Fluvial Processes In Dryland Rivers

Transcription

1 WILLIAM L. GRAF Fluvial Processes In Dryland Rivers

2 Reprint of First Edition, Copyright 1988 Copyright 2002 by William L. Graf All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted by any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, except as may be expressly permitted by the applicable copyright statutes or in writing by the publisher. Fluvial Processes in Dryland Rivers ISBN: Librav of Congress Card Number: TIlE BLACKBURN PRESS P. O. Box 287 Caldwell, New Jersey U.S.A

3 Part I Basic Perspectives 1 Introduction Fluvial Geomorphology An Overview Distribution of Drylands Drylands on Other Planets... I0 1.2 Early Research in the American West Newberry King, Hayden, and Marvine Powell Dutton Gilbert Early Developments from Other Drylands Africa... 2 l Asia South America and Australia Theoretical Perspectives Scientific Methods Logical Positivism Falsification Critical Rationalism General Systems Concepts Temporal Concepts I Uniformitarianism Evolution Equilibrium Rate Laws Spatial Concepts Regions Networks Distance Decay Integrative Concepts Thresholds and Complex Responses Scale Magnitude and Frequency... 56

4 XII Allometric Change Entropy Catastrophe Theory Part II Processes and Forms 3 Surface Water in Drylands Dryland Precipitation I. 1 Mechanisms Spatial and Temporal Characteristics Data Availability Runoff Soil Conservation Service Method Rational Method Impact of Human Activities Streamflow and Floods Streamflow Force, Stress, and Power Types of Dryland Floods Transmission Losses Magnitude and Frequency Significance of Various Flow Magnitudes Sheetfloods Paleohydrology Paleohydrologic Evidence Estimation of Paleoflow Parameters Extension of the Flood Record Fluvial Sediment in Dryland Rivers Sediment Characteristics I. 1 Size, Sorting, and Shape Fabric Facies Sediment Yield from Drainage Basins Factors Controlling Erosion Estimation of Erosion Sediment Yield From Basins Spatial Variation of Sediment Yield Sediment Transport in Dryland Rivers Sediment in Dryland Rivers Suspended Sediment Transport Bedload Sediment Transport Total Load Estimations Definitions and Dimensions Movement of Sediment in Pulses

5 i... XIII 4.4 Contaminants Heavy Metals and Placers Radionuclides Dryland Perspectives Process-Form Relationships Badlands and Piping Processes Badlands Rates of Badland Erosion Piping Pediments Definition, Description, and Distribution Origin Fluvial Processes on Pediments Hazards Alluvial Fans Definition, Description, and Distribution Materials Origins Modem Processes Hazards on Alluvial Fans Channels and Flood Plains Channel Patterns and Controls Channel Change and Recovery Horizontal Instability Flood Plains Near-Channel Hazardous Environments Entrenched Channels Entrenchment Process Causes of Entrenchment Processes in Entrenched Channels Valley Fills Three Landscapes Part HI Modifications of Processes and Forms 6 Vegetation and Dryland Rivers Upland Vegetation Influences on Runoff Influence on Sediment Yield Influence on Channels Impact of Fire Riparian Vegetation Hydrologic Connections Impacts on Channels

6 XIV Exotic Vegetation - Example of Tamarisk Conclusions Direct Human Impacts on Dryland Rivers Upstream Impacts of Dams l.l Impacts on Processes Reservoir Deposits Reservoir Sediment Budgets Impacts Upstream from Backwater Downstream Impacts of Dams Regime Changes by Darns Degradation and Armoring Width and Pattern Changes Impacts on Non-Alluvial Channels Impact of Dams on Riparian Vegetation Impacts of Urban Development Physical Changes Caused by Urbanization Fluvial Responses to Urbanization hnpacts of Agricultural Development Conclusions Generalizations for Dryland Rivers Toward an Integrated Theory Fundamental Precepts Processes and Forms Modifications of Processes and Forms Utility of Generalizations Geomorphology as a Natural Science Geomorphology and Engineering Geomorphology and the Law Geomorphology and Planning-Management Geomorphology and the Nonprofessional 301 References Subject Index