Preface xiii
1 Introduction 1
1.1 Large Rivers 1
1.2 A Book on Large Rivers 3
References 6
2 Geological Framework of Large Rivers 7
2.1 Introduction 7
2.2 The Geological Framework: Elevated Land and a Large Catchment 8
2.3 Smaller Tectonic Movements 9
2.4 The Subsurface Alluvial Fill of Large Rivers 10
2.5 Geological History of Large Rivers 12
2.6 Conclusion 14
Questions 14
References 14
3 Water and Sediment in Large Rivers 17
3.1 Introduction 17
3.2 Discharge of large Rivers 17
3.3 Global Pattern of Precipitation 18
3.4 Large River Discharge: Annual Pattern and Long-Term Variability 21
3.5 Sediment in Large Rivers 26
3.6 Conclusion 32
Questions 32
References 33
4 Morphology of Large Rivers 35
4.1 Introduction 35
4.2 Large Rivers from Source to Sink 35
4.3 The Amazon River 38
4.3.1 The Setting 39
4.3.2 Hydrology 39
4.3.3 Sediment Load 39
4.3.4 Morphology 42
4.4 The Ganga River 44
4.4.1 The Setting 44
4.4.2 Hydrology 46
4.4.3 Sediment Load 46
4.4.4 Morphology 47
4.5 Morphology of Large Rivers: Commonality and Variations 48
4.6 Conclusion 52
Questions 52
References 52
5 Large Rivers and their Floodplains: Structures, Functions, Evolutionary Traits and Management with Special Reference to the Brazilian Rivers 55
Wolfgang J. Junk, Florian Wittmann, Jochen Schongart, Maria Teresa F. Piedade and Catia Nunes da Cunha
5.1 Introduction 55
5.2 Origin and Age of Rivers and Floodplains 57
5.3 Scientific Concepts and their Implications for Rivers and Floodplains 59
5.4 Water Chemistry and Hydrology of Major Brazilian Rivers and their Floodplains 60
5.5 Ecological Characterisation of Floodplains and their Macrohabitats 62
5.6 Ecological Responses of Organisms to Flood-Pulsing Conditions 64
5.6.1 Trees 65
5.6.2 Herbaceous Plants 66
5.6.3 Invertebrates 66
5.6.4 Fish 67
5.6.5 Other Vertebrates 68
5.7 Biodiversity 68
5.7.1 Higher Vegetation 69
5.7.2 Animal Biodiversity 71
5.8 The Role of Rivers and their Floodplains for Speciation and Species Distribution of Trees 71
5.9 Biogeochemical Cycles in Floodplains 73
5.9.1 Biomass and Net Primary Production 73
5.9.1.1 Algae 73
5.9.1.2 Herbaceous Plants 74
5.9.1.3 Trees of the Flooded Forest 75
5.9.2 Decomposition 76
5.9.3 The Nitrogen Cycle 77
5.9.4 Nutrient Transfer Between the Terrestrial and Aquatic Phases 78
5.9.5 Food Webs 79
5.10 Management of Amazonian River Floodplains 80
5.10.1 Amazonian River Floodplains 80
5.10.2 Savanna Floodplains 82
5.11 Policies in Brazilian Wetlands 82
5.12 Discussion and Conclusion 84
Acknowledgements 89
References 89
6 Large River Deltas 103
6.1 Introduction 103
6.2 Large River Deltas: The Distribution 104
6.3 Formation of Deltas 104
6.4 Delta Morphology and Sediment 110
6.5 The Ganga-Brahmaputra Delta: An Example of a Major Deltaic Accumulation 112
6.5.1 The Background 112
6.5.2 Morphology of the Delta 113
6.5.3 Late Glacial and Holocene Evolution of the Delta 114
6.6 Conclusion 115
Questions 115
References 116
7 Geological History of Large River Systems 119
7.1 The Age of Large Rivers 119
7.2 Rivers in the Quaternary 121
7.2.1 The Time Period 121
7.2.2 The Nature of Geomorphic Changes 123
7.2.3 The Pleistocene and Large Rivers 124
7.2.3.1 The Glacial Stage 124
7.2.3.2 The Transition 125
7.2.3.3 The Interglacial Stage 127
7.3 Changes During the Holocene 127
7.4 Evolution and Development of the Mississippi River 128
7.5 The Ganga-Brahmaputra System 133
7.6 Evolution of the Current Amazon 137
7.7 Evolutionary Adjustment of Large Rivers 141
Questions 142
References 142
8 Anthropogenic Alterations of Large Rivers and Drainage Basins 147
8.1 Introduction 147
8.2 Early History of Anthropogenic Alterations 148
8.3 The Mississippi River: Modifications before Big Dams 149
8.4 The Arrival of Large Dams 151
8.5 Evaluating the Impact of Anthropogenic Changes 156
8.5.1 Land Use and Land Cover Changes 157
8.5.2 Channel Impoundments 159
8.6 Effect of Impoundments on Alluvial Rivers 161
8.7 Effect of Impoundments on Rivers in Rock 163
8.8 Large-scale Transfer of River Water 166
8.9 Conclusion 167
Questions 168
References 169
9 Management of Large Rivers 173
9.1 Introduction 173
9.2 Biophysical Management 177
9.3 Social and Political Management 178
9.3.1 Values and Objectives in River Management 179
9.3.2 International Basin Arrangements 180
9.4 The Importance of the Channel, Floodplain, and Drainage Basin 180
9.5 Integrated Water Resources Management 182
9.6 Techniques for Managing Large River Basins 183
9.7 Administering the Nile 184
9.8 Conclusion 188
Questions 189
References 190
10 The Mekong: A Case Study on Morphology and Management 193
10.1 Introduction 193
10.2 Physical Characteristics of the Mekong Basin 194
10.2.1 Geology and Landforms 194
10.2.2 Hydrology 196
10.2.3 Land Use 197
10.3 The Mekong: Source to Sea 199
10.3.1 The Upper Mekong in China 199
10.3.2 The Lower Mekong South of China 199
10.4 Erosion, Sediment Storage and Sediment Transfer in the Mekong 202
10.5 Management of the Mekong and its Basin 204
10.5.1 Impoundments on the Mekong 204
10.5.2 Anthropogenic Modification of Erosion and Sedimentation on Slopes 206
10.5.3 Degradation of the Aquatic Life 207
10.6 Conclusion 208
Questions 208
References 209
11 Large Arctic Rivers 211
Olav Slaymaker
11.1 Introduction 211
11.1.1 The Five Largest Arctic River Basins 213
11.1.2 Climate Change in the Five Large Arctic Basins 213
11.1.3 River Basin Zones 214
11.2 Physiography and Quaternary Legacy 216
11.2.1 Physiographic Regions 216
11.2.1.1 Active Mountain Belts and Major Mountain Belts with Accreted Terranes (Zone 1) 216
11.2.1.2 Interior Plains, Lowlands, and Plateaux (Zone 2) 217
11.2.1.3 Arctic Lowlands (Zone 3) 218
11.2.2 Ice Sheets and Their Influence on Drainage Rearrangement 218
11.2.3 Intense Mass Movement on Glacially Over-steepened Slopes 218
11.3 Hydroclimate and Biomes 220
11.3.1 Climate Regions 220
11.3.2 Biomes 220
11.3.3 Wetlands 224
11.4 Permafrost 224
11.4.1 Permafrost Distribution 224
11.4.2 Permafrost and Surficial Materials 226
11.4.3 Contemporary Warming 226
11.5 Anthropogenic Effects 228
11.5.1 Development and Population 228
11.5.2 Agriculture and Extractive Industry 228
11.5.3 Urbanisation: The Case of Siberia 228
11.6 Discharge of Large Arctic Rivers 229
11.6.1 Problems in Discharge Measurement 229
11.6.2 Water Fluxes 229
11.6.3 Water Budget 231
11.6.4 Nival River Regime 232
11.6.5 Lakes and Glaciers 234
11.6.6 River Ice: Freeze and Break Up 236
11.6.7 Scale Effects 237
11.6.8 Effects of River Regulation 238
11.6.9 Historical Changes 238
11.7 Sediment Fluxes 239
11.7.1 Complications in Determining Sediment Fluxes Both Within Arctic Basins and to the Arctic Ocean 239
11.7.2 Flux of Suspended Sediment and Dissolved Solids 240
11.7.3 Historical Changes in Water and Sediment Discharge in the Siberian Rivers 240
11.7.4 Suspended Sediment Sources and Sinks in the Mackenzie Basin 242
11.7.4.1 Sediment Yield in the Mackenzie Basin 242
11.7.4.2 West Bank Tributary Sources 243
11.7.4.3 Bed and Bank Sources 245
11.8 Nutrients and Contaminants 249
11.8.1 Supply of Nutrients 249
11.8.2 Transport of Contaminants 250
11.9 Mackenzie, Yukon and Lena Deltas 253
11.9.1 Mackenzie Delta 253
11.9.2 Lena Delta 253
11.9.3 Yukon–Kuskokwim Delta 256
11.10 Significance of Large Arctic Rivers 256
Acknowledgment 258
Questions 259
References 259
12 Climate Change and Large Rivers 265
12.1 Introduction 265
12.2 Global Warming: Basic Concept 266
12.3 A Summary of Future Changes in Climate 270
12.4 Impact of Climate Change on Large Rivers 271
12.5 Climate Change and a Typical Large River of the Future 273
12.6 Conclusion 277
Questions 277
References 278
Index 281
