Geology topics
Cliff R. Hupp
Publications and source records attributed to Cliff R. Hupp.
The interactions between vegetation and erosion: new directions for research at the interface of ecology and geomorphology
Vegetation and processes of erosion and deposition are interactive. An objective of this paper is to review selected studies that emphasize the interdependencies. The reviews suggest new directions for research uniting ecology and geomorphology – the sub‐discipline of biogeomorphology. The research, which recently has become vigorous, includes the sources, movement, and fates of fluvial loads of sediment, organic carbon, nutrients, contaminants, and woody debris to low‐energy storage sites; the function of biota in causing soil evolution, stability, and sequestration of carbon; the development of new methods to characterize watersheds based on edaphic conditions; and the refinement of current empirical and conceptual models and dendrochronological techniques to measure landscape change. These well acknowledged topics and others less well anticipated ensure that biogeomorphology will remain vibrant.
Distribution and characterization of in-channel large wood in relation to geomorphic patterns on a low-gradient river
A 177 river km georeferenced aerial survey of in-channel large wood (LW) on the lower Roanoke River, NC was conducted to determine LW dynamics and distributions on an eastern USA low-gradient large river. Results indicate a system with approximately 75% of the LW available for transport either as detached individual LW or as LW in log jams. There were approximately 55 individual LW per river km and another 59 pieces in log jams per river km. Individual LW is a product of bank erosion (73% is produced through erosion) and is isolated on the mid and upper banks at low flow. This LW does not appear to be important for either aquatic habitat or as a human risk. Log jams rest near or at water level making them a factor in bank complexity in an otherwise homogenous fine-grained channel. A segmentation test was performed using LW frequency by river km to detect breaks in longitudinal distribution and to define homogeneous reaches of LWfrequency. Homogeneous reaches were then analyzed to determine their relationship to bank height, channel width/depth, sinuosity, and gradient. Results show that log jams are a product of LW transport and occur more frequently in areas with high snag concentrations, low to intermediate bank heights, high sinuosity, high local LW recruitment rates, and narrow channel widths. The largest concentration of log jams (21.5 log jams/km) occurs in an actively eroding reach. Log jam concentrations downstream of this reach are lower due to a loss of river competency as the channel reaches sea level and the concurrent development of unvegetated mudflats separating the active channel from the floodplain forest. Substantial LW transport occurs on this low-gradient, dam-regulated large river; this study, paired with future research on transport mechanisms should provide resource managers and policymakers with options to better manage aquatic habitat while mitigating possible negative impacts to human interests.
Fluvial processes and vegetation - Glimpses of the past, the present, and perhaps the future.
"Most research before 1960 into interactions among fluvial processes, resulting landforms, and vegetation was descriptive. Since then, however, research has become more detailed and quantitative permitting numerical modeling and applications including agricultural-erosion abatement and rehabilitation of altered bottomlands. Although progress was largely observational, the empiricism increasingly yielded to objective recognition of how vegetation interacts with and influences geomorphic process. A review of advances relating fluvial processes and vegetation during the last 50 years centers on hydrologic reconstructions from tree rings, plant indicators of flow- and flood-frequency parameters, hydrologic controls on plant species, regulation of sediment movement by vegetation, vegetative controls on mass movement, and relations between plant cover and sediment movement. Extension of present studies of vegetation as a regulator of bottomland hydrologic and geomorphic processes may become markedly more sophisticated and widespread than at present. Research emphases that are likely to continue include vegetative considerations for erosion modeling, response of riparian-zone forests to disturbance such as dams and water diversion, the effect of vegetation on channel and bottomland dynamics, and rehabilitation of stream corridors. Research topics that presently are receiving attention are the effect of woody vegetation on the roughness of stream corridors and, hence, processes of flood conveyance and flood-plain sedimentation, the development of a theoretical basis for rehabilitation projects as opposed to fully empirical approaches, the effect of invasive plant species on the dynamics of bottomland vegetation, the quantification of below-surface biomass and related soil-stability factors for use in erosion prediction models, and the effect of impoundments on downstream narrowing of channels and accompanying encroachment of vegetation. Bottomland vegetation partially controls and is controlled by fluvial-geomorphic processes. The purposes of this paper are to identify and review investigations that have related vegetation to bottomland features and processes, to distinguish the present status of these investigations, and to anticipate future research into how hydrologic and fluvial-geomorphic processes of bottomlands interact with vegetation."
Bank erosion, mass wasting, water clarity, bathymetry and a sediment budget along the dam-regulated Lower Roanoke River, North Carolina
Dam construction and its impact on downstream fluvial processes may substantially alter ambient bank stability, floodplain inundation patterns, and channel morphology. Most of the world's largest rivers have been dammed, which has prompted management efforts to mitigate dam effects. Three high dams (completed between 1953 and 1963) occur along the Piedmont portion of the Roanoke River, North Carolina; just downstream, the lower part of the river flows across largely unconsolidated Coastal Plain deposits. To document bank erosion rates along the lower Roanoke River, more than 700 bank erosion pins were installed along 124 bank transects. Additionally, discrete measurements of channel bathymetry, water clarity, and presence or absence of mass wasting were documented along the entire 153-kilometer-long study reach. Amounts of bank erosion in combination with prior estimates of floodplain deposition were used to develop a bank erosion and floodplain deposition sediment budget for the lower river. Present bank erosion rates are relatively high [mean 42 milimeters per year (mm/yr)] and are greatest along the middle reaches (mean 60 mm/yr) and on lower parts of the bank on all reaches. Erosion rates were likely higher along upstream reaches than present erosion rates such that erosion rate maxima have migrated downstream. Mass wasting and water clarity also peak along the middle reaches.
Sources, transport, and storage of sediment at selected sites in the Chesapeake Bay Watershed
The Chesapeake Bay Watershed covers 165,800 square kilometers and is supplied with water and sediment from five major physiographic provinces: Appalachian Plateau, Blue Ridge, Coastal Plain, Piedmont, and the Valley and Ridge. Suspended-sediment loads measured in the Chesapeake Bay Watershed showed that the Piedmont Physiographic Province has the highest rates of modern (20th Century) sediment yields, measured at U.S. Geological Survey streamflow-gaging stations, and the lowest rates of background or geologic rates of erosion (~10,000 years) measured with in situ beryllium-10. In the agricultural and urbanizing Little Conestoga Creek Watershed, a Piedmont watershed, sources of sediment using the 'sediment-fingerprinting' approach showed that streambanks were the most important source (63 percent), followed by cropland (37 percent). Cesium-137 inventories, which quantify erosion rates over a 40-year period, showed average cropland erosion of 19.39 megagrams per hectare per year in the Little Conestoga Creek Watershed. If this erosion rate is extrapolated to the 13 percent of the watershed that is in cropland, then cropland could contribute almost four times the measured suspended-sediment load transported out of the watershed (27,600 megagrams per hectare per year), indicating that much of the eroded sediment is being deposited in channel and upland storage. The Piedmont has had centuries of land-use change, from forest to agriculture, to suburban and urban areas, and in some areas, back to forest. These land-use changes mobilized a large percentage of sediment that was deposited in upland and channel storage, and behind thousands of mill dams. The effects of these land-use changes on erosion and sediment transport are still being observed today as stored sediment in streambanks is a source of sediment. Cropland is also an important source of sediment. The Coastal Plain Physiographic Province has had the lowest sediment yields in the 20th Century and with sandy soils, contributes little fine-grained sediment. In the agricultural Pocomoke River Watershed, a Coastal Plain watershed, cesium-137 mass-balance results indicate that erosion and deposition are both occurring on cropland fields. Sources of sediment using the sediment-fingerprinting approach for the Pocomoke River were distributed as follows: cropland (46 percent), ditch beds (34 percent), ditch banks and streambanks (7 percent), and forest (13 percent). Cropland was a source of sediment for the two largest peak flow events, which occurred during harvesting when the ground may have been bare. The Pocomoke River Watershed is heavily ditched and channelized, conditions that are favorable for ditch bed and bank erosion. In the mixed land use (forested, agricultural, and urbanizing) Mattawoman Creek Watershed, a Coastal Plain watershed, sources of sediment using the sediment-fingerprinting approach were distributed as follows: streambanks (30 percent), forest (29 percent), construction (25 percent), and cropland (17 percent). Mattawoman Creek Watershed drains a rapidly developing region with 182 hectares (approximately 1.26 percent of the watershed) under construction. Sediment from construction sites was also determined as a source of sediment in the Mattawoman Creek Watershed. The sediment-fingerprinting source results for the three watersheds analyzed, show that in all watersheds, both the stream corridor and agriculture were significant sources of sediment. Forest as a source of sediment in the Mattawoman Creek Watershed may indicate that these forests are being disturbed and forest soils are eroding. Bare ground can be an important sediment source. Spatial analysis of bare ground in the Little Conestoga Creek Watershed using satellite imagery between 2000 and 2005 showed that the majority of bare ground was classified as pasture. Bare ground was correlated to the growing season with the highest percentages occurring in the early spring (April, 34 percent) and a
Synthesis of U.S. Geological Survey science for the Chesapeake Bay ecosystem and implications for environmental management
The purpose of this report is to present a synthesis of the USGS Chesapeake Bay science related to the 2001-06 goals and provide implications for environmental management. The report provides USGS findings that address the science needs of the Chesapeake Bay Program (CBP) restoration goals and includes summaries of 1. land-use change; 2. water quality in the watershed, including nutrients, sediment, and contaminants; 3. long-term changes in climate and estuarine water quality; 4. estuary habitats, focusing on submerged aquatic vegetation (SAV) and tidal wetlands; and 5. factors affecting fish and waterbird populations.
Geo-botanical evidence of Late Quaternary mass wasting in block field areas of Virginia
Studies of block fields at Massanutten Mountain, Virginia, document and provide information on the magnitude and frequency of mass movement on these coarse-grained slopes. Although Pleistocene periglacial climate may have facilitated original formation of block fields, some block fields now continue to spread downslope during intense runoff events. Present block-field mass wasting may be the principal erosional process in these areas of resistant rock.
The U.S. Geological Survey and the Chesapeake Bay – The role of science in environmental restoration
The Chesapeake Bay is the Nation's largest estuary and historically supported one of the most productive fisheries in the world. In addition to supporting aquatic communities and wildlife, the bay's watershed serves the economic and recreational needs of 15 million people. The fertile soils of the watershed support significant agricultural production. Unfortunately, the commercial, economic, and recreational value of the bay and its watershed has been degraded by poor water quality, loss of habitat, and overharvesting of living resources. Since the early 1980's, the Chesapeake Bay Program, which is a partnership among Maryland, Virginia, Pennsylvania, the District of Columbia, the Federal Government, and the Chesapeake Bay Commission, has been formulating and implementing restoration goals to restore living resources, minimize habitat loss, and reduce the amount of nutrients, sediment, and toxic substances entering the bay. The U.S. Geological Survey has the critical role of providing unbiased scientific information to be used in helping to formulate, implement, and assess the effectiveness of restoration goals in the bay and its watershed.
Methods for characterizing stream habitat as part of the National Water-Quality Assessment Program
Stream habitat is characterized in the U.S. Geological Survey's National Water-Quality Assessment Program as part of an integrated physical, chemical, and biological assessment of the Nation's water quality. The goal of stream habitat characterization is to relate habitat to other physical, chemical, and biological factors to describe water-quality conditions. To accomplish this goal, environmental settings are described at sites selected for water-quality assessment. In addition, spatial and temporal patterns in habitat are examined at local, regional, and national levels. Although habitat characterization is an important component of a number of Federal, State, and local water-quality assessment programs, no current set of habitat evaluation procedures meets the objectives of the habitat assessment component of the National Water-Quality Assessment Program. Evaluation of stream habitat is based on a spatially hierarchical framework that incorporates habitat data at basin, segment, reach, and microhabitat scales. This framework provides a basis for national consistency in collection techniques while allowing flexibility in habitat assessment within individual study units. Procedures are described for collecting habitat data at basin and stream segment scales that include use of geographic information system data bases, maps, and aerial photographs. Data collected at the stream reach scale include more than 34 riparian and instream habitat characteristics evaluated during onetime site visits, and surveys of the channel and riparian area during repeated sampling.
Riparian vegetation recovery patterns following stream channelization: A geomorphic perspective
Hundreds of kilometres of West Tennessee streams have been channelized since the turn of the century. After a stream is straightened, dredged, or cleared, basinwide ecologic, hydrologic, and geomorphic processes bring about an integrated, characteristic recovery sequence. The rapid pace of channel responses to channelization provides an opportunity to document and interpret vegetation recovery patterns relative to otherwise long—term, concomitant evolution of river geomorphology. Nearly 150 sites along 15 streams were studied in the Obion, Forked Deer, Hatchie, and Wolf River basins. Channels of these streams, except that of the Hatchie River main stem, have undergone major modifications along all or parts of their courses. This paper presents the eco—geomorphic analyses and interpretation of a large multidisciplinary study, with special reference to their interrelated hydrogeomorphic aspects of channel recovery. Quantitative plant ecological analyses were conducted to infer relative bank stability, to identify indicator recovery species, and to determine patterns of vegetation development through the course of accelerated channel evolution. Binary—discriminant and ordination analyses show that distinctive riparian—species patterns reflect a six—stage model of channel evolution and can be used to infer channel stability and hydrogeomorphic conditions. Woody vegetation initially establishes on low— and mid—bank surfaces at the same location and time that bank accretion begins, and corresponds to the site of initial geomorphic restabilization. The linkage of channel bed aggradation, woody vegetation establishment, and bank accretion all lead to recovery of the channel. Pioneer species are hardy and fast growing, and can tolerate moderate amounts of slope instability and sediment deposition; these species include river birch (Betula nigra), black willow (Salix nigra), boxelder (Acer negundo), and silver maple (Acer saccharinum). High stem densities and root—mass development appear to enhance bank stability. Tree—ring analyses suggest that on average 65 yr may be required for recovery after channelization.
Geomorphic and vegetative recovery processes along modified stream channels of West Tennessee
Hundreds of miles of streams in West Tennessee have been channelized or otherwise modified since the turn of century. After all or parts of a stream are straightened, dredged, or cleared, systematic hydrologic, geomorphic, and ecologic processes collectively begin to reduce energy conditions towards the premodified state. One hundred and five sites along 15 streams were studied in the Obion, Forked Deer, Hatchie, and Wolf River basins. All studied streams, except the Hatchie River, have had major channel modification along all or parts of their courses. Bank material shear-strength properties were determined through drained borehole-shear testing (168 tests) and used to interpret present critical bank conditions and factors of safety, and to estimate future channel-bank stability. Mean values of cohesive strength and angle of internal friction were 1.26 pounds per square inch and 30.1 degrees, respectively. Dendrogeomorphic analyses were made using botanical evidence of channel-bank failures to determine rates of channel widening; buried riparian stems were analyzed to determine rates of bank accretion. Channel bed-level changes through time and space were represented by a power equation. Plant ecological analyses were made to infer relative bank stability, to identify indicator species of the stage of bank recovery, and to determine patterns of vegetation development through the course of channel evolution. Quantitative data on morphologic changes were used with previously developed six-stage models of channel evolution and bank-slope development to estimate trends of geomorphic and ecologic processes and forms through time. Immediately after channel modifications, a 10- to 1%yearperiod of channel-bed degradation ensues at and upstream from the most recent modifications (area of maximum disturbance). Channel-bed lowering by &gradation was as much as 20 feet along some stream reaches. Downstream from the area of maximum disturbance, the bed was aggraded by the deposition of sediment supplied by knickpoint migration upstream; aggradation also occurred in initially degraded sites with time. Additionally, if degradation caused an increase in bank height beyond the critical limits of the bank material, a period of channel widening by mass wasting followed. Degradation knickpoints migrated upstream at rates greater than 1 mile per year; the rates attenuated with distance above the area of maximum disturbance. Channel widening rates of up to 16 feet per year were documented along some severely degraded reaches. Planar failures were generally more frequent but rotational failures dominated the most rapidly widening reaches. Total volumes of bank erosion may represent 75percent or more of the total material eroded from the channel, but this material generally exits the drainage basin. Mean factors of safety vary with the stage of channel evolution with the lowest values for planar and rotational failures occurring during the threshold stage (stage IV) 1.00 and 1.15, respectively. As channel gradients decrease, degradation ceases and then a period of “secondary aggradation ” (at lesser rates than degradation) and bank accretion begins that may fill the channel to near floodplain level. This shift@ in process represents an oscillation in channel bed-level adjustment. Streams in basins underlain by loess may require an order of magnitude more time than sand-bed streams to stabilize due to a lack of coarse-grained material (sand) for aggradation. A systematic progression of riparian species that reflects the six-stage model of channel evolution has been identified. This progression can be used to infer ambient channel stability and hydrogeomorphic conditions. Woody vegetation establishes on low- and mid-bank surfaces (the slough line, initially) at about the same time that bank accretion begins. This slough line forms at a mean temporary stability angle of 24 degrees and expands upslope with time by the accretion of sediments. Species involved in this initial revegetation are hardy, fast growing, and can tolerate moderate amounts of slope instability and sedimentation; these species include river birch, black willow, boxelder, and silver maple. Vegetation appears to enhance bank stability, and with increasing stability, species such as bald cypress, tupelo gum, and various hydric oaks, which are more characteristic of stable, premodified riparian settings, begin to establish. Detrended-correspondence analysis indicated species assemblages associated with the six stages of channel evolution and bank-slope development. Ordination of site variables based on species data such as channel widening, bank accretion, and woody vegetative cover also reflects the temporal changes identifies by the models. Long-term channel geometry was estimated from a quantitative model of bed-level change, and from documented trends in channel widening. An idealized stable channel of a major sand-bed stream may have a width/depth ratio near 10 and bank slopes of about 24 degrees. This stable channel will ultimately undergo the development of point-bars and incipient meanders, characteristic of unmodified streams.
CHANNEL EVOLUTION IN MODIFIED ALLUVIAL STREAMS.
This study (a) assesses the channel changes and network trends of bed level response after modifications between 1959 and 1972 of alluvial channels in western Tennessee and (b) develops a conceptual model of bank slope development to qualitatively assess bank stability and potential channel widening. A six-step, semiquantitative model of channel evolution in disturbed channels was developed by quantifying bed level trends and recognizing qualitative stages of bank slope development. Development of the bank profile is defined in terms of three dynamic and observable surfaces: (a) vertical face (70 to 90 degrees), (b) upper bank (25 to 50 degrees), and (c) slough line (20 to 25 degrees).
Bottomland vegetation distribution along Passage Creek, Virginia, in relation to fluvial landforms
Persistent distribution patterns of woody vegetation within the bottomland forest of Passage Creek, Virginia, were related to fluvial landforms, channel geometry, streamflow characteristics, and sediment—size characteristics. Vegetation patterns were determined from species presence as observed in transects and traverses on landforms developed along the stream. Distinct species distributional patterns were found on four common fluvial geomorphic landforms: depositional bar, active—channel shelf, floodplain, and terrace. Independent hydrologic characteristics (flow duration and flood frequency) were determined for each of the landforms. Vegetation data were analyzed by binary discriminant analysis, principal components analysis, and detrended correspondence analysis. Results and related field observations suggest that certain species are significantly associated with specific fluvial landforms. Vegetation patterns appear to develop more as a result of hydrologic processes associated with each fluvial landform rather than from sediment—size characteristics. Flood disturbance may be an important factor in maintaining the vegetation patterns, which may therefore be used as indicators for particular hydrogeomorphic site conditions.
Dendrogeomorphic evidence of debris flow frequency and magnitude at Mount Shasta, California
Debris-flow deposits and woody vegetation adjacent to and growing within the channels of Whitney, Bolam, Mud, Ash, and Panthe creeks provide a 300-year record of debris-flow frequency at Mount Shasta Dendrochronologic (tree-ring) dating methods for the debris flows proved consistent with available documented records of debris flows Nine debris flows not reported in the historic record were documented and dated dendrochronologically. The oldest tree-ring date for a mudflow was about 1670 Combined geomorphic and botanical evidence shows that debris flows are a common occurrence at Mount Shasta Debris flows traveling at least 2 km have occurred at the rate of about 8 3 per century Smaller debris flows occur substantially more frequently and usually do not proceed as far downslope as larger debris flows. Cyclic scouring and filling by debris flows, in and adjacent to the stream channels, is suggested by dendrogeomorphic evidence and appears to be related to their magnitude and frequency Debris flows, small and large, may be the major surficial geomorphic agent in the vicinity of mount Shasta, sculpturing the channels and developing large alluvial fans ?? 1984 Springer-Verlag New York Inc.
Seedling establishment on a landslide site
Two landslide scars (slide tracks) were plot sampled one and two years after landsliding to determine plant species involved in ecesis. The study site is located in a blockfield cove on Massanutten Mountain, northern Virginia. Old growth forest, adjacent to the slide tracks, is composed primarily of hemlock (Tsuga canadensis) and sweet birch (Betula lenta). These species are the first and foremost colonizers on the slide tracks. Dendrochronological analysis shows that landsliding is frequent at the study site and this disturbance may impart non-equilibrium conditions on the forest. Seed bed characteristics, light availability, and mode of dispersal may be important factors in plant ecesis on slide tracks
Stream-grade variation and riparian-forest ecology along Passage Creek, Virginia
Passage Creek, in northwestern Virginia, flows on relatively nonresistant shales, then cuts through a gorge underlain by resistant sandstone In the gorge, the stream gradient steepens, the size of bed material increases, a braided channel forms, and riparian-forest composition and growth form changes relative to areas outside the gorge Effects of flooding are intensified within the gorge and revealed in the pattern and deformation of streamside vegetation Increased stream gradient within the gorge provides for high stream power and coarse sediment deposition relative to the flood plain outside the gorge. A more diverse upland forest grows on the flood plain in the gorge The riparian forest in the gorge may be an example of a nonequilibrium forest, resulting from periodic disturbance by destructive floods. Recognition of vegetation patterns resulting from such disturbances may be useful in detection of potential flooding.