Fluvial Processes in Dryland Rivers: (3 Springer Series in Physical Environment)

From this high promontory, the landforms of the Sonoran Des- ert take on awesome proportions. The mesas, buttes, cinder cones, basalt flows, mountains, and valleys, all carved and modi- fied by water in this dry place, must be measured in kilometers and millions of years. Even the colors are dazzling. The volcanic rocks, altered by ancient hydrothermal activity, glow a warm orange and yellow in the October sun. The bright, clear light illuminates each tiny crevice etched by weathering and erosion in the cliffs. Several hundred meters below and about a kilo- meter away the river rolls, a brown silt-laden ribbon on the floor of the gorge. The water rustles so quietly that I can hear it only when the wind dies. In the distance, sharp mountain peaks rake the bottom of the ocean of air where streamers of clouds stretch over the horizon to the ocean of water. The field is a fitting place to write the preface for a book on geomorphology because of the importance of the field experi- ence in the development of the science. Dramatic landforms and processes, especially in drylands, have excited the imagination and intellect of artists, writers, and scientists. Each observer has explored a different route to knowing and understanding this thin envelope that is the contact between sky and earth. De- scriptions of these striking landscapes have appealed to cataclys- mic forces, operation of machine-like processes, and even ran- dom occurrences governed by happenstance.

Table of Contents:
I Basic Perspectives.- 1 Introduction.- 1.1 Fluvial Geomorphology.- 1.1.1 An Overview.- 1.1.2 Distribution of Drylands.- 1.1.3 Drylands on Other Planets.- 1.2 Early Research in the American West.- 1.2.1 Newberry.- 1.2.2 King, Hayden, and Marvine.- 1.2.3 Powell.- 1.2.4 Dutton.- 1.2.5 Gilbert.- 1.3 Early Developments from Other Drylands.- 1.3.1 Africa.- 1.3.2 Asia.- 1.3.3 South America and Australia.- 2 Theoretical Perspectives.- 2.1 Scientific Methods.- 2.1.1 Logical Positivism.- 2.1.2 Falsification.- 2.1.3 Critical Rationalism.- 2.2 General Systems Concepts.- 2.3 Temporal Concepts.- 2.3.1 Uniformitarianism.- 2.3.2 Evolution.- 2.3.3 Equilibrium.- 2.3.4 Rate Laws.- 2.4 Spatial Concepts.- 2.4.1 Regions.- 2.4.2 Networks.- 2.4.3 Distance Decay.- 2.5 Integrative Concepts.- 2.5.1 Thresholds and Complex Responses.- 2.5.2 Scale.- 2.5.3 Magnitude and Frequency.- 2.5.4 Allometric Change.- 2.5.5 Entropy.- 2.5.6 Catastrophe Theory.- II Processes and Forms.- 3 Surface Water in Drylands.- 3.1 Dryland Precipitation.- 3.1.1 Mechanisms.- 3.1.2 Spatial and Temporal Characteristics.- 3.1.3 Data Availability.- 3.2 Runoff.- 3.2.1 Soil Conservation Service Method.- 3.2.2 Rational Method.- 3.2.3 Impact of Human Activities.- 3.3 Streamflow and Floods.- 3.3.1 Streamflow.- 3.3.2 Force, Stress, and Power.- 3.3.3 Types of Dryland Floods.- 3.3.4 Transmission Losses.- 3.3.5 Magnitude and Frequency.- 3.3.6 Significance of Various Flow Magnitudes.- 3.3.7 Sheetfloods.- 3.4 Paleohydrology.- 3.4.1 Paleohydrologic Evidence.- 3.4.2 Estimation of Paleoflow Parameters.- 3.4.3 Extension of the Flood Record.- 4 Fluvial Sediment in Dryland Rivers.- 4.1 Sediment Characteristics.- 4.1.1 Size, Sorting, and Shape.- 4.1.2 Fabric.- 4.1.3 Facies.- 4.2 Sediment Yield from Drainage Basins.- 4.2.1 Factors Controlling Erosion.- 4.2.2 Estimation of Erosion.- 4.2.3 Sediment Yield From Basins.- 4.2.4 Spatial Variation of Sediment Yield.- 4.3 Sediment Transport in Dryland Rivers.- 4.3.1 Sediment in Dryland Rivers.- 4.3.2 Suspended Sediment Transport.- 4.3.3 Bedload Sediment Transport.- 4.3.4 Total Load Estimations.- 4.3.5 Definitions and Dimensions.- 4.3.6 Movement of Sediment in Pulses.- 4.4 Contaminants.- 4.4.1 Heavy Metals and Placers.- 4.4.2 Radionuclides.- 4.5 Dryland Perspectives.- 5 Process-Form Relationships.- 5.1 Badlands and Piping Processes.- 5.1.1 Badlands.- 5.1.2 Rates of Badland Erosion.- 5.1.3 Piping.- 5.2 Pediments.- 5.2.1 Definition, Description, and Distribution.- 5.2.2 Origin.- 5.2.3 Fluvial Processes on Pediments.- 5.2.4 Hazards.- 5.3 Alluvial Fans.- 5.3.1 Definition, Description, and Distribution.- 5.3.2 Materials.- 5.3.3 Origins.- 5.3.4 Modern Processes.- 5.3.5 Hazards on Alluvial Fans.- 5.4 Channels and Flood Plains.- 5.4.1 Channel Patterns and Controls.- 5.4.2 Channel Change and Recovery.- 5.4.3 Horizontal Instability.- 5.4.4 Flood Plains.- 5.4.5 Near-Channel Hazardous Environments.- 5.5 Entrenched Channels.- 5.5.1 Entrenchment Process.- 5.5.2 Causes of Entrenchment.- 5.5.3 Processes in Entrenched Channels.- 5.6 Valley Fills.- 5.7 Three Landscapes.- III Modifications of Processes and Forms.- 6 Vegetation and Dryland Rivers.- 6.1 Upland Vegetation.- 6.1.1 Influences on Runoff.- 6.1.2 Influence on Sediment Yield.- 6.1.3 Influence on Channels.- 6.1.4 Impact of Fire.- 6.2 Riparian Vegetation.- 6.2.1 Hydrologic Connections.- 6.2.2 Impacts on Channels.- 6.2.3 Exotic Vegetation - Example of Tamarisk.- 6.3 Conclusions.- 7 Direct Human Impacts on Dryland Rivers.- 7.1 Upstream Impacts of Dams.- 7.1.1 Impacts on Processes.- 7.1.2 Reservoir Deposits.- 7.1.3 Reservoir Sediment Budgets.- 7.1.4 Impacts Upstream from Backwater.- 7.2 Downstream Impacts of Dams.- 7.2.1 Regime Changes by Dams.- 7.2.2 Degradation and Armoring.- 7.2.3 Width and Pattern Changes.- 7.2.4 Impacts on Non-Alluvial Channels.- 7.2.5 Impact of Dams on Riparian Vegetation.- 7.3 Impacts of Urban Development.- 7.3.1 Physical Changes Caused by Urbanization.- 7.3.2 Fluvial Responses to Urbanization.- 7.4 Impacts of Agricultural Development.- 7.5 Conclusions.- 8 Generalizations for Dryland Rivers.- 8.1 Toward an Integrated Theory.- 8.1.1 Fundamental Precepts.- 8.1.2 Processes and Forms.- 8.1.3 Modifications of Processes and Forms.- 8.2 Utility of Generalizations.- 8.2.1 Geomorphology as a Natural Science.- 8.2.2 Geomorphology and Engineering.- 8.2.3 Geomorphology and the Law.- 8.2.4 Geomorphology and Planning-Management.- 8.2.5 Geomorphology and the Nonprofessional.- References.