Water Resources Monograph 12. River Meandering. SyunsukeIkeda. Gary Parker. Editors. American Geophysical Union

Transcription

1 Water Resources Monograph 12 River Meandering SyunsukeIkeda Gary Parker Editors American Geophysical Union

2 Published under the aegis of the AGU Water Resources Monograph Board. Library of Congress Cataloging-in-Publication Data River meandering Syunsuke Ikeda and Gary Parker, editors. p. cm. - (Water resources monograph: 12) ISBN Meandering rivers. I. Ikeda, Syunsuke. II. Parker, Gary. III. Series. GB1205.R '3-dc Copyright 1989 by the American Geophysical Union, 2000 Florida Avenue, NW, Washington,,DC Figures, tables, and short excerpts may be reprinted in scientific books and journals if the source is properly cited. Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is granted by the American Geophysical Union for libraries and other users registered with the Copyright Clearance Center (CCC) Transactional Reporting Service, provided that the base fee of $1.00 per copy, plus $0.10 per page is paid directly to CCC, 21 Congress Street, Salem, MA /89/$ This consent does not extend to other kinds of copying, such as copying for creating new collective works or for resale. The reproduction of multiple copies and the use of full articles or the use of extracts, including figures and tables, for commercial purposes requires permission from AGU. Printed in the United States of America.

3 CONTENTS Boundary Shear Stress and Sediment Transport in River Meanders of Sand and Gravel, by Willianl E. Dietrich and Peter Whiting 1 Sedimentary Controls on Channel Migration and Origin of Points Bars in Sand-Bedded Meandering Rivers, by Hiroshi Ikeda 51 Flow in Meandering Channels with Natural Topography, by Jonathan 1v1. Nelson and J. Dungan Smith 69 Sedinlent Transport and Sorting at Bends, by Syunsuke Ikeda 103 Sediment Control by Submerged Vanes. Odgaard and Anita Spoljaric 127 Design Basis, by A. Jacob Q.., Analysis ofn-d Bed Topography Model for Rivers, by Nico Struiks111a and AI~ssandra Crosato 153 Linear Theory of River 1\1eanders, by I-Ielgi Johannesson and Gary Parker 181 Studies on Qualitative and Quantitative Prediction of Meander Channel Shift, by I(azuyoshi Hasegawa 215 Finite Amplitude Development of Alternate Bars, by Shoji Fukuoka 237 Alternate Bars and 1\1eandering; Free, Forced and 1\.fixed Interactions, by G. Seminara and 1\1. Tubino 261 Evolution and Stability of Erodible Channel Beds, by Jonathan 1\/1. Nelson and J. Dungan Slnith 321 Observations on Several Recent Theories of Resonance and Overdeepening in 1\1eandering Channels, by Gary Parker and Helgi Johannesson 379 Bar and Channel Forluation in Braided Streanls, by Yuichiro Fujita 417 Topographic Response of a Bar in the Green River, Utah to Variation in Discharge, by E.D. Andrews and J. 1\1. Nelson 463 iii

4 PREFACE River channel pattern comes in three flavors: straight, meandering, and braided. Of these, meandering is perhaps the most common, but at the same time the most mysterious: it is strikingly rich in pattern, yet is encumbered with neither the sterile order of its straight cousin, nor the undecipherable disorder of its braided relative. Consider Figures 1 and 2 herein. The former is of the artificially straightened Naka River, Shikoku, Japan. Thwarted in its quest for a meandering planform, the river has, nevertheless, generated of its own the precursor known as alternate bars. In the latter photograph, a pair of images of the East Nishnabotna River, Iowa, USA, illustrate the elegance of the sinuous river, and the inexorable migration and deformation of bends so characteristic of freely meandering strealns. The inception and growth of meander bends, and their eventual demise through the mechanism of cut-off formation, have been treated by many, and the literature on the subject lies scattered about the world in such fields as hydraulics, geology, and geography. This volume represents an attempt to dra\v together an international group of theoretical researchers at the cutting edge, supplemented with several leading field-oriented researchers. (Indeed, some among our numbers comfortably occupy both camps.) The underlying philosophy \vas an attempt to extract from the various schools a more unified understanding of the mechanics of meandering, as a base from which to build for the future. The concept \vas originally born in 1981, in a letter communicated fron1 S. Ikeda to G. Parker. It developed rapidly in the aftermath of the Specialty Conference on River Meandering, held in Ne\v Orleans in 1983 under the sponsorship of the American Society of Civil Engineers. Eventually, our proposal, "Development and Application of the Theory of River Meandering", was adopted in 1985 by the U.S. National Science Foundation and the Japan Society for the Promotion of Science, as a bilateral research project. This monograph is not simply a collection of papers from a conference, but rather the product of a joint research effort of unique and unusual character. In order to appreciate the mood of the volunle, it is of use to describe hovv the project proceeded. The core group of participants \\Tas chosen to consist of five Japanese and five Americans, all relatively young. (These \vords will surely come back to haunt us.) The research was organized about three workshops. The first of these, held in Tokyo in July of 1985, was en1bedded in the midst of a t,vo-week tour of rivers and research facilities, one that,vas to take us to three of the four lnajor islands of Japan. Naturally, the Naka River, sho,vn in Figure 1, was on the itinerary. The second \vorkshop was held in September of 1986, at the Brinkerhoff House, a lodge on Jenny Lake, Grand Teton v

5 vi PREFACE Figure 1. Alternate bars in the Naka River, Tokushima Prefecture, Japan (courtesy Tokushima Construction Office, Ministry of Construction, Japan). National Park, Wyoming (Figure 3). It was part of a similar two-week series of site visits which eventually included nine rivers in California, Wyoming, Iowa (Le. the East Nishnabotna River), and Minnesota. The third and final workshop was held at Poipu Beach, Kauai, Hawaii, in October of 1987 (Figure 4). The researchers were in contact not only during the workshops, but through the length of the site visits. We travelled together, ate together, and often jointly occupied hotel rooms. During our stay at Jenny Lake, we even washed dishes and swept the floor together, and in a cooperative effort of special import, chased a bear off the veranda. The workshops were all of relatively free format, with the emphasis on active, and often heated discussion. The' extended period together helped greatly to reduce the language barrier, and facilitated a seemingly unending interplay of ideas. A

6 Ikeda and Parker vii Figure 2. The meandering East Nishnabotna River just south of Red Oak, Iowa: (left) October 5, 1973; (right) May 25, Channel migration can be clearly discerned (courtesy A. J. Odgaard). spin-off of this atmosphere is an exchange of researchers that continues until this day. In order to provide a more complete perspective on the problem, two leading European researchers were invited to participate in the final workshop. The monograph thus includes fourteen papers authored by: the Japanese,

7 viii PREFACE Figure 3. The second workshop, held at Brinkerhoff House, Jenny Lake, Wyoming, on September 8, American, and European participants and their graduate students. It is fair to say that no individual came out of the workshops without a significantly changed perspective on the problem of river meandering. The participants thus included eight civil engineers, three geologists, and a geographer. The tone of the monograph is mechanistic and interdisciplinary. The interplay between theory, computation, experiment, and field observation Figure 4. The third workshop, held at the Poipu Beach Sheraton Hotel, Kauai, Hawaii, on October 21, 1987.

8 Ikeda and Parker ix is fully exploited. One sign evidencing the heightened spirit of cooperation and understanding is the prodigious cross-referencing among the papers. The list of people and organizations deserving thanks for making this effort possible is long. First and foremost are the U.S. National Science Foundation and the Japan Society for the Promotion of Research, who provided the funding. In Japan, the Ministry of Construction and the I-Iokkaido Development Bureau deserve special thanks. In the United States, the Department of the Interior and the Army Corps of Engineers greatly facilitated the program. Various graduate students from the University of California, Berkeley and the University of Minnesota drove vehicles for us. Professor J. F. I(ennedy kindly made a personal trip to the East Nishnabotna River to show us the "Iowa Vanes" being tested there as a means of preventing bank erosion. Patricia Swanson, Diana Dalbotten, and Donna Elftmann spent long hours typing and editing the papers to a common format, enabling us to meet the many externally-imposed deadlines. It is our hope that the volume represents a \vatershed in progress on river meandering, and a stimulus to younger researchers who might be inclined to en1bark upon the study of this most elegant and beautiful of natural phenomena. Syunsuke Ikeda Gary Parker