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W.J. Wolfe

Publications and source records attributed to W.J. Wolfe.

11 recordsLinked to original sources
USGS2007

Alluvial Bars of the Obed Wild and Scenic River, Tennessee

In 2004, the U.S. Geological Survey (USGS) and the National Park Service (NPS) initiated a reconnaissance study of alluvial bars along the Obed Wild and Scenic River (Obed WSR), in Cumberland and Morgan Counties, Tennessee. The study was partly driven by concern that trapping of sand by upstream impoundments might threaten rare, threatened, or endangered plant habitat by reducing the supply of sediment to the alluvial bars. The objectives of the study were to: (1) develop a preliminary understanding of the distribution, morphology, composition, stability, and vegetation structure of alluvial bars along the Obed WSR, and (2) determine whether evidence of human alteration of sediment dynamics in the Obed WSR warrants further, more detailed examination. This report presents the results of the reconnaissance study of alluvial bars along the Obed River, Clear Creek, and Daddys Creek in the Obed WSR. The report is based on: (1) field-reconnaissance visits by boat to 56 alluvial bars along selected reaches of the Obed River and Clear Creek; (2) analysis of aerial photographs, topographic and geologic maps, and other geographic data to assess the distribution of alluvial bars in the Obed WSR; (3) surveys of topography, surface particle size, vegetation structure, and ground cover on three selected alluvial bars; and (4) analysis of hydrologic records.

Scientific Investigations Map↗
USGS2006

Sampling strategies for volatile organic compounds at three karst springs in Tennessee

The influence of different sampling strategies on characterizing volatile organic compound (VOC) concentrations and estimating VOC loads was evaluated at three karst springs in Tennessee. During a 6-month period, water samples for VOC analyses were collected weekly at all three springs and as frequently as every 20 min during storms at the two springs with variable water quality conditions. Total 6-month loads for selected VOCs were calculated, and VOC data were systematically subsampled to simulate and evaluate several potential sampling strategies. Results from the study indicate that sampling strategies for karst springs need to be developed on a site-specific basis. The use of fixed sampling intervals (as infrequently as quarterly or semiannually) produced accurate concentration and load estimates at one of the springs; however, additional sampling was needed to detect storm-related changes at a second spring located in a similar hydrogeologic setting. Continuous discharge data and high-frequency or flow-controlled sampling were needed at the third spring, which had the most variable flow and water quality conditions. The lack of continuous discharge data at the third spring would substantially affect load calculations, and the use of fixed sampling intervals would affect load calculations and the ability to detect pulses of high contaminant concentrations that might exceed toxicity levels for aquatic organisms. ?? 2006 National Ground Water Association.

Ground Water Monitoring and Remediation↗
USGS2000

Superfund GIS - 1:250,000 Geology of Tennessee

This data set is a digital representation of the printed 1:250,000 geologic maps from the Tennessee Department of Environment and Conservation, Division of Geology. The coverage was designed primarily to provide a more detailed geologic base than the 1:2,500,000 King and Beikman (1974). 1:24,000 scale coverage of the state is available for about 40 percent of the state. Formation names and geologic unit codes used in the coverage are from the Tennessee Division of Geology published maps and may not conform to USGS nomenclature. The Tennessee Division of Geology can be contacted at (615) 532-1500

Tennessee↗
USGS1997

Preliminary conceptual models of the occurrence, fate, and transport of chlorinated solvents in karst regions of Tennessee

Published and unpublished reports and data from 22 contaminated sites in Tennessee were reviewed to develop preliminary conceptual models of the behavior of chlorinated solvents in karst aquifers. Chlorinated solvents are widely used in many industrial operations. High density and volatility, low viscosity, and solubilities that are low in absolute terms but high relative to drinkingwater standards make chlorinated solvents mobile and persistent contaminants that are difficult to find or remove when released into the groundwater system. The major obstacle to the downward migration of chlorinated solvents in the subsurface is the capillary pressure of small openings. In karst aquifers, chemical dissolution has enlarged joints, bedding planes, and other openings that transmit water. Because the resulting karst conduits are commonly too large to develop significant capillary pressures, chlorinated solvents can migrate to considerable depth in karst aquifers as dense nonaqueous-phase liquids (DNAPL's). Once chlorinated DNAPL accumulates in a karst aquifer, it becomes a source for dissolved-phase contamination of ground water. A relatively small amount of chlorinated DNAPL has the potential to contaminate ground water over a significant area for decades or longer. Conceptual models are needed to assist regulators and site managers in characterizing chlorinated-solvent contamination in karst settings and in evaluating clean-up alternatives. Five preliminary conceptual models were developed, emphasizing accumulation sites for chlorinated DNAPL in karst aquifers. The models were developed for the karst regions of Tennessee, but are intended to be transferable to similar karst settings elsewhere. The five models of DNAPL accumulation in karst settings are (1) trapping in regolith, (2) pooling at the top of bedrock, (3) pooling in bedrock diffuse-flow zones, (4) pooling in karst conduits, and (5) pooling in isolation from active ground-water flow. More than one conceptual model of DNAPL accumulation may be applicable to a given site, depending on details of the contaminant release and geologic setting. Trapping in regolith is most likely to occur where the regolith is thick and relatively impermeable with few large cracks, fissures, or macropores. Accumulation at the top of rock is favored by flat-lying strata with few fractures or karst features near the bedrock surface. Fractures or karst features near the bedrock surface encourage migration of chlorinated DNAPL into karst conduits or diffuse-flow zones in bedrock. DNAPL can migrate through one bedrock flow regime into an underlying flow regime with different characteristics or into openings that are isolated from significant ground-water flow. As a general rule, the difficulty of finding and removing DNAPL increases with depth, lateral distance from the source, and complexity of the ground-water flow system. The prospects for mitigation are generally best for DNAPL accumulation in the regolith or at the bedrock surface. However, many such accumulations are likely to be difficult to find or remove. Accumulations in bedrock diffuse-flow zones or in fractures isolated from flow may be possible to find and partially mitigate, but will likely leave significant amounts of contaminant in small fractures or as solute diffused into primary pores.

Tennessee↗
USGS1996

Water-surface elevations of wetlands and nearby wells at Arnold Air Force Base, near Manchester, Tennessee

Surface-water stage, ground-water elevations, rainfall, and streamflow were monitored at or near four wetland sites at Arnold Air Force Base, Tennessee. Two of the wetland sites (Sinking Pond and Westall Swamp) included sinkholes with internal relief greater than 7 feet. The other two wetlands (Tupelo Swamp and Goose Pond) were shallow depressions with less than 5 feet internal relief. Stage rose and fell abruptly in the two sinkhole wetlands. Water depths ranged from 0 to 11.4 feet in Sinking Pond and from 0 to 8.5 feet in Westall Swamp. Water levels in wells adjacent to the sinkhole wetlands also rose and fell abruptly. The two shallow depressions filled and drained more gradually and remained flooded longer than the sinkhole wetlands. The maximum recorded water depths were 3.5 feet in Tupelo Swamp and 2.3 feet in Goose Pond. Water levels in nearby wells remained lower than surface-water elevations in the shallow depressions throughout the study period.

Tennessee↗
USGS1996

Hydrology and tree-distribution patterns of karst wetlands at Arnold Engineering Development Center, Tennessee

Flooding regimes, ground-water interactions, and tree distribution patterns were determined in seasonally flooded sinkhole wetlands at Arnold Engineering Development Center near Manchester, Tennessee. The wetlands are ecologically significant because they support coastal-plain plants and animals far from their typical ranges. S urface-water stage, ground-water levels, rainfall, and streamflow were monitored at or near five wetland sites. Sinking Pond, Willow Oak Swamp, and Westall Swamp are compound sinks with depths greater than 2.5 meters, visible internal drains, and complex bottom topography dominated by coalesced sinkholes and connecting channels. Tupelo Swamp and Goose Pond are karst pans with depths less than 1.5 meters, flat bottoms, and without visible internal drains. Stage rose and fell abruptly in the compound sinks. Maximum water depths ranged from 2.6 meters in Westall Swamp to 3.5 meters in Sinking Pond. Water levels in wells adjacent to Sinking Pond and Westall Swamp rose and fell abruptly, corresponding closely to surface-water stage throughout periods of high water. The two karst pans filled and drained more gradually, but remained flooded longer than the compound sinks. The maximum recorded water depths were 1.1 meters in Tupelo Swamp and 0.7 meter in Goose Pond. Water levels in nearby wells remained lower than the stage in the pans throughout the study period. Tree species were identified and the elevations and diameters of individual trees were measured along 10 transects. Two transects crossed Sinking Pond, two crossed Tupelo Swamp, and one crossed Willow Oak Swamp. The remaining five transects crossed intermittent drainageways that carry flow into or out of Sinking Pond. Transects through ponds had fewer trees but more basal area per unit area of land surface than did transects through channels. Water tupelo (Nyssa aquatica L.) dominated the interior of Tupelo Swamp and had minimal overlap in terms of elevation and flooding duration with other wetland trees that were confined to the pond's periphery. Overcup oak (Quercus lyrata Walt.) dominated the interior of Sinking Pond. Overlap between overcup oak and other wetland trees in terms of elevation and flooding frequency was minimal across the deeper Sinking Pond transect but was substantial across the shallow transect. Willow oak (Quercus phellos L.) dominated the interior of Willow Oak Swamp and had a relation to other wetland trees similar to that of overcup oak in the shallow Sinking Pond transect. Transects across broad swales had a relatively large degree of vertical zonation among wetland and upland tree species. Along transects through well defined channels, elevation distributions of wetland and some upland tree species were grouped near each other and near the distribution of land-surface elevations.

Tennessee↗
USGS1993

Recent sedimentation and surface-water flow patterns on the flood plain of the North Fork Forked Deer River, Dyer County, Tennessee

Sedimentation in the 19th and 20th centuries has had a major effect on surface-water drainage conditions along a 7-mile section of the North, Fork Forked Deer River flood plain, Dyer County, Tenn. During the century prior to 1930, 5 to 12 feet of sediment were deposited over much of the flood plain, resulting in channel obstruction and widespread flooding. The estimated bankfull capacity of the natural channel before it was channelized in 19 16 was comparable to the base flow of the river during the 1980's. Ditching of the river between 191i6 and 1;9,21 was followed by reductions in sedimentation rates over parts of the flood plain. However, the effects of sedimentation have persisted. Occlusions along the natural channel of the river have divided this stream reach into a series of sloughs. These sloughs continue to fill with sediment and are surrounded by ponds that have expanded since 1941. Degradation of the North Fork Forked Deer ditch may eventually reduce ponding over much of the flood plain. Active incision of headcuts in both banks of the ditch is enhancing the drainage of widespread ponded areas. These headcuts likely will have limited effect on drainage of most tributaries. The highest recent sedimentation rates, in places more than 0.2 foot per year, are concentrated near the flood-plain margin along tributary streams. In conjunction with beaver dams and debris, ongoing sedimentation has blocked flow in several tributaries, posing a flood hazard to agricultural land near the flood-plain margin. The occluded tributaries likely will continue to overflow unless they are periodically dredged or their sediment loads are reduced.

Tennessee↗
USGS1991

Drought-related West Tennessee channel bank failures

Massive bank failures occurred in 1988 along a 14-kilometer reach of the lower Obion River channel in Dyer County, West Tennessee where the river flows through an abandoned Mississippi River meander. Bank failures in this reach extend as far as 50 meters from the channel and reach depths of 20 meters below ground surface. The critical elements that led to the failures appear to have been the combination of high soil moisture content and low river stage against a background of substantial recent bank accretion.

Conference Paper↗