Introducing Large Rivers

AVIJIT GUPTA, PHD, is Honorary Principal Fellow at the School of Earth, Atmospheric and Life Sciences at University of Wollongong, Australia.

• Preface xiii1 Introduction 11.1 Large Rivers 11.2 A Book on Large Rivers 3References 62 Geological Framework of Large Rivers 72.1 Introduction 72.2 The Geological Framework: Elevated Land and a Large Catchment 82.3 Smaller Tectonic Movements 92.4 The Subsurface Alluvial Fill of Large Rivers 102.5 Geological History of Large Rivers 122.6 Conclusion 14Questions 14References 143 Water and Sediment in Large Rivers 173.1 Introduction 173.2 Discharge of large Rivers 173.3 Global Pattern of Precipitation 183.4 Large River Discharge: Annual Pattern and Long-Term Variability 213.5 Sediment in Large Rivers 263.6 Conclusion 32Questions 32References 334 Morphology of Large Rivers 354.1 Introduction 354.2 Large Rivers from Source to Sink 354.3 The Amazon River 384.3.1 The Setting 394.3.2 Hydrology 394.3.3 Sediment Load 394.3.4 Morphology 424.4 The Ganga River 444.4.1 The Setting 444.4.2 Hydrology 464.4.3 Sediment Load 464.4.4 Morphology 474.5 Morphology of Large Rivers: Commonality and Variations 484.6 Conclusion 52Questions 52References 525 Large Rivers and their Floodplains: Structures, Functions, Evolutionary Traits and Management with Special Reference to the Brazilian Rivers 55Wolfgang J. Junk, Florian Wittmann, Jochen Schöngart, Maria Teresa F. Piedade and Catia Nunes da Cunha5.1 Introduction 555.2 Origin and Age of Rivers and Floodplains 575.3 Scientific Concepts and their Implications for Rivers and Floodplains 595.4 Water Chemistry and Hydrology of Major Brazilian Rivers and their Floodplains 605.5 Ecological Characterisation of Floodplains and their Macrohabitats 625.6 Ecological Responses of Organisms to Flood-Pulsing Conditions 645.6.1 Trees 655.6.2 Herbaceous Plants 665.6.3 Invertebrates 665.6.4 Fish 675.6.5 Other Vertebrates 685.7 Biodiversity 685.7.1 Higher Vegetation 695.7.2 Animal Biodiversity 715.8 The Role of Rivers and their Floodplains for Speciation and Species Distribution of Trees 715.9 Biogeochemical Cycles in Floodplains 735.9.1 Biomass and Net Primary Production 735.9.1.1 Algae 735.9.1.2 Herbaceous Plants 745.9.1.3 Trees of the Flooded Forest 755.9.2 Decomposition 765.9.3 The Nitrogen Cycle 775.9.4 Nutrient Transfer Between the Terrestrial and Aquatic Phases 785.9.5 Food Webs 795.10 Management of Amazonian River Floodplains 805.10.1 Amazonian River Floodplains 805.10.2 Savanna Floodplains 825.11 Policies in Brazilian Wetlands 825.12 Discussion and Conclusion 84Acknowledgements 89References 896 Large River Deltas 1036.1 Introduction 1036.2 Large River Deltas: The Distribution 1046.3 Formation of Deltas 1046.4 Delta Morphology and Sediment 1106.5 The Ganga-Brahmaputra Delta: An Example of a Major Deltaic Accumulation 1126.5.1 The Background 1126.5.2 Morphology of the Delta 1136.5.3 Late Glacial and Holocene Evolution of the Delta 1146.6 Conclusion 115Questions 115References 1167 Geological History of Large River Systems 1197.1 The Age of Large Rivers 1197.2 Rivers in the Quaternary 1217.2.1 The Time Period 1217.2.2 The Nature of Geomorphic Changes 1237.2.3 The Pleistocene and Large Rivers 1247.2.3.1 The Glacial Stage 1247.2.3.2 The Transition 1257.2.3.3 The Interglacial Stage 1277.3 Changes During the Holocene 1277.4 Evolution and Development of the Mississippi River 1287.5 The Ganga-Brahmaputra System 1337.6 Evolution of the Current Amazon 1377.7 Evolutionary Adjustment of Large Rivers 141Questions 142References 1428 Anthropogenic Alterations of Large Rivers and Drainage Basins 1478.1 Introduction 1478.2 Early History of Anthropogenic Alterations 1488.3 The Mississippi River: Modifications before Big Dams 1498.4 The Arrival of Large Dams 1518.5 Evaluating the Impact of Anthropogenic Changes 1568.5.1 Land Use and Land Cover Changes 1578.5.2 Channel Impoundments 1598.6 Effect of Impoundments on Alluvial Rivers 1618.7 Effect of Impoundments on Rivers in Rock 1638.8 Large-scale Transfer of River Water 1668.9 Conclusion 167Questions 168References 1699 Management of Large Rivers 1739.1 Introduction 1739.2 Biophysical Management 1779.3 Social and Political Management 1789.3.1 Values and Objectives in River Management 1799.3.2 International Basin Arrangements 1809.4 The Importance of the Channel, Floodplain, and Drainage Basin 1809.5 Integrated Water Resources Management 1829.6 Techniques for Managing Large River Basins 1839.7 Administering the Nile 1849.8 Conclusion 188Questions 189References 19010 The Mekong: A Case Study on Morphology and Management 19310.1 Introduction 19310.2 Physical Characteristics of the Mekong Basin 19410.2.1 Geology and Landforms 19410.2.2 Hydrology 19610.2.3 Land Use 19710.3 The Mekong: Source to Sea 19910.3.1 The Upper Mekong in China 19910.3.2 The Lower Mekong South of China 19910.4 Erosion, Sediment Storage and Sediment Transfer in the Mekong 20210.5 Management of the Mekong and its Basin 20410.5.1 Impoundments on the Mekong 20410.5.2 Anthropogenic Modification of Erosion and Sedimentation on Slopes 20610.5.3 Degradation of the Aquatic Life 20710.6 Conclusion 208Questions 208References 20911 Large Arctic Rivers 211Olav Slaymaker11.1 Introduction 21111.1.1 The Five Largest Arctic River Basins 21311.1.2 Climate Change in the Five Large Arctic Basins 21311.1.3 River Basin Zones 21411.2 Physiography and Quaternary Legacy 21611.2.1 Physiographic Regions 21611.2.1.1 Active Mountain Belts and Major Mountain Belts with Accreted Terranes (Zone 1) 21611.2.1.2 Interior Plains, Lowlands, and Plateaux (Zone 2) 21711.2.1.3 Arctic Lowlands (Zone 3) 21811.2.2 Ice Sheets and Their Influence on Drainage Rearrangement 21811.2.3 Intense Mass Movement on Glacially Over-steepened Slopes 21811.3 Hydroclimate and Biomes 22011.3.1 Climate Regions 22011.3.2 Biomes 22011.3.3 Wetlands 22411.4 Permafrost 22411.4.1 Permafrost Distribution 22411.4.2 Permafrost and Surficial Materials 22611.4.3 Contemporary Warming 22611.5 Anthropogenic Effects 22811.5.1 Development and Population 22811.5.2 Agriculture and Extractive Industry 22811.5.3 Urbanisation: The Case of Siberia 22811.6 Discharge of Large Arctic Rivers 22911.6.1 Problems in Discharge Measurement 22911.6.2 Water Fluxes 22911.6.3 Water Budget 23111.6.4 Nival River Regime 23211.6.5 Lakes and Glaciers 23411.6.6 River Ice: Freeze and Break Up 23611.6.7 Scale Effects 23711.6.8 Effects of River Regulation 23811.6.9 Historical Changes 23811.7 Sediment Fluxes 23911.7.1 Complications in Determining Sediment Fluxes Both Within Arctic Basins and to the Arctic Ocean 23911.7.2 Flux of Suspended Sediment and Dissolved Solids 24011.7.3 Historical Changes in Water and Sediment Discharge in the Siberian Rivers 24011.7.4 Suspended Sediment Sources and Sinks in the Mackenzie Basin 24211.7.4.1 Sediment Yield in the Mackenzie Basin 24211.7.4.2 West Bank Tributary Sources 24311.7.4.3 Bed and Bank Sources 24511.8 Nutrients and Contaminants 24911.8.1 Supply of Nutrients 24911.8.2 Transport of Contaminants 25011.9 Mackenzie, Yukon and Lena Deltas 25311.9.1 Mackenzie Delta 25311.9.2 Lena Delta 25311.9.3 Yukon–Kuskokwim Delta 25611.10 Significance of Large Arctic Rivers 256Acknowledgment 258Questions 259References 25912 Climate Change and Large Rivers 26512.1 Introduction 26512.2 Global Warming: Basic Concept 26612.3 A Summary of Future Changes in Climate 27012.4 Impact of Climate Change on Large Rivers 27112.5 Climate Change and a Typical Large River of the Future 27312.6 Conclusion 277Questions 277References 278Index 281