Geological Survey Professional Paper 669 The Colorado River Region and John Wesley Powell

THE RAPIDS AND THE POOLS—GRAND CANYON

By
Luna B. Leopold

The rapids and the profile of the Colorado River.

Cover

Foreword

(A) John Wesley Powell: Pioneer statesman of Federal science, by Mary C. Rabbitt

(B) Stratified rocks of the Grand Canyon, by Edwin D. McKee

(C) Geologic history of the Colorado River, by Charles B. Hunt

(D) The rapids and the pools—Grand Canyon, by Luna B. Leopold

Abstract
General statement
Concept of quasi-equilibrium
Response of a river in a rock canyon
   Types of waves and causes of rapids
   Nature and transport of material on the riverbed
Summary
References

FIGURE

86. Photograph showing flow-measurement gear being readied for observations of velocity and depth

87. Cumulative curves showing distribution of river widths and depths in Grand Canyon

88. Photograph showing Hance Rapids

89. Map and profile of Colorado River near Unkar Rapid

90. Photograph looking downstream at Unkar Rapid

91. Diagrammatic sketches showing four types of water waves occurring in rapids

92. Photograph showing a rapid due primarily to convergence where rockbound channel narrows in a part of Granite Gorge

93. Photograph showing rapids unrelated to any tributary entrance and presumably caused by large gravel bar deposited on streambed

94. Graph showing relation of fall in elevation of Colorado River to river distance

95. Diagrams showing channel cross sections, bed and surface velocities, and water-surface appearance near Unkar Rapid

96. Graphs showing changes in flow characteristics during a 10-month period at Lees Ferry

97. Profile of the Colorado River through the Grand Canyon