 18.4. DISCUSSION AND CONCLUSIONS ACKNOWLEDGMENTS REFERENCES 19 Long‐Term Hydrological Variations of the Ogooué River Basin 19.1. INTRODUCTION 19.2. GEOGRAPHY OF THE OGOOUÉ RIVER BASIN 19.3. PRECIPITATION OF THE OGOOUÉ RIVER BASIN 19.4. OGOOUÉ RIVER BASIN HYDROGRAPHIC NETWORK 19.5. DISCHARGE OF THE OGOOUÉ RIVER BASIN 19.6. CARBON FLUXES OF THE OGOOUÉ RIVER 19.7. BRIEF COMPARISON OF CHANGES IN THE OGOOUÉ AND THE CONGO RIVER BASINS 19.8. PAST AND FUTURE MONITORING OF THE OGOOUÉ RIVER BASINS ACKNOWLEDGMENTS REFERENCES

11 Part IV: Sediments and Carbon 20 Fluvial Carbon Dynamics across the Land to Ocean Continuum of Great Tropical Rivers 20.1. INTRODUCTION 20.2. THE REGIONS 20.3. ADVECTIVE FLUXES 20.4. ORGANIC MATTER SOURCES AND METABOLIC POTENTIAL 20.5. METABOLISM 20.6. GAS EXCHANGE 20.7. THE RIVER‐TO‐OCEAN CONTINUUM 20.8. CONCLUSION ACKNOWLEDGMENTS REFERENCES 21 Measuring Geomorphological Change on the Congo River Using Century‐Old Navigation Charts 21.1 INTRODUCTION 21.2. DATA AND METHODOLOGY 21.3. RESULTS AND DISCUSSION 21.4. CONCLUSIONS AND NEXT STEPS ACKNOWLEDGMENTS REFERENCES OTHER CONGO MONOGRAPH PAPERS 22 Site Selection, Design, and Implementation of a Sediment Sampling Program on the Kasai River, a Major Tributary of the Congo River 22.1 INTRODUCTION 22.2. MATERIAL AND METHODS 22.3. RESULTS AND DISCUSSION 22.4. CONCLUSIONS ACKNOWLEDGMENTS REFERENCES 23 New Measurements of Water Dynamics and Sediment Transport along the Middle Reach of the Congo River and the Kasai Tributary 23.1. INTRODUCTION 23.2. STUDY REACH AND RECONNAISSANCE SURVEY 23.3. MATERIALS AND METHODS 23.4. RESULTS AND DISCUSSION 23.5. CONCLUSION, LESSONS LEARNED AND PERSPECTIVES FOR FUTURE MEASUREMENTS ACKNOWLEDGMENTS REFERENCES

12 Part V: Water Resources 24 Towards a Framework of Catchment Classification for Hydrologic Predictions and Water Resources Management in the Ungauged Basin of the Congo River 24.1. INTRODUCTION 24.2. A CONCEPTUAL FRAMEWORK OF CATCHMENT CLASSIFICATION FOR THE CONGO RIVER BASIN 24.3. METHODOLOGICAL APPROACH 24.4. RESULTS AND DISCUSSION 24.5. CONCLUSION AND PERSPECTIVES ACKNOWLEDGMENTS REFERENCES 25 The Environmental Issues of the Ubangui Water Transfer Project to Lake Chad 25.1. INTRODUCTION 25.2. OVERVIEW OF THE WATER TRANSFER PROJECT FROM UBANGUI TO CHAD 25.3. CONTROVERSIES OVER THE PROJECT TO TRANSFER THE UBANGUI TO LAKE CHAD 25.4. THE PREDICTABLE POTENTIAL EFFECTS OF THE PROJECT 25.5. CONCLUSION REFERENCES 26 Variability of Lake Chad 26.1. INTRODUCTION 26.2. MATERIALS AND METHODS 26.3. RESULTS AND DISCUSSIONS 26.4. POSSIBLE IMPACT OF AN INTER‐BASIN TRANSFER: CONGO–LAKE CHAD 26.5. PROPOSAL FOR HYDRAULIC MANAGEMENT TO SUSTAINABLY PRESERVE THE NATURAL RESOURCES OF LAKE CHAD 26.6. CONCLUSION REFERENCES 27 Multi‐Return Periods, Flood Hazards, and Risk Assessment in the Congo River Basin 27.1. INTRODUCTION 27.2. STUDY AREA 27.3. FLOOD RISK ANALYTICAL FRAMEWORK 27.4. DATA AND METHODS 27.5. RESULTS 27.6. DISCUSSION 27.7. CONCLUSION ACKNOWLEDGMENTS REFERENCES 28 Putting River Users at the Heart of Hydraulics and Morphology Research in the Congo Basin 28.1. INTRODUCTION 28.2. RIVER USERS 28.3. GAPS IN SCIENCE KNOWLEDGE RELATED TO RIVER TRANSPORT AND HYDROPOWER 28.4. DESIGNING AND IMPLEMENTING RIVER RESEARCH WITH USERS AT THE HEART: THE CRuHM PROJECT 28.5. CRuHM PROJECT OUTCOMES 28.6. CONCLUSIONS ACKNOWLEDGMENTS REFERENCES