Rivers in the Landscape : Science and Management

Rivers in the Landscape: Science and Management offers a comprehensive and accessible overview of the current state of knowledge for river process and form, taking a holistic approach to the subject with coverage of integrated river science and management in practice. The processes and forms present in channelized surface flow-rivers-are systematically explored in this book to \* emphasize the connectivity between rivers and the greater landscape by explicitly considering the interactions between rivers and tectonics, climate, biota, and human activities; \* provide a concise summary of the current state of knowledge for physical process and form in rivers; \* reflect the diversity of river environments, from mountainous, headwater channels to large, lowland, floodplain rivers and from the arctic to the tropics; \* reflect the diverse methods that scientists use to characterize and understand river process and form, including remote sensing, field measurements, physical experiments, and numerical simulations; \* reflect the increasing emphasis on quantification in fluvial geomorphology and the study of Earth surfaces in general; \* provide both an introduction to the classic, foundational papers on each topic, and a guide to the latest, particularly insightful and integrative references. Aimed at advanced undergraduate students, graduate students, and professionals looking for a concise summary of physical aspects of rivers, this book emphasizes general principles and conceptual models, as well as concrete examples of each topic drawn from the extensive literature on river process and form. Rivers in the Landscape 3 1 Introduction 15 1.1 Connectivity and inequality 15 1.2 Six degrees of connection 17 1.3 Rivers as integrators 20 1.4 Organization of this volume 21 1.5 Understanding rivers 23 1.5.1 The Colorado Front Range 23 1.6 Only connect 33 2 Creating channels and channel networks 35 2.1 Generating water, solutes, and sediment 35 2.1.1 Generating water 35 2.1.2 Generating sediment and solutes 36 2.2 Getting water, solutes, and sediment downslope to channels 37 2.2.1 Downslope pathways ofwater 37 2.2.2 Downslope movement ofsediment 43 2.2.3 Processes and patterns of water chemistry entering channels 46 2.2.4 Influence of the riparian zone on fluxes into channels 46 2.3 Channel initiation 48 2.4 Extension and development of the drainage network 51 2.4.1 Morphometric indices and scaling laws 51 2.4.2 Optimality 54 2.5 Spatial differentiation within drainage basins 55 2.6 Summary 57 Channel processes I 59 3 Water dynamics 61 3.1 Hydraulics 61 3.1.1 Flow classification 62 3.1.2 Energy, flow state, and hydraulic jumps 65 3.1.3 Uniform flow equations and flow resistance 67 3.1.4 Velocity and turbulence 74 3.1.5 Measures of energy exerted against the channel boundaries 79 3.2 Hydrology 81 3.2.1 Measuring, indirectly estimating, and modeling discharge 81 3.2.2 Flood frequency analysis 85 3.2.3 Hydrographs 87 3.2.4 Other parameters used to characterize discharge 89 3.2.5 Hyporheic exchange and hydrology 91 3.2.6 River hydrology in coldregions 91 3.2.7 Human influences on hydrology 92 3.3 Summary 93 Channel processes II 95 4 Fluvial sediment dynamics 97 4.1 The channel bed and initiation of motion 98 4.1.1 Bed sediment characterization 98 4.1.2 Entrainment of non-cohesive sediment 99 4.1.3 Erosion of cohesive beds 103 4.2 Sediment transport 105 4.2.1 Dissolved load 105 4.2.2 Suspended load 108 4.2.3 Bed load 112 4.3 Bedforms 118 4.3.1 Readily mobile bedforms 119 4.3.2 Infrequently mobile bedforms 122 4.3.3 Bedforms in cohesive sediments 129 4.4 In-channel depositional processes 129 4.5 Bank stability and erosion 131 4.6 Sediment budgets 134 4.7 Summary 138 5 Channel forms 139 5.1 Cross-sectional geometry 139 5.1.1 Bankfull, dominant, and effective discharge 139 5.1.2 Width to depth ratio 141 5.1.3 Hydraulic geometry 142 5.1.4 Lanes balance 144 5.1.5 Complex response 146 5.1.6 Channel evolution models 147 5.2 Channel planform 147 5.2.1 Straight channels 149 5.2.2 Meandering channels 150 5.2.3 Wandering channels 153 5.2.4 Braided channels 153 5.2.5 Anabranching channels 156 5.2.6 Compound channels 157 5.2.7 Karst channels 158 5.2.8 Continuum concept 158 5.2.9 River metamorphosis 160 5.3 Confluences 161 5.4 River gradient 163 5.4.1 Longitudinal profile 165 5.4.2 Stream gradient index 167 5.4.3 Knickpoints 168 5.5 Adjustment of channel form 170 5.5.1 Extremal hypotheses of channel adjustment 171 5.5.2 Geomorphic effects of floods 171 5.6 Downstream trends 174 5.6.1 Grain size 174 5.6.2 Instream wood 175 5.7 Summary 177 6 Extra-channel environments 179 6.1 Floodplains 179 6.1.1 Depositional processes and floodplain stratigraphy 181 6.1.2 Erosional processes and floodplain turnover times 186 6.1.3 Downstream trends in floodplain form and process 188 6.1.4 Classification of floodplains 189 6.2 Terraces 189 6.2.1 Terrace classifications 190 6.2.2 Mechanisms of terrace formation and preservation 190 6.2.3 Terraces as paleoprofiles and paleoenvironmental indicators 193 6.3 Alluvial Fans 195 6.3.1 Erosional and depositional processes 196 6.3.2 Fan geometry and stratigraphy 197 6.4 Deltas 199 6.4.1 Processes of erosion and deposition 200 6.4.2 Delta morphology and stratigraphy 201 6.4.3 Paleoenvironmental records 204 6.4.4 Deltas in the Anthropocene 205 6.5 Estuaries 206 6.6 Summary 208 7 Humans and rivers 211 7.1 Indirect impacts 212 7.1.1 Climate change 212 7.1.2 Altered land cover 214 7.2 Direct impacts 219 7.2.1 Flow regulation 219 7.2.2 Altered channel form and connectivity 222 7.3 River management in an environmental context 229 7.3.1 Reference conditions 229 7.3.2 Restoration 231 7.3.3 Instream, channel maintenance, and environmental flows 235 7.4 River health 237 7.5 Summary 238 8 Rivers in the landscape 239 8.1 Rivers and topography 239 8.1.1 Tectonic influences on rivergeometry 240 8.1.2 Effects of river incision on tectonics 242 8.1.3 Indicators of relations between rivers and landscape evolution 242 8.1.4 Tectonics, topography, and large rivers 243 8.2 Geomorphic process domains 244 8.3 Connectivity 246 8.4 Climatic signatures 248 8.4.1 High latitudes 248 8.4.2 Low latitudes 249 8.4.3 Warm drylands 250 8.5 Rivers with a history 251 8.5.1 Upper South Platte River drainage, Colorado, USA 254 8.5.2 Upper Rio Chagres, Panama 256 8.5.3 Mackenzie River drainage,Canada 258 8.5.4 Oregon Coast Range, USA 260 8.5.5 Yuma Wash, Arizona, USA 262 8.6 The greater context 264 References 269 Index 325