Table Of ContentWater Science and Application 4
Geomorphic Processes and Riverine Habitat
Water Science and Application 4
Geomorphic Processes
and Riverine Habitat
Joseph M. Dorava
David R. Montgomery
Betty B. Palcsak
Faith A. Fitzpatrick
Editors
American Geophysical Union
Washington, DC
Published under the aegis of the AGU Books Board
John E. Costa, Chair; David Bercovici, Jeffrey M. Forbes, W. Rockwell Geyer, Rebecca Lange, Douglas S. Luther, Darrell
Strobel, and R. Eugene Turner, members.
Geomorphic Processes and Riverine Habitat
Water Science and Application 4
Library of Congress Cataloging-in-Publication Data
Geomorphic processes and riverine habitat /Joseph M. Dorava ...I et al.].
p.m.--(Water science and application ; 4)
Includes bibliographical references (p.).
ISBN 0-87590-353-3
1. Stream ecology--Congresses.2 . Geomorphology--Congresses. I. Dorava,
Joseph M. II. American Geophysical Union. Meeting (1998 : San Francisco, Calif. Ill.
Series.
ISBN 0-87590-353-3
ISSN 1526-758X
Copyright 2001 by the American Geophysical Union
2000 Florida Avenue, N.W.
Washington, DC 20009
Front Cover: Mosaic of land cover in the Encampment River watershed, approximately
15 kilometers northeast of Two Harbors, Minnesota along Lake Superior's North Shore.
Infrared air photographs reproduced with permission, O State of Minnesota,
Department of Natural Resources. Inset: Photograph of Peshekee River, Fall 1994,
near Champion, Upper Peninsula of Michigan by Kevin Richards, U.S. Geological
Survey, Middleton, Wisconsin.
Back Cover: A small channel with an alluvial morphology forced by logs and log jams
on Chichagof Island in Southeast Alaska (Buckhorn Creek). Photograph by David R.
Montgomery.
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CONTENTS
Preface
......................................................................
JosephM.Dorava vii
Introduction
Understanding Geomorphic Processes and Riverine Habitat
Joseph M. Dorava, David R. Montgomery, Betty B. Palcsak, and Faith A. Fitzpatrick. ................... 3
Section 1: Geomorphic and Habitat Assessments
A Comparison of Multi-Disciplinary Methods for Measuring Physical Conditions of Streams
......................................................................
FaithA.Fitzpatrick 7
Watershed Assessment with Synoptic Base-Flow Surveys
...................................................
Kenneth W Potter and Stephen J. Gafield. 19
Models of Habitat Use and Availability to Evaluate Anthropogenic Changes in Channel Geometry
.........................................................................
JamesA.Gore 27
Holocene and Recent Geomorphic Processes, Land Use, and Salmonid Habitat
in Two North Puget Sound River Basins
Timothy J. Beechie, Brian D. Collins, and George R. Pess. .......................................3 7
Section 2: Pristine Undisturbed Systems
Channel Changes and Habitat Diversity in a Warm-Water, Gravel-Bed Stream
........................................................................
RoseMcKenney 57
Biophysical Gradients Related to Channel Islands, Middle Snake River, Idaho
W R. Osterkamp, W C. Johnson, and M. D. Dixon ............................................. 73
Modeling Sediment and Wood Storage and Dynamics in Small Mountainous Watersheds
...................................
Stephen T. Lancaster, Shannon K Hayes, and Gordon E. Grant. 85
Section 3: Anthropogenically Altered Systems
Stream Geomorphology and Fish Community Structure in Channelized and Meandering Reaches
of an Agricultural Stream
Kelly M. Frothingham, Bruce L. Rhoads, and Edwin E. Herricks .................................. 105
Mass Wasting and Sediment Storage in a Small Montane Watershed:
An Extreme Case of Anthropogenic Disturbance in the Humid 'Ikopics
..............................................
Matthew C. Larsen andAbigail Santiago Rombn 119
Animal Response to River Evolution in the Tidal Freshwater Zone
..................................................................
GregoryB.Pasternack 139
CONTENTS
Spatial Variations in Channel Morphology at Segment and Reach Scales,
Middle Fork John Day River, Northeastern Oregon
Patricia R McDowell. .............................................
The Downstream Effects of Dams on the Regeneration of Riparian Tree Species in Northern Japan
Futoshi Nakamura and Nozomi Shin .......................................................1 73
Section 4: Restoration Strategies
Relations Between Streamflow, Sediment lkansport, and Aquatic Habitat in Regulated Rivers
John Pitlick and Peter Wilcock ........................................................... 185
Fluvial Processes and Passive Rehabilitation of the Lisbon Bottom Side-Channel Chute,
Lower Missouri River
Robert B. Jacobson, Mark S. Laustrup, and Michael D. Chapman ................................ 199
Mitigating Boatwake-Induced Erosion Along the Kenai River, Alaska
JosephM.Dorava ....................................................................2.1 7
Importance of Archival and Process Studies to Characterizing Pre-Settlement Riverine
Geomorphic Processes and Habitat in the Puget Lowland
Brian D. Collins and David R. Montgomery ................................................. 227
Section 5: Synthesis and Overview
Geomorphology, River Ecology, and Ecosystem Management
DavidR.Montgomer y ..................................................................2 47
PREFACE
The study of the physical and biological aspects of our surroundings has interested sci-
entists for centuries. Many physical processes, some as subtle as weathering of rock into
soil, changes in sea level, or global warming and others as violent as volcanic eruptions,
floods, or hurricanes, are influenced by and actively change the surrounding landscape.
Geomorphic processes and the landscape and biological changes that result from their
interactions are of interest to society as well as scientists because of the effects these
processes potentially have on the economic, aesthetic, and health-related aspects of our
lives. When the processes are life threatening, as in the case of volcanic eruptions or
floods, scientists and society are highly motivated to improve their understanding of the
magnitude, frequency, and predictability of future occurrences. When the consequences of
the processes are not as severe, as is the case of weathering, scientific study has been less
urgent. Quite recently, and driven in part by the decline in salmon populations throughout
the Pacific Northwest and a near continuous loss of valuable riverine habitat resulting
from human demands on the environment, there has been increasing interest in improving
our understanding of how geomorphic processes affect riverine habitat and the biotic com-
munities (including humans) that inhabit them.
This monograph describes results of recent research in fluvial geomorphology related
to the assessment and characterization of riverine and riparian habitat, and the response of
biota to changes in their environment. The contributions to the monograph are grouped
into five sections. The first section, "Geomorphic and Habitat Assessments," presents
methods and means to undertake geomorphic habitat investigations, ranging from routine
characterizations or classifications through detailed process models. The next two sec-
tions, "Pristine Undisturbed Systems" and "Anthropogenically Altered Systems," com-
pare and contrast active geomorphic processes and human disturbances. The fourth sec-
tion, "Restoration Strategies," features discussion on various restoration methods and mit-
igation strategies by way of distinctive case studies. In the monograph's closing paper,
"Geomorphology, River Ecology, and Ecosystem Management," issues involved in inte-
grating an understanding of geomorphology and riverine habitat into landscape-scale
environmental management are discussed.
A diverse group of researchers presented studies of geomorphic processes and riverine
habitat at the 1998 fall meeting of the American Geophysical Union in San Francisco,
California. The enthusiastic participation of researchers in that meeting and the reception
of the research results motivated preparation of a monograph containing recent studies on
the subject. This monograph thus brings together researchers who participated in the 1998
meeting with other contributors whose collective background and research breadth cap-
tures the diverse nature of developments on the interface of geomorphic processes and
riverine ecology. In assembling this monograph, interdisciplinary points of view are
brought together through the common focus of understanding the processes that form
riverine habitat and the interactions among these processes and humans as both occupants
and shapers of the environment.
We acknowledge, with sincere thanks, all the contributors, the numerous reviewers, and
those that provided encouragement and support for this project, including AGU staff, our
colleagues, and especially our families.
Joseph M. Dorava
Vierbicher Associates, Znc.
Understanding Geomorphic Processes and Riverine Habitat
Joseph M. ~orava'D, avid R. ~ o n t ~ o r n eBre~tty~ B,. palcsak3, and Faith A. ~itz~atrick~
INTRODUCTION logic for how to rebuild a complex system without an in-
struction manual: assess the ecosystem's condition; com-
It is increasingly recognized that many interesting re- pare its condition to systems in an undisturbed state; de-
search opportunities lie on the interface between traditional termine the desired condition; hypothesize actions neces-
scientific disciplines. In particular, the influence of geo- sary to rehabilitate, restore, or modify key aspects of the
morphic processes on riverine habitat is central to contem- system to attain the desired condition(s); take those ac-
porary programs of river restoration. The role of geomor- tions; monitor and assess the results; and modify the ap-
phologists in ecological studies ranges from understanding proach if the results prove less than desired. This general
habitat-forming mechanisms to defining disturbance re- framework for guiding landscape management from as-
gimes and restoration or rehabilitation objectives. It has sessment to restoration includes studies of the interactions
proven difficult to integrate the efforts of multiple scien- between geomorphology and ecology that address geomor-
tific disciplines when evaluating the effects of humans on phic and habitat assessments, undisturbed and anthropo-
the environment and understanding the complex interac- genically altered systems, and restoration strategies.
tions of natural processes constantly changing the land-
scape. This monograph brings together the work of numer-
ous researchers primarily focused on the study of fluvial Geomorphic and Habitat Assessments
geomorphic processes that create or alter riverine habitats
in an effort to improve our understanding and assessment A wide array of geomorphic and habitat assessments are
of geomorphic processes, to enhance communication presently in use for various applications. These assess-
among scientists, and to integrate the results of ongoing ments range from interpretive check lists of features, to
and future studies. score cards on which system traits are tallied to assess
overall system condition, to classifications of objects (such
FROM ASSESSMENT TO RESTORATION as channel reaches) in manners considered to have
interpretive power, each of which has advantages and
Landscape management for ecosystem restoration or re- disadvantages for practical applications. As a result, in this
habilitation purposes should follow a relatively simple monograph, Fitzpatrick describes various assessment tech-
niques and their use in various studies. Potter and GafJield
show how synoptic baseflow surveys can be used toiden-
'water Resources Department, Vierbicher Associates Inc.,
tify channels within a watershed that have very different
Reedsburg, Wisconsin
habitat characteristics and hydrology to reveal a pattern
2~epartmenotf Earth & Space Sciences, University of Wash-
that would not be identified by typical channel assessment
ington, Seattle, Washington
3~ateRr esources Division, u.S. Geological Survey, Lake- protocols. Gore describes several examples of the applica-
wood. Colorado tion of habitat simulation models to stream restoration.
4~ateRre sources Division, U.S. Geological Survey, Middle- Beechie et al. demonstrate how post-glacial landscape
ton, Wisconsin evolution and recent human activity have changed valley-
bottom landforms and salmonid habitats. These studies
illustrate the wide range of scales over which geomorphic
Geomorphic Processes and Riverine Habitat and habitat assessments can provide structure to the under-
Water Science and Application Volume 4, pages 3-4 standing of interactions between geomorphology and river
Copyright 2001 by the American Geophysical Union ecology.
4 UNDERSTANDING GEOMORPHIC PROCESSES AND RIVERTNE HABITAT
Undisturbed and Anthropogenically Altered Systems Restoration Strategies
Once an initial assessment of the system of interest is The primary goal of ecosystem management is often res-
complete, restoration or rehabilitation programs require toration of a disturbed system. The final section of this
evaluation of current conditions against some benchmark monograph describes various aspects of developing and
expectations, objectives, or reference conditions, which are implementing restoration strategies. Just as for geomorphic
typically based on comparison with a similar undisturbed and habitat assessments, restoration strategies can be cast
system. Evaluation of undisturbed landscapes is essential over a wide range of scales. Perhaps one of the most im-
for defining the degree to which anthropogenically altered portant, and overlooked, elements of any restoration strat-
landscapes have been disturbed ecologically. Such an as- egy is clearly articulated goals. Pitlick and Wilcock address
sessment is central to ecosystem management and in par- how to set what in many western US, river systems is a
ticular for developing landscape rehabilitation and restora- particularly contentious issue-how much flow does a
tion plans. Hence, the second and third sections of this river need? In addressing this basic attribute of aquatic
volume address studies of undisturbed and anthropogeni- habitat, Pitlick and Wilcock use the flow conditions associ-
cally altered systems. ated with the onset of different styles of sediment transport
A common theme throughout this monograph concerns to define minimum flow regimes necessary to maintain
the need to understand the particular landscape or water- channel morphology and characteristics. Jacobson et al.
shed in question within the context of its geological, geo- explore passive approaches to channel restoration-the
morphic, and cultural history. Compare, for example, the attractive idea of letting the river do the work. Their docu-
dominant processes controlling habitat diversity in the mentation of progressive changes in an evolving side-
warm-water, gravel-bed stream studied by McKenney with channel along the Missouri River illustrates the inherent
those influencing channel island formation in the Snake (although not inexhaustible) resilience of river systems.
River, as studied by Osterkamp et al. A clear example of Dorava shows how simple changes in human actions or
the need to understand the dominant processes acting in a behavior can dramatically reduce erosion of riverbanks and
watershed and how wood debris that forms stable log jams disturbance of aquatic ecosystems, if people are willing to
mediates sediment export from small, debris-flow prone accept changes in how they conduct their recreational ac-
headwater streams in the Oregon Coast Range is provided tivities. Collins and Montgomery show how process studies
by Lancaster et al. Their simulations show the importance and archival methods are complementary approaches for
of understanding both anthropogenically altered (wood- generating an understanding of a place adequate for evalu-
poor) and undisturbed (wood-rich) channel conditions in ating restoration plans and options.
trying to connect geomorphological processes to ecological As discussed in the final synthesis chapter by Montgom-
systems. In addition, Larsen and Rombn show how the ery, there are many exciting research opportunities on the
legacy of past disturbances can dominate sediment storage frontier between geomorphology and ecology. These op-
in a channel system. Frothingham et al. report how portunities and new approaches can be integrated into the
changes in channel reach morphology, and in particular, development of landscape management, recovery, and res-
the associated habitat complexity, can influence fish com- toration plans with an improved understanding of the inter-
munity structure. Nakamura and Shin explore the striking active processes. We hope that this monograph will help
effects of flow regulation by dams on the disturbance ecol- catalyze further interest in the study of the influences of
ogy, and therefore stand composition and age structure, of geomorphic processes on riverine habitat, as well as other
riparian forests in Japan. McDowell provides an example ecological systems.
of how local variability in valley width structures channel
Joseph M. Dorava, Water Resources Department, Vierbicher
morphology and valley-bottom ecosystems, a finding that
Associates Inc., 400 Viking Drive, P.O. Box 379, Reedsburg, WI
contrasts with the patterns anticipated by the popular River
53959.
Continuum Concept. Pasternack describes how the actions
Faith A. Fitzpatrick, Water Resources Division, U.S. Geologi-
of animals can counteract anthropogenic alteration of val-
cal Survey, 8505 Research Way, Middleton, WI 53562.
ley-bottom hydrologic conditions and landforms. In total,
David R. Montgomery, Department of Earth & Space Sci-
these papers show the rich variety of geomorphological ences, University of Washington, Seattle, WA 98195-13 10.
processes that influence ecological systems, and thereby Betty B. Palcsak, Water Resources Division, U.S. Geological
underscore the importance of incorporating a high level of Survey, Box 25046, MS 415, Denver Federal Center, Lakewood,
understanding into landscape and watershed management. CO 80225.
A Comparison of Multi-Disciplinary Methods for Measuring
Physical Conditions of Streams
Faith A. Fitzpatrick
US. Geological Survey, Water Resources Division, Middleton, Wisconsin
A wide range of scientists, including fluvial geomorphologists, ecologists, fisheries
managers, and river engineers, study human impacts on the physical characteristics
of streams. Data gathered for stream physical conditions are useful for water- and
fish-resource management, water-quality monitoring, and stream restoration. The
physical condition of streams reflects a variety of natural and anthropogenic effects
and multiple spatial and temporal scales. Thus, systematic approaches among scien-
tific disciplines differ in terms of spatial and temporal scales of measurement and are
heavily dependent on the academic background and field experience of the investiga-
tors. Data-collection efforts range from rapid, qualitative descriptions and categoriza-
tions to more time-consuming quantitative measurements. Most geomorphic assess-
ments, stream classifications, and habitat characterizations measure similar key hy-
drologic and geomorphic features, even though individual methodologies may differ
substantially. These key features include channel morphology and planform, valley
and channel gradient or slope, sediment characteristics and movement, and bank
characteristics. This paper examines several commonly used habitat characteriza-
tions, stream classifications, and geomorphic assessments in terms of how they effec-
tively measure the physical condition of streams that are most likely to change in re-
sponse to land-cover perturbations. Advantages and disadvantages of each type of
assessment are discussed in the context of potential study goals and outcomes, and
time, labor, and expertise constraints. The major goal of this paper is to promote
communication among ecologists, geomorphologists, fisheries managers, and engi-
neers, thereby reducing duplication of effort and increasing the utility of methods
used to describe the physical characteristics of streams. By improving the under-
standing of the geomorphic processes within a watershed and their effect on physical
features in a stream channel, various scientific disciplines will make better interpreta-
tions of the development of riverine habitat. Adjustments in sampling routines for
each discipline may then create a complementary and more uniform data set from
which decision makers can develop management strategies.
INTRODUCTION vegetation, and base level (the level, or elevation, at which
a stream enters a major water body). A change in any of
Streams are dynamic features that adjust their physical these independent factors may alter streamflow and sedi-
characteristics to prevailing climate, geology, topography, ment movement. Human-induced changes in vegetation for
agriculture, silviculture, or urban development have oc-
curred in almost every watershed in North America. Con-
version of land fiom forest or agriculture to urban is a
Geomorphic Processes and Riverine Habitat
common occurrence across much of the United States.
Water Science and Application Volume 4, pages 7-18
Increases in impervious surfaces fiom parking lots, roads,
Copyright 2001 by the American Geophysical Union
and buildings result in a decrease in the time to peak and
7
8 A COMPARISON OF MULTI-DISCIPLINARY METHODS
an increase in the volume and magnitude of floods [for terms of how they effectively measure the physical condi-
example Morisawa and LaFlure, 1979; Schueler, 1994; tion of streams and the geomorphic processes responsible
Sovern and Washington, 19971. In addition, urbanization for their formation. Five major characteristics are dis-
can increase or decrease low flows by increasing effluent cussed here: channel geometry or morphology, channel
discharge or decreasing groundwater contributions [for planform, channel gradient or slope, bank conditions, and
example Snodgrass et al., 1997; Sovern and Washington, sediment characteristics such as size and movement. By
19971. Sediment supply may increase during the construc- closing the gap between specific disciplines and improving
tion phase but eventually decrease after grass, pavement, their understanding of geomorphic processes each will
and buildings cover most of the urban landscape [Wolman, have a better interpretation of the development of aquatic
19671. habitat. Minor adjustments in data collection may also lead
In the process of responding to changes in flood charac- to a more complementary and uniform geomorphic data set
teristics and sediment supply and transport, stream chan- that will assist natural resources managers.
nels alter their physical characteristics of channel geome-
try, planform, gradient, or base level [Leopold and Mad- CHARACTERIZATION OF A STREAM'S PHYSICAL
dock, 1953; Wolman, 1967; Wolman and Schick, 1967; CONDITION
Hammer, 1972; Gregoly and Madew, 1982; Booth and
Jackson, 19971. Channel adjustments in response to land- Geomorphic principles are useful for determining a
cover perturbations are dependent on the position of the stream's response to changes in water discharge or sedi-
stream within the stream network and can occur over time ment transport caused by watershed land-cover change.
periods as brief as individual storms to as long as thou- Schumm's [I9691 qualitative model of channel metamor-
sands of years [Schumm, 1977; Fitzpatrick et al., 1999; phosis describes the geomorphic response of a channel to
Fitzpatrick and Knox, 20001. Channels in an erosional changes in discharge and sediment load. For increasing
zone of a stream network may become steeper and have discharge and sediment loads, the following proportional
eroding stream banks and channel beds, whereas channels relations are possible:
in the depositional zone of a stream network will become
filled with sediment as the additional material from up-
stream is deposited. Over time, continued erosion eventu- where Q is discharge, Q, is sediment load, W is channel
ally reduces the stream gradient until deposition becomes width, D is channel depth, F is widthldepth ratio, h is me-
the dominant sediment process (Hey, 1979). For manage- ander wavelength, S is slope, and P is sinuosity. If dis-
ment purposes, channels experiencing form adjustments charge and sediment load increase, as typically the case
are viewed as being unstable. These hydrogeomorphic during the early stages of urbanization, the expected geo-
adjustments may have substantial effects on aquatic life morphic responses will be increases in channel width,
(for example Wang et al., 1997; Finkenbine et al., 2000). widthldepth ratio, and meander wavelength; a decrease in
Interest in measuring the effects of changes in land cover sinuosity; and increases or decreases in depth and slope.
on the physical characteristics of streams draws scientists Lane's [I9551 description of equilibrium also gives
together from many different backgrounds, including flu- some indication of possible outcomes for sediment size
vial geomorphologists, ecologists, fisheries managers, and and slope:
river engineers. Each discipline has developed field tech-
niques suitable for its area of expertise. Geomorphologists
tend to specialize at multiple scale studies of channel and A stream will adjust its slope (S) and sediment size (d) in
flood-plain characteristics with an important historical or response to changes in discharge and sediment load. These
time component [Knox, 1977; Patrick et al., 1982; Fitz- relations are important for quantifying data and determin-
patrick et al., 19991. Ecologists typically focus on physical ing direction of change and possible causes for geomorphic
features that may be limiting factors for aquatic communi- response [Patrick, et al., 19821. Lane 's [I9551 proportion-
ties, typically fish [Simonson et al., 1994al. River engi- ality has a theoretical base-for a fixed width and straight
neers more commonly concentrate on measurements of channel, equations can be derived from solution of conti-
current hydraulic conditions for purposes of flood control, nuity, resistance, and bed material transport equations.
navigation, irrigation, remediation, and channel stabiliza- Therefore, physical measurements of channel morphology,
tion [Chang, 19921. planform, gradient, and sediment load are important for
This paper attempts to bring together the disciplines of characterizing the physical changes that occur in streams
fluvial geomorphology, ecology, and river engineering by following changes in land cover (Table 1).
providing some background information on several widely Typical aquatic habitat assessments may not be adequate
used field techniques. These techniques are examined in to reveal the inherent relations among land use, subsequent
