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Sample records for abandoned stream channels

  1. Human-induced stream channel abandonment/capture and filling of floodplain channels within the Atchafalaya River Basin, Louisiana

    USGS Publications Warehouse

    Kroes, Daniel E.; Kraemer, Thomas F.

    2013-01-01

    The Atchafalaya River Basin is a distributary system of the Mississippi River containing the largest riparian area in the lower Mississippi River Valley and the largest remaining forested bottomland in North America. Reductions in the area of open water in the Atchafalaya have been occurring over the last 100 years, and many historical waterways are increasingly filled by sediment. This study examines two cases of swamp channels (3/s) that are filling and becoming unnavigable as a result of high sediment loads and slow water velocities. The water velocities in natural bayous are further reduced because of flow capture by channels constructed for access. Bathymetry, flow, suspended sediment, deposited bottom-material, isotopes, and photointerpretation were used to characterize the channel fill. On average, water flowing through these two channels lost 23% of the suspended sediment load in the studied reaches. Along one of the studied reaches, two constructed access channels diverted significant flow out of the primary channel and into the adjacent swamp. Immediately downstream of each of the two access channels, the cross-sectional area of the studied channel was reduced. Isotopic analyses of bottom-material cores indicate that bed filling has been rapid and occurred after detectable levels of Cesium-137 were no longer being deposited. Interpretation of aerial photography indicates that water is bypassing the primary channels in favor of the more hydraulically efficient access channels, resulting in low or no-velocity flow conditions in the primary channel. These swamp channel conditions are typical in the Atchafalaya River Basin where relict large channel dimensions result in flow velocities that are normally too low to carry fine-grained sediment. Constructed channels increase the rate of natural channel avulsion and abandonment as a result of flow capture.

  2. Abandoned Channel Fill Sequences in Tidal Estuaries

    NASA Astrophysics Data System (ADS)

    Gray, A. B.; Pasternack, G. B.; Goni, M. A.; Watson, E. B.

    2014-12-01

    This study proposes a modification of the current model for abandoned channel fill stratigraphy produced in unidirectional flow river reaches to incorporate seasonal tidal deposition. Evidence supporting this concept came from a study of two consecutive channel abandonment sequences in Ropers Slough of the lower Eel River Estuary in northern California. Aerial photographs showed that Ropers Slough was abandoned around 1943, reoccupied after the 1964 flood, and abandoned again in 1974 with fill continuing to the present. Planform geomorphic characteristics derived from these images were used in conjunction with sub-cm resolution stratigraphic analyses to describe the depositional environment processes and their resultant sedimentary deposits. Results showed that both abandonment sequences recorded quasi-annual scale fluvial/tidal deposition couplets. In both cases tidal deposits contained very little sand, and were higher in organic and inorganic carbon content than the sandier fluvial through-flow deposits. However, the two abandonment fills differed significantly in terms of the temporal progression of channel narrowing and fluvial sediment deposition characteristics. The first abandonment sequence led to a more rapid narrowing of Ropers Slough and produced deposits with a positive relationship between grain size/deposit thickness and discharge. The second abandonment resulted in a much slower narrowing of Ropers Slough and generally thinner fluvial deposits with no clear relationship between grain size/deposit thickness and discharge. The δ13C values and organic nitrogen to organic carbon ratios of deposits from the first phase overlapped with Eel River suspended sediment characteristics found for low flows (1-5 times mean discharge), while those of the second phase were consistent suspended sediment from higher flows (7-10 times mean discharge). The abandoned channel fill sequences appeared to differ due to the topographic steering of bed sediment transport and

  3. Hydrology of Channelized and Natural Headwater Streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding hydrology is paramount for optimal ecologic function and management of headwater streams. The objective of this study was to characterize and compare headwater streams within the Upper Big Walnut Creek watershed in Ohio. Two channelized and two unchannelized streams were instrumented w...

  4. Abandoned Rice Fields Make Streams Go Dry in Upland Landscapes

    NASA Astrophysics Data System (ADS)

    Jayawickreme, D.

    2015-12-01

    In South Asia, new economic realities are driving many rural rice farmers out of agriculture. With increasing neglect, abandonment, and rising conversions of centuries old rice fields into other uses, ecological and environmental consequences of these transitions are becoming progressively clear. Field observations in Sri Lanka's central highlands suggest that small shifts in rice to non-rice land uses in headwater watersheds can have a domino effect on the productivity and viability of rice fields and other ecological systems downstream by inflicting groundwater recharge reductions, lowering groundwater yields, and causing other hydrological changes. Preliminary analysis shows that although rice itself is a very water intensive crop, the presence of rain-fed upland rice-fields is hugely beneficial to the watersheds they reside. In particular, water benefits of rice appear to be derived from ponded conditions (3-5 inches of standing water) in which rice is grown, and the contribution rice fields makes to enhance water retention and storage capacity of their watersheds during the monsoon season that coincide with the cropping season. In the absence of well managed rice-fields, hilly upland landscapes produce more runoff and retain little rainwater during the wet season. Furthermore, after centuries of intensive use, much of South Asia's rice fields are nutrient poor and minimally productive without fertilizer applications and other interventions. Consequently, when abandoned, soil erosion and other impacts that affect aquatic ecosystems and watershed health also emerge. Despite these multiple concerns however, little research is currently done to better understand the environmental significance of rice cultivations that are a dominant land-use in many South Asian landscapes. The aim of this presentation is to stir interest among the scientific community to engage more broadly in rice, water, and environmental change research in the face of new economic realities in

  5. The thermal regime of abandoned channels: a preliminary analysis towards a water temperature model for the Allier River, France

    NASA Astrophysics Data System (ADS)

    Casado, Ana; Peiry, Jean-Luc

    2014-05-01

    The growing recognition of the ecological and water quality significance of river water temperature led to a large number of studies assessing thermal processes in streams and rivers. Yet, thermal processes in abandoned channels, which play an important role in maintaining water quality and biological diversity in fluvial corridors, have received minor attention. This study evaluates water temperature regimes in three abandoned channels of the Allier River, France, and quantifies the regime sensitivity to climatic (air temperature) and hydrological (surface and subsurface flow) influence. Analysis was conducted at annual and daily scales, and at two distinct sections of each abandoned channel: (i) the downstream section, which is well connected to the main stream channel, and (ii) the upstream section, which is poorly connected to the main stream channel and hence subject to greater influence of subsurface flow. Annual and daily water temperature regimes for all channels and sections were classified based on relative differences in the 'shape' (timing) and the 'magnitude' (size) of the thermographs. The climatic and hydrological sensitivity of water temperature regimes was quantified using a Sensitivity Index. Analysis at the annual scale revealed relative similarity in patterns of thermal response over time, with clear differentiation between upstream and downstream channel sections in all sites. Water temperature regimes in the upstream channel sections were strongly linked to subsurface water temperature in terms of both timing and size of the annual thermograph; water temperature regimes in the downstream channel sections were more sensitive to air and river water temperature, especially regarding the timing of the annual regimes. Although annual regimes of water temperature exhibited distinct patterns that were similar across sites and over time, analysis of daily water temperature regimes revealed broad differences within and between sites. Day

  6. Floodplain Heterogeneity Drives Riparian Vegetation Composition and Structure Through Channel Meander Migration and Channel Abandonment

    NASA Astrophysics Data System (ADS)

    Fremier, A. K.; Viers, J. H.; Hayden, M. K.; Stella, J. C.

    2008-12-01

    Riparian vegetation composition and structure reflect the legacy of fine- and coarse-scale patterns of hydrology, geomorphology and ecology. Understanding the dynamics of complex systems requires scaling-up mechanistic patterns and processes. Coupling hydro-geomorphic processes with vegetation development is an integral step in understanding habitat evolution in riparian corridors. We quantified floodplain deposition dynamics and topographic complexity to better understand how riparian forest structure and composition changed through time and over the floodplain. We used LiDAR data and a temporally-rich dataset of aerial photography coupled with field data to analyze landscape-scale patterns with species composition and floodplain dynamics. We examined the significance of two definable large-scale floodplain processes - meander migration and channel abandonment - that set-up the spatial structure of riparian forest dynamics. In addition, we analyzed the potential feedback of riparian vegetation on floodplain formation. Canopy structure and floodplain heterogeneity generally showed a log-linear relationship over time and were highly correlated with species composition changes over time and with a range of past hydrologies (inter- and intra- annual patterns). These data suggest that analysis of landscape formation processes, in particularly during the early stages, improves our understanding of riparian forest dynamics and that channel abandonment can be a significant alternative pathway to cottonwood recruitment. By analyzing the coupled eco-geomorphic processes we can more effectively scale-up riparian vegetation patterns by applying a functional knowledge of the corridor-wide channel dynamics and floodplain hydrology.

  7. A Lower Rhine flood chronology based on the sedimentary record of an abandoned channel fill

    NASA Astrophysics Data System (ADS)

    Toonen, W. H. J.; Winkels, T. G.; Prins, M. A.; de Groot, L. V.; Bunnik, F. P. M.; Cohen, K. M.

    2012-04-01

    The Bienener Altrhein is an abandoned channel of the Lower Rhine (Germany). Following a late 16th century abandonment event, the channel was disconnected from the main stream and the oxbow lake gradually filled with 8 meters of flood deposits. This process still continues today. During annual floods, a limited proportion of overbank discharge is routed across the oxbow lake. Large floods produce individual flood layers, which are visually recognized in the sedimentary sequence. Based on the sedimentary characteristics of these event layers, we created a ~450-year flood chronology for the Lower Rhine. Laser-diffraction grain size measurements were used to assess relative flood magnitudes for individual flood event layers. Continuous sampling at a ~2 cm interval provided a high-resolution record, resolving the record at an annual scale. Standard descriptive techniques (e.g., mean grain size, 95th percentile, % sand) and the more advanced 'end member modelling' were applied to zoom in on the coarse particle bins in the grain size distributions, which are indicative of higher flow velocities. The most recent part of the record was equated to modern discharge measurements. This allows to establish relations between deposited grain size characteristics in the abandoned channel and flood magnitudes in the main river. This relation can also be applied on flood event layers from previous centuries, for which only water level measurements and historical descriptions exist. This makes this method relevant to expand data series used in flood frequency analysis from 100 years to more than 400 years. To date event-layers in the rapidly accumulated sequence, we created an age-depth model that uses organic content variations to tune sedimentation rates between the known basal and top ages. No suitable identifiable organic material for radiocarbon dating was found in the cores. Instead, palynological results (introduction of agricultural species) and palaeomagnetic secular

  8. Abandoned coal mine drainage and its remediation: impacts on stream ecosystem structure and function.

    PubMed

    Bott, Thomas L; Jackson, John K; McTammany, Matthew E; Newbold, J Denis; Rier, Steven T; Sweeney, Bernard W; Battle, Juliann M

    2012-12-01

    The effects of abandoned mine drainage (AMD) on streams and responses to remediation efforts were studied using three streams (AMD-impacted, remediated, reference) in both the anthracite and the bituminous coal mining regions of Pennsylvania (USA). Response variables included ecosystem function as well as water chemistry and macroinvertebrate community composition. The bituminous AMD stream was extremely acidic with high dissolved metals concentrations, a prolific mid-summer growth of the filamentous alga, Mougeotia, and > 10-fold more chlorophyll than the reference stream. The anthracite AMD stream had a higher pH, substrata coated with iron hydroxide(s), and negligible chlorophyll. Macroinvertebrate communities in the AMD streams were different from the reference streams, the remediated streams, and each other. Relative to the reference stream, the AMD stream(s) had (1) greater gross primary productivity (GPP) in the bituminous region and undetectable GPP in the anthracite region, (2) greater ecosystem respiration in both regions, (3) greatly reduced ammonium uptake and nitrification in both regions, (4) lower nitrate uptake in the bituminous (but not the anthracite) region, (5) more rapid phosphorus removal from the water column in both regions, (6) activities of phosphorus-acquiring, nitrogen-acquiring, and hydrolytic-carbon-acquiring enzymes that indicated extreme phosphorus limitation in both regions, and (7) slower oak and maple leaf decomposition in the bituminous region and slower oak decomposition in the anthracite region. Remediation brought chlorophyll concentrations and GPP nearer to values for respective reference streams, depressed ecosystem respiration, restored ammonium uptake, and partially restored nitrification in the bituminous (but not the anthracite) region, reduced nitrate uptake to an undetectable level, restored phosphorus uptake to near normal rates, and brought enzyme activities more in line with the reference stream in the bituminous

  9. Evaluation of Metal Toxicity in Streams Affected by Abandoned Mine Lands, Upper Animas River Watershed, Colorado

    USGS Publications Warehouse

    Besser, John M.; Allert, Ann L.; Hardesty, Douglas K.; Ingersoll, Christopher G.; May, Thomas W.; Wang, Ning; Leib, Kenneth J.

    2001-01-01

    Acid drainage from abandoned mines and from naturally-acidic rocks and soil in the upper Animas River watershed of Colorado generates elevated concentrations of acidity and dissolved metals in stream waters and deposition of metal-contaminated particulates in streambed sediments, resulting in both toxicity and habitat degradation for stream biota. High concentrations of iron (Fe), aluminum (Al), zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb) occur in acid streams draining headwaters of the upper Animas River watershed, and high concentrations of some metals, especially Zn, persist in circumneutral reaches of the Animas River and Mineral Creek, downstream of mixing zones of acid tributaries. Seasonal variation of metal concentrations is reflected in variation in toxicity of stream water. Loadings of dissolved metals to the upper Animas River and tributaries are greatest during summer, during periods of high stream discharge from snowmelt and monsoonal rains, but adverse effects on stream biota may be greater during winter low-flow periods, when stream flows are dominated by inputs of groundwater and contain greatest concentrations of dissolved metals. Fine stream-bed sediments of the upper Animas River watershed also contain elevated concentrations of potentially toxic metals. Greatest sediment metal concentrations occur in the Animas River upstream from Silverton, where there are extensive deposits of mine and mill tailings, and in mixing zones in the Animas River and lower Mineral Creek, where precipitates of Fe and Al oxides also contain high concentrations of other metals. This report summarizes the findings of a series of toxicity studies in streams of the upper Animas River watershed, conducted on-site and in the laboratory between 1998 and 2000. The objectives of these studies were: (1) to determine the relative toxicity of stream water and fine stream-bed sediments to fish and invertebrates; (2) to determine the seasonal range of toxicity in stream

  10. A Conceptual Model of Riparian Forest Response to Channel Abandonment on Meandering Rivers

    NASA Astrophysics Data System (ADS)

    Stella, J. C.; Hayden, M. K.; Battles, J. J.; Piegay, H.; Dufour, S.; Fremier, A. K.

    2008-12-01

    On alluvial rivers, hydrogeomorphic regimes exert a primary control on the regeneration of pioneer riparian forest stands and thus their composition and age structure. Seasonal flow patterns provide the necessary conditions for recruitment, and channel migration drives patterns of forest stand dynamics. To date, studies of pioneer riparian forest structure have focused primarily on point bar habitats, where woody vegetation typically recruits with decadal frequency in even-aged bands parallel to the river margin. However, there are indications that other recruitment pathways exist and can be important from a population and conservation perspective. On floodplains where channel migration occurs as infrequent cutoff or avulsion events, the geometry and position of the old channel relative to the new one determines rates and patterns of sedimentation and flood frequency. These conditions provide a brief opportunity for forest recruitment, and geomorphic evolution of the former channel habitat in turn influences forest dynamics. The population implications of this alternative forest regeneration pathway depend on the temporal dynamics of channel abandonment versus the rate of lateral channel migration. Preliminary analysis indicates that the geographic scope of this ecogeomorphological process is sizable. Along the Sacramento River (CA) and Ain River (France), for example, cottonwood-dominated stands associated with abandoned channels tend to be less frequent in number (38% of all stands) but larger in area (accounting for 53% of all forest area) relative to forest stands associated with laterally migrating point bars. Dendrochronological analysis confirms that tree ages in floodplain stands corresponds to the first decade after channel abandonment. These data indicate that changes to the rate and scale of channel abandonment due to human and climatic alterations to the flow regime will likely influence riparian corridor-wide tree population structure and forest

  11. Bioassessment of an Appalachian headwater stream influenced by an abandoned arsenic mine.

    PubMed

    Valenti, Theodore W; Chaffin, Jake L; Cherry, Donald S; Schreiber, Madeline E; Valett, H Maurice; Charles, Megan

    2005-11-01

    Recent debate concerning the modification of safe drinking water standards for arsenic (As) has led to increased awareness of the risks As poses to both humans and the environment. However, few studies have examined the effects of As on the diversity and composition of aquatic assemblages in streams. Benthic macroinvertebrate surveys, chemical analysis of water column and sediment, and laboratory toxicity tests were conducted to assess effects of an abandoned As mine on a headwater stream, and to determine the primary component of toxicity. The average 48-hr LC50 value for Daphnia magna was 4316 microg As/L, and the average 96-hr LC50 value for Lepidostoma spp. was 2138 microg As/L. Reproduction was significantly reduced for D. magna at concentrations > or =312 microg As/L in water column laboratory bioassays, and for treatments in bioassays with sediments containing elevated As (> or =2630 mg/kg). These results support the findings of the in-stream benthic macroinvertebrate survey as the density and percent Ephemeroptera + Plecoptera, + Trichoptera (EPT) were substantially lower at sites downstream of the mine compared to upstream reference sites. Results of bioassays comparing the toxicity of As-contaminated site water and upstream reference water spiked with As salts suggest that As is the primary component of toxicity impacting the stream. Measured As concentrations at downstream sites were above the recommended Criterion Maximum Concentration of 340 microg As/L and Criterion Continuous Concentration of 150 microg As/L for protection of aquatic life published by the United States Environmental Protection Agency. At the study site, elevated As concentrations likely prevent recruitment of benthic macroinvertebrates and recovery of the perturbed headwater stream. PMID:16205987

  12. THERMAL HETEROGENEITY, STREAM CHANNEL MORPHOLOGY, AND SALMONID ABUNDANCE IN NORTHEASTERN OREGON STREAMS

    EPA Science Inventory

    Heterogeneity in stream water temperatures created by local influx of cooler subsurface waters into geomorphically complex stream channels was associated with increased abundance of rainbow trout (Oncorhynchus mykiss) and chinook salmon (O. tshawytscha) in northeastern Oregon. Th...

  13. Measurement of stream channel habitat using sonar

    USGS Publications Warehouse

    Flug, M.; Seitz, H.; Scott, J.

    1998-01-01

    An efficient and low cost technique using a sonar system was evaluated for describing channel geometry and quantifying inundated area in a large river. The boat-mounted portable sonar equipment was used to record water depths and river width measurements for direct storage on a laptop computer. The field data collected from repeated traverses at a cross-section were evaluated to determine the precision of the system and field technique. Results from validation at two different sites showed average sample standard deviations (S.D.s) of 0.12 m for these complete cross-sections, with coefficient of variations of 10%. Validation using only the mid-channel river cross-section data yields an average sample S.D. of 0.05 m, with a coefficient of variation below 5%, at a stable and gauged river site using only measurements of water depths greater than 0.6 m. Accuracy of the sonar system was evaluated by comparison to traditionally surveyed transect data from a regularly gauged site. We observed an average mean squared deviation of 46.0 cm2, considering only that portion of the cross-section inundated by more than 0.6 m of water. Our procedure proved to be a reliable, accurate, safe, quick, and economic method to record river depths, discharges, bed conditions, and substratum composition necessary for stream habitat studies. ?? 1998 John Wiley & Sons, Ltd.

  14. Stream Channelization: Conflict Between Ditchers, Conservationists

    ERIC Educational Resources Information Center

    Gillette, Robert

    1972-01-01

    Summarizes the argument between the advocates of stream straightening for flood control, drainage, and navigation, and those concerned with the maintenance of ecological communities and the aesthetic values of natural" streams. (AL)

  15. Effects of Stream Channel Characteristics on Nitrate Delivery to Streams and In-Stream Denitrification Rates, Raccoon River, Iowa

    NASA Astrophysics Data System (ADS)

    Prestegaard, K. L.; O'Connell, M.

    2004-05-01

    Streams in agricultural areas often exhibit significant channel and sediment modifications; they are often incised and transport more fine sediment than non-agricultural streams. These channel characteristics can influence stream water quality by modifying surface-groundwater interactions. In the Raccoon River basin, channel incision increases the delivery of nitrate from the groundwater to the streams. The sandy in-stream sediments, however, serve as very effective sites for in-stream denitrification. Nitrate delivery and in-stream denitrification was examined in 3 subwatersheds of the Raccoon River. Stream morphology, water quality, and sediment characteristics were measured at 35 sites with varying land uses. Headwater stream nitrate concentration increased with percent row crops and the amount of channel incision. Downstream sites showed a wide variation in nitrate concentration with land use. Stream nitrate concentrations were measured at 6 sites in each of 3 streams with high percentages of row crop land uses during high summer baseflow following the 1993 floods and during average summer baseflow in 1995. Nitrate concentrations were systematically higher for the high baseflow conditions of 1993 than the average year (1995). This change in nitrate concentration is interpreted as the increased effectiveness of nitrate delivery to the stream during periods of high water tables. The effect was most pronounced in incised reaches. All 3 streams show downstream decreases in nitrate concentration. Water samples for all the sites in the watersheds were analyzed for nitrogen isotopic composition. The nitrogen isotopic composition shifts with towards higher d 15N values with decreasing nitrate concentration. This is consistent with denitrification reactions that selectively remove the 14N leaving a higher proportion of 15N in the nitrate. This suggests that most of the downstream decrease in nitrate concentrations is a result of in-stream denitrification. The high rates

  16. MODELING STREAM CHANNEL ADJUSTMENT TO WOODY VEGETATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    River restoration and bank stabilization programs often use vegetation for improving stream corridor habitat, aesthetic, and function. Yet no study has examined the use of managed vegetation plantings to transform a straight, degraded stream corridor into a more functional, aesthetically-pleasing m...

  17. CHANNEL EVOLUTION IN MODIFIED ALLUVIAL STREAMS.

    USGS Publications Warehouse

    Simon, Andrew; Hupp, Cliff R.

    1987-01-01

    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).

  18. Effects of permafrost on stream channel behavior in Arctic Alaska

    USGS Publications Warehouse

    Scott, Kevin M.

    1978-01-01

    Sites with drainage areas ranging from 88 to 12,200 sq km were monitored on five streams in northern Alaska during the breakup in 1976 to determine (1) the effects of frozen bed and bank material on channel behavior, and (2) the importance of the annual breakup flood in forming the channels of arctic streams. The thawing and concomitant erosion of channels varied with changes in bed-material size, channel pattern, drainage area, and climate. The response of channels to breakup flooding ranged from total permafrost control of channel processes, including both bed scour and lateral erosion, to only brief restriction of channel behavior early in the rise of the flooding. The watershed characteristic that appears to explain much of this variation is size of drainage area. (Woodard-USGS)

  19. Optimized transmission of JPEG2000 streams over wireless channels.

    PubMed

    Thomos, Nikolaos; Boulgouris, Nikolaos V; Strintzis, Michael G

    2006-01-01

    The transmission of JPEG2000 images over wireless channels is examined using reorganization of the compressed images into error-resilient, product-coded streams. The product-code consists of Turbo-codes and Reed-Solomon codes which are optimized using an iterative process. The generation of the stream to be transmitted is performed directly using compressed JPEG2000 streams. The resulting scheme is tested for the transmission of compressed JPEG2000 images over wireless channels and is shown to outperform other algorithms which were recently proposed for the wireless transmission of images. PMID:16435536

  20. Reach-scale channel geometry of mountain streams

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen; Merritt, David M.

    2008-01-01

    The basic patterns and processes of steep channels remain poorly known relative to lower-gradient channels. In this analysis, characteristics of step-pool, plane-bed, and pool-riffle channels are examined using a data set of 335 channel reaches from the western United States, Nepal, New Zealand, and Panama. We analyzed differences among the three channel types with respect to hydraulics, channel geometry, boundary roughness, and bedforms. Step-pool channels have significantly steeper gradients, coarser substrate, higher values of shear stress and stream power for a given discharge, and larger ratios of bedform amplitude/wavelength ( H/ L). Pool-riffle channels have greater width/depth ratios and relative grain submergence ( R/ D84) than the other channel types. Plane-bed channels tend to have intermediate values for most variables examined. Relative form submergence ( R/ H) is statistically similar for step-pool and pool-riffle channels. Despite the lesser relative grain submergence and greater bedform amplitude of step-pool channels, mean values of Darcy-Weisbach friction factor do not change in response to changes in relative grain submergence. These patterns suggest that adjustments along mountain streams effectively maximize resistance to flow and minimize downstream variability in resistance among the different channel types.

  1. Groundwater Discharge along a Channelized Coastal Plain Stream

    SciTech Connect

    LaSage, Danita M; Sexton, Joshua L; Mukherjee, Abhijit; Fryar, Alan E; Greb, Stephen F

    2015-10-01

    In the Coastal Plain of the southeastern USA, streams have commonly been artificially channelized for flood control and agricultural drainage. However, groundwater discharge along such streams has received relatively little attention. Using a combination of stream- and spring-flow measurements, spring temperature measurements, temperature profiling along the stream-bed, and geologic mapping, we delineated zones of diffuse and focused discharge along Little Bayou Creek, a channelized, first-order perennial stream in western Kentucky. Seasonal variability in groundwater discharge mimics hydraulic-head fluctuations in a nearby monitoring well and spring-discharge fluctuations elsewhere in the region, and is likely to reflect seasonal variability in recharge. Diffuse discharge occurs where the stream is incised into the semi-confined regional gravel aquifer, which is comprised of the Mounds Gravel. Focused discharge occurs upstream where the channel appears to have intersected preferential pathways within the confining unit. Seasonal fluctuations in discharge from individual springs are repressed where piping results in bank collapse. Thereby, focused discharge can contribute to the morphological evolution of the stream channel.

  2. Groundwater discharge along a channelized Coastal Plain stream

    NASA Astrophysics Data System (ADS)

    LaSage, Danita M.; Sexton, Joshua L.; Mukherjee, Abhijit; Fryar, Alan E.; Greb, Stephen F.

    2008-10-01

    SummaryIn the Coastal Plain of the southeastern USA, streams have commonly been artificially channelized for flood control and agricultural drainage. However, groundwater discharge along such streams has received relatively little attention. Using a combination of stream- and spring-flow measurements, spring temperature measurements, temperature profiling along the stream-bed, and geologic mapping, we delineated zones of diffuse and focused discharge along Little Bayou Creek, a channelized, first-order perennial stream in western Kentucky. Seasonal variability in groundwater discharge mimics hydraulic-head fluctuations in a nearby monitoring well and spring-discharge fluctuations elsewhere in the region, and is likely to reflect seasonal variability in recharge. Diffuse discharge occurs where the stream is incised into the semi-confined regional gravel aquifer, which is comprised of the Mounds Gravel. Focused discharge occurs upstream where the channel appears to have intersected preferential pathways within the confining unit. Seasonal fluctuations in discharge from individual springs are repressed where piping results in bank collapse. Thereby, focused discharge can contribute to the morphological evolution of the stream channel.

  3. Groundwater discharge along a channelized Coastal Plain stream

    USGS Publications Warehouse

    LaSage, D.M.; Sexton, J.L.; Mukherjee, A.; Fryar, A.E.; Greb, S.F.

    2008-01-01

    In the Coastal Plain of the southeastern USA, streams have commonly been artificially channelized for flood control and agricultural drainage. However, groundwater discharge along such streams has received relatively little attention. Using a combination of stream- and spring-flow measurements, spring temperature measurements, temperature profiling along the stream-bed, and geologic mapping, we delineated zones of diffuse and focused discharge along Little Bayou Creek, a channelized, first-order perennial stream in western Kentucky. Seasonal variability in groundwater discharge mimics hydraulic-head fluctuations in a nearby monitoring well and spring-discharge fluctuations elsewhere in the region, and is likely to reflect seasonal variability in recharge. Diffuse discharge occurs where the stream is incised into the semi-confined regional gravel aquifer, which is comprised of the Mounds Gravel. Focused discharge occurs upstream where the channel appears to have intersected preferential pathways within the confining unit. Seasonal fluctuations in discharge from individual springs are repressed where piping results in bank collapse. Thereby, focused discharge can contribute to the morphological evolution of the stream channel. ?? 2008 Elsevier B.V. All rights reserved.

  4. Effects of Concrete Channels on Stream Biogeochemistry, Maryland Coastal Plain

    NASA Astrophysics Data System (ADS)

    Prestegaard, K. L.; Gilbert, L.; Phemister, K.

    2005-05-01

    In the 1950's and 60's, extensive networks of cement-lined channels were built in suburban watersheds near Washington, D.C. to convey storm water to downstream locations. These cement-lined stream channels limit interactions between surface and groundwater and they provide sources of alkalinity in Maryland Coastal Plain watersheds that normally have low alkalinity. This project was designed to 1) compare base flow water chemistry in headwater reaches of urban and non-urban streams, and 2) to evaluate downstream changes in water chemistry in channelized urban streams in comparison with non-urban reference streams. During a drought year, headwater streams in both urban and non-urban sites had significant concentrations of Fe(II) that were discharged from groundwater sources and rapidly oxidized by iron-oxidizing bacteria. During a wet year, the concentrations of Fe(II) were higher in headwater urban streams than in the non-urban streams. This suggests that impervious surfaces in headwater urban watersheds prevent the recharge of oxygen-rich waters during storm events, which maintains iron-rich groundwater discharge to the stream. Downstream changes in water chemistry are prominent in cement-lined urban channels because they are associated with distinctive microbial communities. The headwater zones of channelized streams are dominated by iron-ozidizing bacteria, that are replaced downstream by manganese-oxidizing zones, and replaced further downstream by biofilms dominated by photosynthesizing cyanobacteria. The reaches dominated by cyanobacteria exhibit diurnal changes in pH due to uptake of CO2 for photosynthesis. Diurnal changes range from 7.5 to 8.8 in the summer months to 7.0 to 7.5 in the cooler months, indicating both the impact of photosynthesis and the additional source of alkalinity provided by concrete. The dissolved oxygen, pH, and other characteristics of tributaries dominated by cyanobacteria are similar to the water chemistry characteristics observed in

  5. Implications of fish-habitat relationships for designing restoration projects within channelized agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channelized headwater streams are common throughout agricultural watersheds in the Midwestern United States. Management of these streams focuses on drainage without consideration of the other ecosystem services they are capable of providing. Restoration of channelized agricultural headwater stream...

  6. Public Health Perspectives of Channelized and Unchannelized Headwater Streams in Central Ohio: A Case Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Headwater streams constitute the majority of watersheds in the United States and many headwater streams in the midwest have been channelized for agricultural drainage. Public health implications of water chemistry and aquatic macroinvertebrates within channelized and unchannelized headwater streams ...

  7. Conservation implications of amphibian habitat relationships within channelized agricultural headwater streams in the midwestern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The widespread use of stream channelization and subsurface tile drainage for removing water from agricultural fields has led to the development of numerous channelized agricultural headwater streams within agricultural watersheds of the Midwestern United States. Channelized agricultural headwater s...

  8. Influence of instream habitat and water chemistry on amphibians within channelized agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The widespread use of stream channelization and subsurface tile drainage for draining agricultural fields has led to the development of numerous channelized agricultural headwater streams within agricultural watersheds of the Midwestern United States, Canada, and Europe. Channelized agricultural he...

  9. Antarctic ice streams and outflow channels on Mars

    USGS Publications Warehouse

    Lucchitta, B.K.

    2001-01-01

    New sonar images of the Antarctic sea floor reveal mega-scale glacial lineations that are strikingly similar to longitudinal flutes in martian outflow channels. The analogs suggest that ice moved through the martian channels in places and carved the flutes. The ice in martian channels may have moved like Antarctic ice streams on deformable debris saturated with water under high pore pressure. On Mars, water at the base of ice-filled channels may have come from residual water or melt water liberated during past warmer climates or higher heat flows.

  10. Multiple-channel Streaming Delivery for Omnidirectional Vision System

    NASA Astrophysics Data System (ADS)

    Iwai, Yoshio; Nagahara, Hajime; Yachida, Masahiko

    An omnidirectional vision is an imaging system that can capture a surrounding image in whole direction by using a hyperbolic mirror and a conventional CCD camera. This paper proposes a streaming server that can efficiently transfer movies captured by an omnidirectional vision system through the Internet. The proposed system uses multiple channels to deliver multiple movies synchronously. Through this method, the system enables clients to view the different direction of omnidirectional movies and also support the function to change the view are during playback period. Our evaluation experiments show that our proposed streaming server can effectively deliver multiple movies via multiple channels.

  11. The stream channel incision syndrome and water quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watershed development often triggers channel incision, which accounts for 60-90% of sediments leaving many disturbed watersheds. Impacts of such incision on water quality processes and the implication of such impairment on stream biota are relevant to issues associated with establishing total maxim...

  12. Man-induced channel adjustment in Tennessee streams

    USGS Publications Warehouse

    Robbins, C.H.; Simon, Andrew

    1983-01-01

    Channel modifications in Tennessee, particularly in the western part, have led to large-scale instabilities in the channelized rivers and may have contributed to several bridge failures. These modifications, together with land-use practices, led to downcutting, headward erosion, downstream aggradation, accelerated scour, and bank instabilities. Changes in gradient by channel straightening caused more severe channel response than did dredging or clearing. Large-scale changes continue to occur in all the channelized rivers: the Obion River, its forks, and the South Fork Forked Deer River. However, the non-channelized Hatchie River in west Tennessee not only withstood the natural stresses imposed by the wet years of 1973 to 1975 but continues to exhibit characteristics of stability. Water-surface slope, the primary dependent variable, proved to be a sensitive and descriptive parameter useful in determining channel adjustment. Adjustments to man-induced increases in channel-slope are described by inverse exponential functions of the basic form S=ae(-b(t)); where ' S ' is some function describing channel-slope, ' t ' is the number of years since completion of channel work, and ' a ' and ' b ' are coefficients. Response times for the attainment of ' equilibrium ' channel slopes are a function of the magnitude and extent of the imposed modifications. The adjusted profile gradients attained by the streams following channelization are similar to the predisturbed profile gradients, where no alteration to channel length was made. Where the channels were straightened by constructing cut-offs, thus shortening channel length, then slope adjustments (reduction) proceed past the predisturbed profile gradients, to new profiles with lower gradients. (USGS)

  13. Discrimination between mountain stream channel types using independent control variables

    NASA Astrophysics Data System (ADS)

    Wohl, E.; Merritt, D. M.

    2004-12-01

    We use a large and diverse dataset from mountain streams around the world to explore our ability to classify reach-scale channel morphology using easily measurable control variables. The dataset includes 136 step-pool reaches, 44 plane-bed reaches, and 93 pool-riffle reaches from streams in the western United States, Panama, and New Zealand. We used stepwise discriminant analysis to select the most parsimonious subset of variables for classifying channel type. A 3-variable discriminant function using slope, D84, and channel width produced a classification error rate of 24% (103 reaches correctly classified). Seventy percent of plane-bed reaches were correctly classified (16% incorrectly classified as pool-riffle, 14% incorrectly classified as step-pool). Sixty-seven percent of pool-riffle channels were correctly classified (31% incorrectly classified as plane-bed, 2% as step-pool). Eighty-nine percent of step-pool reaches were correctly classified (9% incorrectly classified as plane-bed, 2% as pool-riffle). The partial R2-values indicate that slope is by far the most significant single explanatory variable. The ability to accurately classify channel type in other regions using the elegant 3-variable discriminant function developed from the entire dataset has important implications for water-resources management and for understanding relationships between process and form in mountain streams.

  14. Variations in heavy metal contamination of stream water and groundwater affected by an abandoned lead-zinc mine in Korea.

    PubMed

    Lee, Jin-Yong; Choi, Jung-Chan; Lee, Kang-Kun

    2005-09-01

    This study evaluated variations in heavy metal contamination of stream waters and groundwaters affected by an abandoned lead-zinc mine, where a rockfill dam for water storage will be built 11 km downstream. For these purposes, a total of 10 rounds of stream and groundwater samplings and subsequent chemical analyses were performed during 2002-2003. Results of an exploratory investigation of stream waters in 2000 indicated substantial contamination with heavy metals including zinc (Zn), iron (Fe) and arsenic (As) for at least 6 km downstream from the mine. Stream waters near the mine showed metal contamination as high as arsenic (As) 8,923 microg L(-1), copper (Cu) 616 microg L(-1), cadmium (Cd) 223 microg L(-1) and lead (Pb) 10,590 microg L(-1), which greatly exceeded the Korean stream water guidelines. Remediation focused on the mine tailing piles largely improved the stream water qualities. However, there have still been quality problems for the waters containing relatively high concentrations of As (6-174 microg L(-1)), Cd (1-46 microg L(-1)) and Pb (2-26 microg L(-1)). Rainfall infiltration into the mine tailing piles resulted in an increase of heavy metals in the stream waters due to direct discharge of waste effluent, while dilution of the contaminated stream waters improved the water quality due to mixing with metal free rain waters. Levels of As, Cu and chromium (Cr) largely decreased after heavy rain but that of Pb was rather elevated. The stream waters were characterized by high concentrations of calcium (Ca) and sulfate (SO(4)), which were derived from dissolution and leaching of carbonate and sulfide minerals. It was observed that the proportions of Ca and SO(4) increased while those of bicarbonate (HCO(3)) and sodium and potassium (Na+K) decreased after a light rainfall event. Most interestingly, the reverse was generally detected for the groundwaters. The zinc, being the metal mined, was the most dominant heavy metal in the groundwaters (1758

  15. Influence of herbaceous riparian buffers on physical habitat, water chemistry, and stream communities within channelized agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbaceous riparian buffers are a widely used agricultural conservation practice in the United States for reducing nutrient, pesticide, and sediment loadings in agricultural streams. The ecological impacts of herbaceous riparian buffers on the channelized agricultural headwater streams that are comm...

  16. Ecohydrologic function and disturbance of desert ephemeral stream channels

    NASA Astrophysics Data System (ADS)

    Bedford, D.; Macias, M.; Miller, D. M.; Newlander, A.; Perkins, K. S.; Sandquist, D. R.; Schwinning, S.

    2011-12-01

    In response to rare high-intensity or long duration rainstorms, runoff in desert ephemeral channels can redistribute water through landscapes and potentially serve as a resource subsidy. We are using transect studies, mapping, monitoring and manipulation experiments to investigate the ecohydrologic relations of these pervasive features with vegetation in the eastern Mojave Desert, USA. We focus on a gently sloping piedmont transected by a ~100 year old railroad that alters natural channel flow by diverting it through staggered culverts to areas downslope of the railroad. This creates three distinct ecohydrologic zones: 1) relatively undisturbed areas above the railroad, 2) areas below the railroad that receive enhanced flow where water is diverted through culverts (enhanced zones), and 3) areas below the railroad where water flow from upslope has been blocked (deprived zones). In all areas we found that vegetation cover and density are higher adjacent to stream channels and decrease with distance from the channels. Relative to the undisturbed areas, vegetation cover is higher in the enhanced areas, and lower in the deprived. Species-specific vegetation changes included higher cover of the drought deciduous sub-shrub Ambrosia dumosa in deprived zones and higher cover of the evergreen drought-tolerant shrub Larrea tridentata in enhanced zones. Using simulated channel runoff experiments, we found that most Larrea within 3 m, and Ambrosia within 1.5 m of an undisturbed stream channel physiologically responded to a water pulse and the responses persisted for over a month. Less pronounced responses were seen adjacent to channels in the deprived zones, and did not persist as long. Electrical resistance imaging of the watering experiments shows that water infiltrates vertically in channels and spreads laterally at depth; vegetation use of channel water in the deprived zones appears to be reduced. While we have no information on the pace of vegetation change due to channel

  17. Small mammal habitat use within restored riparian habitats adjacent to channelized streams in Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian zones of channelized agricultural streams in northwestern Mississippi typically consist of narrow vegetative corridors low in habitat diversity and lacking riparian wetlands. Land clearing practices and stream channelization has led to the development of gully erosion and further fragmenta...

  18. Similarities in fish-habitat relationships within channelized agricultural headwater streams in Ohio and Indiana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channelized agricultural headwater streams are common throughout agricultural watersheds in the Midwestern United States. Understanding the fish-habitat relationships within these streams will provide information that can assist with developing restoration strategies for these degraded streams. We...

  19. Influence of watershed-scale pesticide management on channelized agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channelized agricultural headwater streams are streams that have been created or modified for agricultural drainage. Elevated pesticide concentrations frequently occur within these modified streams and represent a threat to their ecological integrity. Pesticide management (i.e., use of alternative ...

  20. Linking Denitrification to Channel Geomorphology in Agricultural Streams

    NASA Astrophysics Data System (ADS)

    Opdyke, M. R.; David, M. B.; Rhoads, B. L.

    2005-05-01

    Agricultural streams in east-central Illinois have elevated nitrate concentrations (10 to 20 mg N L-1) contributing to greater denitrification rates in sediments. However, reduced retention times and extensive stream channelization limit the effectiveness of denitrification as a removal mechanism for water column nitrate. In this study, we compared geomorphic controls of denitrification in six channel reaches varying in geomorphology, organic matter, and nitrate concentration. Denitrification rates were measured monthly between June 2003 and February 2005 using the acetylene inhibition procedure (chloramphenicol was added to control for denitrifier growth). We found in meandering and channelized reaches of greater nitrate concentrations and fine substrate, denitrification rates averaged 19 mg N m-2 h-1. In areas of lesser nitrate concentrations and coarse substrates, denitrification rates were comparably lower at 3.0 mg N m-2 h-1 in meandering reaches and 0.80 mg N m-2 h-1 in channelized reaches. Our study concluded that denitrification rates were strongly linked to geomorphic variability, organic matter, substrate composition, and nitrate concentration. A strong geomorphic connection appeared with substrate composition showing that greater nitrogen removal in channel conditions of fine substrate are more effective.

  1. Distribution, speciation, and transport of mercury in stream-sediment, stream-water, and fish collected near abandoned mercury mines in southwestern Alaska, USA

    USGS Publications Warehouse

    Gray, J.E.; Theodorakos, P.M.; Bailey, E.A.; Turner, R.R.

    2000-01-01

    Concentrations of total Hg, Hg (II), and methylmercury were measured in stream-sediment, stream-water, and fish collected downstream from abandoned mercury mines in south-western Alaska to evaluate environmental effects to surrounding ecosystems. These mines are found in a broad belt covering several tens of thousands of square kilometers, primarily in the Kuskokwim River basin. Mercury ore is dominantly cinnabar (HgS), but elemental mercury (Hg(o)) is present in ore at one mine and near retorts and in streams at several mine sites. Approximately 1400 t of mercury have been produced from the region, which is approximately 99% of all mercury produced from Alaska. These mines are not presently operating because of low prices and low demand for mercury. Stream-sediment samples collected downstream from the mines contain as much as 5500 ??g/g Hg. Such high Hg concentrations are related to the abundance of cinnabar, which is highly resistant to physical and chemical weathering, and is visible in streams below mine sites. Although total Hg concentrations in the stream-sediment samples collected near mines are high, Hg speciation data indicate that concentrations of Hg (II) are generally less than 5%, and methylmercury concentrations are less than 1% of the total Hg. Stream waters below the mines are neutral to slightly alkaline (pH 6.8-8.4), which is a result of the insolubility of cinnabar and the lack of acid- generating minerals such as pyrite in the deposits. Unfiltered stream-water samples collected below the mines generally contain 500-2500 ng/l Hg; whereas, corresponding stream-water samples filtered through a 0.45-??m membrane contain less than 50 ng/l Hg. These stream-water results indicate that most of the Hg transported downstream from the mines is as finely- suspended material rather than dissolved Hg. Mercury speciation data show that concentrations of Hg (II) and methylmercury in stream-water samples are typically less than 22 ng/l, and generally less than

  2. Scour and deposition patterns in complex flow around stream restoration structures in a meandering stream channel

    NASA Astrophysics Data System (ADS)

    Kozarek, J. L.; Plott, J. R.; Diplas, P.; Sotiropoulos, F.; Lightbody, A.

    2010-12-01

    Instream structures are often employed in stream restoration projects to minimize erosion on the outside of a meander bend where shear stresses are highest, but guidelines for installation are often based on subjective criteria or professional experience. As part of a multiphase study to develop comprehensive quantitative design guidelines for instream structures, a series of experiments were conducted in the sand-bed meandering stream channel in the Outdoor StreamLab (OSL) at the St. Anthony Falls Laboratory (SAFL). Following an experiment with a single rock vane, three arrays of three evenly spaced structures (rock vanes, J-hooks, and bendway weirs) were installed in a single meander bend. To improve fundamental understanding of the interaction of the complex flow field around these structures with the sediment bed in a field-scale meandering stream, high resolution channel topography data were obtained for the entire meander bend at bankfull flow conditions (280 LPS) with and without structure arrays. Three-dimensional flow velocity and turbulence was measured using acoustic Doppler velocimetry for each scenario in nine cross sections located before, after, between, and over the structure installation locations. Velocity point spacing was decreased close to boundaries (bed, bank, or structure). The velocity data confirmed that the velocity core moved away from the outside of the meander bend in the presence of structures; however, increased local shear stresses around the structures increased scour which threatened structure stability. For each structure array, individual structures introduced different velocity patterns including visible recirculation zones and turbulent structures depending on the structure type and where in the meander bend the structure was placed. The results from these experiments will inform stream restoration structure design in a meandering stream.

  3. Grazed Riparian Management and Stream Channel Response in Southeastern Minnesota (USA) Streams

    NASA Astrophysics Data System (ADS)

    Magner, Joseph A.; Vondracek, Bruce; Brooks, Kenneth N.

    2008-09-01

    The U.S. Department of Agriculture-Natural Resources Conservation Service has recommended domestic cattle grazing exclusion from riparian corridors for decades. This recommendation was based on a belief that domestic cattle grazing would typically destroy stream bank vegetation and in-channel habitat. Continuous grazing (CG) has caused adverse environmental damage, but along cohesive-sediment stream banks of disturbed catchments in southeastern Minnesota, short-duration grazing (SDG), a rotational grazing system, may offer a better riparian management practice than CG. Over 30 physical and biological metrics were gathered at 26 sites to evaluate differences between SDG, CG, and nongrazed sites (NG). Ordinations produced with nonmetric multidimensional scaling (NMS) indicated a gradient with a benthic macroinvertebrate index of biotic integrity (IBI) and riparian site management; low IBI scores associated with CG sites and higher IBI scores associated with NG sites. Nongrazed sites were associated with reduced soil compaction and higher bank stability, as measured by the Pfankuch stability index; whereas CG sites were associated with increased soil compaction and lower bank stability, SDG sites were intermediate. Bedrock geology influenced NMS results: sites with carbonate derived cobble were associated with more stable channels and higher IBI scores. Though current riparian grazing practices in southeastern Minnesota present pollution problems, short duration grazing could reduce sediment pollution if managed in an environmentally sustainable fashion that considers stream channel response.

  4. Grazed riparian management and stream channel response in southeastern Minnesota (USA) streams.

    PubMed

    Magner, Joseph A; Vondracek, Bruce; Brooks, Kenneth N

    2008-09-01

    The U.S. Department of Agriculture-Natural Resources Conservation Service has recommended domestic cattle grazing exclusion from riparian corridors for decades. This recommendation was based on a belief that domestic cattle grazing would typically destroy stream bank vegetation and in-channel habitat. Continuous grazing (CG) has caused adverse environmental damage, but along cohesive-sediment stream banks of disturbed catchments in southeastern Minnesota, short-duration grazing (SDG), a rotational grazing system, may offer a better riparian management practice than CG. Over 30 physical and biological metrics were gathered at 26 sites to evaluate differences between SDG, CG, and nongrazed sites (NG). Ordinations produced with nonmetric multidimensional scaling (NMS) indicated a gradient with a benthic macroinvertebrate index of biotic integrity (IBI) and riparian site management; low IBI scores associated with CG sites and higher IBI scores associated with NG sites. Nongrazed sites were associated with reduced soil compaction and higher bank stability, as measured by the Pfankuch stability index; whereas CG sites were associated with increased soil compaction and lower bank stability, SDG sites were intermediate. Bedrock geology influenced NMS results: sites with carbonate derived cobble were associated with more stable channels and higher IBI scores. Though current riparian grazing practices in southeastern Minnesota present pollution problems, short duration grazing could reduce sediment pollution if managed in an environmentally sustainable fashion that considers stream channel response. PMID:18481141

  5. Instream wood recruitment, channel complexity, and their relationship to stream ecology in forested headwater streams under alternative stable states

    NASA Astrophysics Data System (ADS)

    Livers, B.; Wohl, E.

    2015-12-01

    Human alteration to forests has had lasting effects on stream channels worldwide. Such land use changes affect how wood enters and is stored in streams as individual pieces and as logjams. Changes in wood recruitment affect the complexity and benefits wood can provide to the stream environment, such as zones of flow separation that store fine sediment and organic matter, increased nutrient processing, and greater habitat potential, which can enhance biota and cascade through stream-riparian ecosystems. Previous research in our study area shows that modern headwater streams flowing through old-growth, unmanaged forests have more wood than streams in young, managed forests, but does not explicitly evaluate how wood affects channel complexity or local ecology. 'Managed' refers to forests previously or currently exposed to human alteration. Alteration has long since ceased in some areas, but reduced wood loads in managed streams persist. Our primary objective was to quantify stream complexity metrics, with instream wood as a mediator, on streams across a gradient of management and disturbance histories in order to examine legacy effects of human alteration to forests. Data collected in the Southern Rocky Mountains include 24 2nd to 3rd order subalpine streams categorized into: old-growth unmanaged; younger, naturally disturbed unmanaged; and younger managed. We assessed instream wood loads and logjams and evaluated how they relate to channel complexity using a number of metrics, such as standard deviation of bed and banks, volume of pools, ratios of stream to valley lengths and stream to valley area, and diversity of substrate, gradient, and morphology. Preliminary results show that channel complexity is directly related to instream wood loads and is greatest in streams in old-growth. Related research in the field area indicates that streams with greater wood loads also have increased nutrient processing and greater abundance and diversity of aquatic insect predators.

  6. Developing restoration strategies for channelized headwater streams within a central Ohio watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channelized headwater streams are a common landscape feature in the midwestern United States. These streams have been channelized and maintained for removal of excess water from agricultural fields without regard for the aquatic biota. Development of restoration strategies for channelized headwater ...

  7. Importance of instream wood characteristics for developing restoration designs for channelized agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channelized agricultural headwater streams are a common feature within agricultural watersheds of the Midwestern United States. These small streams have been impacted by the physical and chemical habitat alterations incurred to facilitate agricultural drainage. Quantitative information on the instr...

  8. Characteristics of instream wood within channelized agricultural headwater streams in the Midwestern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channelized agricultural headwater streams are a common feature within agricultural watersheds of the Midwestern United States. These small streams have been impacted by the physical and chemical habitat alterations incurred to facilitate agricultural drainage. Quantitative information on the instre...

  9. Differences in instream wood characteristics between channelized and unchannelized agricultural headwater streams in central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Instream wood is an important resource for stream biota because it provides cover for fishes, substrate for macroinvertebrates, and increases habitat diversity. However, current management of instream wood within channelized agricultural headwater streams (drainage ditches) involves removing instrea...

  10. Simple measures of channel habitat complexity predict transient hydraulic storage in streams

    EPA Science Inventory

    Stream thalweg depth profiles (along path of greatest channel depth) and woody debris tallies have recently become components of routine field procedures for quantifying physical habitat in national stream monitoring efforts. Mean residual depth, standard deviation of thalweg dep...

  11. Influence of Gully Erosion Control on Amphibian and Reptile Communities within Riparian Zones of Channelized Streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian zones of streams in northwestern Mississippi have been impacted by agriculture, channelization, channel incision, and gully erosion. Riparian gully formation has resulted in the fragmentation of remnant riparian zones within agricultural watersheds. One widely used conservation practice for...

  12. A standardized sampling protocol for channel catfish in prairie streams

    USGS Publications Warehouse

    Vokoun, Jason C.; Rabeni, Charles F.

    2001-01-01

    Three alternative gears—an AC electrofishing raft, bankpoles, and a 15-hoop-net set—were used in a standardized manner to sample channel catfish Ictalurus punctatus in three prairie streams of varying size in three seasons. We compared these gears as to time required per sample, size selectivity, mean catch per unit effort (CPUE) among months, mean CPUE within months, effect of fluctuating stream stage, and sensitivity to population size. According to these comparisons, the 15-hoop-net set used during stable water levels in October had the most desirable characteristics. Using our catch data, we estimated the precision of CPUE and size structure by varying sample sizes for the 15-hoop-net set. We recommend that 11–15 repetitions of the 15-hoop-net set be used for most management activities. This standardized basic unit of effort will increase the precision of estimates and allow better comparisons among samples as well as increased confidence in management decisions.

  13. Sensitivity of Off-Channel Salmon Rearing Habitats to Changing Base Flows in Low-Gradient Reaches of Central Idaho Mountain Streams

    NASA Astrophysics Data System (ADS)

    McKean, J. A.; Thurow, R.; Tonina, D.; Isaak, D.; Bohn, C.

    2010-12-01

    Critical rearing habitats for juvenile salmon and trout are frequently in off-channel areas of shallow, low-velocity water. Typically, these are remnants of abandoned channel positions that are still hydraulically connected to the contemporary main channel. However, the size and spatial arrangement of this habitat is strongly dependent on water stage in the main channel. In two salmon-bearing streams in the Middle Fork Salmon River, Idaho, we used a high-resolution channel DEM and a 1D fluid dynamics model to define the location, depth, total area, frequency, and timing and duration of flooding of off-channel habitat. We then predicted changes in water surface elevation in the main channel over a range of low flow discharges and remapped the functional off-channel areas at each flow stage. Measurements at nearby gages indicate that average late summer and autumn low flows in these streams have declined by about 7% per decade over the prior 60 years. Modern off-channel habitat along the 20km of study streams is not uniformly arranged, even at high flows, and the distribution becomes still more restricted in space and time as flows decline. Progeny of summer- and early fall-spawning Chinook salmon rear for up to 2 years in these streams before migrating to the ocean, with much of that time spent in the off-channel habitat. Progeny of spring-spawning steelhead use the same areas for up to 3 years. While much prior research has focused on the effects of climate change on the availability and condition of spawning sites and on water temperatures, this study documents likely changes in the amount and condition of rearing habitat. Further investigation is needed to understand the ecological consequences and whether the declining anadromous fish populations may be at some risk from diminishing rearing habitat during declining base flows caused by external forces, such as a changing climate, dams, or water extractions.

  14. Long-term impacts of land cover changes on stream channel loss

    EPA Science Inventory

    Land cover change and stream channel loss are two related global environmental changes that are expanding and intensifying. Here, we examine how different types and transitions of land cover change impact stream channel loss across a large urbanizing watershed with large areas of...

  15. Rain and channel flow supplements to subsurface water beneath hyper-arid ephemeral stream channels

    NASA Astrophysics Data System (ADS)

    Kampf, Stephanie K.; Faulconer, Joshua; Shaw, Jeremy R.; Sutfin, Nicholas A.; Cooper, David J.

    2016-05-01

    In hyper-arid regions, ephemeral stream channels are important sources of subsurface recharge and water supply for riparian vegetation, but few studies have documented the subsurface water content dynamics of these systems. This study examines ephemeral channels in the hyper-arid western Sonoran Desert, USA to determine how frequently water recharges the alluvial fill and identify variables that affect the depth and persistence of recharge. Precipitation, stream stage, and subsurface water content measurements were collected over a three-year study at six channels with varying contributing areas and thicknesses of alluvial fill. All channels contain coarse alluvium composed primarily of sands and gravels, and some locations also have localized layers of fine sediment at 2-3 m depth. Rain alone contributed 300-400 mm of water input to these channels over three years, but water content responses were only detected for 36% of the rain events at 10 cm depth, indicating that much of the rain water was either quickly evaporated or taken up by plants. Pulses of water from rain events were detected only in the top meter of alluvium. The sites each experienced ⩽5 brief flow events, which caused transient saturation that usually lasted only a few hours longer than flow. These events were the only apparent source of water to depths >1 m, and water from flow events quickly percolated past the deepest measurement depths (0.5-3 m). Sustained saturation in the shallow subsurface only developed where there was a near-surface layer of finer consolidated sediments that impeded deep percolation.

  16. Meteorite impact - A suggestion for the origin of some stream channels on Mars

    NASA Technical Reports Server (NTRS)

    Maxwell, T. A.; Otto, E. P.; Picard, M. D.; Wilson, R. C.

    1973-01-01

    The appearance of many streamlike features on Mars indicates the formation of channels through erosion by liquid water. We suggest that streams originating at meteorite crater boundaries are the result of impact which released subsurface water trapped below the Martian surface by a layer of permafrost. Features indicating surface erosion are the presence of alluvial plains at the downstream ends of channels, an increase in stream width with distance from the meteorite craters, and a direct correlation among several examples between crater diameter and stream length. Water released from the subsurface is preferred over rainfall as a mechanism for the origin of stream channels originating from craters on Mars.

  17. A comparison of hydrology and channel hydraulics in headwater streams of the Central Oregon Cascades

    NASA Astrophysics Data System (ADS)

    Hempel, L. A.; Grant, G.; Lewis, S.

    2013-12-01

    Streams with distinctly different flow regimes can be found within close proximity of each other in the Central Oregon Cascades due to the unique hydrogeology of the region. Spring-fed streams with stable discharge regimes tend to have rectangular cross-sections, uniform grain sizes, and frequent channel-spanning wood. In contrast, flashier surface-runoff channels tend to have more variable cross-sections, a wider grain-size distribution, and woody debris accumulations along channel margins. To examine differences in channel hydraulics, we collected high-resolution 3-D maps of 12 channel reaches from tributaries of the McKenzie and Metolius Rivers, OR. Stream channel maps were then used to run a 2-D channel stability model (MD_SWMS). We also compared stream hydrology using 10+ years of stream gage data. We expect bed particles are mobilized more frequently in spring-fed systems, but the opportunity for channel form development-- which occurs when sediment is mobile and when flow reaches or exceeds the active channel flow--is higher in surface-runoff channels. Therefore, each channel-type is characterized by a unique set of hydraulic processes that lead to observed differences in channel form.

  18. Groundwater exchanges near a channelized versus unmodified stream mouth discharging to a subalpine lake

    NASA Astrophysics Data System (ADS)

    Constantz, J.; Naranjo, R.; Niswonger, R.; Allander, K.; Neilson, B.; Rosenberry, D.; Smith, D.; Rosecrans, C.; Stonestrom, D.

    2016-03-01

    The terminus of a stream flowing into a larger river, pond, lake, or reservoir is referred to as the stream-mouth reach or simply the stream mouth. The terminus is often characterized by rapidly changing thermal and hydraulic conditions that result in abrupt shifts in surface water/groundwater (sw/gw) exchange patterns, creating the potential for unique biogeochemical processes and ecosystems. Worldwide shoreline development is changing stream-lake interfaces through channelization of stream mouths, i.e., channel straightening and bank stabilization to prevent natural meandering at the shoreline. In the central Sierra Nevada (USA), Lake Tahoe's shoreline has an abundance of both "unmodified" (i.e., not engineered though potentially impacted by broader watershed engineering) and channelized stream mouths. Two representative stream mouths along the lake's north shore, one channelized and one unmodified, were selected to compare and contrast water and heat exchanges. Hydraulic and thermal properties were monitored during separate campaigns in September 2012 and 2013 and sw/gw exchanges were estimated within the stream mouth-shoreline continuum. Heat-flow and water-flow patterns indicated clear differences in the channelized versus the unmodified stream mouth. For the channelized stream mouth, relatively modulated, cool-temperature, low-velocity longitudinal streambed flows discharged offshore beneath warmer buoyant lakeshore water. In contrast, a seasonal barrier bar formed across the unmodified stream mouth, creating higher-velocity subsurface flow paths and higher diurnal temperature variations relative to shoreline water. As a consequence, channelization altered sw/gw exchanges potentially altering biogeochemical processing and ecological systems in and near the stream mouth.

  19. Groundwater exchanges near a channelized versus unmodified stream mouth discharging to a subalpine lake

    USGS Publications Warehouse

    Constantz, James; Naranjo, Ramon C.; Niswonger, Richard; Allander, Kip K.; Neilson, B.; Rosenberry, Donald O.; Smith, David W.; Rosecrans, C.; Stonestrom, David A.

    2016-01-01

    The terminus of a stream flowing into a larger river, pond, lake, or reservoir is referred to as the stream-mouth reach or simply the stream mouth. The terminus is often characterized by rapidly changing thermal and hydraulic conditions that result in abrupt shifts in surface water/groundwater (sw/gw) exchange patterns, creating the potential for unique biogeochemical processes and ecosystems. Worldwide shoreline development is changing stream-lake interfaces through channelization of stream mouths, i.e., channel straightening and bank stabilization to prevent natural meandering at the shoreline. In the central Sierra Nevada (USA), Lake Tahoe's shoreline has an abundance of both “unmodified” (i.e., not engineered though potentially impacted by broader watershed engineering) and channelized stream mouths. Two representative stream mouths along the lake's north shore, one channelized and one unmodified, were selected to compare and contrast water and heat exchanges. Hydraulic and thermal properties were monitored during separate campaigns in September 2012 and 2013 and sw/gw exchanges were estimated within the stream mouth-shoreline continuum. Heat-flow and water-flow patterns indicated clear differences in the channelized versus the unmodified stream mouth. For the channelized stream mouth, relatively modulated, cool-temperature, low-velocity longitudinal streambed flows discharged offshore beneath warmer buoyant lakeshore water. In contrast, a seasonal barrier bar formed across the unmodified stream mouth, creating higher-velocity subsurface flow paths and higher diurnal temperature variations relative to shoreline water. As a consequence, channelization altered sw/gw exchanges potentially altering biogeochemical processing and ecological systems in and near the stream mouth.

  20. Channel erosion in steep gradient, gravel-paved streams

    SciTech Connect

    Lepp, L.R.; Koger, C.J.; Wheeler, J.A.

    1993-12-01

    Discharges were measured in steep gradient (> 5 percent) gravel-paved streams from 1988 to 1991 in order to empirically determine erosional thresholds based on sediment size, related to critical velocity, tractive force, and unit stream power. Results suggest that the empirical relationship between sediment size and unit stream power provides an accurate and simple methodology for determining the minimum erosion threshold discharge for steep gradient streams common in western Washington and other similar mountain terrains.

  1. Understanding Stream Channel Sediment Source Contributions For The Paradise Creek Watershed In Northern Idaho

    NASA Astrophysics Data System (ADS)

    Rittenburg, R.; Boll, J.; Brooks, E. S.

    2013-12-01

    Excess sediment from agricultural areas has been a major source of impairment for water bodies, resulting in the implementation of mitigation measures across landscapes. Watershed scale reductions often target upland erosion as key non-point sources for sediment loading. Stream channel dynamics, however, also play a contributing role in sediment loading in the form of legacy sediments, channel erosion and deposition, and buffering during storm events. In-stream contributions are not well understood, and are a potentially important consideration for Total Maximum Daily Loads (TMDLs). The objective of this study is to differentiate stream bank and stream bed sediment contributions and better understand the role of legacy sediments. The study area is the Paradise Creek Watershed in northern Idaho. We modeled sediment yield to the channel system using the Water Erosion Prediction Project (WEPP) model, and subsequent channel erosion and deposition using CONCEPTs. Field observations of cross-sections along the channel system over a 5-year period were collected to verify model simulations and to test the hypothesis that the watershed load was composed predominantly of legacy sediments. Our modeling study shows that stream channels contributed to 39% of the total annual sediment load for the basin, with a 19-year time lag between sediments entering the stream to leaving the watershed outlet. Observations from long-term cross sectional data in the watershed, and a sediment fingerprinting analysis will be presented to better understand sediment contributions from within the stream channel system.

  2. Long-term impacts of land cover changes on stream channel loss.

    PubMed

    Julian, Jason P; Wilgruber, Nicholas A; de Beurs, Kirsten M; Mayer, Paul M; Jawarneh, Rana N

    2015-12-15

    Land cover change and stream channel loss are two related global environmental changes that are expanding and intensifying. Here, we examine how different types and transitions of land cover change impact stream channel loss across a large urbanizing watershed. We present historical land cover in the 666-km(2) Lake Thunderbird watershed in central Oklahoma (USA) over a 137 year period and coinciding stream channel length changes for the most recent 70 years of this period. Combining these two datasets allowed us to assess the interaction of land cover changes with stream channel loss. Over this period, the upper third of the watershed shifted from predominantly native grassland to an agricultural landscape, followed by widespread urbanization. The lower two-thirds of the watershed changed from a forested landscape to a mosaic of agriculture, urban, forest, and open water. Most channel length lost in the watershed over time was replaced by agriculture. Urban development gradually increased channel loss and disconnection from 1942 to 2011, particularly in the headwaters. Intensities of channel loss for both agriculture and urban increased over time. The two longest connected segments of channel loss came from the creation of two large impoundments, resulting in 46 km and 25 km of lost stream channel, respectively. Overall, the results from this study demonstrate that multiple and various land-use changes over long time periods can lead to rapid losses of large channel lengths as well as gradual (but increasing) losses of small channel lengths across all stream sizes. When these stream channel losses are taken into account, the environmental impacts of anthropogenic land-use change are compounded. PMID:26282774

  3. Mean annual runoff and peak flow estimates based on channel geometry of streams in southeastern Montana

    USGS Publications Warehouse

    Omang, R.J.; Parrett, Charles; Hull, J.A.

    1983-01-01

    Equations using channel-geometry measurements were developed for estimating mean runoff and peak flows of ungaged streams in southeastern Montana. Two separate sets of esitmating equations were developed for determining mean annual runoff: one for perennial streams and one for ephemeral and intermittent streams. Data from 29 gaged sites on perennial streams and 21 gaged sites on ephemeral and intermittent streams were used in these analyses. Data from 78 gaged sites were used in the peak-flow analyses. Southeastern Montana was divided into three regions and separate multiple-regression equations for each region were developed that relate channel dimensions to peak discharge having recurrence intervals of 2, 5, 10, 25, 50, and 100 years. Channel-geometery relations were developed using measurements of the active-channel width and bankfull width. Active-channel width and bankfull width were the most significant channel features for estimating mean annual runoff for al types of streams. Use of this method requires that onsite measurements be made of channel width. The standard error of estimate for predicting mean annual runoff ranged from about 38 to 79 percent. The standard error of estimate relating active-channel width or bankfull width to peak flow ranged from about 37 to 115 percent. (USGS)

  4. Reach-Scale Channel Adjustments to Channel Network Geometry in Mountain Bedrock Streams

    NASA Astrophysics Data System (ADS)

    Plitzuweit, S. J.; Springer, G. S.

    2008-12-01

    surveys in order to analyze whether stream power and shear stress are adjusted to reflect CNG at the reach- scale. These models are compared to those with discharges calculated using drainage area and precipitation totals alone. We conclude that gradients in bedrock mountain streams may reflect basin-scale hydrology (CNG) and not simply local geological or geomorphic factors. This challenges the conclusions of others who ascribe local channel adjustments to: i) lithology and structure alone, or ii) local colluvium grain sizes.

  5. West-Antarctic Ice Streams: Analog to Ice Flow in Channels on Mars

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.

    1997-01-01

    Sounding of the sea floor in front of the Ross Ice Shelf in Antarctica recently revealed large persistent patterns of longitudinal megaflutes and drumlinoid forms, which are interpreted to have formed at the base of ice streams during the list glacial advance. The flutes bear remarkable resemblance to longitudinal grooves and highly elongated streamlined islands found on the floors of some large martian channels, called outflow channels. ln addition, other similarities exist between Antarctic ice streams and outflow channels. Ice streams are 30 to 80 km wide and hundreds of kilometers long, as are the martian channels. Ice stream beds are below sea level. Floors of many martian outflow channels lie below martian datum, which may have been close to or below past martian sea levels. The Antarctic ice stream bed gradient is flat and locally may go uphill, and surface slopes are exceptionally low. So are gradients of martian channels. The depth to the bed in ice streams is 1 to 1.5 km. At bankful stage, the depth of the fluid in outflow channels would have been 1 to 2 km. These similarities suggest that the martian outflow channels, whose origin is commonly attributed to gigantic catastrophic floods, were locally filled by ice that left a conspicuous morphologic imprint. Unlike the West-Antarctic-ice streams, which discharge ice from an ice sheet, ice in the martian channels came from water erupting from the ground. In the cold martian environment, this water, if of moderate volume, would eventually freeze. Thus it may have formed icings on springs, ice dams and jams on constrictions in the channel path, or frozen pools. Given sufficient thickness and downhill surface gradient, these ice masses would have moved; and given the right conditions, they could have moved like Antarctic ice streams.

  6. Hydroclimatic signal and LBK cultural activity in the Upper and Lower Rhine, inferred from abandoned channel fill deposits

    NASA Astrophysics Data System (ADS)

    Berger, J. F.; Salvador, P. G.; Erkens, G.; Toonen, W. H. J.; Purdue, L.; Barra, A.; Houben, P.

    2012-04-01

    The Linear Band Ceramic (LBK) culture represents a major event in the spread of agriculture in Europe. Occupation particularly occurred in river valleys, with largest densities found along the rivers Danube, Elbe and Rhine. The interaction between the emergence of this culture and the dominant climatic and hydrological conditions is not yet fully established. As part of the ANR OBRESOC project, in which LBK activity is investigated in a transect from France (Marne river) to the catchment of the Danube river (Tisza), we studied palaeo-environmental changes in the Rhine valley between 7600-6600 cal. yrs. BP. Focus is on the Upper Rhine Graben and the Lower Rhine valley near the Rhine Delta apex, which is thought to be a peripheral region of LBK-activity. In these regions, a total of five cores from abandoned channels were analysed to reconstruct palaeo-environmental dynamics in vegetation and fluvial activity during the period of LBK development. Abandoned channel fills are excellent sites to perform detailed studies of palaeo-environmental dynamics, as they (i) form proximal locations to occupation sites of the LBK culture, (ii) act as efficient traps of sediments in which different environmental proxies are well preserved, (iii) contain well-datable material for the construction of detailed age-depth models, and (iv) provide a long proxy record, potentially over more than a millennium at a single site. On all cores, high resolution analysis of channel fill deposits (grain size and geophysical properties) and biotic proxies (micro-charcoal fluxes and pollen assemblages) were preformed to reconstruct palaeo-environmental signals, such as changes in fluvial activity, forest fires, and vegetation evolution, which may be related to agricultural activity, and climatic and hydrogeomorphic changes in the region. In this contribution we compare the results of the high-resolution core analyses (1,5 to 5m sequences for the studied timeframe) derived from the more densely

  7. Instream Wood Loads and Channel Complexity in Headwater Streams Under Alternative Stable States

    NASA Astrophysics Data System (ADS)

    Livers, B.; Wohl, E.

    2014-12-01

    Channel morphology and irregularities in stream boundaries can create zones of flow separation, where lower velocities trap fine sediment and organic matter and increase opportunities for nutrient processing and biological uptake. This effect is most pronounced with channel-spanning structures such as logjams. Humans have changed the spatial and temporal characteristics of wood distribution in streams, with lasting effects on instream wood recruitment, wood loads, logjam distribution, and hydraulic roughness. Previous studies in the Colorado Front Range show that contemporary headwater streams flowing through old-growth, unmanaged forests have more wood than streams flowing through younger-growth, managed forests, but do not evaluate the effects of wood on channel complexity. 'Managed' versus 'unmanaged' refers to whether forests were or are currently exposed to human alteration. Although some alteration has long since ceased, reduced wood loads in managed streams persist. Our primary objective was to quantify differences in logjams, wood volumes, stream complexity, and organic carbon storage on streams with different management and disturbance histories in order to examine legacy effects across a gradient of stream management. Data were collected during the summers of 2013 and 2014 in the Southern Rocky Mountains. The 25 stream reaches studied are 2nd to 3rd order, subalpine streams that are categorized into: old-growth unmanaged forests; younger, naturally disturbed unmanaged forests; and younger managed forests. We assessed instream and floodplain wood loads and logjams and evaluated the role that large wood plays in local channel complexity, pool volume, and storage of organic carbon. Preliminary results show that greatest wood and carbon storage in sediments, as well as channel complexity, occurs in streams in old-growth, unmanaged forests and the least wood and carbon storage and channel complexity occurs in younger-growth, managed forests.

  8. Channel stability downstream from a dam assessed using aerial photographs and stream-gage information

    USGS Publications Warehouse

    Juracek, K.E.

    2000-01-01

    The stability of the Neosho River channel downstream from John Redmond Dam, in southeast Kansas, was investigated using multiple-date aerial photographs and stream-gage information. Bankfull channel width was used as the primary indicator variable to assess pre- and post-dam channel change. Five six-mile river reaches and four stream gages were used in the analysis. Results indicated that, aside from some localized channel widening, the overall channel change has been minor with little post-dam change in bankfull channel width. The lack of a pronounced postdam channel change may be attributed to a substantial reduction in the magnitude of the post-dam annual peak discharges in combination with the resistance to erosion of the bed and bank materials. Also, the channel may have been overwidened by a series of large floods that predated construction of the dam, including one with an estimated 500-year recurrence interval.

  9. Computer-aided mapping of stream channels beneath the Lawrence Livermore National Laboratory Super Fund Site

    SciTech Connect

    Sick, M.

    1994-12-01

    The Lawrence Livermore National Laboratory (LLNL) site rests upon 300-400 feet of highly heterogeneous braided stream sediments which have been contaminated by a plume of Volatile Organic Compounds (VOCs). The stream channels are filled with highly permeable coarse grained materials that provide quick avenues for contaminant transport. The plume of VOCs has migrated off site in the TFA area, making it the area of greatest concern. I mapped the paleo-stream channels in the TFA area using SLICE an LLNL Auto-CADD routine. SLICE constructed 2D cross sections and sub-horizontal views of chemical, geophysical, and lithologic data sets. I interpreted these 2D views as a braided stream environment, delineating the edges of stream channels. The interpretations were extracted from Auto-CADD and placed into Earth Vision`s 3D modeling and viewing routines. Several 3D correlations have been generated, but no model has yet been chosen as a best fit.

  10. The importance of instream habitat modifications for restoring channelized agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Science based information on the influence of restoration practices on fishes within channelized agricultural headwater streams in the Midwestern United States is currently lacking. Understanding fish-habitat relationships and fish responses to specific restoration practices will provide informatio...

  11. Design and performance of a channel reconstruction project in a coastal California gravel-bed stream.

    PubMed

    Kondolf, G M; Smeltzer, M W; Railsback, S F

    2001-12-01

    A 0.9 km-reach of Uvas Creek, California, was reconstructed as a sinuous, meandering channel in November 1995. In February 1996, this new channel washed out. We reviewed project documents to determine the basis for the project design and conducted our own historical geomorphological study to understand the processes operating in the catchment and project reach. The project was designed using a popular stream classification system, based on which the designers assumed that a "C4" channel (a meandering gravel-bed channel) would be stable at the site. Our historical geomorphological analysis showed that the reach had been braided historically, typical of streams draining the Franciscan Formation in the California Coast Ranges, with episodic flows and high sand and gravel transport. After the project washed out, Uvas Creek reestablished an irregular, braided sand-and-gravel channel, although the channel here was narrower than it had been historically, probably due to such factors as incision caused by gravel mining. Our study casts doubt on several assumptions common in many stream restoration projects: that channel stability is always an appropriate goal; that channel forms are determined by flows with return periods of about 1.5 years; that a channel classification system is an easy, appropriate basis for channel design; and that a new channel form can be imposed without addressing the processes that determine channel form. PMID:11915965

  12. HOW WELL CAN YOU ESTIMATE LOW FLOW AND BANKFULL DISCHARGE FROM STREAM CHANNEL HABITAT DATA?

    EPA Science Inventory

    Modeled estimates of stream discharge are becoming more important because of reductions in the number of gauging stations and increases in flow alteration from land development and climate change. Field measurements of channel morphology are available at thousands of streams and...

  13. Relationships between water chemistry and fish communities within channelized headwater streams in Indiana and Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many headwater streams in the midwestern United States were channelized for draining agricultural fields. Agricultural conservation practices are implemented to reduce nutrient and pesticide loadings within these altered streams. The impact of these practices is uncertain because the influence of wa...

  14. Substrate, sediment, and slope controls on bedrock channel geometry in postglacial streams

    NASA Astrophysics Data System (ADS)

    Whitbread, Katie; Jansen, John; Bishop, Paul; Attal, Mikaël.

    2015-05-01

    The geometry of channels controls the erosion rate of rivers and the evolution of topography following environmental change. We examine how sediment, slope, and substrate interact to constrain the development of channels following deglaciation and test whether theoretical relationships derived from streams reacting to tectonic uplift apply in these settings. Using an extensive data set of channel geometry measurements from postglacial streams in the Scottish Highlands, we find that a power law width-drainage area scaling model accounts for 81% of the spatial variation in channel width. Substrate influences channel form at the reach scale, with bedrock channels found to be narrower and deeper than alluvial channels. Bedrock channel width does not covary with slope, which may be due to downstream variations in sediment flux. Bedrock channel width-to-depth ratios increase with discharge (or area) and sediment flux, consistent with increasing bed cover promoting lateral widening. We find steep, wide, and shallow bedrock channels immediately below lakes, which we interpret as the result of limited erosion due to a lack of sediment "tools." Where sediment supply is sufficient to exceed transport capacity, alluvial channels develop wider, shallower geometries constrained primarily by flow hydraulics. Our results indicate that simple scaling models of channel width with drainage area are applicable at regional scale, but locally, channel width varies with substrate, and in the case of bedrock channels, with sediment flux.

  15. The Blurred Line between Form and Process: A Comparison of Stream Channel Classification Frameworks

    PubMed Central

    Kasprak, Alan; Hough-Snee, Nate

    2016-01-01

    Stream classification provides a means to understand the diversity and distribution of channels and floodplains that occur across a landscape while identifying links between geomorphic form and process. Accordingly, stream classification is frequently employed as a watershed planning, management, and restoration tool. At the same time, there has been intense debate and criticism of particular frameworks, on the grounds that these frameworks classify stream reaches based largely on their physical form, rather than direct measurements of their component hydrogeomorphic processes. Despite this debate surrounding stream classifications, and their ongoing use in watershed management, direct comparisons of channel classification frameworks are rare. Here we implement four stream classification frameworks and explore the degree to which each make inferences about hydrogeomorphic process from channel form within the Middle Fork John Day Basin, a watershed of high conservation interest within the Columbia River Basin, U.S.A. We compare the results of the River Styles Framework, Natural Channel Classification, Rosgen Classification System, and a channel form-based statistical classification at 33 field-monitored sites. We found that the four frameworks consistently classified reach types into similar groups based on each reach or segment’s dominant hydrogeomorphic elements. Where classified channel types diverged, differences could be attributed to the (a) spatial scale of input data used, (b) the requisite metrics and their order in completing a framework’s decision tree and/or, (c) whether the framework attempts to classify current or historic channel form. Divergence in framework agreement was also observed at reaches where channel planform was decoupled from valley setting. Overall, the relative agreement between frameworks indicates that criticism of individual classifications for their use of form in grouping stream channels may be overstated. These form

  16. The Blurred Line between Form and Process: A Comparison of Stream Channel Classification Frameworks.

    PubMed

    Kasprak, Alan; Hough-Snee, Nate; Beechie, Tim; Bouwes, Nicolaas; Brierley, Gary; Camp, Reid; Fryirs, Kirstie; Imaki, Hiroo; Jensen, Martha; O'Brien, Gary; Rosgen, David; Wheaton, Joseph

    2016-01-01

    Stream classification provides a means to understand the diversity and distribution of channels and floodplains that occur across a landscape while identifying links between geomorphic form and process. Accordingly, stream classification is frequently employed as a watershed planning, management, and restoration tool. At the same time, there has been intense debate and criticism of particular frameworks, on the grounds that these frameworks classify stream reaches based largely on their physical form, rather than direct measurements of their component hydrogeomorphic processes. Despite this debate surrounding stream classifications, and their ongoing use in watershed management, direct comparisons of channel classification frameworks are rare. Here we implement four stream classification frameworks and explore the degree to which each make inferences about hydrogeomorphic process from channel form within the Middle Fork John Day Basin, a watershed of high conservation interest within the Columbia River Basin, U.S.A. We compare the results of the River Styles Framework, Natural Channel Classification, Rosgen Classification System, and a channel form-based statistical classification at 33 field-monitored sites. We found that the four frameworks consistently classified reach types into similar groups based on each reach or segment's dominant hydrogeomorphic elements. Where classified channel types diverged, differences could be attributed to the (a) spatial scale of input data used, (b) the requisite metrics and their order in completing a framework's decision tree and/or, (c) whether the framework attempts to classify current or historic channel form. Divergence in framework agreement was also observed at reaches where channel planform was decoupled from valley setting. Overall, the relative agreement between frameworks indicates that criticism of individual classifications for their use of form in grouping stream channels may be overstated. These form

  17. Influence of Beaver Dams on Channel Complexity, Hydrology, and Temperature Regime in a Mountainous Stream

    NASA Astrophysics Data System (ADS)

    Majerova, M.; Neilson, B. T.; Schmadel, N. M.; Wheaton, J. M.; Snow, C. J.

    2013-12-01

    Beaver dams and beaver activity affect hydrologic processes, sediment transport, channel complexity and water quality of streams. Beaver ponds, which form behind beaver dams, increase in-channel water storage affecting the timing and volume of flow and resulting in the attenuation and flattening of the hydrograph. Channel complexity also increases the potential for transient storage (both surface and subsurface) and influences stream temperature. Impacts of beaver dams and beaver activity on stream responses are difficult to quantify because responses are dynamic and spatially variable. Few studies have focused on the reach scale temporal influences on stream responses and further research is needed particularly in quantifying the influence of beaver dams and their role in shaping the stream habitat. This study explores the changing hydrology and temperature regime of Curtis Creek, a mountainous stream located in Northern Utah, in a 560 m long reach where groundwater exchanges and temperature differences were observed over a three-year period. We have collected continuous stream discharge, stream temperature data and performed tracer experiments. During the first year, we were able to capture the pre-beaver activity. In the second year, we captured the impacts of some beaver activity with only a few dams built in the reach, while the third year included the effects of an entire active beaver colony. By the end of the study period, a single thread channel had been transformed into a channel with side channels and backwaters at multiple locations therefore increasing channel complexity. The cumulative influence of beaver dams on reach scale discharge resulted in a slightly losing reach that developed into a gaining reach. At the smaller sub-reach scale, both losing to gaining and gaining to losing transformations were observed. Temperature differences showed a warming effect of beaver dams at the reach scale. The reach stream temperature difference increased on

  18. Influence of gully erosion control on amphibian and reptile communities within riparian zones of channelized streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian zones of streams in northern Mississippi have been impacted by agriculture, channelization, channel incision, and gully erosion. Gully erosion is the most severe form of erosion and has resulted in the fragmentation of remnant riparian zones within agricultural watersheds. One widely used c...

  19. Influence of Gully Erosion Control on Amphibian and Reptile Communities Within Riparian Zones of Channelized Streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian zones of streams in northern Mississippi have been impacted by agriculture, channelization, channel incision, and gully erosion. Gully erosion is the most severe form of erosion and has resulted in the fragmentation of remnant riparian zones within agricultural watersheds. One widely used c...

  20. Stream Corridor Lowering for Servicing: Considerations and Approaches to Natural Channel Design in Southern Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Villard, P. V.

    2009-05-01

    Although there are numerous approaches to natural channel design, all approaches generally advocate application of geomorphic principles to develop stable watercourses with improved habitat function. In southern Ontario, natural channel design approaches are increasingly utilized in stream corridor management. In numerous greenfield developments within southern Ontario, creek corridors are lowered and relocated to address potential hazards and facilitate development. These projects usually utilize natural channel design approaches. Although lowering for servicing can be a controversial technique, this approach has resulted in the maintenance of channels that may have previously been enclosed and lost. In the southern Ontario context mimicking natural corridor form and function is complicated by a surficial geology dominated by glacial sediments. Approaches to natural channel design have evolved over time to address this encumbrance. This presentation examines the geomorphology of streams and stream corridors within southern Ontario. Case studies from southern Ontario are provided to illustrate many of the impediments to, and innovations in, natural channel design. This lays the foundation for illustrating how these design approaches address potential hazards, provide for stream form and function, and mimic much of the physical and biological interactions found within natural stream corridors.

  1. Hierarchical influences on the biophysical properties of natural stream channels

    NASA Astrophysics Data System (ADS)

    Stanfield, L. W.; Kilgour, B.

    2005-05-01

    In this paper we focus on how catchment and proximity effects influence the biophysical properties of streams and these conditions are modified by overall landuse in the catchment and site conditions. Biophysical data (fish, inverts, instream habitat, temperature and baseflow) were collected on wadable streams flowing into the Lake Ontario basin. A GIS application was developed to characterize the landscape conditions for each site. For each of 700 -1400 sites, biophysical and GIS data (drainage area, geology, landuse, slope, stream length, and climatic conditions) were summarized. We explored the relationship between slope and drainage area and two composite indices, one the baseflow index (BFI) combined geology and drainage potential and the other, percent impervious cover (PIC) provided a single metric of disturbance on the landscape. Multivariate approaches were used to develop models to relate each metric to landscape conditions, and PIC. Residuals of this analysis were related to local conditions to determine how much of the remaining variance was explained by these conditions. Our results indicate that several metrics demonstrate a threshold response to PIC and that local conditions have minimal capacity to mitigate these effects. Below the threshold several metrics demonstrated a linear response to PIC that enables predictions to be made of effects from development in a catchment. Instream habitat conditions were more important for some biota (e.g. brown trout) than others. We demonstrate how model results can be used to classify sites or stream segments based on predicted conditions and how results can be used to generate coarse population estimates

  2. On the ecohydrologic function and disturbance effects of ephemeral desert stream channels

    NASA Astrophysics Data System (ADS)

    Bedford, David; Schwinning, Susan; Newlander, April; Miller, David; Sandquist, Darren

    2010-05-01

    Ephemeral stream channels are widespread features throughout desert landscapes, particularly on alluvial fans. These channels range in width from a few tens of centimeters to many meters. Runoff in these channels can redistribute water from upper portions of the landscape in response to rare high-intensity or long duration rainstorms. Visual observations suggest that shrubland vegetation is often clustered at higher cover alongside these channels. We are using transect studies, mapping, monitoring and manipulation experiments to investigate the hydrologic relations of these features to vegetation in the eastern Mojave Desert of the USA. We use a piedmont that is perpendicularly transected by a ~100 year old railroad that alters natural flow by diverting it through staggered culverts to areas below the railroad. This creates an opportunity to study: 1) relatively undisturbed areas above the railroad, 2) areas below the railroad that receive enhanced flow where water is diverted through culverts (enhanced) and, 3) areas below the railroad where water flow from upslope has been blocked (deprived). In all areas we found that vegetation cover and density is higher alongside stream channels and decreases with distance from the channels. In all but the deprived areas, vegetation is nearly absent in the stream channels. Relative to the upper undisturbed areas, vegetation cover is higher in the enhanced areas, and lower in the deprived areas; however, when diversion is not considered cover above and below the road is equal overall. Furthermore, species-specific differences were present. The drought deciduous sub-shrub Ambrosia dumosa shows increased cover in deprived areas and in all areas peaked closer to the channel margin than the evergreen drought-tolerant shrub Larrea tridentata, we believe due to differences in root morphology. In a simulated channel runoff event, we found that vegetation within 3 meters of the stream channel physiologically responded (elevated water

  3. In situ production of methylmercury within a stream channel in northern California.

    PubMed

    Tsui, Martin Tsz Ki; Finlay, Jacques C; Balogh, Steven J; Nollet, Yabing H

    2010-09-15

    Natural stream ecosystems throughout the world are contaminated by methylmercury, a highly toxic compound that bioaccumulates and biomagnifies in aquatic food webs. Wetlands are widely recognized as hotspots for the production of methylmercury and are often assumed to be the main sources of this neurotoxin in downstream ecosystems. However, many streams lacking wetlands in their drainage basins (e.g., montane and semiarid regions in the western United States) have significant methylmercury contamination, and the sources of methylmercury in these streams remain largely unknown. In this study, we observed substantial production of methylmercury within a highly productive stream channel in northern California (South Fork Eel River) within a drainage basin lacking wetlands. We found that in situ methylmercury production is positively related to phosphorus removal and water temperature within the stream channel, supporting hypothesized biological mediation of in situ mercury transformation. Moreover, our data suggest that epiphytic microbial communities on a dominant filamentous alga (Cladophora glomerata) could play a role in in situ methylmercury production. Because peak in situ methylmercury production coincides with the period of the highest biological productivity during summer baseflow, methylmercury produced internally may be efficiently routed into local stream food webs. Our study provides strong evidence that stream channels, especially those associated with high primary productivity, can be important for regulating the bioavailability and toxicity of this global contaminant. PMID:20715863

  4. Hydrology of the Creeping Swamp Watershed, North Carolina with reference to potential effects of stream channelization

    USGS Publications Warehouse

    Winner, M.D.; Simmons, C.E.

    1977-01-01

    Hydrologic data were collected for four years at six sites in the Creeping Swamp watershed in eastern North Carolina in a preliminary effort to study the effects of stream channelization on the hydrology of a small watershed. A water-budget evaluation for pre-channelized conditions showed that runoff accounts for about 17 percent of the total rainfall, base runoff about 20 percent, ground-water outflow about 2 percent, and evapotranspiration about 61 percent. Channelization would have caused the greatest decline in ground-water levels nearest the stream, with the decline diminishing with increased distance from the stream. Channelization would also have resulted in a decrease in overland runoff and an increase in the amount of water reaching Creeping Swamp through the ground-water system, although the total volume of runoff would not change significantly. The water-quality characteristics of Creeping Swamp indicate that the stream is relatively free of pollution, although it is likely that channelization would increase (1) suspended-sediment loads, (2) stream temperatures, and (3) concentrations of dissolved solids, especially during low flows.

  5. A catchment-scale model of mountain stream channel morphologies in southeast Australia

    NASA Astrophysics Data System (ADS)

    Thompson, Chris; Croke, Jacky; Takken, Ingrid

    2008-03-01

    The position of mountain streams high in the channel network and their proportional dominance mean that channel modifications and adjustments within these systems will have important implications for downstream processes and linkages. This study develops an analysis framework for examining the catchment-scale distribution of reach morphologies, and the relationship among reach type, catchment lithology and flow competence in southeast Australian mountain streams. The analysis framework is applied to three catchments which have contrasting proportions of the two dominant lithologies of the region, Devonian granites and Ordovician metasediments. The model successfully delineated 68% of reach types, and the resultant spatial maps allowed the effects of stream network position and catchment specific controls on channel morphology to be evaluated. Maximum lengths of the majority of reach morphology types were in second-order streams and the maximum number of morphology types (six) was present in third-order streams, with dramatic reductions in reach type variability as the network expands. The position of catchment lithology within the channel network structure was recognized as more important than the aerial extent of a particular lithology on the distribution and abundance of reach morphologies. The model provides an important tool in the management of channel networks for the protection or restoration of ecological diversity, by identifying river segments and tributaries with high morphological diversity.

  6. Predicting stream channel erosion in the lacustrine core of the upper Nemadji River, Minnesota (USA) using stream geomorphology metrics

    NASA Astrophysics Data System (ADS)

    Magner, Joseph A.; Brooks, Kenneth N.

    2008-06-01

    The USA Clean Water Act requires the development of a total maximum daily load (TMDL) when Minnesota’s water quality standard for turbidity is exceeded; however, regions underlain with fine-grained lacustrine deposits yield large natural background loads of suspended inorganic sediment. A review of hydrogeologic pathways was conducted along with the statistical analysis of geomorphic metrics, collected at 15 sites with varying drainage areas in the upper Nemadji River basin, northeastern Minnesota. Regression analysis indicated a strong linkage between bankfull cross-sectional area and drainage area. Dimensionless geomorphic metric ratios were developed to predict channel evolution potential and associated channel erosion risk. Sites located in drainage areas less than 2 km2 had low erosion risk and showed a correlation between channel slope and relative roughness ( D 84/mean bankfull channel depth, 88%). A principal components analysis explained over 98% of the variance between sites and indicated five important channel shape metrics to predict channel erosion: bankfull width, bankfull depth, maximum depth, cross-sectional area, and valley beltwidth. Mass wasting of cohesive stream channel sediment was influenced by groundwater discharge and produced turbid waters in the upper Nemadji River.

  7. AN INTERREGIONAL COMPARISON OF CHANNEL STRUCTURE, TRANSIENT STORAGE AND NUTRIENT UPTAKE IN STREAMS DRAINING MANAGED AND OLD GROWTH WATERSHEDS

    EPA Science Inventory

    We compared stream channel structure (width, depth, substrate composition) and riparian canopy with transient storage and nutrient uptake in 32 streams draining old-growth and managed watersheds in the Appalachian Mountains (North Carolina), Ouachita Mountains (Arkansas), Cascade...

  8. Sources and interpretation of channel complexity in forested subalpine streams of the Southern Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Livers, Bridget; Wohl, Ellen

    2016-05-01

    We evaluate correlations between stream geomorphic complexity and characteristics of the adjacent riparian forest, valley geometry, and land use history in forested subalpine streams of the Colorado Front Range. Measures of geomorphic complexity focus on cross-sectional, planform, and instream wood piece and logjam variables. We categorize adjacent riparian forests as old-growth unmanaged forest (OU), younger unmanaged forest (YU), and younger managed forest (YM), and valley geometry as laterally confined, partly confined, or unconfined. Significant differences in geomorphic stream complexity between OU, YU, and YM result primarily from differences in wood pieces and logjams, and these differences correlate strongly with pool volume and organic matter storage. Significant differences in planform and cross-sectional complexity correlate more strongly with valley geometry, but do not explain as much of the observed variability in complexity between streams as do the wood variables. Unconfined OU streams have the largest wood loads and the greatest complexity, whereas legacy effects of logging, tie-drives, and channel simplification create lower complexity in YM streams, even relative to YU streams flowing through similarly aged forest. We find that management history of riparian forests exerts the strongest control on reduced functional stream channel complexity, regardless of riparian forest stand age.

  9. EZBC video streaming with channel coding and error concealment

    NASA Astrophysics Data System (ADS)

    Bajic, Ivan V.; Woods, John W.

    2003-06-01

    In this text we present a system for streaming video content encoded using the motion-compensated Embedded Zero Block Coder (EZBC). The system incorporates unequal loss protection in the form of multiple description FEC (MD-FEC) coding, which provides adequate protection for the embedded video bitstream when the loss process is not very bursty. The adverse effects of burst losses are reduced using a novel motion-compensated error concealmet method.

  10. Cross-stream migration of compliant particles in microfluidic channels

    NASA Astrophysics Data System (ADS)

    Kilimnik, Alex; Nur, Soojung Claire; di Carlo, Dino; Alexeev, Alexander

    2010-11-01

    Using a 3D hybrid lattice Boltzmann and lattice spring computational method, the motion of rigid and soft particles in a pressure-driven microfluidic flow was examined. The particles were modeled as neutrally buoyant fluid-filled elastic shells. The equilibrium positions of these particles were obtained in a low-Reynolds-number flow while accounting for non-linear inertial effects. Microchannels of different width were examined and it was found that the equilibrium position of the rigid particles moves away from the channel walls as the ratio between particle diameter and channel width increases. Furthermore, it was found that capsule deformability enhances the particle migration toward the channel centerline. The simulation results were compared with experimental data obtained with varying size and viscosity oil droplets suspended in water indicating favorable agreement. These findings could aid in the design of devices to sort particles based on their mechanical stiffness.

  11. Technical Note: Variability of flow discharge in lateral inflow-dominated stream channels

    NASA Astrophysics Data System (ADS)

    Chang, C.-M.; Yeh, H.-D.

    2015-02-01

    The influence of the temporal changes in lateral inflow rate on the discharge variability in stream channels is explored through the analysis of diffusion wave equation (the linearized St. Venant equations). To account for variability and uncertainty, the lateral inflow rate is regarded as a temporal random function. Based on the spectral representation theory, analytical expressions for the covariance function and evolutionary power spectral density of the random discharge perturbation process are derived to quantify variability in stream flow discharge induced by the temporal changes in lateral inflow rate. Upon evaluating the closed-form expressions, it is found that the variability in stream flow discharge increases with distance from the upstream boundary of the channel and time as well. The temporal correlation scale of inflow rate fluctuations plays a positive role in enhancing the variability of the flow discharge in channels. The treatment of the discharge variance gives us a quantitative estimate of uncertainty from the use of the deterministic model.

  12. Geomorphic and vegetative recovery processes along modified stream channels of West Tennessee

    USGS Publications Warehouse

    Simon, Andrew; Hupp, C.R. Tennessee

    1992-01-01

    Hundreds of miles of streams in West Tennessee have been channelized or otherwise modt@ed 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 modi@cation 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 ma& 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 modr@cations, 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

  13. Stream Sediment Sources in Midwest Agricultural Basins with Land Retirement along Channel.

    PubMed

    Williamson, T N; Christensen, V G; Richardson, W B; Frey, J W; Gellis, A C; Kieta, K A; Fitzpatrick, F A

    2014-09-01

    Documenting the effects of agricultural land retirement on stream-sediment sources is critical to identifying management practices that improve water quality and aquatic habitat. Particularly difficult to quantify are the effects from conservation easements that commonly are discontinuous along channelized streams and ditches throughout the agricultural midwestern United States. Our hypotheses were that sediment from cropland, retired land, stream banks, and roads would be discernible using isotopic and elemental concentrations and that source contributions would vary with land retirement distribution along tributaries of West Fork Beaver Creek in Minnesota. Channel-bed and suspended sediment were sampled at nine locations and compared with local source samples by using linear discriminant analysis and a four-source mixing model that evaluated seven tracers: In, P, total C, Be, Tl, Th, and Ti. The proportion of sediment sources differed significantly between suspended and channel-bed sediment. Retired land contributed to channel-bed sediment but was not discernible as a source of suspended sediment, suggesting that retired-land material was not mobilized during high-flow conditions. Stream banks were a large contributor to suspended sediment; however, the percentage of stream-bank sediment in the channel bed was lower in basins with more continuous retired land along the riparian corridor. Cropland sediments had the highest P concentrations; basins with the highest cropland-sediment contributions also had the highest P concentrations. Along stream reaches with retired land, there was a lower proportion of cropland material in suspended sediment relative to sites that had almost no land retirement, indicating less movement of nutrients and sediment from cropland to the channel as a result of land retirement. PMID:25603248

  14. Recent (circa 1998 to 2011) channel-migration rates of selected streams in Indiana

    USGS Publications Warehouse

    Robinson, Bret A.

    2013-01-01

    An investigation was completed to document recent (circa 1998 to 2011) channel-migration rates at 970 meander bends along 38 of the largest streams in Indiana. Data collection was completed by using the Google Earth™ platform and, for each selected site, identifying two images with capture dates separated by multiple years. Within each image, the position of the meander-bend cutbank was measured relative to a fixed local landscape feature visible in both images, and an average channel-migration rate was calculated at the point of maximum cutbank displacement. From these data it was determined that 65 percent of the measured sites have recently been migrating at a rate less than 1 ft/yr, 75 percent of the sites have been migrating at a rate less than 10 ft/yr, and while some sites are migrating in excess of 20 ft/yr, these occurrences are rare. In addition, it is shown that recent channel-migration activity is not evenly distributed across Indiana. For the stream reaches studied, far northern and much of far southern Indiana are drained by streams that recently have been relatively stationary. At the same time, this study shows that most of the largest streams in west-central Indiana and many of the largest streams in east-central Indiana have shown significant channel-migration activity during the recent past. It is anticipated that these results will support several fluvial-erosion-hazard mitigation activities currently being undertaken in Indiana.

  15. Relationships among rotational and conventional grazing systems, stream channels, and macroinvertebrates

    USGS Publications Warehouse

    Raymond, K.L.; Vondracek, B.

    2011-01-01

    Cattle grazing in riparian areas can reduce water quality, alter stream channel characteristics, and alter fish and macroinvertebrate assemblage structure. The U.S. Department of Agriculture, Natural Resources Conservation Services has recommended Rotational Grazing (RG) as an alternative management method on livestock and dairy operations to protect riparian areas and water quality. We evaluated 13 stream channel characteristics, benthic macroinvertebrate larvae (BML), and chironomid pupal exuviae (CPE) from 18 sites in the Upper Midwest of the United States in relation to RG and conventional grazing (CG). A Biotic Composite Score comprised of several macroinvertebrate metrics was developed for both the BML assemblage and the CPE assemblage. Multi-Response Permutation Procedures (MRPP) indicated a significant difference in stream channel characteristics between RG and CG. Nonmetric Multidimensional Scaling indicated that RG sites were associated with more stable stream banks, higher quality aquatic habitat, lower soil compaction, and larger particles in the streambed. However, neither MRPP nor Mann-Whitney U tests demonstrated a difference in Biotic Composite Scores for BML or CPE along RG and CG sites. The BML and CPE metrics were significantly correlated, indicating that they were likely responding to similar variables among the study sites. Although stream channel characteristics appeared to respond to grazing management, BML and CPE may have responded to land use throughout the watershed, as well as local land use. ?? 2011 Springer Science+Business Media B.V. (outside the USA).

  16. Analysis of temperature profiles for investigating stream losses beneath ephemeral channels

    USGS Publications Warehouse

    Constantz, J.; Stewart, A.E.; Niswonger, R.; Sarma, L.

    2002-01-01

    Continuous estimates of streamflow are challenging in ephemeral channels. The extremely transient nature of ephemeral streamflows results in shifting channel geometry and degradation in the calibration of streamflow stations. Earlier work suggests that analysis of streambed temperature profiles is a promising technique for estimating streamflow patterns in ephemeral channels. The present work provides a detailed examination of the basis for using heat as a tracer of stream/groundwater exchanges, followed by a description of an appropriate heat and water transport simulation code for ephemeral channels, as well as discussion of several types of temperature analysis techniques to determine streambed percolation rates. Temperature-based percolation rates for three ephemeral stream sites are compared with available surface water estimates of channel loss for these sites. These results are combined with published results to develop conclusions regarding the accuracy of using vertical temperature profiles in estimating channel losses. Comparisons of temperature-based streambed percolation rates with surface water-based channel losses indicate that percolation rates represented 30% to 50% of the total channel loss. The difference is reasonable since channel losses include both vertical and nonvertical component of channel loss as well as potential evapotranspiration losses. The most significant advantage of the use of sediment-temperature profiles is their robust and continuous nature, leading to a long-term record of the timing and duration of channel losses and continuous estimates of streambed percolation. The primary disadvantage is that temperature profiles represent the continuous percolation rate at a single point in an ephemeral channel rather than an average seepage loss from the entire channel.

  17. Potential risk assessment in stream sediments, soils and waters after remediation in an abandoned W>Sn mine (NE Portugal).

    PubMed

    Antunes, I M H R; Gomes, M E P; Neiva, A M R; Carvalho, P C S; Santos, A C T

    2016-11-01

    The mining complex of Murçós belongs to the Terras de Cavaleiros Geopark, located in Trás-os-Montes region, northeast Portugal. A stockwork of NW-SE-trending W>Sn quartz veins intruded Silurian metamorphic rocks and a Variscan biotite granite. The mineralized veins contain mainly quartz, cassiterite, wolframite, scheelite, arsenopyrite, pyrite, sphalerite, chalcopyrite, galena, rare pyrrhotite, stannite, native bismuth and also later bismuthinite, matildite, joseite, roosveltite, anglesite, scorodite, zavaritskite and covellite. The exploitation produced 335t of a concentrate with 70% of W and 150t of another concentrate with 70% of Sn between 1948 and 1976. The exploitation took place mainly in four open pit mines as well as underground. Three lakes were left in the area. Remediation processes of confination and control of tailings and rejected materials and phytoremediation with macrophytes from three lakes were carried out between 2005 and 2007. Stream sediments, soils and water samples were collected in 2008 and 2009, after the remediation process. Most stream sediments showed deficiency or minimum enrichment for metals. The sequential enrichment factor in stream sediments W>Bi>As>U>Cd>Sn=Ag>Cu>Sb>Pb>Be>Zn is mainly associated with the W>Sn mineralizations. Stream sediments receiving drainage of a mine dump were found to be significantly to extremely enriched with W, while stream sediments and soils were found to be contaminated with As. Two soil samples collected around mine dumps and an open pit lake were also found to be contaminated with U. The waters from the Murçós W>Sn mine area were acidic to neutral. After the remediation, the surface waters were contaminated with F(-), Al, As, Mn and Ni and must not be used for human consumption, while open pit lake waters must also not be used for agriculture because of contamination with F(-), Al, Mn and Ni. In most waters, the As occurred as As (III), which is toxic and is easily mobilized in the drainage

  18. A cost-effective laser scanning method for mapping stream channel geometry and roughness

    NASA Astrophysics Data System (ADS)

    Lam, Norris; Nathanson, Marcus; Lundgren, Niclas; Rehnström, Robin; Lyon, Steve

    2015-04-01

    In this pilot project, we combine an Arduino Uno and SICK LMS111 outdoor laser ranging camera to acquire high resolution topographic area scans for a stream channel. The microprocessor and imaging system was installed in a custom gondola and suspended from a wire cable system. To demonstrate the systems capabilities for capturing stream channel topography, a small stream (< 2m wide) in the Krycklan Catchment Study was temporarily diverted and scanned. Area scans along the stream channel resulted in a point spacing of 4mm and a point cloud density of 5600 points/m2 for the 5m by 2m area. A grain size distribution of the streambed material was extracted from the point cloud using a moving window, local maxima search algorithm. The median, 84th and 90th percentiles (common metrics to describe channel roughness) of this distribution were found to be within the range of measured values while the largest modelled element was approximately 35% smaller than its measured counterpart. The laser scanning system captured grain sizes between 30mm and 255mm (coarse gravel/pebbles and boulders based on the Wentworth (1922) scale). This demonstrates that our system was capable of resolving both large-scale geometry (e.g. bed slope and stream channel width) and small-scale channel roughness elements (e.g. coarse gravel/pebbles and boulders) for the study area. We further show that the point cloud resolution is suitable for estimating ecohydraulic parameters such as Manning's n and hydraulic radius. Although more work is needed to fine-tune our system's design, these preliminary results are encouraging, specifically for those with a limited operational budget.

  19. Characteristics of channel steps and reach morphology in headwater streams, southeast Alaska

    NASA Astrophysics Data System (ADS)

    Gomi, Takashi; Sidle, Roy C.; Woodsmith, Richard D.; Bryant, Mason D.

    2003-03-01

    The effect of timber harvesting and mass movement on channel steps and reach morphology was examined in 16 headwater streams of SE Alaska. Channel steps formed by woody debris and boulders are significant channel units in headwater streams. Numbers, intervals, and heights of steps did not differ among management and disturbance regimes. A negative exponential relationship between channel gradient and mean length of step intervals was observed in the fluvial reaches (<0.25 unit gradient) of recent landslide and old-growth channels. No such relationship was found in upper reaches (≥0.25 gradient) where colluvial processes dominated. Woody debris and sediment recruitment from regenerating riparian stands may have obscured any strong relationship between step geometry and channel gradient in young alder, young conifer, and recent clear-cut channels. Channel reaches are described as pool-riffles, step-pools, step-steps, cascades, rapids, and bedrock. Geometry of channel steps principally characterized channel reach types. We infer that fluvial processes dominated in pool-riffle and step-pool reaches, while colluvial processes dominated in bedrock reaches. Step-step, rapids, and cascade reaches occurred in channels dominated by both fluvial processes and colluvial processes. Step-step reaches were transitional from cascades (upstream) to step-pool reaches (downstream). Woody debris recruited from riparian corridors and logging activities formed steps and then sequentially might modify channel reach types from step-pools to step-steps. Scour, runout, and deposition of sediment and woody debris from landslides and debris flows modified the distribution of reach types (bedrock, cascade, and step-pool) and the structure of steps within reaches.

  20. Variability of rock erodibility in bedrock-floored stream channels based on abrasion mill experiments

    NASA Astrophysics Data System (ADS)

    Small, Eric E.; Blom, Tevis; Hancock, Gregory S.; Hynek, Brian M.; Wobus, Cameron W.

    2015-08-01

    We quantify variations in rock erodibility, Kr, within channel cross sections using laboratory abrasion mill experiments on bedrock surfaces extracted from streams with sandstone bedrock in Utah and basaltic bedrock in the Hawaiian Islands. Samples were taken from the thalweg and channel margins, the latter at a height that is inundated annually. For each sample, a sequence of abrasion mill experiments was completed to quantify variations in erosion rate with erosion depth. Erosion rate data from these experiments shows two things. First, the erosion rate from channel margin samples is greater than for thalweg samples, with the greatest difference observed for the rock surface that was exposed in the stream channel. Second, erosion rate decreases with depth beneath the original rock surface, by an order of magnitude in most cases. The erosion rate becomes steady at depths of 1-3 mm for channel margin samples and 0.1-0.4 mm for thalweg samples. Because only rock properties and microtopography vary throughout the sequence of mill experiments, these results suggest that Kr of the bedrock surface exposed in stream channels is higher at the margins than near the channel center and that Kr decreases over depths of ~1 mm. The simplest explanation for these patterns is that Kr is enhanced, at the bedrock surface and along the channel margins, due to the effects of weathering on rock strength and surface roughness. We hypothesize that a balance exists between weathering-enhanced erodibility and episodic incision to allow channel margins to lower at rates similar to the thalweg.

  1. SIMULATING SUB-DECADAL CHANNEL MORPHOLOGIC CHANGE IN EPHEMERAL STREAM NETWORKS

    EPA Science Inventory

    A distributed watershed model was modified to simulate cumulative channel morphologic
    change from multiple runoff events in ephemeral stream networks. The model incorporates the general design of the event-based Kinematic Runoff and" Erosion Model (KINEROS), which describes t...

  2. Streaming potentials reveal a short ryanodine-sensitive selectivity filter in cardiac Ca2+ release channel.

    PubMed Central

    Tu, Q; Vélez, P; Brodwick, M; Fill, M

    1994-01-01

    Single cardiac sarcoplasmic reticulum Ca2+ release channels were reconstituted into planar bilayer membranes. Streaming potentials were measured in osmotically asymmetric solutions as a shift in the reversal potential. Potential changes induced by water movement through the bilayer (concentration polarization) and reduced ion activity in the concentrated non-electrolyte solutions were determined using valinomycin. In 400 mM symmetrical CsCH3SO3, the average streaming potential was 2.74 +/- 0.2 mV (n = 5, mean +/- SE; 2 osmol/kg) and independent of the osmoticant used (sucrose or diglycine). Identical streaming potential magnitudes were obtained regardless of which side of the membrane the nonelectrolyte was placed. This suggests that the narrow part of the pore where single file diffusion occurs is relatively short (i.e., accommodates a minimum of 3 H2O molecules). This value is comparable to similar measurements in a variety of surface membrane channels. Ryanodine-modified channels had no measurable streaming potential, an increased Tris+ permeability relative to Cs+, and decreased divalent selectivity (PCs/PTris 5.1 +/- 1.1 to 1.7 +/- 0.3, n = 3; PBa/PCs 8.2 +/- 0.7 to 1.8 +/- 0.5, n = 4). Cation/anion selectivity was essentially unaltered in ryanodine-modified channels. These results suggests that the narrow region of the permeation pathway (i.e., the selectivity filter) is relatively short and widens after ryanodine modification. PMID:7696468

  3. Do post-mining constructed channels replace functional characteristics of headwater streams?

    EPA Science Inventory

    Mountaintop mining and valley fill (MTMVF) is a method of coal mining common in eastern Kentucky and southern West Virginia. Over 1200 miles of stream channel have been buried by MTMVF. Permits for surface coal mining have recognized constructed drainage ditches associated with ...

  4. Biotic drivers of anastomosing channel pattern in headwater streams of the Colorado Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Wohl, E. E.

    2010-12-01

    Most of the headwater rivers in the Colorado Rocky Mountains, USA occur as single channels in steep, narrow valleys. Where variations in bedrock erodibility create segments of wider, lower gradient valleys, however, anastomosing channels can occur if one of two biotic drivers is present. Where a disturbance such as a forest fire or windstorm allows pioneer woody species to colonize valley bottoms, beavers can establish colonies. Beavers build dams that enhance overbank flooding and raise the local water table, limiting the return of conifers and promoting aspen-willow (Populus-Salix) forests that provide food for the beavers. Beavers facilitate the formation of multiple channels by digging small canal-like features across the floodplain and by damming the main channel and promoting channel avulsion. In old-growth conifer forests, channel-spanning logjams can enhance overbank flows that facilitate the development of multiple (sub)parallel channels that extend for 50-300 m downstream. Enhanced overbank flows and multiple channels increase the retention of instream wood, creating a self-enhancing feedback of more jams. At least two thresholds must be crossed for anastomosing driven by logjams to develop; a valley morphology threshold and a wood load threshold. Anastomosing channels are present where stream gradient < 4% and the ratio of (channel width/valley-bottom width) < 0.2; only single channels flow through old-growth forests in valley segments that are steeper and narrower. The average wood piece diameter in old-growth anastomosing channel segments > 20 cm, whereas average piece diameter in forests that have not been disturbed in a century is 10-20 cm; channels in these younger forests do not exhibit anastomosing planforms. Wood load in old-growth anastomosing channels averages 200 m3/ha; old-growth and younger forest single channels average < 100 m3/ha.

  5. Modeling channel morphodynamic response to variations in large wood: Implications for stream rehabilitation in degraded watersheds

    NASA Astrophysics Data System (ADS)

    Davidson, Sarah L.; Eaton, Brett C.

    2013-11-01

    Anthropogenic modification of forests has often decoupled streams from riparian ecosystems and altered natural wood recruitment processes. Extensive research has shown that large wood significantly impacts channel dynamics, especially in small and intermediate sized forested streams where wood pieces are similar in length to channel width, and many stream rehabilitation efforts now involve the addition of large wood to streams. The primary objective of this research is to investigate the relation between large wood and reach scale channel morphology and hydraulics using a physical model, in order to better inform stream rehabilitation programs and future modeling efforts. Four experiments, each comprising numerous five hour runs, were conducted using a Froude-scaled stream table with wood loads scaled to 0 m3/m2, 0.011 m3/m2, 0.016 m3/m2, and 0.022 m3/m2. The addition of large wood significantly decreased the reach-averaged velocity in all experiments, and was associated with decreased sediment transport and increased sediment storage in the reach. Increases in bed and water surface slope compensated for the loss of energy available to transport sediment, and enabled the system to reach a new steady state within the equivalent of 6 to 9 years. Adding wood increased pool frequency, as well as the variability in cross-sectional depth, while causing the reach to undergo a transition from a plane-bed to a riffle-pool morphology. Retention of fine sediment increased the availability of fish spawning substrate, while increased water stage improved connectivity between the channel and the floodplain. The changes in habitat complexity were generally related to the wood load added to the reach, but were also dependent on the orientation and arrangement of the pieces. These results demonstrate that wood may exert a primary control on channel morphodynamics and the availability of aquatic habitat in intermediate sized streams, and suggest that the benefits from stream

  6. Water quality, organic chemistry of sediment, and biological conditions of streams near an abandoned wood-preserving plant site at Jackson, Tennessee

    USGS Publications Warehouse

    Bradfield, A.D.; Flexner, N.M.; Webster, D.A.

    1993-01-01

    An investigation of water quality, organic sediment chemistry, and biological conditions of streams near an abandoned wood-preserving plant site at Jackson, Tennessee, was conducted during December 1990. The study was designed to assess the extent of possible contamination of water and biota in the streams from creosote-related discharge originating at this Superfund site. Central Creek, adjacent to the plant, had degraded water quality and biological conditions. Water samples from the most downstream station on Central Creek contained 30 micrograms per liter of pentachlorophenol, which exceeds the State's criterion maximum concentrations of 9 micrograms per liter for fish and aquatic life. Bottom-sediment samples from stations on Central Creek contained concentrations of acenaphthene, napthalene, and phenanthrene ranging from 1,400 to 2,500 micrograms per kilogram. Chronic or acute toxicity resulted during laboratory experiments using test organisms exposed to creosote-related contaminants. Sediment elutriate samples from Central Creek caused slightly to highly toxic effects on Ceriodaphnia dubia. Pimephales promelas, and Photobacterium phosphoreum. Fish-tissue samples from this station contained concentrations of naphthalene. dibenzofuran, fluorene, and phenanthrene ranging from 1.5 to 3.9 micrograms per kilogram Blue-green algae at this station represented about 79 percent of the organisms counted, whereas diatoms accounted for only 11 percent. Benthic invertebrate and fish samples from Central Creek had low diversity and density. Sediment samples from a station on the South Fork Forked Deer River downstream from its confluence with Central Creek contained concentrations of acenaphthene, anthracene, chrysene, fluoranthene, fluorene, pyrere, and phenanthrene ranging from 2,800 to 69,000 micrograms per kilogram. Sediment elutriate samples using water as elutriate from this station contained concentrations of extractable organic compounds ranging from an estimated

  7. Guidelines for Surveying Bankfull Channel Geometry and Developing Regional Hydraulic-Geometry Relations for Streams of New York State

    USGS Publications Warehouse

    Powell, Rocky O.; Miller, Sarah J.; Westergard, Britt E.; Mulvihill, Christiane I.; Baldigo, Barry P.; Gallagher, Anne S.; Starr, Richard R.

    2004-01-01

    Many disturbed streams within New York State are being restored in an effort to provide bank and bed stability and thereby decrease sedimentation and erosion. Efforts to identify and provide accurate indicators for stable-channel characteristics for ungaged streams have been hampered by the lack of regional equations or relations that relate drainage area to bankfull discharge and to channel depth, width, and cross-sectional area (bankfull hydraulic-geometry relations). Regional equations are needed to confirm bankfull hydraulic-geometry, assess stream stability, evaluate restoration needs, and verify restoration design for ungaged streams that lack stage-to-discharge ratings or historic peak-flow records. This report presents guidelines for surveying bankfull channel geometry at USGS stream gages and developing regional hydraulic-geometry relations (equations) for wadeable streams in New York. It summarizes methods to (1) compile and assess existing hydrologic, geometric, photographic, and topographic data, (2) conduct stream-reconnaissance inspections, (3) identify channel-bankfull characteristics, (4) conduct longitudinal and cross-section surveys, (5) measure stream discharge, (6) develop and refine bankfull hydraulic-geometry equations, and (7) analyze and assure data completeness and quality. The techniques primarily address wadeable streams with either active or discontinued surface-water and crest-stage gages. The relations can be applied to ungaged or actively gaged streams that are wadeable, and may be extended to non-wadeable streams (with some limitations) if they have drainage areas comparable to those used to develop the relations.

  8. Measuring flood discharge in unstable stream channels using ground-penetrating radar

    USGS Publications Warehouse

    Spicer, K.R.; Costa, J.E.; Placzek, G.

    1997-01-01

    Field experiments were conducted to test the ability of ground-penetrating radar (GPR) to measure stream-channel cross sections at high flows without the necessity of placing instruments in the water. Experiments were conducted at four U.S. Geological Survey gaging stations in southwest Washington State. With the GPR antenna suspended above the water surface from a bridge or cableway, traverses were made across stream channels to collect radar profile plots of the streambed. Subsequent measurements of water depth were made using conventional depth-measuring equipment (weight and tape) and were used to calculate radar signal velocities. Other streamflow-parameter data were collected to examine their relation to radar signal velocity and to claritv of streambed definition. These initial tests indicate that GPR is capable of producing a reasonably accurate (??20%) stream-channel profile and discharge far more quickly than conventional stream-gaging procedures, while avoiding the problems and hazards associated with placing instruments in the water.

  9. Impact of riverine wetlands construction and operation on stream channel stability: Conceptual framework for geomorphic assessment

    NASA Astrophysics Data System (ADS)

    Rhoads, Bruce L.; Miller, Michael V.

    1990-11-01

    Wetland conservation is a critical environmental management issue. An emerging approach to this issue involves the construction of wetland environments. Because our understanding of wetlands function is incomplete and such projects must be monitored closely because they may have unanticipated impacts on ecological, hydrological, and geomorphological systems. Assessment of project-related impacts on stream channel stability is an important component of riverine wetlands construction and operation because enhanced erosion or deposition associated with unstable rivers can lead to loss of property, reductions in channel capacity, and degradation of water quality, aquatic habitat, and riparian aesthetics. The water/sediment budget concept provides a scientific framework for evaluating the impact of riverine wetlands construction and operation on stream channel stability. This concept is based on the principle of conservation of mass, i.e., the total amount of water and sediment moving through a specific reach of river must be conserved. Long-term measurements of channel sediment storage and other water/sediment budget components provide the basis for distinguishing between project-related impacts and those resulting from other causes. Changes in channel sediment storage that occur as a result of changes in internal inputs of water or sediment signal a project-related impact, whereas those associated with changes in upstream or tributary inputs denote a change in environmental conditions elsewhere in the watershed. A geomorphic assessment program based on the water/sediment budget concept has been implemented at the site of the Des Plaines River Wetlands Demonstration Projection near Chicago, Illinois, USA. Channel sediment storage changed little during the initial construction phase, suggesting that thus far the project has not affected stream channel stability.

  10. Downstream reduction of rural channel size with contrasting urban effects in small coastal streams of southeastern Australia

    NASA Astrophysics Data System (ADS)

    Nanson, G. C.; Young, R. W.

    1981-07-01

    Although most streams show a downstream increase in channel size corresponding to a downstream increase in flood discharges, those flowing off the Illawarra escarpment of New South Wales show a marked reduction of channel size, accompanied by a down-stream increase in flood frequency in their lower reaches. Within the confined and steeply sloping valleys of the escarpment foothills, bed and bank sediments are relatively coarse and uncohesive, and channels increase in size, corresponding to increasing discharge downstream. However, once these streams emerge into more open rural valleys at lower slopes and are accompanied by extensive floodplains formed of fine cohesive sediment, there is a dramatic reduction in channel size. This decrease in channel size apparently results from a sudden decline in channel slope and associated stream power, the cohesive nature of downstream alluvium, its retention on the channel banks by a dense cover of pasture grasses, and the availability of an extensive floodplain to carry displaced floodwater. Under these conditions floodwaters very frequently spill out over the floodplain and the downstream channel-flow becomes a relatively unimportant component of the total peak discharge. This emphasizes the importance of these floodplains as a part of the total channel system. In situations where urban development has increased peak runoff and reduced the available area of effective floodplain, stream channels formed in this fine alluvium rapidly entrench and increase in cross-sectional area by 2-3 times. Minor man-induced channel alteration and maintenance appears to trigger this enlargement.

  11. Coupled Radon and Water Temperature Measurements to Characterize the Effects of Altered Stream Channel Planform

    NASA Astrophysics Data System (ADS)

    Amerson, B. E.; Poole, G. C.; O'Daniel, S. J.

    2013-12-01

    In summer 2011, a 2.6 km reach of Meacham Creek, Oregon, USA, was altered from a straight, steep wall-based channel to more a sinuous, low-gradient channel. Key objectives of this restoration project were to increase the rate and magnitude of hyporheic exchange. The overarching goal was to initiate increased buffering and lagging of water temperature in the subsurface to mitigate warm surface water temperature in Meacham Creek, an important spawning and rearing stream for depressed populations of Chinook salmon and summer steelhead. To evaluate progress toward project goals and objectives, stream temperature and groundwater temperature in 22 wells have been measured hourly at the restoration site since March 2011. In addition, the radioactive isotope 222Rn was measured in each well and in the surface water on two occasions. The relative residence time of down welling stream water measured in the wells can be determined by ranked amplitude depression and lagged phase of annual temperature signals in the wells relative to that of the open channel flow. Residence times predicted by annual temperature signal dynamics are corroborated by 222Rn concentrations in each well. The data collected to date provide a foundation for developing a groundwater thermal model to predict the effects of channel reconfiguration on ground-surface water exchange and associated temperature effects at the reach scale.

  12. Detection of regolith buried water stream channels on Mars with the help of synthetic aperture radar

    NASA Astrophysics Data System (ADS)

    Rzhiga, O. N.

    The major problem of Mars research is search of water on its surface Biological life is connected to water In this connection the intense interest represents detection of water stream channels which in the past flew on Mars In these areas the petrified rests of the former life on Mars may be found out Now these channels may be under regolith layer However radio waves penetrating ability allows seeing these channels under a regolith The radio wave falls on a regolith surface under some angle The part of the falling wave power is reflected by regolith Other part of it refracts under a regolith surface and reaches bottom of a channel Here there is reflection because of a difference in refraction index of regolith and bedrock of a channel bottom The part of reflected power gets back to the spacecraft Passage through regolith is accompanied by electric losses In result we receive the image of a channel which contrast depends on regolith depth difference in refraction index of regolith and bedrock of a channel bottom as well as wavelength In this work in some assumptions concerning regolith and bedrock electric properties the model of the channel image is received The optimum wavelength for detection of the water stream channels now buried by regolith is determined The analysis of the reflected signal level dependence from an angle under which SAR onboard aerial is directed to a planet surface is carried out It is shown that power of the SAR transmitter and the size of the onboard aerial will be moderate if radar survey to carry out

  13. Channel-Reach Morphology in Formerly Glaciated, Mountain Streams: Controls and Prediction

    NASA Astrophysics Data System (ADS)

    Hassan, M. A.; Brardinoni, F.

    2006-12-01

    The spatial distribution of channel types in mountain drainage basins of coastal British Columbia is examined. Using field- and GIS-based data we show that the local channel slope and degree of colluvial-alluvial coupling imposed by the glacial valley morphology dictate the spatial organization of channel-reach morphology. In particular, the glacially-induced channel long profile generates characteristic sequences of channel reaches (with repetitions and inversions) that depart from the downstream succession distinctive of unglaciated mountain streams. For example, the presence of one hanging valley in the river long profile produces and separates two full successions of channel types a headmost one characterized by an ephemeral/seasonal hydrologic regime, and a downstream one, where water runoff is perennial. Exploratory scatter plots indicate that slope, shear stress, and relative roughness ensure best separation between reach types. At a confirmatory level, highest prediction of channel types is achieved by discriminant functions containing the same three variates. Success rates, depending on whether or not boulder-cascade reaches are grouped with step-pools, vary between 89% and 76%. Notwithstanding the glacially-inherited slope and the transient geomorphic dynamics of this landscape, similar to the case of unglaciated mountain streams, channel types are chiefly segregated by local slope (albeit characterized by significantly higher ranges), and to a lesser extent by shear stress and relative roughness. This outcome, while adding considerable strength to prior empirical knowledge, indicates that first-order physical conditions at which distinct channel states form are insensitive to very different landscape structures, hence histories.

  14. Stream Channel Change in an Intensively Managed Agricultural Landscape: Implications for Critical Zone Processes

    NASA Astrophysics Data System (ADS)

    Lewis, Q. W.; Rhoads, B. L.; Andresen, W.

    2014-12-01

    During the Anthropocene, humans have had a substantial impact on fluvial systems throughout the world. Perhaps nowhere is the human imprint on stream systems more pronounced than in the intensively managed agriculture landscapes of the midwestern United States. This study examines changes in the structure of the stream network and in the planform dynamics of stream channels within the upper Sangamon River basin in Illinois - a watershed that is part of a new Critical Zone Observatory focusing on intensively managed landscapes (IML-CZO). The research explores changes in network structure as the landscape changed from prairie and forest into drained farmland dominated by row crop agriculture. It also documents the planform dynamics of stream and river channels over the past 80 to 100 years. Results show that the spatial extent of channels within the stream network expanded greatly as land was cleared and drained for agriculture. Expansion of the network into headwater portions of the watershed occurred through the construction of drainage ditches that serve as outlets for tile drainage systems underlying relatively flat, poorly drained farmland. Analysis of planform dynamics reveals that most of these drainage ditches have not changed alignment since initial construction. Although drainage ditches are maintained by local drainage districts, these human-created channels also are remarkably resistant to change in planform over time. The major type of planform change in headwater streams involves artificial straightening of meandering channels to expand the extent of drainage channels. Many sections of the meandering Sangamon River are heavily forested and exhibit little or no planform change over the past 80-100 years. Sections that are most active tend to occur where forest cover is less prevalent due to clearing of trees for pasture or cropland. Overall, the results demonstrate the pronounced imprint of humans on the structure and planform dynamics of a fluvial

  15. Riparian Vegetation Influence on Stream Channel Dimensions: Key Driving Mechanisms and Their Timescales

    NASA Astrophysics Data System (ADS)

    McBride, M.; Hession, W.; Rizzo, D. M.; Thompson, D. M.

    2006-05-01

    Combined results from field-based investigations and flume experiments demonstrated key mechanisms driving channel widening following the reforestation of riparian zones in small streams. Riparian reforestation is a common occurrence either due to restoration efforts, intended to improve water quality, temperature regimes, and in-stream physical habitat or due to passive reforestation that is common when agricultural land uses decline. Previous studies have documented the influence of riparian vegetation on channel size, but driving mechanisms and the timescales at which they operate have not been evaluated. Field-based investigations were conducted in the Sleepers River basin in northeastern Vermont to revisit streams that were previously surveyed in the 1960s. We measured channel dimensions, large woody debris (LWD), and steam velocities in reaches with non-forested and forested riparian vegetation, in reaches currently in transition between vegetation types, and reaches with no change in riparian vegetation over the last 40 years. Flume experiments were performed with a 1:5 scale, fixed-bed model of a tributary to Sleepers River. Two types of riparian vegetation scenarios were simulated: 1) forested, with rigid, wooden dowels; and 2) non-forested, with synthetic grass carpeting. Three-dimensional velocities were measured during flume runs to determine turbulent kinetic energy (TKE) during overbank flows. Results showed that stream reaches with recently reforested vegetation have widened since the mid 1960s, but are not as wide as reaches with older riparian forests. LWD was more abundant in reaches with older riparian forests than in reaches with younger forests; however, scour around LWD did not appear to be a significant driving mechanism for channel widening. Velocity and TKE measurements from the prototype stream and the flume model indicate that TKE was significantly elevated in reforested reaches. Given that bed and bank erosion can be amplified in flows

  16. Channel and Catchment Morphology, Spatial Intermittency, and Carbon Chemistry of a Headwater Stream

    NASA Astrophysics Data System (ADS)

    O'Donnell, B.; Wondzell, S. M.; Serchan, S. P.; Haggerty, R.; Ward, A. S.; Schmadel, N. M.

    2015-12-01

    We investigated carbon dynamics in a steep, forested, headwater stream in the Cascade Mountains of western Oregon, USA. Measurements from a continuously recording pCO2 probe located near the mouth of the catchment showed that the stream was always super saturated with CO2 with respect to atmospheric concentrations, ranging from 500 ppm in mid-winter to as much as 3,500 ppm in late summer. Continuous measurements of pCO2 from a hyporheic well suggested that the hyporheic zone was a likely source of the super-saturated stream water because the hyporheic concentrations of CO2 ranged from a mid-winter low of 4,000 ppm to a late summer high of 16,000 ppm. Here, we investigate the causes for the large seasonal changes in pCO2 in the stream water. We conducted longitudinal synoptic surveys of flow and carbon chemistry over the period of baseflow recession during summer 2015. The channel is narrow and steep with occasional bedrock segments. However, debris flow deposits in the lower portions of the studied reach create wider valley floors where hyporheic exchange can capture 100% of the streamflow when discharge is very low. At the beginning of the summer when discharge was relatively high, flow was spatially continuous, but by mid-summer, stream flow became spatially discontinuous. Upwelling hyporheic water in these locations appears to be super saturated with CO2. In early summer, the amount of upwelling hyporheic water was small relative to stream discharge so that hyporheic exchange had only a modest influence on stream pCO2. Later in the summer, when discharge was much smaller relative to hyporheic exchange, we observed much greater spatial variability in CO2, which averaged 2720 ppm downstream of dry segments longer than 5 m but only averaged 980 ppm in wet segments and below shorter dry segments. Over the intervening wet segments, CO2 appears to be evaded from the stream as concentrations decreased rapidly. Also, upslope accumulated area appears to control lateral

  17. Effects of Snow-making, Grading, and Timber Harvest on Stream Channel Morphology in the White River National Forest, Colorado

    NASA Astrophysics Data System (ADS)

    David, G. C.; Bledsoe, B. P.; Merritt, D. M.; Wohl, E.

    2005-12-01

    The White River National Forest Service is responsible for managing and protecting the ecological integrity of many streams in some of the major ski resorts in Colorado. The combined effects of timber harvesting, snow-making, grading and road construction can increase streamflows but the effects of these four activities on stream channel stability are not well documented. Increased flow can result in bank failure, increased amounts of large woody debris, pool scour and bed coarsening. Specific stream channel response to increased flows associated with ski resort activities partly depends on the type of vegetation growing along stream banks and the amount of human development in the basin. We hypothesize that a threshold of development must be attained for each vegetation type before the stream channel is significantly impacted. To test this hypothesis, we surveyed channel condition, channel dimensions, and vegetation along 49 stream reaches (200 - 300 m in length). Twenty-four of these streams are within ski areas (project streams), either adjacent to or downstream from ski slopes. Twenty-five ""reference"" streams have very little to no development in their basins. These streams are used to define reference conditions bank stability, bank undercutting, bank height, bank angle, percent of large woody debris, pool depth, sediment size, and vegetation structure. A Principle Component Analysis will be utilized to ordinate and allow comparison of project and reference streams. The effects of overstory and understory vegetation on bank height, angle and stability will also be determined. A larger percentage of willows adjacent to stream channels may decrease bank height and angle thereby increasing stability. These data will help in the revision of a forest management plan to provide guidelines for planning and development of ski areas on public lands.

  18. Hydrograph peaks caused by ice channel melt in Black Hills streams

    SciTech Connect

    Rahn, P.H. . Dept. of Geology and Geological Engineering)

    1992-01-01

    The Black Hills has an average annual precipitation of approximately 20 inches, most of which occurs in early summer. The winters are typically cold and fairly dry. Most streams within the Precambrian central Black Hills have perennial and ephemeral reaches which are related to the presence of surficial deposits. During the winter, ice accumulates in the channels of some stream reaches, completely filling the channels, particularly in shady locations below springs or seeps. High discharges occur during warm spells in late winter and early spring. These high discharges are not due to snow melt because many watersheds are often void of snow. Ice-channel surveys were conducted on Spring, Battle, French, Slate, and Grace Coolidge Creeks during 1988. High discharges occurred during the warm spells at the end of March. Since no precipitation occurred during this time, and the watersheds were barren of snow, the discharge peaks are believed due to melting of ice stored in the channels. This hypothesis is supported by the fact that the volume of the water stored as ice was approximately the same as the volume of water represented by the discharge anomaly. The ice stored in channels primarily results from ground water discharge over the winter. It is not due to melting snow or surface water runoff per se. Separation of the hydrograph into surface and ground water components should take into account this phenomena.

  19. Detection Of Regolith Buried Water Stream Channels On Mars With The Help Of Synthetic Aperture Radar

    NASA Astrophysics Data System (ADS)

    Rzhiga, O. N.

    The major problem of Mars research is search of water on its surface. Biological life is connected to water. In this connection the intense interest represents detection of water stream channels, which in the past flew on Mars. In these areas the petrified rests of the former life on Mars may be found out. Now these channels may be under regolith layer. However radio waves penetrating ability allows seeing these channels under a regolith. The radio wave falls on a regolith surface under some angle. The part of the falling wave power is reflected by regolith. Other part of it refracts under a regolith surface and reaches bottom of a channel. Here there is reflection because of a difference in refraction index of regolith and bedrock of a channel bottom. The part of reflected power gets back to the spacecraft. Passage through regolith is accompanied by electric losses. In result we receive the image of a channel which contrast depends on regolith depth, difference in refraction index of regolith and bedrock of a channel bottom as well as wavelength. In this work the optimum wavelength for detection of the water stream channels, now buried by regolith, is determined. In some assumptions concerning regolith and bedrock electric properties the model of the channel image is received. The analysis of the reflected signal level dependence from an angle under which SAR onboard aerial is directed to a planet surface is carried out. It is shown, that power of the SAR transmitter and the size of the onboard aerial will be moderate if radar survey to carry out under a small angle to a local vertical. The way, which allows suppressing the altimetric clutter arising in nadir, is specified. Here one method of search of water on Mars indications - detection of a regolith buried water stream channels is advanced only. However the radar with similar characteristics may be used as well for global survey a planet surface. Owing to a difference in character of reflection and penetrating

  20. Tracing sources of organic matter in adjacent urban streams having different degrees of channel modification.

    PubMed

    Duan, Shuiwang; Amon, Rainer M W; Brinkmeyer, Robin L

    2014-07-01

    Urbanization and stream-channel modifications affect organic matter concentrations and quality in streams, by altering allochthonous organic matter input and in-stream transformation. This study uses multiple tracers (δ(13)C, δ(15)N, C/N ratio, and chlorophyll-a) to track sources of organic matter in two highly urbanized bayous in Houston (Texas, USA). Wastewater treatment plants (WWTPs) are located in headwaters of both bayous and contribute more than 75% to water flow. Low isotopic relatedness to natural end-members and enriched δ(15)N values suggest the influence of WWTPs on the composition of all organic matter fractions. The two bayous differ in degree of channel improvement resulting in different responses to hydrological conditions. During high flow conditions, the influence of terrestrial organic matter and sediment resuspension was much more pronounced in the Buffalo Bayou than in the concrete-lined White Oak Bayou. Particulate organic matter (POM) in White Oak Bayou had similar values of enriched δ(15)N in all subsegments, whereas in Buffalo Bayou, the degree of δ(15)N enrichment was less in the subsegments of the lower watershed. The difference in riparian zone contributions and interactions with sediments/soils was likely responsible for the compositional differences between the two bayous. Phytoplankton inputs were significantly higher in the bayous, especially in slow-flowing sections, relative to the reference sites, and elevated phytoplankton inputs accounted for the observed stable C isotope differences between FPOM and high molecular weight dissolved organic matter (HMW DOM). Relative to POM, HMW DOM in the bayous was similar to WWTP effluents and showed minor longitudinal variability in both streams suggesting that WWTPs contribute much of the DOM in the systems. Urbanization has a major influence on organic matter sources and quality in these urban water bodies and these changes seem further enhanced by stream channel modifications. PMID

  1. Monitoring stream stage, channel profile, and aqueous conductivity with time domain reflectometry (TDR).

    SciTech Connect

    Brainard, James Robert; Tidwell, Vincent Carroll; Coplen, Amy K.; Ruby, Douglas Scott; Coombs, Jason R.; Wright, Jerome L.; Roberts, Jesse Daniel

    2004-11-01

    Time domain reflectometry (TDR) operates by propagating a radar frequency electromagnetic pulse down a transmission line while monitoring the reflected signal. As the electromagnetic pulse propagates along the transmission line, it is subject to impedance by the dielectric properties of the media along the transmission line (e.g., air, water, sediment), reflection at dielectric discontinuities (e.g., air-water or water-sediment interface), and attenuation by electrically conductive materials (e.g., salts, clays). Taken together, these characteristics provide a basis for integrated stream monitoring; specifically, concurrent measurement of stream stage, channel profile and aqueous conductivity. Here, we make novel application of TDR within the context of stream monitoring. Efforts toward this goal followed three critical phases. First, a means of extracting the desired stream parameters from measured TDR traces was required. Analysis was complicated by the fact that interface location and aqueous conductivity vary concurrently and multiple interfaces may be present at any time. For this reason a physically based multisection model employing the S11 scatter function and Cole-Cole parameters for dielectric dispersion and loss was developed to analyze acquired TDR traces. Second, we explored the capability of this multisection modeling approach for interpreting TDR data acquired from complex environments, such as encountered in stream monitoring. A series of laboratory tank experiments were performed in which the depth of water, depth of sediment, and conductivity were varied systematically. Comparisons between modeled and independently measured data indicate that TDR measurements can be made with an accuracy of {+-}3.4x10{sup -3} m for sensing the location of an air/water or water/sediment interface and {+-}7.4% of actual for the aqueous conductivity. Third, monitoring stations were sited on the Rio Grande and Paria rivers to evaluate performance of the TDR system

  2. The storage of bed material in mountain stream channels as assessed using Optically Stimulated Luminescence dating

    NASA Astrophysics Data System (ADS)

    Thompson, Chris; Rhodes, Ed; Croke, Jacky

    2007-01-01

    A detailed understanding of channel forming and maintenance processes in mountain streams requires some measurement and/or prediction of bed load transport and sediment mobility. Traditional field based measurements of such processes are problematic because of the high formative discharges characteristic of such streams. The application of Optically Stimulated Luminescence (OSL) dating is proposed here as a new way of determining actual residency times of fine sediments and consequently validating selected predictions for the entrainment of sediment in these streams. Model predictions of sediment mobility for selected step-pool and plane-bed channels in a mountain catchment in south eastern Australia are initially calculated using equations of hydraulic competence and the one-dimensional HEC-RAS model. Results indicate that floods exceeding bankfull with recurrence intervals up to 13 years are competent to mobilise the maximum overlying surface grain sizes at both sites. OSL minimum age model results from 7 samples of well bleached quartz in the fine matrix particles indicate general agreement with selected competence equations. The apparent long (100-1400 y) burial age of most of the mineral quartz, however, suggests that competent flows are not able to flush all subsurface fine-bed material. The depth of maximum bed load exchange (flushing) was limited to ≤ twice the depth of the overlying D90 grain size. Application of OSL in this study provides important insight into the nature of storage and flushing of matrix material in mountain streams.

  3. Analyzing Hydro-Geomorphic Responses in Post-Fire Stream Channels with Terrestrial LiDAR

    NASA Astrophysics Data System (ADS)

    Nourbakhshbeidokhti, S.; Kinoshita, A. M.; Chin, A.

    2015-12-01

    Wildfires have potential to significantly alter soil properties and vegetation within watersheds. These alterations often contribute to accelerated erosion, runoff, and sediment transport in stream channels and hillslopes. This research applies repeated Terrestrial Laser Scanning (TLS) Light Detection and Ranging (LiDAR) to stream reaches within the Pike National Forest in Colorado following the 2012 Waldo Canyon Fire. These scans allow investigation of the relationship between sediment delivery and environmental characteristics such as precipitation, soil burn severity, and vegetation. Post-fire LiDAR images provide high resolution information of stream channel changes in eight reaches for three years (2012-2014). All images are processed with RiSCAN PRO to remove vegetation and triangulated and smoothed to create a Digital Elevation Model (DEM) with 0.1 m resolution. Study reaches with two or more successive DEM images are compared using a differencing method to estimate the volume of sediment erosion and deposition. Preliminary analysis of four channel reaches within Williams Canyon and Camp Creek yielded erosion estimates between 0.035 and 0.618 m3 per unit area. Deposition was estimated as 0.365 to 1.67 m3 per unit area. Reaches that experienced higher soil burn severity or larger rainfall events produced the greatest geomorphic changes. Results from LiDAR analyses can be incorporated into post-fire hydrologic models to improve estimates of runoff and sediment yield. These models will, in turn, provide guidance for water resources management and downstream hazards mitigation.

  4. Bankfull Discharge and Channel Characteristics of Streams in New York State

    USGS Publications Warehouse

    Mulvihill, Christiane I.; Baldigo, Barry P.; Miller, Sarah J.; DeKoskie, Douglas; DuBois, Joel

    2009-01-01

    Equations that relate drainage area to bankfull discharge and channel characteristics (such as width, depth, and cross-sectional area) at gaged sites are needed to help define bankfull discharge and channel characteristics at ungaged sites and can be used in stream-restoration and protection projects, stream-channel classification, and channel assessments. These equations are intended to serve as a guide for streams in areas of similar hydrologic, climatic, and physiographic conditions. New York State contains eight hydrologic regions that were previously delineated on the basis of high-flow (flood) characteristics. This report seeks to increase understanding of the factors affecting bankfull discharge and channel characteristics to drainage-area size relations in New York State by providing an in-depth analysis of seven previously published regional bankfull-discharge and channel-characteristics curves. Stream-survey data and discharge records from 281 cross sections at 82 streamflow-gaging stations were used in regression analyses to relate drainage area to bankfull discharge and bankfull-channel width, depth, and cross-sectional area. The R2 and standard errors of estimate of each regional equation were compared to the R2 and standard errors of estimate for the statewide (pooled) model to determine if regionalizing data reduced model variability. It was found that regional models typically yield less variable results than those obtained using pooled statewide equations, which indicates statistically significant regional differences in bankfull-discharge and channel-characteristics relations. All but two of the bankfull-discharge curves are within the 95-percent confidence interval bands of the statewide model; all the models have statistically similar slopes, and only one model has a unique intercept. Regional variations in channel-characteristics models of bankfull width, depth, and cross-sectional area were more prevalent than for bankfull discharge, though

  5. Debris-flow activity in abandoned channels of the Manival torrent reconstructed with LiDAR and tree-ring data

    NASA Astrophysics Data System (ADS)

    Lopez Saez, J.; Corona, C.; Stoffel, M.; Gotteland, A.; Berger, F.; Liébault, F.

    2011-05-01

    Hydrogeomorphic processes are a major threat in many parts of the Alps, where they periodically damage infrastructure, disrupt transportation corridors or even cause loss of life. Nonetheless, past torrential activity and the analysis of areas affected during particular events remain often imprecise. It was therefore the purpose of this study to reconstruct spatio-temporal patterns of past debris-flow activity in abandoned channels on the forested cone of the Manival torrent (Massif de la Chartreuse, French Prealps). A Light Detecting and Ranging (LiDAR) generated Digital Elevation Model (DEM) was used to identify five abandoned channels and related depositional forms (lobes, lateral levees) in the proximal alluvial fan of the torrent. A total of 156 Scots pine trees (Pinus sylvestris L.) with clear signs of debris flow events was analyzed and growth disturbances (GD) assessed, such as callus tissue, the onset of compression wood or abrupt growth suppression. In total, 375 GD were identified in the tree-ring samples, pointing to 13 debris-flow events for the period 1931-2008. While debris flows appear to be very common at Manival, they have only rarely propagated outside the main channel over the past 80 years. Furthermore, analysis of the spatial distribution of disturbed trees contributed to the identification of four patterns of debris-flow routing and led to the determination of three preferential breakout locations. Finally, the results of this study demonstrate that the temporal distribution of debris flows did not exhibit significant variations since the beginning of the 20th century.

  6. Rapid estimation of recharge potential in ephemeral-stream channels using electromagnetic methods, and measurements of channel and vegetation characteristics

    USGS Publications Warehouse

    Callegary, J.B.; Leenhouts, J.M.; Paretti, N.V.; Jones, C.A.

    2007-01-01

    To classify recharge potential (RCP) in ephemeral-stream channels, a method was developed that incorporates information about channel geometry, vegetation characteristics, and bed-sediment apparent electrical conductivity (??a). Recharge potential is not independently measurable, but is instead formulated as a site-specific, qualitative parameter. We used data from 259 transects across two ephemeral-stream channels near Sierra Vista, Arizona, a location with a semiarid climate. Seven data types were collected: ??a averaged over two depth intervals (0-3 m, and 0-6 m), channel incision depth and width, diameter-at-breast-height of the largest tree, woody-plant and grass density. A two-tiered system was used to classify a transect's RCP. In the first tier, transects were categorized by estimates of near-surface-sediment hydraulic permeability as low, moderate, or high using measurements of 0-3 m-depth ??a. Each of these categories was subdivided into low, medium, or high RCP classes using the remaining six data types, thus yielding a total of nine RCP designations. Six sites in the study area were used to compare RCP and ??a with previously measured surrogates for hydraulic permeability. Borehole-averaged percent fines showed a moderate correlation with both shallow and deep ??a measurements, however, correlation of point measurements of saturated hydraulic conductivity, percent fines, and cylinder infiltrometer measurements with ??a and RCP was generally poor. The poor correlation was probably caused by the relatively large measurement volume and spatial averaging of ??a compared with the spatially-limited point measurements. Because of the comparatively large spatial extent of measurement transects and variety of data types collected, RCP estimates can give a more complete picture of the major factors affecting recharge at a site than is possible through point or borehole-averaged estimates of hydraulic permeability alone. ?? 2007 Elsevier B.V. All rights reserved.

  7. Scaling relationships between bed load volumes, transport distances, and stream power in steep mountain channels

    NASA Astrophysics Data System (ADS)

    Schneider, Johannes M.; Turowski, Jens M.; Rickenmann, Dieter; Hegglin, Ramon; Arrigo, Sabrina; Mao, Luca; Kirchner, James W.

    2014-03-01

    Bed load transport during storm events is both an agent of geomorphic change and a significant natural hazard in mountain regions. Thus, predicting bed load transport is a central challenge in fluvial geomorphology and natural hazard risk assessment. Bed load transport during storm events depends on the width and depth of bed scour, as well as the transport distances of individual sediment grains. We traced individual gravels in two steep mountain streams, the Erlenbach (Switzerland) and Rio Cordon (Italy), using magnetic and radio frequency identification tags, and measured their bed load transport rates using calibrated geophone bed load sensors in the Erlenbach and a bed load trap in the Rio Cordon. Tracer transport distances and bed load volumes exhibited approximate power law scaling with both the peak stream power and the cumulative stream energy of individual hydrologic events. Bed load volumes scaled much more steeply with peak stream power and cumulative stream energy than tracer transport distances did, and bed load volumes scaled as roughly the third power of transport distances. These observations imply that large bed load transport events become large primarily by scouring the bed deeper and wider, and only secondarily by transporting the mobilized sediment farther. Using the sediment continuity equation, we can estimate the mean effective thickness of the actively transported layer, averaged over the entire channel width and the duration of individual flow events. This active layer thickness also followed approximate power law scaling with peak stream power and cumulative stream energy and ranged up to 0.57 m in the Erlenbach, broadly consistent with independent measurements.

  8. Estimating design-flood discharges for streams in Iowa using drainage-basin and channel-geometry characteristics

    USGS Publications Warehouse

    Eash, D.A.

    1993-01-01

    Procedures provided for applying the drainage-basin and channel-geometry regression equations depend on whether the design-flood discharge estimate is for a site on an ungaged stream, an ungaged site on a gaged stream, or a gaged site. When both a drainage-basin and a channel-geometry regression-equation estimate are available for a stream site, a procedure is presented for determining a weighted average of the two flood estimates. The drainage-basin regression equations are applicable to unregulated rural drainage areas less than 1,060 square miles, and the channel-geometry regression equations are applicable to unregulated rural streams in Iowa with stabilized channels.

  9. STREAM CHANNELS OF THE UPPER SAN PEDRO BASIN WITH PERCENT DIFFERENCE BETWEEN RESULTS FROM TWO SWAT SIMULATIONS

    EPA Science Inventory

    Stream channels of the Upper San Pedro with percent difference between results from two SWAT simulations run through AGWA: one using the 1973 NALC landcover for model parameterization, and the other using the 1997 NALC landcover.

  10. RESULTS FROM KINEROS STREAM CHANNEL ELEMENTS MODEL OUTPUT THROUGH AGWA DIFFERENCING 1973 AND 1997 NALC LANDCOVER DATA

    EPA Science Inventory

    Results from differencing KINEROS model output through AGWA for Sierra Vista subwatershed. Percent change between 1973 and 1997 is presented for all KINEROS output values (and some derived from the KINEROS output by AGWA) for the stream channels.

  11. Relative influence of different habitat factors on creek chub population structure within channelized agricultural headwater streams in central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Creek chubs (Semotilus atromaculatus) are commonly found within channelized agricultural headwater streams within the Midwestern United States. Understanding the relationships of this headwater fish species with different habitat factors will provide information that can assist with developing resto...

  12. Glacially induced organization of channel-reach morphology in mountain streams

    NASA Astrophysics Data System (ADS)

    Brardinoni, Francesco; Hassan, Marwan A.

    2007-09-01

    We examine the spatial distribution of channel-reach morphologies in formerly glaciated mountain drainage basins of coastal British Columbia, Canada. Using field- and geographic information systems-derived data, we show that the local channel slope and the degree of colluvial-alluvial coupling imposed by the glacial valley morphology dictate the spatial organization of channel types. In particular, the complex, glacially induced channel long profile produces characteristic sequences of channel reaches that depart from the downstream succession (colluvial/boulder-cascade/step-pool/rapids/riffle-pool) distinctive of simple unglaciated mountain streams. Typically, the presence of one hanging valley in the river long profile produces and separates two full successions of channel types: a headmost one characterized by an ephemeral/seasonal hydrologic regime and a downstream one, where water runoff is perennial. We document that channel types are well separated in plots of slope versus shear stress, area versus shear stress, and slope versus relative roughness. In agreement with these outcomes, multivariate discriminant analyses coupled with principal component analysis of 98 study reaches yield a highly successful channel-type classification when slope, shear stress, and relative roughness are considered. Success rates, depending on whether or not boulder-cascade reaches are pooled together with step-pools, are 88% and 75%, respectively. Previous work in unglaciated settings has suggested that mountain channels have distinct bed morphology states that vary primarily with slope; our study reveals that even in formerly glaciated valleys, where slope is largely inherited from glacial times, these distinct bed states exist and vary (mostly) with slope, adding considerable strength to this empirical knowledge.

  13. Controls of channel response to cattle-grazing exclosures on five streams in the Blue Mountains of eastern Oregon

    NASA Astrophysics Data System (ADS)

    Mowry, A. D.; McDowell, P. F.

    2002-12-01

    Riparian-corridor fencing has been shown to be effective in allowing streams to recover from grazing pressure, but relative response of different stream types is poorly understood. This study compares processes of geomorphic response of five mountain streams to removal of cattle-grazing pressure. The streams differ in basin size, type of bed material and suspended sediment, vegetation type, channel slope, sinuosity, age of cattle fencing, and previous grazing history. The relative ability of each stream to adjust by depositional processes, such as construction of gravel bars and in-channel sedge benches, vertical accretion, and trapping of sediment by woody debris, was analyzed in terms of the controls. Cross-section resurveys were used to document large changes in channel geometry, and mapping based on field evidence was used to identify dominant processes and capture more localized areas of deposition and erosion. Dynamic segmentation in GIS was used to construct channel maps for visualization of adjustment processes relative to channel planform and geomorphic surfaces. Frequency of mobilization of bed material was estimated using particle entrainment calculations for each stream. The streams that appear to adjust by multiple processes show evidence of adjustment along the greatest percentage of their length. Lower-gradient streams with the largest drainage basins show the most evidence of both bar development and erosion on outsides of bends, while frequency of vertical accretion and development of sedge benches may be less related to stream size. Sedges and rushes appear to be effective in promoting and stabilizing low depositional surfaces (sedge benches) at sites with fine sediment availability. Large wood influences deposition on up to 12% of the length of some sites, but may not be as important as in streams west of the Cascades. Bar development may be most important in controlling response rate, and appears to associated with larger streams, higher

  14. Channel Morphology and Hydraulics as Controls on Spatial Patterns of Invertebrate Drift in a Mountain Stream.

    NASA Astrophysics Data System (ADS)

    Cienciala, P.; Hassan, M. A.

    2015-12-01

    In this research we linked spatial variability of invertebrate drift characteristics (e.g. flux, concentration, mean body size) in a mountain stream to channel morphology and hydraulic properties such as at-a-point and depth-averaged velocity and shear velocity. The study was conducted in East Creek, a small stream in British Columbia in which reach-scale morphology transitions from cobble-dominated plane-bed to gravel-bed pool-riffle. To achieve our goal, we collected vertical profiles of invertebrate drift and time-averaged velocity in various morphological units within the study reaches. The data were analyzed using linear mixed model. Our reach-scale results suggested that, generally, the study reaches had statistically similar drift characteristics despite their contrasting morphologies. At the within-reach scale, different drift characteristics displayed different trends in relation to morphological and hydraulic properties of the channel. Longitudinally, highest drift flux occurred in riffle-pool transitions. We attributed this finding primarily to higher flow velocity because there were no statistically significant differences in drift concentration between morphological units. In the vertical dimension, highest drift flux occurred near the surface owing to a combination of higher drift concentration and higher flow velocity. A different pattern was observed for mean body size of drifting invertebrates. On average, body size was smallest in riffle-pool transitions and largest near the bed. The combination of velocity, drift concentration, and drift body size structure resulted in similar biomass flux estimates in all morphological units. In the vertical dimension, biomass flux appeared to be highest near the water surface. Generally, hydraulic variables seemed to be relatively poor predictors of drift concentration and mean body size of drifting invertebrates. Our findings reveal a complex relationship between channel morphology and hydraulics and various

  15. Channel water balance and exchange with subsurface flow along a mountain headwater stream in Montana, United States

    USGS Publications Warehouse

    Payn, R.A.; Gooseff, M.N.; McGlynn, B.L.; Bencala, K.E.; Wondzell, S.M.

    2009-01-01

    Channel water balances of contiguous reaches along streams represent a poorly understood scale of stream-subsurface interaction. We measured reach water balances along a headwater stream in Montana, United States, during summer base flow recessions. Reach water balances were estimated from series of tracer tests in 13 consecutive reaches delineated evenly along a 2.6 km valley segment. For each reach, we estimated net change in discharge, gross hydrologic loss, and gross hydrologic gain from tracer dilution and mass recovery. Four series of tracer tests were performed during relatively high, intermediate, and low base flow conditions. The relative distribution of channel water along the stream was strongly related to a transition in valley structure, with a general increase in gross losses through the recession. During tracer tests at intermediate and low flows, there were frequent substantial losses of tracer mass (>10%) that could not be explained by net loss in flow over the reach, indicating that many of the study reaches were concurrently losing and gaining water. For example, one reach with little net change in discharge exchanged nearly 20% of upstream flow with gains and losses along the reach. These substantial bidirectional exchanges suggest that some channel interactions with subsurface flow paths were not measurable by net change in flow or transient storage of recovered tracer. Understanding bidirectional channel water balances in stream reaches along valleys is critical to an accurate assessment of stream solute fate and transport and to a full assessment of exchanges between the stream channel and surrounding subsurface.

  16. Implications of fish-habitat relationships for developing conservation plans for channelized headwater streams in the midwestern United States.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many headwater streams in the midwestern United States were channelized for agricultural drainage. Conservation practices are implemented to reduce nutrient and pesticide loadings within these altered streams. The impact of these practices is uncertain because the influence of water chemistry on st...

  17. Management implications of the relationships between water chemistry and fishes within channelized headwater streams in the midwestern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many headwater streams in the midwestern United States were channelized for agricultural drainage. Conservation practices are implemented to reduce nutrient and pesticide loadings within these altered streams. The impact of these practices is uncertain because the influence of water chemistry on str...

  18. Implications of Fish-Habitat Relationships for Developing Conservation Plans for Channelized Headwater Streams in the Midwestern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many headwater streams in the midwestern United States were channelized for agricultural drainage. Conservation practices are implemented to reduce nutrient and pesticide loadings within these altered streams. The impact of these practices is uncertain because the influence of water chemistry on str...

  19. Main-channel slopes of selected streams in Iowa for estimation of flood-frequency discharges

    USGS Publications Warehouse

    Eash, David A.

    2003-01-01

    This report describes a statewide study conducted to develop main-channel slope (MCS) curves for 138 selected streams in Iowa with drainage areas greater than 100 square miles. MCS values determined from the curves can be used in regression equations for estimating floodfrequency discharges. Multivariable regression equations previously developed for two of the three hydrologic regions defined for Iowa require the measurement of MCS. Main-channel slope is a difficult measurement to obtain for large streams using 1:24,000-scale topographic maps. The curves developed in this report provide a simplified method for determining MCS values for sites located along large streams in Iowa within hydrologic Regions 2 and 3. The curves were developed using MCS values quantified for 2,058 selected sites along 138 selected streams in Iowa. A geographic information system (GIS) technique and 1:24,000-scale topographic data were used to quantify MCS values for the stream sites. The sites were selected at about 5-mile intervals along the streams. River miles were quantified for each stream site using a GIS program. Data points for river-mile and MCS values were plotted and a best-fit curve was developed for each stream. An adjustment was applied to all 138 curves to compensate for differences in MCS values between manual measurements and GIS quantifications. The multivariable equations for Regions 2 and 3 were developed using manual measurements of MCS. A comparison of manual measurements and GIS quantifications of MCS indicates that manual measurements typically produce greater values of MCS compared to GIS quantifications. Median differences between manual measurements and GIS quantifications of MCS are 14.8 and 17.7 percent for Regions 2 and 3, respectively. Comparisons of percentage differences between flood-frequency discharges calculated using MCS values of manual measurements and GIS quantifications indicate that use of GIS values of MCS for Region 3 substantially

  20. Machine-Learning Based Channel Quality and Stability Estimation for Stream-Based Multichannel Wireless Sensor Networks.

    PubMed

    Rehan, Waqas; Fischer, Stefan; Rehan, Maaz

    2016-01-01

    Wireless sensor networks (WSNs) have become more and more diversified and are today able to also support high data rate applications, such as multimedia. In this case, per-packet channel handshaking/switching may result in inducing additional overheads, such as energy consumption, delays and, therefore, data loss. One of the solutions is to perform stream-based channel allocation where channel handshaking is performed once before transmitting the whole data stream. Deciding stream-based channel allocation is more critical in case of multichannel WSNs where channels of different quality/stability are available and the wish for high performance requires sensor nodes to switch to the best among the available channels. In this work, we will focus on devising mechanisms that perform channel quality/stability estimation in order to improve the accommodation of stream-based communication in multichannel wireless sensor networks. For performing channel quality assessment, we have formulated a composite metric, which we call channel rank measurement (CRM), that can demarcate channels into good, intermediate and bad quality on the basis of the standard deviation of the received signal strength indicator (RSSI) and the average of the link quality indicator (LQI) of the received packets. CRM is then used to generate a data set for training a supervised machine learning-based algorithm (which we call Normal Equation based Channel quality prediction (NEC) algorithm) in such a way that it may perform instantaneous channel rank estimation of any channel. Subsequently, two robust extensions of the NEC algorithm are proposed (which we call Normal Equation based Weighted Moving Average Channel quality prediction (NEWMAC) algorithm and Normal Equation based Aggregate Maturity Criteria with Beta Tracking based Channel weight prediction (NEAMCBTC) algorithm), that can perform channel quality estimation on the basis of both current and past values of channel rank estimation. In the end

  1. Arroyo channel head evolution in a flash-flood-dominated discontinuous ephemeral stream system

    USGS Publications Warehouse

    DeLong, Stephen B.; Johnson, Joel P.L.; Whipple, Kelin X.

    2014-01-01

    We study whether arroyo channel head retreat in dryland discontinuous ephemeral streams is driven by surface runoff, seepage erosion, mass wasting, or some combination of these hydrogeomorphic processes. We monitored precipitation, overland flow, soil moisture, and headcut migration over several seasonal cycles at two adjacent rangeland channel heads in southern Arizona. Erosion occurred by headward retreat of vertical to overhanging faces, driven dominantly by surface runoff. No evidence exists for erosion caused by shallow-groundwater–related processes, even though similar theater-headed morphologies are sometimes attributed to seepage erosion by emerging groundwater. At our field site, vertical variation in soil shear strength influenced the persistence of the characteristic theater-head form. The dominant processes of erosion included removal of grains and soil aggregates during even very shallow (1–3 cm) overland flow events by runoff on vertical to overhanging channel headwalls, plunge-pool erosion during higher-discharge runoff events, immediate postrunoff wet mass wasting, and minor intra-event dry mass wasting on soil tension fractures developing subparallel to the headwall. Multiple stepwise linear regression indicates that the migration rate is most strongly correlated with flow duration and total precipitation and is poorly correlated with peak flow depth or time-integrated flow depth. The studied channel heads migrated upslope with a self-similar morphologic form under a wide range of hydrological conditions, and the most powerful flash floods were not always responsible for the largest changes in landscape form in this environment. 

  2. Self-adjustment of stream bed roughness and flow velocity in a steep mountain channel

    NASA Astrophysics Data System (ADS)

    Schneider, Johannes M.; Rickenmann, Dieter; Turowski, Jens M.; Kirchner, James W.

    2015-10-01

    Understanding how channel bed morphology affects flow conditions (and vice versa) is important for a wide range of fluvial processes and practical applications. We investigated interactions between bed roughness and flow velocity in a steep, glacier-fed mountain stream (Riedbach, Ct. Valais, Switzerland) with almost flume-like boundary conditions. Bed gradient increases along the 1 km study reach by roughly 1 order of magnitude (S = 3-41%), with a corresponding increase in streambed roughness, while flow discharge and width remain approximately constant due to the glacial runoff regime. Streambed roughness was characterized by semivariograms and standard deviations of point clouds derived from terrestrial laser scanning. Reach-averaged flow velocity was derived from dye tracer breakthrough curves measured by 10 fluorometers installed along the channel. Commonly used flow resistance approaches (Darcy-Weisbach equation and dimensionless hydraulic geometry) were used to relate the measured bulk velocity to bed characteristics. As a roughness measure, D84 yielded comparable results to more laborious measures derived from point clouds. Flow resistance behavior across this large range of steep slopes agreed with patterns established in previous studies for both lower-gradient and steep reaches, regardless of which roughness measures were used. We linked empirical critical shear stress approaches to the variable power equation for flow resistance to investigate the change of bed roughness with channel slope. The predicted increase in D84 with increasing channel slope was in good agreement with field observations.

  3. Scale-dependent interactions between wood and channel dynamics: Modeling jam formation and sediment storage in gravel-bed streams

    NASA Astrophysics Data System (ADS)

    Eaton, B. C.; Hassan, M. A.

    2013-12-01

    A stochastic model is used to investigate how the geomorphic function of wood changes with watershed scale, assuming wood recruitment occurs due to the mortality of individual trees, not to mass recruitment events such as landslides or episodic bank erosion. The model replicates the downstream decline in total wood load observed in the field, but predicts that the functional wood load peaks in channels having bankfull widths about 33% of the characteristic riparian tree height. The model also predicts that the greatest potential impact of jams on channel pattern—both in terms of sediment stored behind individual jams and the potential for jams to trigger avulsions—will typically be associated with channel widths between 25% and 67% of the riparian tree height. The simulation results are used to refine the categories that describe wood in alluvial channels, and the equivalent terms that describe the size of streams with forested riparian areas: small channels (or channels with large wood) are associated with widths less than 25% of the tree height; large channels (or channels with small wood) are associated with widths greater than 67% of tree height; and medium channels (or channels with intermediate wood) have widths between 25% and 67% of the tree height. We surmise that large wood acts primarily to store bed material (in small channels); intermediate wood tends to form channel-spanning jams, which can induce channel avulsions and create anabranched channel patterns (in medium channels); and small wood may increase the morphologic diversity, but does not store significant quantities of bed material or form channel-spanning jams capable of inducing stream avulsions (in large channels).

  4. Estimating seepage flux from ephemeral stream channels using surface water and groundwater level data

    NASA Astrophysics Data System (ADS)

    Noorduijn, Saskia L.; Shanafield, Margaret; Trigg, Mark A.; Harrington, Glenn A.; Cook, Peter G.; Peeters, L.

    2014-02-01

    Seepage flux from ephemeral streams can be an important component of the water balance in arid and semiarid regions. An emerging technique for quantifying this flux involves the measurement and simulation of a flood wave as it moves along an initially dry channel. This study investigates the usefulness of including surface water and groundwater data to improve model calibration when using this technique. We trialed this approach using a controlled flow event along a 1387 m reach of artificial stream channel. Observations were then simulated using a numerical model that combines the diffusion-wave approximation of the Saint-Vénant equations for streamflow routing, with Philip's infiltration equation and the groundwater flow equation. Model estimates of seepage flux for the upstream segments of the study reach, where streambed hydraulic conductivities were approximately 101 m d-1, were on the order of 10-4 m3 d-1 m-2. In the downstream segments, streambed hydraulic conductivities were generally much lower but highly variable (˜10-3 to 10-7 m d-1). A Latin Hypercube Monte Carlo sensitivity analysis showed that the flood front timing, surface water stage, groundwater heads, and the predicted streamflow seepage were most influenced by specific yield. Furthermore, inclusion of groundwater data resulted in a higher estimate of total seepage estimates than if the flood front timing were used alone.

  5. Effect of stream channel size on the delivery of nitrogen to the Gulf of Mexico

    USGS Publications Warehouse

    Alexander, R.B.; Smith, R.A.; Schwarz, G.E.

    2000-01-01

    An increase in the flux of nitrogen from the Mississippi river during the latter half of the twentieth century has caused eutrophication and chronic seasonal hypoxia in the shallow waters of the Louisiana shelf in the northern Gulf of Mexico. This has led to reductions in species diversity, mortality of benthic communities and stress in fishery resources. There is evidence for a predominantly anthropogenic origin of the increased nitrogen flux, but the location of the most significant sources in the Mississippi basin responsible for the delivery of nitrogen to the Gulf of Mexico have not been clearly identified, because the parameters influencing nitrogen-loss rates in rivers are not well known. Here we present an analysis of data from 374 US monitoring stations, including 123 along the six largest tributaries to the Mississippi, that shows a rapid decline in the average first-order rate of nitrogen loss with channel size-from 0.45 day-1 in small streams to 0.005 day-1 in the Mississippi river. Using stream depth as an explanatory variable, our estimates of nitrogen-loss rates agreed with values from earlier studies. We conclude that the proximity of sources to large streams and rivers is an important determinant of nitrogen delivery to the estuary in the Mississippi basin, and possibly also in other large river basins.

  6. Disentangling the responses of boreal stream assemblages to low stressor levels of diffuse pollution and altered channel morphology.

    PubMed

    Turunen, Jarno; Muotka, Timo; Vuori, Kari-Matti; Karjalainen, Satu Maaria; Rääpysjärvi, Jaana; Sutela, Tapio; Aroviita, Jukka

    2016-02-15

    Non-point diffuse pollution from land use and alteration of hydromorphology are among the most detrimental stressors to stream ecosystems. We explored the independent and interactive effects of morphological channel alteration (channelization for water transport of timber) and diffuse pollution on species richness and community structure of four organism groups in boreal streams: diatoms, macrophytes, macroinvertebrates, and fish. Furthermore, the effect of these stressors on stream condition was evaluated by Ecological Quality Ratios (EQR) from the national Water Framework Directive (WFD) assessment system. We grouped 91 study sites into four groups that were impacted by either diffuse pollution or hydromorphological alteration, by both stressors, or by neither one. Macroinvertebrate richness was reduced by diffuse pollution, whereas other biological groups were unaltered. Hydromorphological modification had no effect on taxon richness of any of the assemblages. Community structure of all groups was significantly affected by diffuse pollution but not by hydromorphology. Similarly, EQRs indicated negative response by diatoms, macroinvertebrates and fish to diffuse pollution, but not to hydromorphological alteration. Agricultural diffuse pollution thus affected species identities and abundances rather than taxonomic richness. Our results suggest that channelization of boreal streams for timber transport has not altered hydromorphological conditions sufficiently to have a strong impact on stream biota, whereas even moderate nutrient enrichment may be ecologically harmful. Controlling diffuse pollution and associated land use stressors should be prioritized over restoration of in-stream habitat structure to improve the ecological condition of boreal streams. PMID:26706766

  7. Equations for estimating bankfull channel geometry and discharge for streams in Massachusetts

    USGS Publications Warehouse

    Bent, Gardner C.; Waite, Andrew M.

    2013-01-01

    Regression equations were developed for estimating bankfull geometry—width, mean depth, cross-sectional area—and discharge for streams in Massachusetts. The equations provide water-resource and conservation managers with methods for estimating bankfull characteristics at specific stream sites in Massachusetts. This information can be used for the adminstration of the Commonwealth of Massachusetts Rivers Protection Act of 1996, which establishes a protected riverfront area extending from the mean annual high-water line corresponding to the elevation of bankfull discharge along each side of a perennial stream. Additionally, information on bankfull channel geometry and discharge are important to Federal, State, and local government agencies and private organizations involved in stream assessment and restoration projects. Regression equations are based on data from stream surveys at 33 sites (32 streamgages and 1 crest-stage gage operated by the U.S. Geological Survey) in and near Massachusetts. Drainage areas of the 33 sites ranged from 0.60 to 329 square miles (mi2). At 27 of the 33 sites, field data were collected and analyses were done to determine bankfull channel geometry and discharge as part of the present study. For 6 of the 33 sites, data on bankfull channel geometry and discharge were compiled from other studies done by the U.S. Geological Survey, Natural Resources Conservation Service of the U.S. Department of Agriculture, and the Vermont Department of Environmental Conservation. Similar techniques were used for field data collection and analysis for bankfull channel geometry and discharge at all 33 sites. Recurrence intervals of the bankfull discharge, which represent the frequency with which a stream fills its channel, averaged 1.53 years (median value 1.34 years) at the 33 sites. Simple regression equations were developed for bankfull width, mean depth, cross-sectional area, and discharge using drainage area, which is the most significant explanatory

  8. Nitrogen cycling in stream-groundwater exchange zones of a channeled peatland

    NASA Astrophysics Data System (ADS)

    Westbrook, C. J.; Bedard-Haughn, A.

    2011-12-01

    The flow of stream water through riparian soils is known to influence the nitrogen (N) patterns in streams. Needed is an improved understanding of how filtration capacity, the extent to which water residence time and riparian sediment hydraulic conductivity regulates water characteristics, acts to influence the concentration of N that emerges back to the stream. Tested was the hypothesis that where filtration capacity is high, N availability is low yet production rates are high. Compared were water chemistry and gross N mineralization rates along two previously characterized riparian areas of a channeled Canadian Rocky Mountain peatland; one of which contains a beaver dam. Although average peat hydraulic conductivity was similar between sites, throughflow was 10 times higher at the site with the beaver dam. Water samples from 32 shallow riparian wells show that the biogeochemical conditions of the two sites differ, with the beaver dam site having lower conductivity, DOC, TDN, and NH4+, warmer temperatures, and higher pH. Coincident measures of gross mineralization and nitrification rates were obtained using the stable 15N isotope dilution technique. NH4+ and NO3- turnover rates were all <1 day and rates of gross N production and consumption were high (up to 75 mg/kg/d). There was net NH4+ consumption at both sites. In contrast, the beaver dam site had significantly lower rates of NO3- production and consumption, and showed net NO3- production whereas the no dam site showed net NO3- consumption. The results imply that enhanced filtration capacity near beaver dams leads to flushing of N from riparian soils. Thus, beaver dams should be considered in assessments and models of stream ecosystem function.

  9. Landform assemblages and sedimentary processes along the Norwegian Channel Ice Stream

    NASA Astrophysics Data System (ADS)

    Ottesen, Dag; Stokes, Chris R.; Bøe, Reidulv; Rise, Leif; Longva, Oddvar; Thorsnes, Terje; Olesen, Odleiv; Bugge, Tom; Lepland, Aave; Hestvik, Ole B.

    2016-06-01

    Several regional and detailed bathymetric datasets together with 2D and 3D seismic data are compiled to investigate the landform assemblages and sedimentary processes along the former path of the Norwegian Channel Ice Stream (NCIS). At the broad scale, the glacial geomorphology and sedimentary architecture reveals three different zones along the ice-stream path, characterized by: (1) glacial erosion in the onset zone and inner shelf area, (2) sediment transport through the main trunk of the ice stream across the mid-shelf, and (3) a zone of deposition towards the outer continental shelf edge. Along the first 400 km of the ice stream bed (outer Oslofjord-Skagerrak-Stavanger) a major overdeepening is associated with suites of crag-and-tail features at the transition from the crystalline bedrock to the sedimentary bedrock, together with evidence of glaciotectonic thrusting in the form of hill-hole pairs. Here we interpret extensive erosion of both sedimentary rocks and Quaternary sediments. This zone is succeeded by an approximately 400 km long zone, through which most of the sediments eroded from the inner shelf were transported, rather than being deposited. We infer that sediment was transported subglacially and is likely to have been advected downstream by soft sediment deformation. The thickness of till of inferred Weichselian age generally varies from 0 and 50 m and this zone is characterized by mega-scale glacial lineations (MSGLs) which we interpret to be formed in a dynamic sedimentary system dominated by high sediment fluxes, but with some localized sediment accretion associated with lineations. Towards the shelf break, the North Sea Fan extends to the deep Norwegian Sea, and reflects massive sedimentation of glacigenic debris onto the continental slope. Numerous glacigenic debris flows accumulated and constructed a unit up to 400 m thick during the Last Glacial Maximum. The presence of these three zones (erosion, transport, deposition) is consistent with

  10. Relationship between channel morphology and foraging habitat for stream salmonids: Effects of body size

    NASA Astrophysics Data System (ADS)

    Cienciala, P.; Hassan, M. A.

    2014-12-01

    Channel morphology and dynamics strongly influence fish populations in running waters by defining habitat template for movement, spawning, incubation, and foraging. In this research we adopted a modeling approach to investigate how body size controls the relationship between salmonid fish and their foraging habitat in streams. Body size is a fundamental ecological parameter which affects resource acquisition, locomotory costs, metabolic rates, and competitive abilities. We focus on two specific questions. First, we examined how distinct types of channel morphology and associated flow fields shape specific growth potential for different body size classes of trout. Second, we modeled these fish-habitat relationships in a size-structured population in the presence of intraspecific competition. In the latter scenario, fish may not be able to occupy energetically optimal foraging habitat and the predicted specific growth potential may differ from the intrinsic habitat quality. To address the research questions, we linked a 2D hydrodynamic model with a bioenergetic foraging model for drift-feeding trout. Net energy intake, simulated for four study reaches with different channel morphology, was converted into maps of specific growth rate potential. We extended this model by including a component that enabled us to estimate territory size for fish of a given body size and account for the effects of competition on spatial distribution of fish. The predictions that emerge from our simulations highlight that fish body size is an important factor that determines the relationship between channel morphology and the quality of foraging habitat. The results also indicate that distinct types of channel morphology may give rise to different energetic conditions for different body size classes of drift-feeding salmonids.

  11. Interactions among forest age, valley and channel morphology, and log jams regulate animal production in mountain streams

    NASA Astrophysics Data System (ADS)

    Walters, D. M.; Venarsky, M. P.; Hall, R. O., Jr.; Herdrich, A.; Livers, B.; Winkelman, D.; Wohl, E.

    2014-12-01

    Forest age and local valley morphometry strongly influence the form and function of mountain streams in Colorado. Streams in valleys with old growth forest (>350 years) have extensive log jam complexes that create multi-thread channel reaches with extensive pool habitat and large depositional areas. Streams in younger unmanaged forests (e.g., 120 years old) and intensively managed forests have much fewer log jams and lower wood loads. These are single-thread streams dominated by riffles and with little depositional habitat. We hypothesized that log jam streams would retain more organic matter and have higher metabolism, leading to greater production of stream macroinvertebrates and trout. Log jam reaches should also have greater emergence of adult aquatic insects, and consequently have higher densities of riparian spiders taking advantage of these prey. Surficial organic matter was 3-fold higher in old-growth streams, and these streams had much higher ecosystem respiration. Insect production (g m2 y-1) was similar among forest types, but fish density was four times higher in old-growth streams with copious log jams. However, at the valley scale, insect production (g m-1 valley-1) and trout density (number m-1 valley-1) was 2-fold and 10-fold higher, respectively, in old growth streams. This finding is because multi-thread reaches created by log jams have much greater stream area and stream length per meter of valley than single-thread channels. The more limited response of macroinvertebrates may be related to fish predation. Trout in old growth streams had similar growth rates and higher fat content than fish in other streams in spite of occurring at higher densities and higher elevation/colder temperatures. This suggests that the positive fish effect observed in old growth streams is related to greater availability of invertebrate prey, which is consistent with our original hypothesis. Preliminary analyses suggest that spider densities do not respond strongly to

  12. The effect of inundation frequency on ground beetle communities in a channelized mountain stream

    NASA Astrophysics Data System (ADS)

    Skalski, T.; Kedzior, R.; Radecki-Pawlik, A.

    2012-04-01

    Under natural conditions, river channels and floodplains are shaped by flow and sediment regime and are one of the most dynamic ecosystems. At present, European river floodplains are among the most endangered landscapes due to human modifications to river systems, including channel regulation and floodplain urbanization, and land use changes in the catchments. Situated in a transition zone between terrestrial and aquatic environments, exposed riverine sediments (ERS) play a key role in the functioning of riverine ecosystems. This study aimed to verify whether the bare granular substrate is the only factor responsible for sustaining the biota associated with ERS or the inundation frequency also plays a role, modifying the potential of particular species to colonize these habitats. Ground beetles (Col. Carabidae) were selected as the investigated group of organisms and the study was carried out in Porębianka, a Polish Carpathian stream flowing through both unconstrained channel sections and sections with varied channelization schemes (rapid hydraulic structures, concrete revetments or rip-rap of various age). In each of the distinguished channel types, four replicates of 10 pitfall traps were established in three rows varying in distance to the mean water level (at three different benches). Almost 7000 individuals belonging to 102 species were collected on 60 plots. Forward selection of redundancy analysis revealed four factors significantly describing the variation in ground beetle species data: bank modification, potential bankfull discharge, frequency of inundation and plant height. Most of the biggest species were ordered at the positive site of first axis having the highest values of periods between floods. Total biomass of ground beetles and mean biomass of individuals differed significantly between sites of various frequency of inundation, whereas the variation in abundance and species richness of ground beetles was independent of the river dynamics. The body

  13. Channel water balance and exchange with subsurface flow along a mountain headwater stream in Montana, United States

    USGS Publications Warehouse

    Payn, R.A.; Gooseff, M.N.; McGlynn, B.L.; Bencala, K.E.; Wondzell, S.M.

    2009-01-01

    Channel water balances of contiguous reaches along streams represent a poorly understood scale of stream-subsurface interaction. We measured reach water balances along a headwater stream in Montana, United States, during summer base flow recessions. Reach water balances were estimated from series of tracer tests in 13 consecutive reaches delineated evenly along a 2.6 km valley segment. For each reach, we estimated net change in discharge, gross hydrologic loss, and gross hydrologic gain from tracer dilution and mass recovery. Four series of tracer tests were performed during relatively high, intermediate, and low base flow conditions. The relative distribution of channel water along the stream was strongly related to a transition in valley structure, with a general increase in gross losses through the recession. During tracer tests at intermediate and low flows, there were frequent substantial losses of tracer mass (>10%) that could not be explained by net loss in flow over the reach, indicating that many of the study reaches were concurrently losing and gaining water. For example, one reach with little net change in discharge exchanged nearly 20% of upstream flow with gains and losses along the reach. These substantial bidirectional exchanges suggest that some channel interactions with subsurface flow paths were not measurable by net change in flow or transient storage of recovered tracer. Understanding bidirectional channel water balances in stream reaches along valleys is critical to an accurate assessment of stream solute fate and transport and to a full assessment of exchanges between the stream channel and surrounding subsurface. Copyright 2009 by the American Geophysical Union.

  14. Baseline Channel Geometry and Aquatic Habitat Data for Selected Streams in the Matanuska-Susitna Valley, Alaska

    USGS Publications Warehouse

    Curran, Janet H.; Rice, William J.

    2009-01-01

    Small streams in the rapidly developing Matanuska-Susitna Valley in south-central Alaska are known to support anadromous and resident fish but little is known about their hydrologic and riparian conditions, or their sensitivity to the rapid development of the area or climate variability. To help address this need, channel geometry and aquatic habitat data were collected in 2005 as a baseline of stream conditions for selected streams. Three streams were selected as representative of various stream types, and one drainage network, the Big Lake drainage basin, was selected for a systematic assessment. Streams in the Big Lake basin were drawn in a Geographic Information System (GIS), and 55 reaches along 16 miles of Meadow Creek and its primary tributary Little Meadow Creek were identified from orthoimagery and field observations on the basis of distinctive physical and habitat parameters, most commonly gradient, substrate, and vegetation. Data-collection methods for sites at the three representative reaches and the 55 systematically studied reaches consisted of a field survey of channel and flood-plain geometry and collection of 14 habitat attributes using published protocols or slight modifications. Width/depth and entrenchment ratios along the Meadow-Little Meadow Creek corridor were large and highly variable upstream of Parks Highway and lower and more consistent downstream of Parks Highway. Channel width was strongly correlated with distance, increasing downstream in a log-linear relation. Runs formed the most common habitat type, and instream vegetation dominated the habitat cover types, which collectively covered 53 percent of the channel. Gravel suitable for spawning covered isolated areas along Meadow Creek and about 29 percent of Little Meadow Creek. Broad wetlands were common along both streams. For a comprehensive assessment of small streams in the Mat-Su Valley, critical additional data needs include hydrologic, geologic and geomorphic, and biologic data

  15. Evaluating the use of drone photogrammetry for measurement of stream channel morphology and response to high flow events

    NASA Astrophysics Data System (ADS)

    Price, Katie; Ballow, William

    2015-04-01

    Traditional high-precision survey methods for stream channel measurement are labor-intensive and require wadeability or boat access to streams. These conditions limit the number of sites researchers are able to study and generally prohibit the possibility of repeat channel surveys to evaluate short-term fluctuations in channel morphology. In recent years, unmanned aerial vehicles (drones) equipped with photo and video capabilities have become widely available and affordable. Concurrently, developments in photogrammetric software offer unprecedented mapping and 3D rendering capabilities of drone-captured photography. In this study, we evaluate the potential use of drone-mounted cameras for detailed stream channel morphometric analysis. We used a relatively low-cost drone (DJI Phantom 2+ Vision) and commercially available, user friendly software (Agisoft Photscan) for photogrammetric analysis of drone-captured stream channel photography. Our test study was conducted on Proctor Creek, a highly responsive urban stream in Atlanta, Georgia, within the crystalline Piedmont region of the southeastern United States. As a baseline, we performed traditional high-precision survey methods to collect morphological measurements (e.g., bankfull and wetted width, bankfull and wetted thalweg depth) at 11 evenly-spaced transects, following USGS protocols along reaches of 20 times average channel width. We additionally used the drone to capture 200+ photos along the same reaches, concurrent with the channel survey. Using the photogrammetry software, we generated georeferenced 3D models of the stream channel, from which morphological measurements were derived from the 11 transects and compared with measurements from the traditional survey method. We additionally explored possibilities for novel morphometric characterization available from the continuous 3D surface, as an improvement on the limited number of detailed cross-sections available from standard methods. These results showed

  16. Disintegration of a marine-based ice stream - evidence from the Norwegian Channel, north-eastern North Sea

    NASA Astrophysics Data System (ADS)

    Morén, Björn M.; Petter Sejrup, Hans; Hjelstuen, Berit O.; Haflidason, Haflidi; Schäuble, Cathrina; Borge, Marianne

    2014-05-01

    The Norwegian Channel Ice Stream repeatedly drained large part of the Fennoscandian Ice Sheet through Mid and Late Pleistocene glacial stages. During parts of Marine Isotope Stages 2 and 3, glacial ice from Fennoscandia and the British Isles coalesced in the central North Sea and the Norwegian Channel Ice Stream reached the shelf edge on multiple occasions. Through the last decades a large amount of acoustic and sediment core data have been collected from the Norwegian Channel, providing a good background for studies focussing on stability- and development-controlling parameters for marine-based ice streams, the retreat rate of the Norwegian Channel Ice Stream, and the behaviour of the Fennoscandian Ice Sheet. Further, this improved understanding can be used to develop more accurate numerical climate models and models which can be used to model ice-sheet behaviour of the past as well as the future. This study presents new acoustic records and data from sediment cores which contribute to a better understanding of the retreat pattern and the retreat rate of the last ice stream that occupied the Norwegian Channel. From bathymetric and TOPAS seismic data, mega-scale glacial lineations, grounding-zone wedges, and end moraines have been mapped, thereby allowing us to reconstruct the pro- and subglacial conditions at the time of the creation of these landforms. It is concluded that the whole Norwegian Channel was deglaciated in just over 1 000 years and that for most of this time the ice margin was located at positions reflected by depositional grounding-zone wedges. Further work will explore the influence of channel shape and feeding of ice from western Norwegian fjords on this retreat pattern through numerical modelling.

  17. Mapping Spatial Distributions of Stream Power and Channel Change along a Gravel-Bed River in Northern Yellowstone

    NASA Astrophysics Data System (ADS)

    Lea, D. M.; Legleiter, C. J.

    2014-12-01

    Stream power represents the rate of energy expenditure along a river and can be calculated using topographic data acquired via remote sensing. This study used remotely sensed data and field measurements to quantitatively relate temporal changes in the form of Soda Butte Creek, a gravel-bed river in northeastern Yellowstone National Park, to stream power gradients along an 8 km reach. Aerial photographs from 1994-2012 and cross-section surveys were used to assess lateral channel mobility and develop a morphologic sediment budget for quantifying net sediment flux for a series of budget cells. A drainage area-to-discharge relationship and digital elevation model (DEM) developed from LiDAR data were used to obtain the discharge and slope values, respectively, needed to calculate stream power. Local and lagged relationships between mean stream power gradient at median peak discharge and volumes of erosion, deposition, and net sediment flux were quantified via spatial cross-correlation analyses. Similarly, autocorrelations of locational probabilities and sediment fluxes were used to examine spatial patterns of channel mobility and sediment transfer. Energy expended above critical stream power was calculated for each time period to relate the magnitude and duration of peak flows to the total volume of sediment eroded or deposited during each time increment. Our results indicated a lack of strong correlation between stream power gradients and sediment flux, which we attributed to the geomorphic complexity of the Soda Butte Creek watershed and the inability of our relatively simple statistical approach to link sediment dynamics expressed at a sub-budget cell scale to larger-scale driving forces such as stream power gradients. Future studies should compare the moderate spatial resolution techniques used in this study to very-high resolution data acquired from new fluvial remote sensing technologies to better understand the amount of error associated with stream power

  18. Spreading of a ferrofluid core in three-stream micromixer channels

    NASA Astrophysics Data System (ADS)

    Wang, Zhaomeng; Varma, V. B.; Xia, Huan Ming; Wang, Z. P.; Ramanujan, R. V.

    2015-05-01

    Spreading of a water based ferrofluid core, cladded by a diamagnetic fluid, in three-stream micromixer channels was studied. This spreading, induced by an external magnetic field, is known as magnetofluidic spreading (MFS). MFS is useful for various novel applications where control of fluid-fluid interface is desired, such as micromixers or micro-chemical reactors. However, fundamental aspects of MFS are still unclear, and a model without correction factors is lacking. Hence, in this work, both experimental and numerical analyses were undertaken to study MFS. We show that MFS increased for higher applied magnetic fields, slower flow speed of both fluids, smaller flow rate of ferrofluid relative to cladding, and higher initial magnetic particle concentration. Spreading, mainly due to connective diffusion, was observed mostly near the channel walls. Our multi-physics model, which combines magnetic and fluidic analyses, showed, for the first time, excellent agreement between theory and experiment. These results can be useful for lab-on-a-chip devices.

  19. Spreading of a ferrofluid core in three-stream micromixer channels

    SciTech Connect

    Wang, Zhaomeng; Varma, V. B.; Ramanujan, R. V.; Xia, Huan Ming; Wang, Z. P.

    2015-05-15

    Spreading of a water based ferrofluid core, cladded by a diamagnetic fluid, in three-stream micromixer channels was studied. This spreading, induced by an external magnetic field, is known as magnetofluidic spreading (MFS). MFS is useful for various novel applications where control of fluid-fluid interface is desired, such as micromixers or micro-chemical reactors. However, fundamental aspects of MFS are still unclear, and a model without correction factors is lacking. Hence, in this work, both experimental and numerical analyses were undertaken to study MFS. We show that MFS increased for higher applied magnetic fields, slower flow speed of both fluids, smaller flow rate of ferrofluid relative to cladding, and higher initial magnetic particle concentration. Spreading, mainly due to connective diffusion, was observed mostly near the channel walls. Our multi-physics model, which combines magnetic and fluidic analyses, showed, for the first time, excellent agreement between theory and experiment. These results can be useful for lab-on-a-chip devices.

  20. Turbulent flow in pipes and channels as cross-stream ``inverse cascades'' of vorticity

    NASA Astrophysics Data System (ADS)

    Eyink, Gregory L.

    2008-12-01

    A commonplace view of pressure-driven turbulence in pipes and channels is as "cascades" of streamwise momentum toward the viscous layer at the wall. We present in this paper an alternative picture of these flows as "inverse cascades" of spanwise vorticity in the cross-stream direction but away from the viscous sublayer. We show that there is a constant spatial flux of spanwise vorticity due to vorticity conservation and that this flux is necessary to produce pressure drop and energy dissipation. The vorticity transport is shown to be dominated by viscous diffusion at distances closer to the wall than the peak Reynolds stress, well into the classical log layer. The Perry-Chong model based on "representative" hairpin/horseshoe vortices predicts a single sign of the turbulent vorticity flux over the whole log layer, whereas the actual flux must change sign at the location of the Reynolds-stress maximum. Sign reversal may be achieved by assuming a slow power-law decay of the Townsend "eddy-intensity function" for wall-normal distances greater than the hairpin length scale. The vortex-cascade picture presented here has a close analog in the theory of quantum superfluids and superconductors, the "phase slippage" of quantized vortex lines. Most of our results should therefore apply as well to superfluid turbulence in pipes and channels. We also discuss issues about drag reduction from this perspective.

  1. Process-Based Restoration and the Rise of the Stage Zero Channel As a Stream Restoration Goal

    NASA Astrophysics Data System (ADS)

    Pollock, M. M.

    2015-12-01

    The stage zero channel (sensu Cluer and Thorne 2013) is increasingly recognized as having intrinsic high value because of the multiple and synergistic ecosystem goods and services that such channels provide. Stage zero channels have well connected floodplains with elevated water tables, spatially variable hydrologic regimes and structurally complex aquatic and riparian habitat. As such, they provide incredibly valuable habitat for a suite of terrestrial and aquatic taxa, including several Pacific salmon species that are in decline. In this presentation, we provide an overview of the features and types of stage zero channels, where in the landscape they are likely to be found, how they evolve under natural conditions, and restoration techniques for converting less ecologically valuable channel types into stage zero channels. We compare the structure and function of stage zero channels to more traditional channel restoration targets. We conclude that new approaches to stream restoration are needed that take into account society's economic and ecological imperatives to create resilient, structurally complex and dynamic systems, and that the spatial scale of restorative actions should be expanded where possible to better recognize and integrate the interdependent nature of longitudinal, lateral and vertical linkages in stream systems.

  2. The fan of influence of streams and channel feedbacks to simulated land surface water and carbon dynamics

    NASA Astrophysics Data System (ADS)

    Shen, Chaopeng; Riley, William J.; Smithgall, Kurt R.; Melack, John M.; Fang, Kuai

    2016-02-01

    Large-scale land models assume unidirectional land-to-river hydrological interactions, without considering feedbacks between channels and land. Using a tested, physically based model with explicit multiway interactions between overland, channel, wetland, and groundwater flows, we assessed how the representation and properties of channels influence simulated land surface hydrologic, biogeochemical, and ecosystem dynamics. A zone near the channels where various fluxes and states are significantly influenced by the channels, referred to as the fan of influence (FoI) of channels, has been identified. We elucidated two mechanisms inducing the model-derived FoI: the base flow mechanism, in which incised, gaining streams lower the water table and induce more base flow, and the relatively more efficient conveyance of the channel network compared to overland flow. We systematically varied drainage density and grid resolution to quantify the size of the FoI, which is found to span a large fraction of the watershed (25-50%) for hydrologic variables including depth to water table and recharge, etc. The FoI is more pronounced with low-resolution simulations but remains noticeable in hyperresolution (25 m) subbasin simulations. The FoI and the channel influence on basin-average fluxes are also similar in simulations with alternative parameter sets. We found that high-order, entrenched streams cause larger FoI. In addition, removing the simulated channels has disproportionally large influence on modeled wetland areas and inundation duration, which has implications for coupled biogeochemical or ecological modeling. Our results suggest that explicit channel representation provides important feedbacks to land surface dynamics which should be considered in meso or large-scale simulations. Since grid refinement incurs prohibitive computational cost, subgrid channel parameterization has advantages in efficiency over grid-based representations that do not distinguish between overland

  3. Early break-up of the Norwegian Channel Ice Stream during the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Svendsen, John Inge; Briner, Jason P.; Mangerud, Jan; Young, Nicolás E.

    2015-01-01

    We present 18 new cosmogenic 10Be exposure ages that constrain the breakup time of the Norwegian Channel Ice Stream (NCIS) and the initial retreat of the Scandinavian Ice Sheet from the Southwest coast of Norway following the Last Glacial Maximum (LGM). Seven samples from glacially transported erratics on the island Utsira, located in the path of the NCIS about 400 km up-flow from the LGM ice front position, yielded an average 10Be age of 22.0 ± 2.0 ka. The distribution of the ages is skewed with the 4 youngest all within the range 20.2-20.8 ka. We place most confidence on this cluster of ages to constrain the timing of ice sheet retreat as we suspect the 3 oldest ages have some inheritance from a previous ice free period. Three additional ages from the adjacent island Karmøy provided an average age of 20.9 ± 0.7 ka, further supporting the new timing of retreat for the NCIS. The 10Be ages from Utsira and Karmøy suggest that the ice stream broke up about 2000 years earlier than the age assignment based on 14C ages on foraminifera and molluscs from marine sediment cores. We postulate that the Scandinavian Ice Sheet flowed across the Norwegian Channel to Denmark and onto the North Sea plateau during early phases of the LGM. When the NCIS started to operate this ice supply to the North Sea was cut off and the fast flow of the NCIS also led to a lowering of the ice surface along the Norwegian Channel and thereby drawdown of the entire ice sheet. This facilitated rapid calving of the ice front in the North Sea and we reconstruct a large open bay across the entire northern North Sea by ˜20 ka based on our 10Be ages in the east and radiocarbon ages from marine cores in the west. Additional 10Be ages show that the mainland slightly east of the islands Utsira and Karmøy remained ice covered until about 16 ka, indicating almost no net ice-margin retreat for the 4000 years between 20 and 16 ka. After 16 ka the ice margin retreated quickly up-fjord.

  4. Stream channel surface water - groundwater interactions in a fire impacted watershed

    NASA Astrophysics Data System (ADS)

    Russo, T. A.; Fisher, A. T.

    2010-12-01

    We are conducting a study of surface water - groundwater interactions within the Scott Creek watershed, a 4th order catchment of 76.6 km2 in central coastal California, to assess the impacts of fire on channel and riparian conditions. Scott Creek and its tributaries are valuable spawning habitat for Coho salmon and Steelhead trout. The Scott Creek watershed is located on the western (windward) side of the Santa Cruz Mountains, where the most intense precipitation falls from November to April, and includes a mixture of protected land and areas used for agriculture, grazing, and selective timber harvesting. 37% of the watershed was burned in a fire in August 2009, and we hypothesize that this could result in enhanced delivery of fine grained hill slope sediments to stream channels for several years post fire, reducing the extent of hyporheic exchange downstream of burned areas. This could reduce the survival rates of Coho and Steelhead redds (egg nests), which are dependent on surface water - groundwater exchange for regulation of water nutrient content and temperature. We are monitoring streambed seepage rates and hydraulic conductivity, and performing repeated tracer discharge experiments at three sites on Scott Creek, two within and one upstream of the area burned in the 2009 fire. Streambed seepage rates are calculated using a time series method applied to heat as a tracer, using naturally occurring diurnal changes in stream temperature, and extended to calculations of streambed hydraulic conductivity based on measured head gradients. Hyporheic exchange parameters are assessed using tracer breakthrough data, as fit by an optimized model of one-dimensional advection, dispersion and transient storage. Variations in hydrologic characteristics (e.g., transient storage area, exchange coefficient) over time at each site are being used to assess the magnitude and timing of channel modifications independent to, and associated with, the burning of catchment hill slopes

  5. Mapping spatial patterns of stream power and channel change along a gravel-bed river in northern Yellowstone

    NASA Astrophysics Data System (ADS)

    Lea, Devin M.; Legleiter, Carl J.

    2016-01-01

    Stream power represents the rate of energy expenditure along a river and can be calculated using topographic data acquired via remote sensing or field surveys. This study sought to quantitatively relate temporal changes in the form of Soda Butte Creek, a gravel-bed river in northeastern Yellowstone National Park, to stream power gradients along an 8-km reach. Aerial photographs from 1994 to 2012 and ground-based surveys were used to develop a locational probability map and morphologic sediment budget to assess lateral channel mobility and changes in net sediment flux. A drainage area-to-discharge relationship and DEM developed from LiDAR data were used to obtain the discharge and slope values needed to calculate stream power. Local and lagged relationships between mean stream power gradient at median peak discharge and volumes of erosion, deposition, and net sediment flux were quantified via spatial cross-correlation analyses. Similarly, autocorrelations of locational probabilities and sediment fluxes were used to examine spatial patterns of sediment sources and sinks. Energy expended above critical stream power was calculated for each time period to relate the magnitude and duration of peak flows to the total volumetric change in each time increment. Collectively, we refer to these methods as the stream power gradient (SPG) framework. The results of this study were compromised by methodological limitations of the SPG framework and revealed some complications likely to arise when applying this framework to small, wandering, gravel-bed rivers. Correlations between stream power gradients and sediment flux were generally weak, highlighting the inability of relatively simple statistical approaches to link sub-budget cell-scale sediment dynamics to larger-scale driving forces such as stream power gradients. Improving the moderate spatial resolution techniques used in this study and acquiring very-high resolution data from recently developed methods in fluvial remote

  6. Electrical resistivity mapping of the buried stream channel of the Canopic branch in the western Nile Delta, Egypt

    NASA Astrophysics Data System (ADS)

    El-Gamili, M. M.; Shaaban, F. F.; El-Morsi, O. A.

    1994-08-01

    Buried stream channels, which can often be mapped accurately by resistivity, are favoured targets for exploration. Horizontal profiling, electrical soundings, or both, are generally used. In the western Nile Delta, the electrical sounding method was applied using a Schlumberger electrode array with the maximum AB distance being 200 m. The field survey was conducted along profiles extending NE-SW, perpendicular to the expected historical Canopic buried stream channel. About 107 vertical electrical soundings (VES) were measured along eleven profiles. The (VES) field curves were interpreted using the automatic interpretation method of Zohdy and Bisdorf (1989) in which a layered model is obtained directly from a digitized sounding curve. The interpreted results were correlated with borehole data to delineate the main lithological units and to help construct geoelectrical cross-sections based on layer thicknesses and their corresponding ranges in litho-resistivity. The lithological information from borehole data, surface geology and the present layer resistivities indicate three major lithofacies: Holocene clay and silt at the top, Pleistocene sands, and then gravelly sands and gravels (El-Tahrir gravels) at the bottom. From the thickness of the riverine topmost clay-silt facies and the paleotopograph of the Pleistocene sands, the buried stream channels can be delineated. It is evident that two streams existed for the defunct Canopic branch. These defunct streams are discussed and correlated with the historical records.

  7. Streambed and water profile response to in-channel restoration structures in a laboratory meandering stream

    NASA Astrophysics Data System (ADS)

    Han, Bangshuai; Chu, Hong-Hanh; Endreny, Theodore A.

    2015-11-01

    In-channel structures are often installed in alluvial rivers during restoration to steer currents, but they also modify the streambed morphology and water surface profile, and alter hydraulic gradients driving ecologically important hyporheic exchange. Although river features before and after restoration need to be compared, few studies have collected detailed observations to facilitate this comparison. We created a laboratory mobile-bed alluvial meandering river and collected detailed measurements in the highly sinuous meander before and after installation of in-channel structures, which included one cross vane and six J-hooks situated along 1 bar unit. Measurements of streambed and water surface elevation with submillimeter vertical accuracy and horizontal resolution were obtained using close-range photogrammetry. Compared to the smooth gradually varied water surface profile for control runs without structures, the structures created rapidly varied flow with subcritical to supercritical flow transitions, as well as backwater and forced-morphology pools, which increased volumetric storage by 74% in the entire stream reach. The J-hooks, located along the outer bank of the meander bend and downstream of the cross vane, created stepwise patterns in the streambed and water surface longitudinal profiles. The pooling of water behind the cross vane increased the hydraulic gradient across the meander neck by 1% and increased local groundwater gradients by 4%, with smaller increases across other transects through the intrameander zone. Scour pools developed downstream of the cross vane and around the J-hooks situated near the meander apex. In-channel structures significantly changed meander bend hydraulic gradients, and the detailed streambed and water surface 3-D maps provide valuable data for computational modeling of changes to hyporheic exchange.

  8. AN INTERREGIONAL COMPARISON OF CHANNEL STRUCTURE WITH TRANSIENT STORAGE IN STREAMS DRAINING HARVESTED AND OLD-GROWTH WATERSHEDS

    EPA Science Inventory

    We compared measures of channel structure and riparian canopy with estimates of transient storage in 32 streams draining old-growth and harvested watersheds in the Southern Appalachian Mountains of North Carolina (n=4), the Ouachita Mountains of Arkansas (n=5), the Cascade Mounta...

  9. Detecting the impact of bank and channel modification on invertebrate communities in Mediterranean temporary streams (Sardinia, SW Italy).

    PubMed

    Buffagni, Andrea; Tenchini, Roberta; Cazzola, Marcello; Erba, Stefania; Balestrini, Raffaella; Belfiore, Carlo; Pagnotta, Romano

    2016-09-15

    We hypothesized that reach-scale, bank and channel modification would impact benthic communities in temporary rivers of Sardinia, when pollution and water abstraction are not relevant. A range of variables were considered, which include both artificial structures/alterations and natural features observed in a stream reach. Multivariate regression trees (MRT) were used to assess the effects of the explanatory variables on invertebrate assemblages and five groups, characterized by different habitat modification and/or features, were recognized. Four node variables determined the splits in the MRT analysis: channel reinforcement, tree-related bank and channel habitats, channel modification and bank modification. Continuity of trees in the river corridor diverged among MRT groups and significant differences among groups include presence of alders, extent of channel shading and substrate diversity. Also, the percentage of in-stream organic substrates, in particular CPOM/Xylal, showed highly significant differences among groups. For practical applications, thresholds for the extent of channel reinforcement (40%) and modification (10%) and for bank alteration (≈30%) were provided, that can be used to guide the implementation of restoration measures. In moderately altered river reaches, a significant extent of tree-related habitats (≈5%) can noticeably mitigate the effects of morphological alteration on aquatic invertebrates. The outcomes highlight the importance of riparian zone management as an opportune, achievable prospect in the restoration of Mediterranean temporary streams. The impact of bank and channel modification on ecological status (sensu WFD) was investigated and the tested benthic metrics, especially those based on abundance data, showed legible differences among MRT groups. Finally, bank and channel modification appears to be a potential threat for the conservation of a few Sardo-Corsican endemic species. The introduction of management criteria that

  10. Mapping spatial patterns of stream power and channel change along a gravel-bed river in northern Yellowstone

    NASA Astrophysics Data System (ADS)

    Lea, Devin M.

    Stream power represents the rate of energy expenditure along a river and can be calculated using topographic data acquired via remote sensing or field surveys. This study used remote sensing and GIS tools along with field data to quantitatively relate temporal changes in the form of Soda Butte Creek, a gravel-bed river in northeastern Yellowstone National Park, to stream power gradients along an 8 km reach. Aerial photographs from 1994-2012 and cross-section surveys were used to develop a locational probability map and morphologic sediment budget to assess lateral channel mobility and changes in net sediment flux. A drainage area-to-discharge relationship and digital elevation model (DEM) developed from light detection and ranging (LiDAR) data were used to obtain the discharge and slope values needed to calculate stream power. Local and lagged relationships between mean stream power gradient at median peak discharge and volumes of erosion, deposition, and net sediment flux were quantified via spatial cross-correlation analyses. Similarly, autocorrelations of locational probabilities and sediment fluxes were used to examine spatial patterns of sediment sources and sinks. Energy expended above critical stream power was calculated for each time period to relate the magnitude and duration of peak flows to the total volumetric change in each time increment. Results indicated a lack of strong correlation between stream power gradients and sediment response, highlighting the geomorphic complexity of Soda Butte Creek and the inability of relatively simple statistical approaches to link sub-budget cell-scale sediment dynamics to larger-scale driving forces such as stream power gradients. Improving the moderate spatial resolution techniques used in this study and acquiring very-high resolution data from recently developed methods in fluvial remote sensing could help improve understanding of the spatial organization of stream power, sediment transport, and channel change in

  11. Water quality of streams draining abandoned and reclaimed mined lands in the Kantishna Hills area, Denali National Park and Preserve, Alaska, 2008–11

    USGS Publications Warehouse

    Brabets, Timothy P.; Ourso, Robert T.

    2013-01-01

    The Kantishna Hills are an area of low elevation mountains in the northwest part of Denali National Park and Preserve, Alaska. Streams draining the Kantishna Hills are clearwater streams that support several species of fish and are derived from rain, snowmelt, and subsurface aquifers. However, the water quality of many of these streams has been degraded by mining. Past mining practices generated acid mine drainage and excessive sediment loads that affected water quality and aquatic habitat. Because recovery through natural processes is limited owing to a short growing season, several reclamation projects have been implemented on several streams in the Kantishna Hills region. To assess the current water quality of streams in the Kantishna Hills area and to determine if reclamation efforts have improved water quality, a cooperative study between the U.S. Geological Survey and the National Park Service was undertaken during 2008-11. High levels of turbidity, an indicator of high concentrations of suspended sediment, were documented in water-quality data collected in the mid-1980s when mining was active. Mining ceased in 1985 and water-quality data collected during this study indicate that levels of turbidity have declined significantly. Turbidity levels generally were less than 2 Formazin Nephelometric Units and suspended sediment concentrations generally were less than 1 milligram per liter during the current study. Daily turbidity data at Rock Creek, an unmined stream, and at Caribou Creek, a mined stream, documented nearly identical patterns of turbidity in 2009, indicating that reclamation as well as natural revegetation in mined streams has improved water quality. Specific conductance and concentrations of dissolved solids and major ions were highest from streams that had been mined. Most of these streams flow into Moose Creek, which functions as an integrator stream, and dilutes the specific conductance and ion concentrations. Calcium and magnesium are the

  12. Analysis of Stream Channel Geometry Temporal and Spatial Evolution after Historic Dam Removal - two French case studies

    NASA Astrophysics Data System (ADS)

    Slawson, Deborah; Manière, Louis; Marchandeau, Florent

    2014-05-01

    IRSTEA, in partnership with the French Office national de l'eau et des milieux aquatiques (ONEMA), has begun a study of channel geomorphology in small streams where dams have been removed or breached between two and 200 years ago, without any subsequent restoration of the channel in the legacy sediments. A preliminary analysis of two sites in the Morvan, Burgundy, will be presented; a dam breached at the beginning of the 20th century and another in the last decade. Using ergodic reasoning, historical and recent upstream and downstream channel geometry is being used to predict the future temporal and spatial scales of channel physical habitat restoration. With the implementation of the European Water Framework Directive (WFD), dam removal has become a more frequently used method for restoring stream ecological continuity. In France, these obstacles are ubiquitous in medium and small streams and considerably reduce lateral and longitudinal connectivity. Improvement in the hydromorphologically controlled, physical habitat, particularly flow and sediment transport regimes, is often essential to improvement in stream biology. However, dam removal may cause long-term disturbances in flow and sediment transport regimes. In the absence of channel restoration measures in addition to dam removal, these disturbances may result in long-term negative impacts on fish, macroinvertebrate, and riparian plant physical habitat. These negative impacts may include channel incision and lowering of the water table, disconnection from floodplains, increased stream power and bed scouring, and increased sediment load from headcutting and bank erosion. Over time, these negative impacts may resolve themselves. However, the time frame necessary for reestablishing adequate physical habitat is not well-known. Some studies have indicated that many decades or longer may be required, depending on a variety of factors. Under the WFD, the REstoring rivers FOR effective catchment Management (REFORM

  13. Imaging and spectroscopic observations of a filament channel and the implications for the nature of counter-streamings

    SciTech Connect

    Chen, P. F.; Fang, C.; Harra, L. K.

    2014-03-20

    The dynamics of a filament channel are observed with imaging and spectroscopic telescopes before and during the filament eruption on 2011 January 29. The extreme ultraviolet (EUV) spectral observations reveal that there are no EUV counterparts of the Hα counter-streamings in the filament channel, implying that the ubiquitous Hα counter-streamings found by previous research are mainly due to longitudinal oscillations of filament threads, which are not in phase between each other. However, there exist larger-scale patchy counter-streamings in EUV along the filament channel from one polarity to the other, implying that there is another component of unidirectional flow (in the range of ±10 km s{sup –1}) inside each filament thread in addition to the implied longitudinal oscillation. Our results suggest that the flow direction of the larger-scale patchy counter-streaming plasma in the EUV is related to the intensity of the plage or active network, with the upflows being located at brighter areas of the plage and downflows at the weaker areas. We propose a new method to determine the chirality of an erupting filament on the basis of the skewness of the conjugate filament drainage sites. This method suggests that the right-skewed drainage corresponds to sinistral chirality, whereas the left-skewed drainage corresponds to dextral chirality.

  14. Channel Incision and Water-Table Decline Along a Recently Formed Proglacial Stream, Mendenhall Valley, Southeastern Alaska

    USGS Publications Warehouse

    Neal, Edward G.

    2009-01-01

    Retreat of the Mendenhall Glacier, in southeastern Alaska, resulted in the formation of Mendenhall Lake, which has reduced the supply of coarse sediment to the proglacial Mendenhall River. Channel geometry surveys conducted in 1969 and 1998 over a 5.3 km reach of the Mendenhall River revealed reductions in mean bed elevations ranging from 0.4 to 1.5 meters based on cross sections replicated at 7 locations. Channel incision in the Mendenhall River is believed to be the result of a combination of factors resulting from localized and region-wide glacial retreat. In addition to a reduction of river stage due to channel incision, a decline in water-table elevations of about 0.6 m during a 17-year period from 1984 to 2001 was identified in an observation well located 250 m from the incising stream channel. Water-table elevations 600 m from the incising channel in the adjacent alluvial outwash aquifer respond in phase to changes in river stage, indicating water-levels in the adjacent aquifer are declining in response to river-channel incision. This study suggests channel incision can rapidly lower water-table elevations for large distances in the adjacent aquifer, potentially modifying the hydrology to a degree capable of influencing adjacent surface-water features, such as off-channel wetlands and flood-plain side channels.

  15. Larval salamanders and channel geomorphology are indicators of hydrologic permanence in forested headwater streams

    EPA Science Inventory

    Regulatory agencies need rapid indicators of hydrologic permanence for jurisdictional determinations of headwater streams. Our study objective was to assess the utility of larval salamander presence and assemblage structure and habitat variables for determining stream permanence ...

  16. The effect of macropores on bi-directional hydrologic exchange between a stream channel and riparian groundwater

    NASA Astrophysics Data System (ADS)

    Menichino, Garrett T.; Hester, Erich T.

    2015-10-01

    Macropores and soil pipes in stream banks are common geomorphic features. Macropores and soil pipes that are open to the channel (i.e. "bank face-connected" macropores) are inundated when channel stage is elevated (e.g., from precipitation, snowmelt, dam release). However, previous studies have not investigated macropore impact on bi-directional water exchange between the channel and bank/riparian groundwater under variable hydrologic conditions. We monitored two transects of riparian groundwater wells perpendicular to the bank of a 2nd order stream for a year: one with bank face-connected macropores (M transect) and one without bank face-connected macropores (NM transect). Fluctuations in water level and temperature during storms in those wells closest to the channel were on average 139% and 29% higher, respectively, in the presence of macropores. Rising head tests in the same wells indicated that hydraulic conductivity was 61-140 times higher in the presence of macropores. Bank storage, indicated by gradient reversals between channel and riparian zone, occurred on two temporal scales. Bank storage during storms was more frequent in the M transect (occurred all year) than in the NM transect (occurred just in winter and spring). Smaller magnitude gradient reversals at the M transect are consistent with faster head equilibration and greater exchange volume. Bank storage also occurred on an annual basis, with channel water entering storage during summer and fall and returning to the channel during winter and spring. Taken together, these results suggest that macropores act as preferential flow paths that enhance the connectivity between channels and riparian groundwater that influences bank storage. Where bank macropores are present, conceptual models of hyporheic and groundwater flow should account for their effects.

  17. Influences of high-flow events on a stream channel altered by construction of a highway bridge: a case study

    USGS Publications Warehouse

    Hedrick, Lara B.; Welsh, Stuart A.; Anderson, James T.

    2009-01-01

    Impacts of highway construction on streams in the central Appalachians are a growing concern as new roads are created to promote tourism and economic development in the area. Alterations to the streambed of a first-order stream, Sauerkraut Run, Hardy County, WV, during construction of a highway overpass included placement and removal of a temporary culvert, straightening and regrading of a section of stream channel, and armourment of a bank with a reinforced gravel berm. We surveyed longitudinal profiles and cross sections in a reference reach and the altered reach of Sauerkraut Run from 2003 through 2007 to measure physical changes in the streambed. During the four-year period, three high-flow events changed the streambed downstream of construction including channel widening and aggradation and then degradation of the streambed. Upstream of construction, at a reinforced gravel berm, bank erosion was documented. The reference section remained relatively unchanged. Knowledge gained by documenting channel changes in response to natural and anthropogenic variables can be useful for managers and engineers involved in highway construction projects.

  18. Distribution of chemical elements in soils and stream sediments in the area of abandoned Sb-As-Tl Allchar mine, Republic of Macedonia.

    PubMed

    Bačeva, Katerina; Stafilov, Trajče; Šajn, Robert; Tănăselia, Claudiu; Makreski, Petre

    2014-08-01

    The aim of this study was to investigate the distribution of some toxic elements in topsoil and subsoil, focusing on the identification of natural and anthropogenic element sources in the small region of rare As-Sb-Tl mineralization outcrop and abandoned mine Allchar known for the highest natural concentration of Tl in soil worldwide. The samples of soil and sediments after total digestion were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Factor analysis (FA) was used to identify and characterize element associations. Six associations of elements were determined by the method of multivariate statistics: Rb-Ta-K-Nb-Ga-Sn-Ba-Bi-Li-Be-(La-Eu)-Hf-Zr-Zn-In-Pd-Ag-Pt-Mg; Tl-As-Sb-Hg; Te-S-Ag-Pt-Al-Sc-(Gd-Lu)-Y; Fe-Cu-V-Ge-Co-In; Pd-Zr-Hf-W-Be and Ni-Mn-Co-Cr-Mg. The purpose of the assessment was to determine the nature and extent of potential contamination as well as to broadly assess possible impacts to human health and the environment. The results from the analysis of the collected samples in the vicinity of the mine revealed that As and Tl elements have the highest median values. Higher median values for Sb are obviously as a result of the past mining activities and as a result of area surface phenomena in the past. PMID:24906071

  19. Assessing element distribution and speciation in a stream at abandoned Pb-Zn mining site by combining classical, in-situ DGT and modelling approaches.

    PubMed

    Omanović, Dario; Pižeta, Ivanka; Vukosav, Petra; Kovács, Elza; Frančišković-Bilinski, Stanislav; Tamás, János

    2015-04-01

    The distribution and speciation of elements along a stream subjected to neutralised acid mine drainage (NAMD) effluent waters (Mátra Mountain, Hungary; Toka stream) were studied by a multi-methodological approach: dissolved and particulate fractions of elements were determined by HR-ICPMS, whereas speciation was carried out by DGT, supported by speciation modelling performed by Visual MINTEQ. Before the NAMD discharge, the Toka is considered as a pristine stream, with averages of dissolved concentrations of elements lower than world averages. A considerable increase of element concentrations caused by effluent water inflow is followed by a sharp or gradual concentration decrease. A large difference between total and dissolved concentrations was found for Fe, Al, Pb, Cu, Zn and As in effluent water and at the first downstream site, with high correlation factors between elements in particulate fraction, indicating their common behaviour, governed by the formation of ferri(hydr)oxides (co)precipitates. In-situ speciation by the DGT technique revealed that Zn, Cd, Ni, Co, Mn and U were predominantly present as a labile, potentially bioavailable fraction (>90%). The formation of strong complexes with dissolved organic matter (DOM) resulted in a relatively low DGT-labile concentration of Cu (42%), while low DGT-labile concentrations of Fe (5%) and Pb (12%) were presumably caused by their existence in colloidal (particulate) fraction which is not accessible to DGT. Except for Fe and Pb, a very good agreement between DGT-labile concentrations and those predicted by the applied speciation model was obtained, with an average correlation factor of 0.96. This study showed that the in-situ DGT technique in combination with model-predicted speciation and classical analysis of samples could provide a reasonable set of data for the assessment of the water quality status (WQS), as well as for the more general study of overall behaviour of the elements in natural waters subjected

  20. Abandoned mine drainage in the Swatara Creek Basin, southern anthracite coalfield, Pennsylvania, USA: 1. stream quality trends coinciding with the return of fish

    USGS Publications Warehouse

    Cravotta, Charles A., III; Brightbill, Robin A.; Langland, Michael J.

    2010-01-01

    Acidic mine drainage (AMD) from legacy anthracite mines has contaminated Swatara Creek in eastern Pennsylvania. Intermittently collected base-flow data for 1959–1986 indicate that fish were absent immediately downstream from the mined area where pH ranged from 3.5 to 7.2 and concentrations of sulfate, dissolved iron, and dissolved aluminum were as high as 250, 2.0, and 4.7 mg/L, respectively. However, in the 1990s, fish returned to upper Swatara Creek, coinciding with the implementation of AMD treatment (limestone drains, limestone diversion wells, limestone sand, constructed wetlands) in the watershed. During 1996–2006, as many as 25 species of fish were identified in the reach downstream from the mined area, with base-flow pH from 5.8 to 7.6 and concentrations of sulfate, dissolved iron, and dissolved aluminum as high as 120, 1.2, and 0.43 mg/L, respectively. Several of the fish taxa are intolerant of pollution and low pH, such as river chub (Nocomis icropogon) and longnose dace (Rhinichthys cataractae). Cold-water species such as brook trout (Salvelinus fontinalis) and warm-water species such as rock bass (Ambloplites rupestris) varied in predominance depending on stream flow and stream temperature. Storm flow data for 1996–2007 indicated pH, alkalinity, and sulfate concentrations decreased as the stream flow and associated storm-runoff component increased, whereas iron and other metal concentrations were poorly correlated with stream flow because of hysteresis effects (greater metal concentrations during rising stage than falling stage). Prior to 1999, pH\\5.0 was recorded during several storm events; however, since the implementation of AMD treatments, pH has been maintained near neutral. Flow-adjusted trends for1997–2006 indicated significant increases in calcium; decreases in hydrogen ion, dissolved aluminum, dissolved and total manganese, and total iron; and no change in sulfate or dissolved iron in Swatara Creek immediately downstream from the

  1. Distribution of chemical elements in soils and stream sediments in the area of abandoned Sb–As–Tl Allchar mine, Republic of Macedonia

    SciTech Connect

    Bačeva, Katerina; Stafilov, Trajče; Šajn, Robert; Tănăselia, Claudiu; Makreski, Petre

    2014-08-15

    The aim of this study was to investigate the distribution of some toxic elements in topsoil and subsoil, focusing on the identification of natural and anthropogenic element sources in the small region of rare As–Sb–Tl mineralization outcrop and abandoned mine Allchar known for the highest natural concentration of Tl in soil worldwide. The samples of soil and sediments after total digestion were analyzed by inductively coupled plasma–mass spectrometry (ICP–MS) and inductively coupled plasma–atomic emission spectrometry (ICP–AES). Factor analysis (FA) was used to identify and characterize element associations. Six associations of elements were determined by the method of multivariate statistics: Rb–Ta–K–Nb–Ga–Sn–Ba–Bi–Li–Be–(La–Eu)–Hf–Zr–Zn–In–Pd–Ag–Pt–Mg; Tl–As–Sb–Hg; Te–S–Ag–Pt–Al–Sc–(Gd–Lu)–Y; Fe–Cu–V–Ge–Co–In; Pd–Zr–Hf–W–Be and Ni–Mn–Co–Cr–Mg. The purpose of the assessment was to determine the nature and extent of potential contamination as well as to broadly assess possible impacts to human health and the environment. The results from the analysis of the collected samples in the vicinity of the mine revealed that As and Tl elements have the highest median values. Higher median values for Sb are obviously as a result of the past mining activities and as a result of area surface phenomena in the past. - Highlights: • Soil and river sediments were analyzed from Sb–As–Tl Allchar locality. • An increased content of certain toxic elements for environment was determined. • Highest As and Tl contents are obtained in the close vicinity of Allchar mine. • River sediments portray 160 times higher content of Sb than EU values. • The results classify Allchar as probably the highest natural Tl-deposit worldwide.

  2. Influence of Herbaceous Riparian Buffers on Channelized Headwater Streams in Central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbaceous riparian buffers are a widely used conservation practice in the United States for reducing nutrient, pesticide, and sediment loadings in agricultural streams. The importance of forested riparian buffers for headwater streams has been documented, but the ecological impacts of herbaceous ri...

  3. Annual and seasonal differences in pesticide mixtures within channelized agricultural headwater streams in central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Only a limited amount of information on pesticide mixtures within agricultural headwater streams is available. A greater understanding of the characteristics of pesticide mixtures and their spatial and temporal trends within agricultural headwater streams is needed to evaluate the risks of pesticid...

  4. Using stream sediment lithology to explore the roles of abrasion and channel network structure in shaping downstream sediment yields

    NASA Astrophysics Data System (ADS)

    Mueller, E. R.; Smith, M. E.; Pitlick, J.

    2012-12-01

    Both the flux and characteristics of stream sediment evolve downstream in response to variations in sediment supply, abrasion rate, and channel network structure. We use a simple erosion-abrasion mass balance to model the downstream evolution of sediment flux in two adjacent watersheds draining differing mixtures of soft and resistant rock types in the northern Rocky Mountains. Measurements of bed sediment grain size and lithology are used in conjunction with measured bed load and suspended load sediment fluxes to constrain the model. The results show that the downstream evolution in bed load flux and composition can be strongly influenced by subtle differences in underlying geology, which shapes both the abrasion characteristics and travel path lengths of individual rock types. In the Big Wood basin, abrasion rapidly reduces the size of soft sedimentary and volcanic rocks exposed in headwater areas, concentrating resistant granitic rocks in the stream bed and depressing bed load in favor of suspended load. Alternatively, in the North Fork Big Lost basin, volcanic and sedimentary lithologies are exposed throughout the catchment, and the bed material becomes dominated by erodible but resistant quartzitic sandstones. The result is a much higher bed load flux best modeled with modest abrasion rates. In both cases, the best-fit model can reproduce within 5% the composition of the stream bed substrate using realistic erosion and abrasion parameters. The results also demonstrate a strong linkage between modern hillslopes and channel systems even in these formerly glaciated landscapes, as the sediment signature of the primary streams reflects the systematic tapping of distinct source areas. While this work shows promise, measurement of the spatial patterns in the size and composition of bed and suspended load fluxes at locations throughout a channel network would better elucidate that relative importance of supply, sorting, and abrasion processes.

  5. Complex channel responses to changes in stream flow and sediment supply on the lower Duchesne River, Utah

    USGS Publications Warehouse

    Gaeuman, D.; Schmidt, J.C.; Wilcock, P.R.

    2005-01-01

    Channel responses to flow depletions in the lower Duchesne River over the past 100 years have been highly complex and variable in space and time. In general, sand-bed reaches adjusted to all perturbations with bed-level changes, whereas the gravel-bed reaches adjusted primarily through width changes. Gravel-bed reaches aggraded only when gravel was supplied to the channel through local bank erosion and degraded only during extreme flood events. A 50% reduction in stream flow and an increase in fine sediment supply to the study area occurred in the first third of the 20th century. The gravel-bed reach responded primarily with channel narrowing, whereas bed aggradation and four large-scale avulsions occurred in the sand-bed reaches. These avulsions almost completely replaced a section of sinuous channel about 14 km long with a straighter section about 7 km long. The most upstream avulsion, located near a break in valley slope and the transition from a gravel bed upstream and a sand bed downstream, transformed a sinuous sand-bed reach into a braided gravel-bed reach and eventually into a meandering gravel-bed reach over a 30-year period. Later, an increase in flood magnitudes and durations caused widening and secondary bed aggradation in the gravel-bed reaches, whereas the sand-bed reaches incised and narrowed. Water diversions since the 1950s have progressively eliminated moderate flood events, whereas larger floods have been less affected. The loss of frequent flooding has increased the duration and severity of drought periods during which riparian vegetation can establish along the channel margins. As a result, the channel has gradually narrowed throughout the study area since the late 1960s, despite the occasional occurrence of large floods. No tributaries enter the Duchesne River within the study area, so all reaches have experienced identical changes in stream flow and upstream sediment supply. ?? 2004 Elsevier B.V. All rights reserved.

  6. General view of north portals showing three abandoned roadbeds. View ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of north portals showing three abandoned roadbeds. View south - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  7. Groundwater-derived contaminant fluxes along a channelized Coastal Plain stream

    SciTech Connect

    LaSage, Danita m; Fryar, Alan E; Mukherjee, Abhijit; Sturchio, Neil C; Heraty, Linnea J

    2008-10-01

    Recent studies in various settings across eastern North America have examined the movement of volatile organic compound (VOC) plumes from groundwater to streams, but few studies have addressed focused discharge of such plumes in unlithified sediments. From 1999 through 2002, we monitored concentrations of trichloroethene (TCE) and the non-volatile co-contaminant technetium-99 along Little Bayou Creek, a first -order perennial stream in the Coastal Plain of western Kentucky. Spring flow contributed TCE and technetium-99 to the creek, and TCE concentrations tended to vary with technetium-99 in springs. Contaminant concentrations in stream water fluctuated seasonally, but not always synchronously with stream flow. However, contaminant influxes varied seasonally with stream flow and were dominated by a few springs. Concentrations of O2, NO3⁻, and SO2-4, values of δ37CL in groundwater, and the lack of less-chlorinated ethenes in groundwater and stream water indicated that aerobic biodegradation of TCE was unlikely. Losses of TCE along Little Bayou Creek resulted mainly from volatilization, in contrast to streams receiving diffuse contaminated discharge, where intrinsic bioremediation of VOCs appears to be prevalent.

  8. Groundwater-derived contaminant fluxes along a channelized Coastal Plain stream

    NASA Astrophysics Data System (ADS)

    LaSage, Danita M.; Fryar, Alan E.; Mukherjee, Abhijit; Sturchio, Neil C.; Heraty, Linnea J.

    2008-10-01

    SummaryRecent studies in various settings across eastern North America have examined the movement of volatile organic compound (VOC) plumes from groundwater to streams, but few studies have addressed focused discharge of such plumes in unlithified sediments. From 1999 through 2002, we monitored concentrations of trichloroethene (TCE) and the non-volatile co-contaminant technetium-99 ( 99Tc) along Little Bayou Creek, a first-order perennial stream in the Coastal Plain of western Kentucky. Spring flow contributed TCE and 99Tc to the creek, and TCE concentrations tended to vary with 99Tc in springs. Contaminant concentrations in stream water fluctuated seasonally, but not always synchronously with stream flow. However, contaminant influxes varied seasonally with stream flow and were dominated by a few springs. Concentrations of O 2, NO3-, and SO42-, values of δ 37Cl DOCl in groundwater, and the lack of less-chlorinated ethenes in groundwater and stream water indicated that anaerobic biodegradation of TCE was unlikely. Losses of TCE along Little Bayou Creek resulted mainly from volatilization, in contrast to streams receiving diffuse contaminated discharge, where intrinsic bioremediation of VOCs appears to be prevalent.

  9. Development of Relations of Stream Stage to Channel Geometry and Discharge for Stream Segments Simulated with Hydrologic Simulation Program-Fortran (HSPF), Chesapeake Bay Watershed and Adjacent Parts of Virginia, Maryland, and Delaware

    USGS Publications Warehouse

    Moyer, Douglas; Bennett, Mark

    2007-01-01

    The U.S. Geological Survey (USGS), U.S. Environmental Protection Agency (USEPA), Chesapeake Bay Program (CBP), Interstate Commission for the Potomac River Basin (ICPRB), Maryland Department of the Environment (MDE), Virginia Department of Conservation and Recreation (VADCR), and University of Maryland (UMD) are collaborating to improve the resolution of the Chesapeake Bay Regional Watershed Model (CBRWM). This watershed model uses the Hydrologic Simulation Program-Fortran (HSPF) to simulate the fate and transport of nutrients and sediment throughout the Chesapeake Bay watershed and extended areas of Virginia, Maryland, and Delaware. Information from the CBRWM is used by the CBP and other watershed managers to assess the effectiveness of water-quality improvement efforts as well as guide future management activities. A critical step in the improvement of the CBRWM framework was the development of an HSPF function table (FTABLE) for each represented stream channel. The FTABLE is used to relate stage (water depth) in a particular stream channel to associated channel surface area, channel volume, and discharge (streamflow). The primary tool used to generate an FTABLE for each stream channel is the XSECT program, a computer program that requires nine input variables used to represent channel morphology. These input variables are reach length, upstream and downstream elevation, channel bottom width, channel bankfull width, channel bankfull stage, slope of the floodplain, and Manning's roughness coefficient for the channel and floodplain. For the purpose of this study, the nine input variables were grouped into three categories: channel geometry, Manning's roughness coefficient, and channel and floodplain slope. Values of channel geometry for every stream segment represented in CBRWM were obtained by first developing regional regression models that relate basin drainage area to observed values of bankfull width, bankfull depth, and bottom width at each of the 290 USGS

  10. Watershed scale influence of pesticide reduction practices on pesticides and fishes within channelized agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Implementation of pesticide reduction practices to reduce pesticide usage within agricultural watersheds has the potential to reduce pesticide concentrations within agricultural streams. The watershed scale influence of pesticide reduction practices on pesticides and the biota within agricultural he...

  11. DISTURBANCE, STREAM INCISION, AND CHANNEL EVOLUTION: THE ROLES OF EXCESS TRANSPORT CAPACITY AND BOUNDARY MATERIALS IN CONTROLLING CHANNEL RESPONSE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel incision is part of denudation, drainage-network development, and landscape evolution. Large, anthropogenic disturbances, similar to large or catastrophic “natural” events, greatly compress time scales for incision and related processes by creating enormous imbalances between upstream sedime...

  12. Investigation of Biogeochemical Functional Proxies in Headwater Streams Across a Range of Channel and Catchment Alterations

    NASA Astrophysics Data System (ADS)

    Berkowitz, Jacob F.; Summers, Elizabeth A.; Noble, Chris V.; White, John R.; DeLaune, Ronald D.

    2014-03-01

    Historically, headwater streams received limited protection and were subjected to extensive alteration from logging, farming, mining, and development activities. Despite these alterations, headwater streams provide essential ecological functions. This study examines proxy measures of biogeochemical function across a range of catchment alterations by tracking nutrient cycling (i.e., inputs, processing, and stream loading) with leaf litter fall, leaf litter decomposition, and water quality parameters. Nutrient input and processing remained highest in second growth forests (the least altered areas within the region), while recently altered locations transported higher loads of nutrients, sediments, and conductivity. Biogeochemical functional proxies of C and N input and processing significantly, positively correlated with rapid assessment results (Pearson coefficient = 0.67-0.81; P = 0.002-0.016). Additionally, stream loading equations demonstrate that N and P transport, sediment, and specific conductivity negatively correlated with rapid assessment scores (Pearson coefficient = 0.56-0.81; P = 0.002-0.048). The observed increase in stream loading with lower rapid assessment scores indicates that catchment alterations impact stream chemistry and that rapid assessments provide useful proxy measures of function in headwater ecosystems. Significant differences in nutrient processing, stream loading, water quality, and rapid assessment results were also observed between recently altered (e.g., mined) headwater streams and older forested catchments (Mann-Whitney U = 24; P = 0.01-0.024). Findings demonstrate that biogeochemical function is reduced in altered catchments, and rapid assessment scores respond to a combination of alteration type and recovery time. An analysis examining time and economic requirements of proxy measurements highlights the benefits of rapid assessment methods in evaluating biogeochemical functions.

  13. Measurement of Channel Morphology in a Headwater Stream using Low-Altitude Photography and a 3D Model Software

    NASA Astrophysics Data System (ADS)

    Nidaira, K.; Hiraoka, M.; Gomi, T.; Uchiyama, Y.

    2015-12-01

    We developed a method for measuring detail channel morphology using a low elevation photographic scanning. This study was conducted in a 36-m step-pool channel segment in a headwater stream of Ooborazawa watershed located in 20 km south of Tokyo. The channels were covered by Boenninghausenia japonica and Oplismenus undulatifolius var. undulatifolius. Therefore, topographic measurement in high altitude (up to 5 m) using a drone is not applicable. D50 and D90 of channel substrates were 4 cm and 21 cm, respectively. A plastic case that equipped with two digital cameras (RICOH CX5) is mounted at the top of 2.2 m of a glass fiber pole. Photos were taken every 5 seconds from 1.8 m above ground surface. Eleven ground control points (GCP) were installed and measured coordinates. We developed digital 3D topographic model using PhotoScan Pro edition version 1.0.0 and the developed 1 cm contour map using ArcGIS version 10.2. Furthermore, we measured the number, height, and length of steps for examining the accuracy of data. Resolution of obtained topographic model was from 9 to 11 mm per pixel. 1 cm of particle was identified using photo was 1 cm. Estimated step height was agreed to the measured step height in the field. We detected maximum channel scour from October to December, 2014 with (146.5 mm/day for maximum daily rain) occurred at pools with 13cm changes , while 5 to 10 cm of changes in sediment deposition occurred from Mya to June, 2015 with 78.5 mm/day of maximum daily rain. Disposition of sediment was concentration within the sequences of step structures. Our method allows us for understanding detail sediment movement and resultant localized channel changes in steep channels.

  14. Reactivation of a cryptobiotic stream ecosystem in the McMurdo Dry Valleys, Antarctica: A long-term geomorphological experiment

    NASA Astrophysics Data System (ADS)

    McKnight, D. M.; Tate, C. M.; Andrews, E. D.; Niyogi, D. K.; Cozzetto, K.; Welch, K.; Lyons, W. B.; Capone, D. G.

    2007-09-01

    The McMurdo Dry Valleys of Antarctica contain many glacial meltwater streams that flow for 6 to 12 weeks during the austral summer and link the glaciers to the lakes on the valley floors. Dry valley streams gain solutes longitudinally through weathering reactions and microbial processes occurring in the hyporheic zone. Some streams have thriving cyanobacterial mats. In streams with regular summer flow, the mats are freeze-dried through the winter and begin photosynthesizing with the onset of flow. To evaluate the longer term persistence of cyanobacterial mats, we diverted flow to an abandoned channel, which had not received substantial flow for approximately two decades. Monitoring of specific conductance showed that for the first 3 years after the diversion, the solute concentrations were greater in the reactivated channel than in most other dry valley streams. We observed that cyanobacterial mats became abundant in the reactivated channel within a week, indicating that the mats had been preserved in a cryptobiotic state in the channel. Over the next several years, these mats had high rates of productivity and nitrogen fixation compared to mats from other streams. Experiments in which mats from the reactivated channel and another stream were incubated in water from both of the streams indicated that the greater solute concentrations in the reactivated channel stimulated net primary productivity of mats from both streams. These stream-scale experimental results indicate that the cryptobiotic preservation of cyanobacterial mats in abandoned channels in the dry valleys allows for rapid response of these stream ecosystems to climatic and geomorphological change, similar to other arid zone stream ecosystems.

  15. Using Multiple Watershed-scale Dye Tracing Tests to Study Water and Solute Transport in Naturally Obstructed Stream Channels

    NASA Astrophysics Data System (ADS)

    Jin, L.; Meeks, J. L.; Hubbard, K. A.; Kurian, L. M.; Siegel, D. I.; Lautz, L. K.; Otz, M. H.

    2007-12-01

    Temporary storage of surface water at channel sides and pools significantly affects water and solute transport downstream in watersheds. Beavers, natural "stream channel engineers", build dams which obstruct stream flow and temporarily store water in small to large ponds within stream channels. These ponds substantially delay water movement and increase the water residence time in the system. To study how water and solutes move through these obstructed stream channels, we did multiple dye tracing tests at Cherry Creek, a main tributary to Red Canyon Creek (Wind River Range, Wyoming). First we surveyed beaver dam distributions in detail within the study reaches. We then introduced dyes four times from July 2nd to 6th, 2007 using a scale-up approach. The observation site was fixed at the mouth of Cherry Creek, and 1.5 grams of Rhodamine WT (RWT) dye was injected sequentially at upstream sites with increasing test reach length. The reach lengths scaled up from 500m to 2.5 km. A field fluorometer recorded RWT concentrations every 15 seconds. The results show non-linear decreases of the peak concentration of the dye tracing cloud as the reach scaled up. Also, the times to 1.) the arrivals of the leading edges (Tl), 2.) the peak concentrations (Tp) and 3.) the tailing edges (Tt) and 4) the durations of the tracer cloud (Td) behaved non-linearly as function of length scale. For example, plots of arrivals of leading edges and tailing edges with scale distance appear to define curves of the form; Tl=27.665e1.07× Distance (r2=0.99) and Tt=162.62e0.8551× Distance (r2=0.99), respectively. The greatest non-linearity occurred for the time of tailing and the least for the time of leading edge. These observations are consistent with what would be expected with greater density of dams and/or storage volumes as the reach length increased upgradient. To come to a first approximation, we are currently modeling the breakthrough curves with the solute transport code OTIS to address

  16. The influence of stream channels on distributions of Larrea tridentata and Ambrosia dumosa in the Mojave Desert, CA, USA: Patterns, mechanisms and effects of stream redistribution

    USGS Publications Warehouse

    Schwinning, S.; Sandquist, D.R.; Miller, D.M.; Bedford, D.R.; Phillips, S.L.; Belnap, J.

    2011-01-01

    Drainage channels are among the most conspicuous surficial features of deserts, but little quantitative analysis of their influence on plant distributions is available. We analysed the effects of desert stream channels ('washes') on Larrea tridentata and Ambrosia dumosa density and cover on an alluvial piedmont in the Mojave Desert, based on a spatial analysis of transect data encompassing a total length of 2775 m surveyed in 5 cm increments. Significant deviations from average transect properties were identified by bootstrapping. Predictably, shrub cover and density were much reduced inside washes, and elevated above average levels adjacent to washes. Average Larrea and Ambrosia cover and density peaked 1??2-1??6 m and 0??5-1??0 m from wash edges, respectively. We compared wash effects in runon-depleted (-R) sections, where washes had been cut off from runon and were presumably inactive, with those in runon-supplemented (+R) sections downslope from railroad culverts to help identify mechanisms responsible for the facilitative effect of washes on adjacent shrubs. Shrub cover and density near washes peaked in both + R and - R sections, suggesting that improved water infiltration and storage alone can cause a facilitative effect on adjacent shrubs. However, washes of < 2 m width in + R sections had larger than average effects on peak cover, suggesting that plants also benefit from occasional resource supplementation. The data suggest that channel networks significantly contribute to structuring plant communities in the Mojave Desert and their disruption has notable effects on geomorphic and ecological processes far beyond the original disturbance sites. ?? 2010 John Wiley & Sons, Ltd.

  17. Influence of large wood on channel morphology and sediment storage in headwater mountain streams, Fraser Experimental Forest, Colorado

    NASA Astrophysics Data System (ADS)

    Ryan, Sandra E.; Bishop, Erica L.; Daniels, J. Michael

    2014-07-01

    Large fallen wood can have a significant impact on channel form and process in forested mountain streams. In this study, four small channels on the Fraser Experimental Forest near Fraser, Colorado, USA, were surveyed for channel geometries and large wood loading, including the size, source, and characteristics of individual pieces. The study is part of a larger effort to understand the impact of mountain pine beetle infestation on a suite of watershed properties. Here, we present baseline data collected at the onset of widespread tree mortality. Channels range from 1.5 to 2 m in width, with slopes ranging from 3 to > 10%. Median (D50) streambed particle sizes range from gravel to very coarse gravel. Channels are characterized as cascade, step-pool, and plane bed over varying scales. Large wood loads ranged from about 0.4 to 1.0 piece per meter length of channel, which is comparable to values reported for other Colorado sites. Much of the wood showed indications of being in place for long periods of time (decayed/rotten, broken into ramps, and partially buried in beds and banks). Nearly all surveyed reaches contained steps formed from small boulders and/or logs. Significant portions of the elevation drop in some of the reaches were made up by log steps, though the percentages varied (0 to 60%). Individual log steps trap a portion of the coarse sediment moved as bedload, forming wedge-shaped accumulations upstream of the logs. The particle size distributions for measured bedload and step accumulations largely overlapped, but more so for the coarse ends of the distributions, suggesting a trapping inefficiency for the finer component of bedload. Estimates of the total volume of sediment stored behind log steps were approximately an order of magnitude greater than the mean sediment volume exported on an annual basis, as determined from measured accumulations in weir ponds. The particle size distribution of sediment in the ponds - ranging from sand to medium gravel - is

  18. Regionalized Equations for Bankfull-Discharge and Channel Characteristics of Streams in New York State - Hydrologic Region 3 East of the Hudson River

    USGS Publications Warehouse

    Mulvihill, Christiane I.; Baldigo, Barry P.

    2007-01-01

    Equations that relate drainage area to bankfull discharge and channel characteristics (such as width, depth, and cross-sectional area) at gaged sites are needed to define bankfull discharge and channel characteristics at ungaged sites and can be used for stream-restoration and protection projects, stream-channel classification, and channel assessments. These equations are intended to serve as a guide for streams in areas of similar hydrologic, climatic, and physiographic conditions. New York State contains eight hydrologic regions that were previously delineated on the basis of high-flow (flood) characteristics. This report presents predictive equations for bankfull characteristics (discharge and channel characteristics) for streams east of the Hudson River, referred to as Hydrologic Region 3. Stream-survey data and discharge records from 12 streamflow-gaging stations were used in regression analyses to relate drainage area to bankfull discharge and bankfull channel width, depth, and cross-sectional area. The four predictive equations are: bankfull discharge (cubic feet per second) = 83.8 (drainage area (square miles))0.679, (1) bankfull-channel width (feet) = 24.0 (drainage area (square miles))0.292, (2) bankfull-channel depth (feet) = 1.66 (drainage area (square miles))0.210, (3) bankfull-channel cross-sectional area (square feet) = 39.8 (drainage area (square miles))0.503. (4) The coefficients of determination (R2) for these four equations are 0.93, 0.85, 0.77, and 0.92, respectively. The high coefficients of determination for bankfull discharge and cross-sectional area indicate that much of the range in the variables is explained by the size of the drainage area; the smaller correlation coefficients for bankfull channel width and depth indicate that other factors also affect these relations. Recurrence intervals for the estimated bankfull discharge of each stream ranged from 1.16 to 3.35 years; the mean recurrence interval was 2.08 years. The 12 surveyed

  19. Channel processes following land use changes in a degrading steep headwater stream in North Island, New Zealand

    NASA Astrophysics Data System (ADS)

    Kasai, Mio

    2006-11-01

    In headwater streams in steep land settings, narrow and steep valley floors provide closely coupled relationships between geomorphic components including hillslopes, tributary fans, and channel reaches. These relationships together with small catchment sizes result in episodic changes to the amount of stored sediment in channels. Major sediment inputs follow high magnitude events. Subsequent exponential losses via removal of material can be represented by a relaxation curve. The influence of hillslope and tributary processes on relaxation curves, and that of altered coupling relations between components, were investigated along a 1.3 km reach of a degrading channel in the 4.8 km 2 Weraamaia Catchment, New Zealand. Extensive deforestation in the late 19th and early 20th centuries, followed by invasion of scrubs and reforestation, induced changes to major erosion types from gully complexes to shallow landslides. Changes in the size and pattern of sediment slugs from 1938 to 2002 were analysed from air photographs tied to detailed field measurement. The rate and calibre of sediment flux changed progressively following substantive hillslope input in a storm in 1938. Subsequently, the channel narrowed and incised, decoupling tributary fans from the main stem, thereby scaling down the size of sediment slugs. As a consequence, the dominant influence on the behaviour of sediment slugs and associated relaxation processes, changed from tributary fans to the type and distribution of bedrock outcrops along the reach.

  20. River profile controls on channel morphology, debris flow disturbance, and the spatial extent of salmonids in steep mountain streams

    NASA Astrophysics Data System (ADS)

    May, Christine L.; Lisle, Thomas E.

    2012-12-01

    In the geologically and topographically diverse mountain ranges of the Pacific Northwest, a broad-scale means of prioritizing salmonid habitat conservation areas based on geomorphic process domains is examined. We propose that steepness and concavity indices derived from the relation between drainage area and channel slope provide a means of identifying basins that express different reach-scale morphologies, fish habitat capacity, and risk of episodic disturbance. Strongly concave river profiles that develop in mountainous terrain indicate that almost all of the relief in the drainage network occurs in headwater streams. In these basins a large proportion of the channel network has low-gradient morphologies, which provide favorable habitat for many salmonid species. The severity of pulse disturbances is also reduced because low-gradient main stem channels inhibit debris flow conveyance, and in these networks the distribution of fish can expand into tributaries, allowing for a spatial spreading of risk. In contrast, rivers with poorly concave or steeper profiles have a greater abundance of high gradient reaches that limit the distribution of fish to a small portion of the channel network and facilitate debris flow-passage. The combined influence of a limited spatial distribution of fish and an increased risk of debris flows may cause populations in these basins to be less resilient to pulse disturbances. A case example from the Klamath Mountains, an area with broad variation in the steepness and concavity of river profiles, was used to develop this approach and aid conservation planning for imperiled populations of anadromous salmonids.

  1. Decoding the attended speech stream with multi-channel EEG: implications for online, daily-life applications

    NASA Astrophysics Data System (ADS)

    Mirkovic, Bojana; Debener, Stefan; Jaeger, Manuela; De Vos, Maarten

    2015-08-01

    Objective. Recent studies have provided evidence that temporal envelope driven speech decoding from high-density electroencephalography (EEG) and magnetoencephalography recordings can identify the attended speech stream in a multi-speaker scenario. The present work replicated the previous high density EEG study and investigated the necessary technical requirements for practical attended speech decoding with EEG. Approach. Twelve normal hearing participants attended to one out of two simultaneously presented audiobook stories, while high density EEG was recorded. An offline iterative procedure eliminating those channels contributing the least to decoding provided insight into the necessary channel number and optimal cross-subject channel configuration. Aiming towards the future goal of near real-time classification with an individually trained decoder, the minimum duration of training data necessary for successful classification was determined by using a chronological cross-validation approach. Main results. Close replication of the previously reported results confirmed the method robustness. Decoder performance remained stable from 96 channels down to 25. Furthermore, for less than 15 min of training data, the subject-independent (pre-trained) decoder performed better than an individually trained decoder did. Significance. Our study complements previous research and provides information suggesting that efficient low-density EEG online decoding is within reach.

  2. Influence of instream habitat and water quality on aggressive behavior in crayfish of channelized headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many agricultural drainage ditches that border farm fields of the Midwestern United States are degraded headwater streams that possess communities of crayfish. We hypothesized that crayfish communities at sites with low instream habitat diversity and poor water quality would show greater evidence of...

  3. REGIONAL ASSESSMENT OF LAND USE IMPACTS ON STREAM CHANNEL HABITAT IN THE MIDDLE COLUMBIA RIVER BASIN

    EPA Science Inventory

    Many human land uses and land cover modifications (e.g., logging, grazing, roads) tend to increase erosion, leading to an increase in fine sediment supplied to streams and potentially degrading aquatic habitat for benthic organisms. This study evaluated potential human impacts o...

  4. Relating Field Observed Changes in the Active Stream Channel Network to Features of dQ/dt-Q Recession Curves

    NASA Astrophysics Data System (ADS)

    Shaw, S. B.

    2013-12-01

    Hydrologists have long plotted the rate of recession (dQ/dt) versus the absolute discharge (Q) to infer aquifer hydraulic properties. In recent years, these dQ/dt-Q plots have been examined in new ways, in particular, looking at individual event curves within the full dQ/dt-Q plot. When examining individual curves (in log-log space), in many cases one observes relatively constant slopes (usually near two) but finds that intercept values shift seasonally. Some have hypothesized that these two features of the dQ/dt-Q plots can be explained by the nature of the contraction of the stream channel network as flow diminishes (e.g. Biswal and Marani, 2010, GRL). To investigate this hypothesis, I have been mapping changes in the active channel network in a 250 ha catchment nested within the larger 69,000 ha Six Mile Creek watershed in central NY. Direct observations of the active channel network have been supplemented with streamflow measurements at 1st and 2nd order channels and the main channel. The larger Six Mile Creek watershed exhibits the expected constant dQ/dt-Q slopes and varying intercepts. However, the 250 ha catchment (assumed to be representative of the upland areas in the larger watershed) maintains a relatively constant active channel network, even during dry periods, and exhibits no systematic contraction of channel lengths. Most 1st order channels appear to be at least in part spring fed from their upper most point of origin. These field observations suggest that at least in this basin, the slope of two in log(dQ/dt) vs log(Q) plots is not directly related to contraction of the channel network. The fractional contribution of subbasins to total basin flow does indicate that these small upland basins contribute a decreased portion of total watershed flow during drier periods, supporting the notion that shifts in intercept may occur because of spatial changes in dominant contributing zones.

  5. Hydraulic and channel characteristics of selected streams in the Kantishna Hills area, Denali National Park and Preserve, Alaska, 1982-84

    USGS Publications Warehouse

    Van Maanen, J.L.; Solin, G.L.

    1988-01-01

    The Kantishna Hills area of the Denali National Park and Preserve contains extensive placer gold deposits. In order to develop plans for the management of this natural resource, and to assess the effects of placer mining on aquatic systems, documentation of the physical characteristics of the streams in the area is needed. Channel morphology, streamflow and streambed composition data were collected at 14 stream reaches in the Kantishna Hills area in September 1982 and in June, July, August , and September of 1983 and 1984. The reaches selected include locations of historical and current mining activity and locations which are undisturbed. The data indicate only minor differences in the physical properties of the streams in mined and unmined drainage basins. The composition of streambeds below mined areas tended to consist of finer sized particles and exhibited less variation in mean particle size than streambed in unmined basins. This may be due in part to the natural sorting of material in stream channels because mined areas, and thus study reaches below them, tended to be located relatively farther downstream (nearer the stream mouth) than were study reaches in basins where no mining has occurred. Changes in the physical properties of the streams which could be directly attributed to mining activity were noted at only one location, Rainy Creek near Kantishna, where the stream had been diverted from its natural channel by the construction of settling ponds. (Author 's abstract)

  6. Influences of wildfire and channel reorganization on spatial and temporal variation in stream temperature and the distribution of fish and amphibians

    USGS Publications Warehouse

    Dunham, J.B.; Rosenberger, A.E.; Luce, C.H.; Rieman, B.E.

    2007-01-01

    Wildfire can influence a variety of stream ecosystem properties. We studied stream temperatures in relation to wildfire in small streams in the Boise River Basin, located in central Idaho, USA. To examine the spatio-temporal aspects of temperature in relation to wildfire, we employed three approaches: a pre-post fire comparison of temperatures between two sites (one from a burned stream and one unburned) over 13 years, a short-term (3 year) pre-post fire comparison of a burned and unburned stream with spatially extensive data, and a short-term (1 year) comparative study of spatial variability in temperatures using a "space for time" substitutive design across 90 sites in nine streams (retrospective comparative study). The latter design included streams with a history of stand-replacing wildfire and streams with severe post-fire reorganization of channels due to debris flows and flooding. Results from these three studies indicated that summer maximum water temperatures can remain significantly elevated for at least a decade following wildfire, particularly in streams with severe channel reorganization. In the retrospective comparative study we investigated occurrence of native rainbow trout (Oncorhynchus mykiss) and tailed frog larvae (Ascaphus montanus) in relation to maximum stream temperatures during summer. Both occurred in nearly every site sampled, but tailed frog larvae were found in much warmer water than previously reported in the field (26.6??C maximum summer temperature). Our results show that physical stream habitats can remain altered (for example, increased temperature) for many years following wildfire, but that native aquatic vertebrates can be resilient. In a management context, this suggests wildfire may be less of a threat to native species than human influences that alter the capacity of stream-living vertebrates to persist in the face of natural disturbance. ?? 2007 Springer Science+Business Media, LLC.

  7. Retention and transport of nutrients in a third-order stream: channel processes

    USGS Publications Warehouse

    Triska, F.J.; Kennedy, V.C.; Avanzino, R.J.; Zellweger, G.W.; Bencala, K.E.

    1989-01-01

    Chloride was injected as a conservative tracer with nitrate to examine nitrate retention (storage plus biotic uptake) and transport in a 327-m reach of a third-order stream draining a forested basin in northwestern California. Prior to injections, diel patterns of nutrient concentrations were measured under background conditions. Nitrate concentration of stream water increased downstream, indicating that the reach was a source of dissolved inorganic nitrogen to downstream communities under background, low-flow conditions, despite uptake by photoautotrophs. At the onset of continuous solute injection over a 10-d period, timing the passage of the solute front indicated that storage dominated nitrate retention. Instantaneous concentration differences at the base of the reach at hour 24 indicated that biotic uptake accounted for 13% of the nitrate amendment while hydrologic storage constituted 29%. -from Authors

  8. The role of water exchange between a stream channel and its hyporheic zone in nitrogen cycling at the terrestrial-aquatic interface

    USGS Publications Warehouse

    Triska, F.J.; Duff, J.H.; Avanzino, R.J.

    1993-01-01

    The subsurface riparian zone was examined as an ecotone with two interfaces. Inland is a terrestrial boundary, where transport of water and dissolved solutes is toward the channel and controlled by watershed hydrology. Streamside is an aquatic boundary, where exchange of surface water and dissolved solutes is bi-directional and flux is strongly influenced by channel hydraulics. Streamside, bi-directional exchange of water was qualitatively defined using biologically conservative tracers in a third order stream. In several experiments, penetration of surface water extended 18 m inland. Travel time of water from the channel to bankside sediments was highly variable. Subsurface chemical gradients were indirectly related to the travel time. Sites with long travel times tended to be low in nitrate and DO (dissolved oxygen) but high in ammonium and DOC (dissolved organic carbon). Sites with short travel times tended to be high in nitrate and DO but low in ammonium and DOC. Ammonium concentration of interstitial water also was influenced by sorption-desorption processes that involved clay minerals in hyporheic sediments. Denitrification potential in subsurface sediments increased with distance from the channel, and was limited by nitrate at inland sites and by DO in the channel sediments. Conversely, nitrification potential decreased with distance from the channel, and was limited by DO at inland sites and by ammonium at channel locations. Advection of water and dissolved oxygen away from the channel resulted in an oxidized subsurface habitat equivalent to that previously defined as the hyporheic zone. The hyporheic zone is viewed as stream habitat because of its high proportion of surface water and the occurrence of channel organisms. Beyond the channel's hydrologic exchange zone, interstitial water is often chemically reduced. Interstitial water that has not previously entered the channel, groundwater, is viewed as a terrestrial component of the riparian ecotone. Thus

  9. Exploring geomorphic controls on fish bioenergetics in mountain streams: linkages between channel morphology and rearing habitat for cutthroat trout

    NASA Astrophysics Data System (ADS)

    Cienciala, P.; Hassan, M. A.

    2013-12-01

    Landscape heterogeneity constitutes an important control on spatial distribution of habitat for living organisms, at a range of spatial scales. For example, spatial variation in geomorphic processes can spatially structure populations as well as entire communities, and affect various ecosystem processes. We have coupled a 2D hydrodynamic model with a bioenergetic model to study the effects of various channel morphologies and bed textures on rearing habitat for coastal cutthroat trout (Oncorhynchus clarki clarki) in four reaches of a mountain stream. The bioenergetic model uses energy conservation principle to calculate energy budget for fish at any point of the study domain, given a set of relevant local conditions. Specifically, the energy intake is a function of food availability (invertebrate drift) while the energy expenditure occurs through, for example, basal metabolism and swimming to hold position against the flow. Channel morphology and bed texture, through their influence on channel hydraulics, can exert strong control on the spatial pattern of both food flux and swimming cost for drift-feeding fish. Therefore, the coupled hydrodynamic and bioenergetic models, parameterized using an extensive field data set, enabled us to explore mechanistic linkages between geomorphic properties of the study reaches, food resource availability, and the energetic profitability of rearing habitat for different age-classes at both between- and within-reach spatial scales.

  10. Assessment of channel changes in a Mediterranean ephemeral stream since the early twentieth century. The Rambla de Cervera, eastern Spain

    NASA Astrophysics Data System (ADS)

    Segura-Beltrán, Francisca; Sanchis-Ibor, Carles

    2013-11-01

    An analysis of morphological changes during the last six decades is presented for a 16.5-km reach of the Rambla de Cervera, a Mediterranean ephemeral stream located in eastern Spain. Channel changes were analysed through a range of techniques, specifically the analysis of aerial photographs with geographical information systems (GIS) and comparison of topographic surveys. The gravel channel underwent a general decline over the study period, losing width (68.5%) and surface area (45.7%) caused by the development of established islands frequently attached to the floodplain. These morphological changes exhibit an interesting temporal variability, with a maximum decrease of the gravel channel in the period 1946-1956 and another narrowing stage between 1977 and 1991. Two periods (1956-1977 and 1991-2006) also had mixed performance. In addition, incision processes occurred along the entire study reach at an average depth of 3.5 m. Natural and human-induced factors producing contradictory effects are considered responsible for changes in the Rambla de Cervera.

  11. NATURAL CHANNEL STREAM RESTORATION USING FLUVIAL GEOMORPHOLOGY, LITTLE CREEK, CHATTOOGA RIVER WATERSHED, CHATTAHOOCHEE NATIONAL FOREST, GEORGIA

    EPA Science Inventory

    This project involved removing a portion of an earthen dam that had collapsed. The problem solved by the project was to stabilize the eroding banks left from the remnants of the dam as well as stabilizing eroding banks adjacent to the forest service road. The channel constructe...

  12. A Comparison of In-Channel Dead Zone and Hyporheic Zone Transient Storage Parameter Estimates Between a 1st and 5th Order Stream

    NASA Astrophysics Data System (ADS)

    Briggs, M.; Gooseff, M.; Morkeski, K.; Wollheim, W.; Hopkinson, C.; Peterson, B.; Vorosmarty, C.

    2007-12-01

    A major enhancement to our understanding of how watersheds function would be the ability to discriminate between in-channel dead zone ( DZ) and hyporheic zone ( HZ) transient storage, and an evaluation of how these properties scale across stream orders. The nature of DZ storage is to display faster exchange rates with the main channel and less overall sediment contact time than HZ storage. These differences have great significance to many in-stream processes such as nutrient cycling. The combination of high slope, coarse bed material and fluvial structure endemic to many 1st order streams can provide greater forcing of hyporheic flow paths than occurs within the lower gradient 5th order streams. Conversely many 5th order reaches exhibit large side pool and back eddy DZ areas not common along 1st order streams. This study builds on existing methods to delineate the DZ and HZ from the integrated signal of a conservative solute's breakthrough curve ( BTC). Data for this comparison were collected over the summer of 2007 within the Ipswich River watershed, a basin which drains into Plum Island Sound on the north shore of Massachusetts, USA. The conservative solute NaCl was injected into both a 1st order medium gradient stream and a 5th order low gradient stream. The BTCs collected in thalwegs from the NaCl injections were simulated using a version of the solute transport model OTIS containing two zones of transient storage. Hydrometric measurements of stream velocity were used to estimate average main channel cross sectional area ( A) and DZ cross sectional area ( ASDZ) for each reach to constrain parameter estimates and avoid model equifinality between the storage zones. Initial values for the exchange rate between main channel flow and DZ storage ( αDZ) were estimated from DZ BTCs. Our results indicate that although the overall storage zone is much larger in proportion to the main channel for the 1st order reach than for the 5th order reach, the percentage of median

  13. Ice in Channels and Ice-Rock Mixtures in Valleys on Mars: Did They Slide on Deformable Rubble Like Antarctic Ice Streams?

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.

    1997-01-01

    Recent studies of ice streams in Antarctica reveal a mechanism of basal motion that may apply to channels and valleys on Mars. The mechanism is sliding of the ice on deformable water-saturated till under high pore pressures. It has been suggested by Lucchitta that ice was present in outflow channels on Mars and gave them their distinctive morphology. This ice may have slid like Antarctic ice streams but on rubbly weathering products rather than till. However, to generate water under high pore pressures, elevated heatflow is needed to melt the base of the ice. Either volcanism or higher heatflow more than 2 b.y. ago could have raised the basal temperature. Regarding valley networks, higher heatflow 3 b.y. ago could have allowed sliding of ice-saturated overburden at a few hundred meters depth. If the original, pristine valleys were somewhat deeper than they are now, they could have formed by the same mechanism. Recent sounding of the seafloor in front of the Ross Ice Shelf in Antarctica reveals large persistent patterns of longitudinal megaflutes and drumlinoid forms, which bear remarkable resemblance to longitudinal grooves and highly elongated streamlined islands found on the floors of martian outflow channels. The flutes are interpreted to have formed at the base of ice streams during the last glacial advance. Additional similarities of Antarctic ice streams with martian outflow channels are apparent. Antarctic ice streams are 30 to 80 km wide and hundreds of kilometers long. Martian outflow channels have similar dimensions. Ice stream beds are below sea level. Carr determined that most common floor elevations of martian outflow channels lie below martian datum, which may have been close to or below past martian sea levels. The Antarctic ice stream bed gradient is flat and locally may go uphill, and surface slopes are exceptionally. Martian channels also have floor gradients that are shallow or go uphill locally and have low surface gradients. The depth to the

  14. An Alternative to Channel-Centered Views of the Landscape for Understanding Modern Streams in the Mid-Atlantic Piedmont Region, Eastern USA

    NASA Astrophysics Data System (ADS)

    Merritts, D. J.; Walter, R. C.; Rahnis, M. A.; Oberholtzer, W.

    2008-12-01

    Stream channels generally are the focus of conceptual models of valley bottom geomorphology. The channel-centered model prevalent in the tectonically inactive eastern U. S. invokes meandering stream channels migrating laterally across valley floors, eroding one bank while depositing relatively coarse sediment in point bars on the other. According to this model, overbank deposition during flooding deposits a veneer of fine sediment over the gravel substrate. Erosion is considered normal, and the net volume of sediment is relatively constant with time. A dramatic change in conditions-land-clearing during European settlement--led to widespread aggradation on valley bottoms. This historic sedimentation was incorporated in the channel-centered view by assuming that meandering streams were overwhelmed by the increased sediment load and rapidly aggraded vertically. Later, elevated stream channels cut through these deposits because of decreased sediment supply and increased stormwater runoff accompanying urbanization. This view can be traced to early ideas of stream equilibrium in which incoming sediment supply and runoff determine stream-channel form. We propose a different conceptual model. Our trenching and field work along hundreds of km of stream length in the mid-Atlantic Piedmont reveal no point bars prior to European settlement. Instead, a polygenetic valley-bottom landscape underlies the drape of historic sediment. The planar surface of this veneer gives the appearance of a broad floodplain generated by long-term meandering and overbank deposition, but the "floodplain" is a recent aggradational surface from regional base-level rise due to thousands of early American dams that spanned valley bottoms. As modern streams incise into the historic fine-grained slackwater sediment, they expose organic-rich hydric soils along original valley bottom centers; talus, colluvium, bedrock, and saprolite with forest soils along valley margins; and weathered Pleistocene (and

  15. Erosion, sediment discharge, and channel morphology in the upper Chattahoochee River basin, Georgia, with a discussion of the contribution of suspended sediment to stream quality

    USGS Publications Warehouse

    Faye, Robert E.; Carey, W.P.; Stamer, J.K.; Kleckner, R.L.

    1980-01-01

    The 3,550 square miles of the Upper Chattahoochee River basin is an area of diverse physiographic and land-use characteristics. The headwater areas are mountainous with steep, relatively narrow channels. Land in the headwater areas is heavily forested, but small towns and farms are common in the valleys of large streams. Downstream, the basin is characterized by low hills and wider stream channels. Land in this part of the basin is also predominantly forested; however, large agricultural and urban areas are common. Urban land use is particularly intensive within the Atlanta Metropolitan Area.

  16. Response of fish populations to natural channel design restoration in streams of the Catskill Mountains, New York

    USGS Publications Warehouse

    Baldigo, Barry P.; Warren, D.R.; Ernst, A.G.; Mulvihill, C.I.

    2008-01-01

    Many streams and rivers throughout North America have been extensively straightened, widened, and hardened since the middle 1800s, but related effects on aquatic ecosystems have seldom been monitored, described, or published. Beginning in the early 1990s, reach-level restoration efforts began to base projects on natural channel design (NCD) techniques and Rosgen's (1994b, 1996) river classification system in an effort to duplicate or mimic stable reference reach geomorphology. Four reaches in three streams of the Catskill Mountains, New York, were restored from 2000 to 2002 using NCD techniques to decrease bed and bank erosion rates, decrease sediment loads, and improve water quality. The effects of restoration on the health of fish assemblages were assessed through a before-after, control-impact (BACI) study design to quantify the net changes in population and community indices at treatment reaches relative to index changes at unaltered reference reaches from 1999 to 2004. After restoration, community richness and biomass at treatment reaches increased by more than one-third. Changes in fish communities were caused mainly by shifts in dominant species populations; fish community biomass and total fish abundance were generally dominated by daces or daces and sculpins before restoration and by one or more salmonid species after restoration. Density and biomass of eastern blacknose dace Rhinichthys atratulus, longnose dace R. cataractae, and slimy sculpin Cottus cognatus did not change appreciably, whereas net salmonid density and biomass increased substantially after restoration. These changes were driven primarily by large increases in populations of brown trout Salmo trutta. The findings demonstrate that the structure, function, and ultimately the health of resident fish populations and communities can be improved, at least over the short term, through NCD restoration in perturbed streams of the Catskill Mountains. ?? Copyright by the American Fisheries Society

  17. A Reach-Scale Characterization of a Second-Order, Tropical, Montane Stream: Using Terrestrial Laser Scanning to Relate Channel Morphology to the Distribution of Stream Power and Shear Stress

    NASA Astrophysics Data System (ADS)

    Lisenby, P.; Wasklewicz, T. A.; Slattery, M.

    2012-12-01

    The relationship between stream channel morphology and hydrology can be described at varying scales within a drainage network. Progression in quantifying this relationship has come from the advancement of field instruments and methodology. Despite refinements of remote sensing tools and techniques, field methods are still dictated by the accessibility of the study area, especially in mountain catchments. Steep, mountain streams are often subject to intense precipitation, have coarser bed materials, and can react dynamically to a range of effective discharge conditions, producing significant channel changes that can be linked to specific flow conditions. Though these characteristics make mountain streams especially interesting, they also pose significant challenges to field research. In this study, we show that a detailed, small-scale understanding of the channel morphology/hydrology relationship can be gained using reimagined terrestrial laser scanning (TLS) techniques despite challenging topographic and climatic field conditions in a small, steep, 2nd order, tropical mountain stream in north-central Costa Rica. A true orthographic surface is derived by suspending a Leica HDS 7000 terrestrial laser scanner upside-down from a rigid frame placed in the stream bed. The technique produces a high-resolution point cloud that accommodates dense tropical canopy, steep stream gradient (≈10%), and large boulder-bed material (D84 = 60-70cm). Two sets of TLS data represent separate stream reaches. Two 1cm planimetric resolution digital elevation models were interpolated using ArcGIS 10 software after data filtering and cleaning using Leica Cyclone software V. 7.4. Analysis of these surfaces using ArcMap 10 in conjunction with the River Bathymetry Toolkit (RBT) permits the measurement of a cross-section for every meter of channel length. The streamwise distribution of stream power and average boundary shear stress at a reach-scale given user-defined bankfull conditions are

  18. Headwater Stream Temperature Response to Forest Harvesting in Coastal British Columbia, Canada: Influences of Riparian Buffer Width, Channel Morphology and Weather

    NASA Astrophysics Data System (ADS)

    Moore, R.; Gomi, T.; Dhakal, A.

    2003-12-01

    Forest harvesting can influence stream temperature regimes, and the potentially deleterious impacts of higher temperatures on salmonids and other species have generated significant debate. One common approach to protecting streams is to leave a riparian buffer to provide shade. However, little information has been collected on the effectiveness of different buffer widths. We report the results of a 6-year field experiment to evaluate the effects of different riparian buffer widths on stream and riparian ecosystems, including stream temperature response, in headwater streams in coastal British Columbia. The experiment included 13 streams, with at least three being assigned to each of four treatments, including no harvesting (80 yr-old second growth conifer riparian forest), clear-cut harvesting with 10 m and 30 m riparian buffers, and clear-cut harvesting with no buffer. Regression analysis was used to calibrate the pre-harvest data for each treatment stream with one of the control streams, to provide a basis for estimating post-harvest treatment effects. Autoregressive and heteroskedastic errors were included in the regression model, because stream temperature exhibited serial correlation and the error variance increased with stream temperature. Temperature response was substantial in the clearcut treatments with no buffers, with maximum temperatures increasing by up to 8 degrees C. The magnitude of temperature response amongst the no-buffer treatments varied with channel morphology, particularly in relation to bank shading and stream depth. The treatment effect for daily maximum water temperature increased with decreasing flow and increasing maximum air temperature on the current day, and also exhibited significant autocorrelation, indicating that the sequence of daily weather conditions can influence the magnitude of temperature response.

  19. Abandoned Texas oil fields

    SciTech Connect

    Not Available

    1980-12-01

    Data for Texas abandoned oil fields were primarily derived from two sources: (1) Texas Railroad Commission (TRRC), and (2) Dwight's ENERGYDATA. For purposes of this report, abandoned oil fields are defined as those fields that had no production during 1977. The TRRC OILMASTER computer tapes were used to identify these abandoned oil fields. The tapes also provided data on formation depth, gravity of oil production, location (both district and county), discovery date, and the cumulative production of the field since its discovery. In all, the computer tapes identified 9211 abandoned fields, most of which had less than 250,000 barrel cumulative production. This report focuses on the 676 abandoned onshore Texas oil fields that had cumulative production of over 250,000 barrels. The Dwight's ENERGYDATA computer tapes provided production histories for approximately two-thirds of the larger fields abandoned in 1966 and thereafter. Fields which ceased production prior to 1966 will show no production history nor abandonment date in this report. The Department of Energy hopes the general availability of these data will catalyze the private sector recovery of this unproduced resource.

  20. Regional Relations in Bankfull Channel Characteristics determined from flow measurements at selected stream-gaging stations in West Virginia, 1911-2002

    USGS Publications Warehouse

    Messinger, Terence; Wiley, Jeffrey B.

    2004-01-01

    Three bankfull channel characteristics?cross-sectional area, width, and depth?were significantly correlated with drainage area in regression equations developed for two regions in West Virginia. Channel characteristics were determined from analysis of flow measurements made at 74 U.S. Geological Survey stream-gaging stations at flows between 0.5 and 5.0 times bankfull flow between 1911 and 2002. Graphical and regression analysis were used to delineate an 'Eastern Region' and a 'Western Region,' which were separated by the boundary between the Appalachian Plateaus and Valley and Ridge Physiographic Provinces. Streams that drained parts of both provinces had channel characteristics typical of the Eastern Region, and were grouped with it. Standard error for the six regression equations, three for each region, ranged between 8.7 and 16 percent. Cross-sectional area and depth were greater relative to drainage area for the Western Region than they were for the Eastern Region. Regression equations were defined for streams draining between 46.5 and 1,619 square miles for the Eastern Region, and between 2.78 and 1,354 square miles for the Western Region. Stream-gaging stations with two or more cross sections where flow had been measured at flows between 0.5 and 5.0 times the 1.5-year flow showed poor replication of channel characteristics compared to the 95-percent confidence intervals of the regression, suggesting that within-reach variability for the stream-gaging stations may be substantial. A disproportionate number of the selected stream-gaging stations were on large (drainage area greater than 100 square miles) streams in the central highlands of West Virginia, and only one stream-gaging station that met data-quality criteria was available to represent the region within about 50 miles of the Ohio River north of Parkersburg, West Virginia. Many of the cross sections were at bridges, which can change channel shape. Although the data discussed in this report may not be

  1. Scour and fill in a stream channel, East Fork River, western Wyoming

    USGS Publications Warehouse

    Andrews, Edmund D.

    1978-01-01

    Frequent soundings of 11 cross sections located on the East Fork River, western Wyoming, during a spring flood revealed two sequences of channel scour and fill. All sections either scoured or filled at the flood crests relative to their low-flow condition. The sections which scoured at high flow (called scouring sections) generally tended to fill at low flow. Conversely, the sections which filled at high flow (called filling sections) generally tended to scour at low flow. The critical discharge at which the character of a section changed from scouring to filling or vice versa was approximately the bankfull discharge. Therefore, at any discharge except bankfull, some sections were accumulating bed material (fill), while others were being depleted of bed material (scour). (Woodard-USGS)

  2. Channel adjustment of an unstable coarse-grained stream: Opposing trends of boundary and critical shear stress, and the applicability of extremal hypotheses

    USGS Publications Warehouse

    Simon, A.; Thorne, C.R.

    1996-01-01

    Channel adjustments in the North Fork Toutle River and the Toutle River main stem were initiated by deposition of a 2.5km3 debris avalanche and associated lahars that accompanied the catastrophic eruption of Mount St. Helens, Washington on 18 May 1980. Channel widening was the dominant process. In combination, adjustments caused average boundary shear stress to decrease non-linearly with time and critical shear stress to increase non-linearly with time. At the discharge that is equalled or exceeded 1 per cent of the time, these trends converged by 1991-1992 so that excess shear stress approached minimum values. Extremal hypotheses, such as minimization of unit stream power and minimization of the rate of energy dissipation (minimum stream power), are shown to be applicable to dynamic adjustments of the Toutle River system. Maximization of the Darcy-Weisbach friction factor did not occur, but increases in relative bed roughness, caused by the concomitant reduction in hydraulic depths and bed-material coarsening, were documented. Predictions of stable channel geometries using the minimum stream power approach were unsuccessful when compared to the 1991-1992 geometries and bed-material characteristics measured in the field. It is concluded that the predictions are not applicable because the study reaches are not truly stable and cannot become so until a new floodplain has been formed by renewed channel incision, retreat of stream-side hummocks, and establishment of riparian vegetation to limit the destabilizing effects of large floods. Further, prediction of energy slope (and consequently stream power) by the sediment transport equations is inaccurate because of the inability of the equations to account for significant contributions of finer grained (sand and gravel) bank materials (relative to the coarsened channel bed) from bank retreat and from upstream terrace erosion.

  3. Detecting channel riparian vegetation response to best-management-practices implementation in ephemeral streams with the use of spot high-resolution visible imagery

    USGS Publications Warehouse

    Kamp, Kendall Vande; Rigge, Matthew B.; Troelstrup, Nels H., Jr.; Smart, Alexander J.; Wylie, Bruce

    2013-01-01

    Heavily grazed riparian areas are commonly subject to channel incision, a lower water table, and reduced vegetation, resulting in sediment delivery above normal regimes. Riparian and in-channel vegetation functions as a roughness element and dissipates flow energy, maintaining stable channel geometry. Ash Creek, a tributary of the Bad River in western South Dakota contains a high proportion of incised channels, remnants of historically high grazing pressure. Best management practices (BMP), including off-stream watering sources and cross fencing, were implemented throughout the Bad River watershed during an Environmental Protection Agency (EPA) 319 effort to address high sediment loads. We monitored prairie cordgrass (Spartina pectinata Link) establishment within stream channels for 16 yr following BMP implementation. Photos were used to group stream reaches (n = 103) subjectively into three classes; absent (estimated  40% cover; n = 16) based on the relative amount of prairie cordgrass during 2010 assessments of ephemeral channels. Reaches containing drainage areas of 0.54 to 692 ha were delineated with the use of 2010 National Agriculture Imagery Program (NAIP) imagery. Normalized difference vegetation index (NDVI) values were extracted from 5 to 39 sample points proportional to reach length using a series of Satellite Pour l'Observation de la Terre (SPOT) satellite imagery. Normalized NDVI (nNDVI) of 2 152 sample points were determined from pre- and post-BMP images. Mean nNDVI values for each reach ranged from 0.33 to 1.77. ANOVA revealed significant increase in nNDVI in locations classified as present prairie cordgrass cover following BMP implementation. Establishment of prairie cordgrass following BMP implementation was successfully detected remotely. Riparian vegetation such as prairie cordgrass adds channel roughness that reduces the flow energy responsible for channel degradation.

  4. Is in-stream macrophyte growth predictable and what are its impacts on channel-averaged flow characteristics?

    NASA Astrophysics Data System (ADS)

    Jordan, David N.; Thomas, Robert E.; Keevil, Gareth M.; Parsons, Daniel R.; Hardy, Richard J.

    2016-04-01

    Understanding how the growth of aquatic vegetation impacts stage-discharge coupling is vital for river management planning. This study presents an annual record of monthly spatial distribution surveys of the in-stream macrophyte Ranunculus penicillatus coupled with channel form and flow velocity measurements, within a 50 m-long reach of a gravel-bed river. Whereas stage has varied by up to 0.4 m, there has been little change in channel form over the monitoring period (ongoing since 23/07/2014). Macrophyte growth continued from the start of the monitoring period until October 2014 when mean patch area was 6.74 m2, and then decreased throughout a decay phase until January 2015 when mean patch area was 1.12 m2. There was a 75.2% loss of macrophyte surface area between October 2014 and January 2015. The largest patches that remained in January 2015 continued to decay until February. Conversely, new macrophyte patches also began to recolonize the channel during this time. To our knowledge, this is the first evidence of a transition period during which aquatic vegetation is in both decay and recolonization phases simultaneously. In total 69% of patches present in January exhibited regrowth without further decay to form a base for recolonization. Therefore, the spatial distribution of macrophyte patches could be determined to be somewhat persistent. Despite this, due to several different growth factors, there are recognisable differences in both macrophyte patch shape and distribution when comparing data from July 2014 and July 2015, emphasising the unpredictability of macrophyte growth. The decay period of the Ranunculus p. coincided with seasonal high discharges in this catchment. Discharge remained high from January until March 2015, but then began to decrease, reflecting annual peaks in historical records for the study area. Large discharge variations were not matched by a large stage range. Displacement of water by vegetation growth maintained the stage height when

  5. Abandoning wells working group

    SciTech Connect

    1997-03-01

    The primary objective of this working group is to identify major technical, regulatory, and environmental issues that are relevant to the abandonment of offshore wellbores. Once the issues have been identified, the working group also has the objective of making recommendations or providing potential solutions for consideration. Areas for process improvement will be identified and {open_quotes}best practices{close_quotes} will be discussed and compared to {open_quotes}minimum standards.{close_quotes} The working group will primarily focus on wellbore abandonment in the Gulf of Mexico. However, workshop participants are encouraged to discuss international issues which may be relevant to wellbore abandonment practices in the Gulf of Mexico. The Abandoning Wells Group has identified several major areas for discussion that have concerns related to both operators and service companies performing wellbore abandonments in the Gulf of Mexico. The following broad topics were selected for the agenda: (1) MMS minimum requirements and state regulations. (2) Co-existence of best practices, new technology, and P & A economics. (3) Liability and environmental issues relating to wellbore abandonment.

  6. Performance of an open limestone channel for treating a stream affected by acid rock drainage (León, Spain).

    PubMed

    Santofimia, Esther; López-Pamo, Enrique

    2016-07-01

    The generation of acid rock drainage (ARD) was observed after the oxidation dissolution of pyrite-rich black shales, which were excavated during the construction of a highway in León (Spain). ARDs are characterized by the presence of high concentrations of sulfate and metals (Al, Fe, Mn, Zn, Cu, Co, Ni, Th, and U) that affect the La Silva stream. Dissolved element concentrations showed values between one and four orders of magnitude higher than those of natural waters of this area. A passive treatment system was constructed; the aim of which was to improve the quality of the water of the stream. This work provides a hydrochemical characterization of the La Silva stream after its transit through the different elements that constitute the passive treatment system (open limestone channel (OLC), small ponds, and a wetland), during its first year of operation. The passive treatment system has two sections separated by a tunnel 230 m long. The first section, which stretches between the highway and the tunnel entrance, is an OLC 350 m long with a slope of 16 %. The second section, which stretches from the tunnel exit to the end wetland, has a length of 700 m and a slope of 6 %; it is in this section where six small ponds are located. In the first section of this passive treatment system, the OLC was effectively increasing the pH from 3 to 4-4.5 and eliminating all of the dissolved Fe and the partially dissolved Al. These elements, after hydrolysis at a pH 3-3.5 and 4-4.5, respectively, had precipitated as schwertmannite and hydrobasaluminite, while other dissolved metals were removed totally or partially for adsorption by the precipitates and/or by coprecipitation. The second section receives different inputs of water such as ARDs and natural waters. After exiting the treatment system, the stream is buffered by Al at a pH of 4-4.3, showing high Al concentrations (19-101 mg/L) but with a complete removal of dissolved Fe. Unfortunately, the outflow shows similar or

  7. Preliminary characterization of abandoned septic tank systems. Volume 1

    SciTech Connect

    1995-12-01

    This report documents the activities and findings of the Phase I Preliminary Characterization of Abandoned Septic Tank Systems. The purpose of the preliminary characterization activity was to investigate the Tiger Team abandoned septic systems (tanks and associated leachfields) for the purpose of identifying waste streams for closure at a later date. The work performed was not to fully characterize or remediate the sites. The abandoned systems potentially received wastes or effluent from buildings which could have discharged non-domestic, petroleum hydrocarbons, hazardous, radioactive and/or mixed wastes. A total of 20 sites were investigated for the preliminary characterization of identified abandoned septic systems. Of the 20 sites, 19 were located and characterized through samples collected from each tank(s) and, where applicable, associated leachfields. The abandoned septic tank systems are located in Areas 5, 12, 15, 25, and 26 on the Nevada Test Site.

  8. Scour and fill in a stream channel, East Fork River, western Wyoming

    USGS Publications Warehouse

    Andrews, Edmund D.

    1979-01-01

    Frequent soundings of 11 cross sections located on the East Fork River, western Wyoming, during a spring flood revealed two sequences of channel scour and fill. All sections either scoured or filled at the flood crests relative to their low flow condition. The sections which scoured at high flow (called scouring sections) generally tended to fill at low flow. Conversely, the sections which filled at high flow (called filling sections) generally tended to scour at low flow. The critical discharge at which the character of a section changed from scouring to filling or vice-versa was approximately the bankfull discharge. Therefore, at any discharge except bankfull, some sections were accumulating bed material (fill), while others were being depleted of bed material (scour). The mean at-a-station hydraulic geometry of the East Fork River agrees with the theoretical minimum-variance hydraulic geometry. Thus, on the average, the East Fork River accommodates a change in discharge by mutually minimizing the adjustment of velocity, width, and depth. The hydraulic geometry of every cross section, however, deviated from the mean of the reach, and the associated sequence of scour and fill was a consequence of the deviation. The scouring sections had larger velocity and smaller width and roughness hydraulic exponents than the mean of the reach. Consequently, the sediment-transport rate varied more rapidly with discharge in the scouring sections than the mean of the reach. Hence, these sections had relatively large sediment-transport rates and scoured when discharge exceeded bankfull, and relatively small sediment-transport rates and filled when discharge was less than bankfull. Conversely, the filling sections had smaller velocity and larger width and roughness hydraulic exponents than the mean of the reach. Consequently, the sediment-transport rate varied with discharge in the filling sections less rapidly than the mean of the reach. These sections had relatively small

  9. Spatial contributions of diffuse inputs and within-channel processes to the form of stream water phosphorus over storm events

    NASA Astrophysics Data System (ADS)

    Stutter, M. I.; Langan, S. J.; Cooper, R. J.

    2008-02-01

    SummaryConcentrations of suspended particulate matter (SPM), NO 3-N and P fractions: PO 4-P, dissolved organic P (DOP), particulate P (PP) and bioavailable exchangeable P were examined over 5 storm events in two nested agricultural catchments in NE Scotland: a (51 km 2) catchment and its headwater (4 km 2). NO 3-N showed anticlockwise hysteresis for all storms in both catchments. In contrast, the headwater showed strong clockwise hysteresis of SPM, dissolved and particulate P concentrations, but which weakened through summer to spring. Less pronounced hysteresis of P forms in the larger catchment was attributed to a combination of factors: a less energetic system, nutrient leaching from the floodplain, a point source of a small sewage treatment works and the occurrence of coarser soil and sediment parent materials with less P adsorption and transport capacity. The headwater exhibited a strong 'first flush' effect of sediment and dissolved P, particularly following dry conditions, received a significant transfer of readily-solubilized organic P from the surrounding soils in late summer and after manure applications in winter, and was the likely cause of large sediment associated P signals observed in the 51 km 2 catchment. Our results suggest that steeper gradient headwaters should be targeted for riparian improvements to mitigate soil erosion from headwater fields. The efficiency of riparian erosion controls is also dependant on the size of the store of fine sediment material within the stream channel and this may be large.

  10. Single-channel 40 Gbit/s digital coherent QAM quantum noise stream cipher transmission over 480 km.

    PubMed

    Yoshida, Masato; Hirooka, Toshihiko; Kasai, Keisuke; Nakazawa, Masataka

    2016-01-11

    We demonstrate the first 40 Gbit/s single-channel polarization-multiplexed, 5 Gsymbol/s, 16 QAM quantum noise stream cipher (QNSC) transmission over 480 km by incorporating ASE quantum noise from EDFAs as well as the quantum shot noise of the coherent state with multiple photons for the random masking of data. By using a multi-bit encoded scheme and digital coherent transmission techniques, secure optical communication with a record data capacity and transmission distance has been successfully realized. In this system, the signal level received by Eve is hidden by both the amplitude and the phase noise. The highest number of masked signals, 7.5 x 10(4), was achieved by using a QAM scheme with FEC, which makes it possible to reduce the output power from the transmitter while maintaining an error free condition for Bob. We have newly measured the noise distribution around I and Q encrypted data and shown experimentally with a data size of as large as 2(25) that the noise has a Gaussian distribution with no correlations. This distribution is suitable for the random masking of data. PMID:26832295

  11. MWSA's physical habitat approach - combining knowledge of habitat requirements with mechanisms of geomorphic and anthropogenic influence on stream channel form

    EPA Science Inventory

    Effective environmental policy decisions benefit from stream habitat information that is accurate, precise, and relevant. The recent National Wadeable Streams Assessment (NWSA) carried out by the U.S. EPA required physical habitat information sufficiently comprehensive to facilit...

  12. Mode couplings in a two-stream free-electron laser with a helical wiggler and an ion-channel guiding

    SciTech Connect

    Mohsenpour, Taghi Alirezaee, Hajar

    2014-08-15

    In this study, the method of perturbation has been applied to obtain the dispersion relation (DR) of a two-stream free-electron laser (FEL) with a helical wiggler and an ion-channel with all relativistic effects on waves. This DR has been solved numerically to find the unstable modes and their growth rate. Numerical solutions of DR show that the growth rate is considerably enhanced in comparison with single-stream free-electron laser. In group II orbits, with relatively large wiggler induced velocities, new couplings are found. The effect of the velocity difference of the two electron beams on the instabilities has also been investigated in this study. Moreover, the effect of the ion-channel density on the maximum growth rate of FEL resonance has been analyzed.

  13. Development of regional curves of bankfull-channel geometry and discharge for streams in the non-urban, Piedmont Physiographic Province, Pennsylvania and Maryland

    USGS Publications Warehouse

    Cinotto, Peter J.

    2003-01-01

    Stream-restoration projects utilizing natural stream designs frequently are based on the bankfull-channel characteristics of stream reaches that can accommodate streamflow and sediment transport without excessive erosion or deposition and lie within a watershed that has similar runoff characteristics. The bankfull channel at an ungaged impaired site or reference reach is identified by use of field indicators and is confirmed with tools such as regional curves. Channel dimensions were surveyed at 14 streamflow-measurement stations operated by the U.S. Geological Survey (USGS) in the Gettysburg-Newark Lowland Section, Piedmont Lowland Section, and the Piedmont Upland Section of the Piedmont Physiographic Province1 in Pennsylvania and Maryland. From the surveyed channel dimensions, regional curves were developed from regression analyses of the relations between drainage area and the cross-sectional area, mean depth, width, and streamflow of the bankfull channel at these sites. Bankfull cross-sectional area and bankfull discharge have the strongest relation to drainage area as evidenced by R2 values of 0.94 and 0.93, respectively. The relation between bankfull crosssectional area and drainage area has a p-value of less than 0.001; no p-value is presented for the relation between bankfull discharge and drainage area because of a non-normal residual distribution. The relation between bankfull width and drainage area has an R2 value of 0.80 and a p-value of less than 0.001 indicating a moderate linear relation between all stations. The relation between bankfull mean depth and drainage area, with an R2 value of 0.72 and a p-value of less than 0.001, also indicates a moderate linear relation between all stations. The concept of regional curves can be a valuable tool to support efforts in stream restoration. Practitioners of stream restoration need to recognize it as such and realize the limitations. The small number of USGS streamflow-measurement stations available for

  14. Glacial Meltwater Streams of the McMurdo Dry Valleys, Antarctica: Ecosystems Waiting for Water

    NASA Astrophysics Data System (ADS)

    McKnight, D. M.; Gooseff, M.; Cozzetto, K.

    2007-12-01

    The McMurdo Dry Valleys of Antarctica contain many glacial meltwater streams that flow for 6 to 12 weeks during the austral summer and link the glaciers to the lakes on the valley floors. Dry valley streams gain solutes longitudinally through weathering reactions and microbial processes occurring in the hyporheic zone, evident as a damp area underneath and adjacent to the stream. The lower boundary of the hyporheic zone is determined by the depth to permafrost. On sunny days, stream temperatures can reach 15 °C, and advection of this warm water can erode the frozen lower boundary of the hyporheic zone. In cold summers, streamflow is fed mostly by melt from the faces of the source glaciers and a large portion of this meltwater may be stored in the hyporheic zone and then lost through sublimation, rather than discharged to the lakes. Some streams have thriving microbial mats composed of cyanobacteria and diatoms. These mats are freeze-dried through the winter and begin photosynthesizing with the onset of flow. To evaluate the longer term persistence of cynaobacterial mats, we diverted flow to an abandoned channel, which had not received substantial flow for approximately two decades. We observed that cyanobacterial mats became abundant in the reactivated channel within a week, indicating that the mats had been preserved in a cryptobiotic state in the channel. Over the next several years, these mats had high rates of productivity and nitrogen fixation compared to mats from other streams. These stream-scale experimental results indicate that the cryptobiotic preservation of cyanobacterial mats in abandoned channels in the dry valleys allows for rapid response of stream ecosystems to climatic and geomorphological change.

  15. Immediate changes in stream channel geomorphology, aquatic habitat, and fish assemblages following dam removal in a small upland catchment

    NASA Astrophysics Data System (ADS)

    Magilligan, F. J.; Nislow, K. H.; Kynard, B. E.; Hackman, A. M.

    2016-01-01

    Dam removal is becoming an increasingly important component of river restoration, with > 1100 dams having been removed nationwide over the past three decades. Despite this recent progression of removals, the lack of pre- to post-removal monitoring and assessment limits our understanding of the magnitude, rate, and sequence of geomorphic and/or ecological recovery to dam removal. Taking advantage of the November 2012 removal of an old (~ 190 year-old) 6-m high, run-of-river industrial dam on Amethyst Brook (26 km2) in central Massachusetts, we identify the immediate eco-geomorphic responses to removal. To capture the geomorphic responses to dam removal, we collected baseline data at multiple scales, both upstream (~ 300 m) and downstream (> 750 m) of the dam, including monumented cross sections, detailed channel-bed longitudinal profiles, embeddedness surveys, and channel-bed grain size measurements, which were repeated during the summer of 2013. These geomorphic assessments were combined with detailed quantitative electrofishing surveys of stream fish richness and abundance above and below the dam site and throughout the watershed and visual surveys of native anadromous sea lamprey (Petromyzon marinus) nest sites. Post-removal assessments were complicated by two events: (1) upstream knickpoint migration exhumed an older (ca. late eighteenth century) intact wooden crib dam ~ 120 m upstream of the former stone dam, and (2) the occurrence of a 10-20 year RI flood 6 months after removal that caused further upstream incision and downstream aggradation. Now that the downstream reach has been reconnected to upstream sediment supply, the predominant geomorphic response was bed aggradation and associated fining (30-60% reduction). At dam proximal locations, aggradation ranged from 0.3 to > 1 m where a large woody debris jam enhanced aggradation. Although less pronounced, distal locations still showed aggradation with a mean depth of deposition of ~ 0.20 m over the 750-m

  16. Acoustic signal propagation and measurement in natural stream channels for application to surrogate bed load measurements: Halfmoon Creek, Colorado.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monitoring sediment-generated noise using submerged hydrophones is a surrogate method for measuring bed load transport in streams with the potential for improving estimates of bed load transport through widespread, inexpensive monitoring. Understanding acoustic signal propagation in natural stream e...

  17. Influence of Herbaceous Riparian Buffers on Fish and Amphibian Communities Within Channelized Headwater Streams in Central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbaceous riparian buffers are a widely used conservation practice in the United States for reducing nutrient, pesticide, and sediment loadings in agricultural streams. The importance of forested riparian zones for headwater streams has been documented, but the ecological impacts of herbaceous ripa...

  18. Influence of Herbaceous Filter Strips on Physical Habitat, Water Chemistry, and Fish Communities Within Channelized Headwater Streams in Central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbaceous filter strips are a widely used conservation practice in the United States for reducing nutrient, pesticide, and sediment loadings in agricultural streams. The importance of forested riparian zones for headwater streams has been documented, but the ecological impacts of herbaceous filter ...

  19. Geomorphic connectivity within abandoned small catchments (Stołowe Mts, SW Poland)

    NASA Astrophysics Data System (ADS)

    Latocha, Agnieszka

    2014-05-01

    Studying 5 small catchments (0.6-2.7 km2) located in the central part of the Stołowe Mountains (SW Poland), which are partly or totally abandoned, has revealed the substantial changes of connectivity within the catchments. Field investigation (geomorphic mapping, morphometric analyses) and GIS based analyses of historical data show that slope-channel coupling is much less efficient than in the past, mainly due to the decrease of unpaved road network, especially roads linked directly with streams. Also land-use change with considerable loss of arable land does not support erosion from slopes. The general direction of geomorphic change due to depopulation and lack of maintenance of anthropogenic features tends towards higher stability and lower efficiency of morphological processes, connected with a sustained decrease in slope-channel coupling. This tendency is evidenced by relict landscape features (e.g. road gullies, abandoned roads) formed in the period of more intensive land use, for which higher dynamics of the morphogenetic system may be inferred. The evidence of contemporary erosion and mineral material transport is very local and spatially limited to a few roads which are still in use. Sediment transfer is additionally slowed down by the presence of numerous anthropogenic barriers within slope and valley-floor domains. Even though their total impact may seem only local and negligible at the catchment scale, their contribution to increase the diversity of morphological processes is significant. Especially the neglect of hydrotechnical constructions enhances trapping of material within the catchments.

  20. Ephemeral-Stream Channel and Basin-Floor Infiltration and Recharge in the Sierra Vista Subwatershed of the Upper San Pedro Basin, Southeastern Arizona

    USGS Publications Warehouse

    Coes, A.L.; Pool, D.R.

    2007-01-01

    The timing and location of streamflow in the San Pedro River are partially dependent on the aerial distribution of recharge in the Sierra Vista subwatershed. Previous investigators have assumed that recharge in the subwatershed occurs only along the mountain fronts by way of stream-channel infiltration near the contact between low-permeability rocks of the mountains and the basin fill. Recent studies in other alluvial basins of the Southwestern United States, however, have shown that significant recharge can occur through the sediments of ephemeral stream channels at locations several kilometers distant from the mountains. The purpose of this study was to characterize the spatial distribution of infiltration and subsequent recharge through the ephemeral channels in the Sierra Vista subwatershed. Infiltration fluxes in ephemeral channels and through the basin floor of the subwatershed were estimated by using several methods. Data collected during the drilling and coring of 16 boreholes included physical, thermal, and hydraulic properties of sediments; chloride concentrations of sediments; and pore-water stable-isotope values and tritium activity. Surface and subsurface sediment temperatures were continuously measured at each borehole. Twelve boreholes were drilled in five ephemeral stream channels to estimate infiltration within ephemeral channels. Active infiltration was verified to at least 20 meters at 11 of the 12 borehole sites on the basis of low sediment-chloride concentrations, high soil-water contents, and pore-water tritium activity similar to present-day precipitation. Consolidated sediments at the twelfth site prevented core recovery and estimation of infiltration. Analytical and numerical methods were applied to determine the surface infiltration flux required to produce the observed sediment-temperature fluctuations at six sites. Infiltration fluxes were determined for summer ephemeral flow events only because no winter flows were recorded at the sites

  1. Comparing the Influence of Different Habitat Factors on Fish Communities in Channelized Headwater Streams in Indiana and Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation practices, such as herbaceous riparian buffers, pesticide management, and conservation tillage, are implemented to reduce nutrient, pesticide, and sediment loadings within agricultural streams. The impact of these practices is uncertain because previous studies have focused on evaluatin...

  2. Meta-Analysis of Lost Ecosystem Attributes in Urban Streams and the Effectiveness of Out-of-Channel Management Practices

    EPA Science Inventory

    Watershed development is a leading cause of stream impairment, and it increasingly threatens the availability, quality, and sustainability of freshwater resources as human populations continue to grow and migrate. Most efforts have focused on trying to improve ecological conditio...

  3. Relationships of macroinvertebrate communities with nutrients, pesticides, and physicochemical parameters in channelized headwater streams in Indiana and Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many headwater streams in the midwestern United States have been modified or constructed to transport agricultural runoff downstream. Effective implementation of agricultural conservation practices to reduce nutrient and pesticide loadings requires information about the influence of water chemistry ...

  4. Abandoned floodplain plant communities along a regulated dryland river

    USGS Publications Warehouse

    Reynolds, L. V.; Shafroth, Patrick B.; House, P. K.

    2014-01-01

    Rivers and their floodplains worldwide have changed dramatically over the last century because of regulation by dams, flow diversions and channel stabilization. Floodplains no longer inundated by river flows following dam-induced flood reduction comprise large areas of bottomland habitat, but the effects of abandonment on plant communities are not well understood. Using a hydraulic flow model, geomorphic mapping and field surveys, we addressed the following questions along the Bill Williams River, Arizona: (i) What per cent of the bottomland do abandoned floodplains comprise? and (ii) Are abandoned floodplains quantitatively different from adjacent xeric and riparian surfaces in terms of vegetation composition and surface sediment? We found that nearly 70% of active channel and floodplain area was abandoned following dam installation. Abandoned floodplains along the Bill Williams River tend to be similar to each other yet distinct from neighbouring habitats: they have been altered physically from their historic state, leading to distinct combinations of surface sediments, hydrology and plant communities. Abandoned floodplains may transition to xeric communities over time but are likely to retain some riparian qualities as long as there is access to relatively shallow ground water. With expected increases in water demand and drying climatic conditions in many regions, these surfaces and associated vegetation will continue to be extensive in riparian landscapes worldwide

  5. Near-Channel Sources and Sinks along a Mountainous Stream: Establishing the Controls and Time Scales of the Lateral Transfer of Sediment and Carbon

    NASA Astrophysics Data System (ADS)

    Gartner, J. D.; Renshaw, C. E.

    2015-12-01

    River channels exchange sediment, carbon, and other matter with hillslopes and floodplains. An ongoing challenge is to quantify the time and length scales of these lateral interactions, and to establish physical controls on direction of transfer. Here we investigate whether downstream changes in stream power (Ω) can predict near-channel sources or sinks of matter on decadal time scales in a case study of Mink Brook, a 50 km2 watershed in New Hampshire, USA. Building on the Exner equation, we hypothesize that reaches with downstream increases in stream power (Ω↑) exhibit near-channel deposition and accumulation of organic matter, and reaches of downstream decreases in stream power (Ω↓) exhibit near-channel erosion and stripping of organic matter. We measured 210Pbex inventory (an indicator of erosion versus deposition), organic matter inventory, grain size, and depth of alluvium/colluvium in 29 soil pits at 6 cross sections along the brook. Sites had equivalent total Ω for a given storm event. However, 3 cross sections exhibited Ω↑, and 3 exhibited Ω↓. All cross sections showed a general trend of stripping of organic matter and fine sediment particles in the channel, paired with loading of matter at the ~2-year flood elevation. From the ~2- to ~25-year flood elevation, a marked difference appeared between sites. The Ω↑ cross sections exhibited several locations of erosion and stripping of organic matter, as evidenced by low 210Pbex inventories (70 to 1,000 bq m-2), low organic matter inventories (17 to 219 kg m-2), and thin alluvial cover (average 23 cm). The low 210Pbex inventories, below the characteristic 6,000 bq m-2 of stable soil profiles in this region, suggest no areas had consistent deposition over the last century. In contrast, the Ω↓ cross sections exhibited deposition of fine particles and organic matter from the ~2- to ~25-year flood elevation, as evidenced by elevated 210Pbex inventories (up to 9,100 bq m-2), elevated organic matter

  6. Field Observations of Supraglacial Streams on the Juneau Icefield

    NASA Astrophysics Data System (ADS)

    Zok, A.; Karlstrom, L.; Hood, E. W.; Manga, M.; Wenzel, R.; Kite, E. S.

    2010-12-01

    of frictional heat dissipation to this heating trend. Cross-sectional water velocity profiles show that most streams have very low bed friction and are affected strongly by the free surface, resulting in large deviations from logarithmic velocity profiles. Measured changes of the water table depth in porous ice allow the permeability of ice to be quantified. It appears that rapid channel formation and abandonment near the neve line occurs via seepage. We observe large differences in hydrogen and oxygen isotopes in water from the two sites, and between ice, rainwater, and streams of different sizes within each site. The sinuosity of supraglacial streams is correlated with local slope, and we find supraglacial stream meanders to follow the linear wavelength-width relation also seen in alluvial and bedrock channels, with a smaller intercept. These measurements of meander characteristics are in accord with a linear stability analysis of supraglacial meander formation.

  7. Influence of adding small instream wood on fishes and hydrology within channelized agricultural headwater streams in central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Large instream wood is well known for its importance in headwater streams because it promotes the development of pool habitat for fishes and provides them with cover from predators during the summer. However, little is known about the influence of small instream wood (diameter < 10 cm, length < 1 m...

  8. CHNTRN: a CHaNnel TRaNsport model for simulating sediment and chemical distribution in a stream/river network

    SciTech Connect

    Yeh, G.T.

    1983-09-01

    This report presents the development of a CHaNnel TRaNsport model for simulating sediment and chemical distribution in a stream/river network. A particular feature of the model is its capability to deal with the network system that may consist of any number of joined and branched streams/rivers of comparable size. The model employs a numerical method - an integrated compartment method (ICM) - which greatly facilitates the setup of the matrix equation for the discrete field approximating the corresponding continuous field. Most of the possible boundary conditions that may be anticipated in real-world problems are considered. These include junctions, prescribed concentration, prescribed dispersive flux, and prescribed total flux. The model is applied to two case studies: (1) a single river and (2) a five-segment river in a watershed. Results indicate that the model can realistically simulate the behavior of the sediment and chemical variations in a stream/river network. 11 references, 10 figures, 3 tables.

  9. Salmon carcasses increase stream productivity more than inorganic fertilizer pellets: A test on multiple trophic levels in streamside experimental channels

    USGS Publications Warehouse

    Wipfli, Mark S.; Hudson, John P.; Caouette, John P.; Mitchell, N.L.; Lessard, Joanna L.; Heintz, Ron A.; Chaloner, D.T.

    2010-01-01

    Inorganic nutrient amendments to streams are viewed as possible restoration strategies for re-establishing nutrients and stream productivity throughout the western coast of North America, where salmon runs and associated marine-derived nutrient subsidies have declined. In a mesocosm experiment, we examined the short-term (6 weeks) comparative effects of artificial nutrient pellets and salmon carcasses, alone (low and high amounts) and in combination, on stream food webs. Response variables included dissolved nutrient concentrations, biofilm ash-free dry mass (AFDM) and chlorophyll-alevels, macroinvertebrate density, growth and body condition of juvenile coho salmon Oncorhynchus kisutch, and whole-body lipid content of invertebrates and juvenile coho salmon. Most of the response variables were significantly influenced by carcass treatment; the only response variable significantly influenced by fertilizer pellet treatment was soluble reactive phosphorus (SRP) concentration. Ammonium-nitrogen concentration was the only response variable affected by both (low and high) levels of carcass treatment; all others showed no significant response to the two carcass treatment levels. Significant treatment × time interactions were observed for all responses except nitrate; for most responses, significant treatment effects were detected at certain time periods and not others. For example, significantly higher SRP concentrations were recorded earlier in the experiment, whereas significant fish responses were observed later. These results provide evidence that inorganic nutrient additions do not have the same ecological effects in streams as do salmon carcasses, potentially because inorganic nutrient additions lack carbon-based biochemicals and macromolecules that are sequestered directly or indirectly by consumers. Salmon carcasses, preferably deposited naturally during spawning migrations, appear to be far superior to inorganic nutrient amendments for sustaining and restoring

  10. The Abandonment of Social Studies?

    ERIC Educational Resources Information Center

    Griffith, Bryant

    1991-01-01

    Addresses the question of whether the social studies should be abandoned. Discusses Kieran Egan's analysis of the importance of storytelling and Egan's proposal to abandon the social studies curriculum in favor of a pedagogy more consistent with the way children think. Critiques Egan's view and examines implications for educators. (SG)

  11. Nature of flow and turbulence structure around an in-stream vertical plate in a shallow channel and the implications for sediment erosion

    NASA Astrophysics Data System (ADS)

    Kirkil, Gokhan; Constantinescu, George

    2009-06-01

    Detailed knowledge of the dynamics of large-scale turbulence structures is needed to understand the geomorphodynamic processes around in-stream obstacles present in rivers. Detached Eddy Simulation is used to study the flow past a high-aspect-ratio rectangular cylinder (plate) mounted on a flat-bed relatively shallow channel at a channel Reynolds number of 2.4 × 105. Similar to other flows past surface-mounted bluff bodies, the large amplification of the turbulence inside the horseshoe vortex system is because the core of the main necklace vortex is subject to large-scale bimodal oscillations. The presence of a sharp edge at the flanks of the obstruction fixes the position of the flow separation at all depths and induces the formation and shedding of very strong wake rollers over the whole channel depth. Compared with the case of a circular cylinder where the intensity of the rollers decays significantly in the near-bed region because the incoming flow velocity is not sufficient to force the wake to transition from subcritical to supercritical regime, in the case of a high-aspect-ratio rectangular cylinder the passage of the rollers was found to induce high bed-shear stresses at large distances (6-8 D) behind the obstruction. Also, the nondimensional values of the pressure root-mean-square fluctuations at the bed were found to be about 1 order of magnitude higher than the ones predicted for circular cylinders. Overall, this shows that the shape of the in-stream obstruction can greatly modify the dynamics of the large-scale coherent structures, the nature of their interactions, and ultimately, their capability to entrain and transport sediment particles and the speed at which the scour process evolves during its initial stages.

  12. Mean annual runoff and peak flow estimates based on channel geometry of streams in northeastern and western Montana

    USGS Publications Warehouse

    Parrett, Charles; Omang, R.J.; Hull, J.A.

    1983-01-01

    Equations for estimating mean annual runoff and peak discharge from measurements of channel geometry were developed for western and northeastern Montana. The study area was divided into two regions for the mean annual runoff analysis, and separate multiple-regression equations were developed for each region. The active-channel width was determined to be the most important independent variable in each region. The standard error of estimate for the estimating equation using active-channel width was 61 percent in the Northeast Region and 38 percent in the West region. The study area was divided into six regions for the peak discharge analysis, and multiple regression equations relating channel geometry and basin characteristics to peak discharges having recurrence intervals of 2, 5, 10, 25, 50 and 100 years were developed for each region. The standard errors of estimate for the regression equations using only channel width as an independent variable ranged from 35 to 105 percent. The standard errors improved in four regions as basin characteristics were added to the estimating equations. (USGS)

  13. Channel

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03693 Channel

    This channel is located south of Iani Chaos.

    Image information: VIS instrument. Latitude -10.9N, Longitude 345.5E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  14. Modeling Tidal Stream Energy Extraction and its Effects on Transport Processes in a Tidal Channel and Bay System Using a Three-dimensional Coastal Ocean Model

    SciTech Connect

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea E.

    2013-02-28

    This paper presents a numerical modeling study for simulating in-stream tidal energy extraction and assessing its effects on the hydrodynamics and transport processes in a tidal channel and bay system connecting to coastal ocean. A marine and hydrokinetic (MHK) module was implemented in a three-dimensional (3-D) coastal ocean model using the momentum sink approach. The MHK model was validated with the analytical solutions for tidal channels under one-dimensional (1-D) conditions. Model simulations were further carried out to compare the momentum sink approach with the quadratic bottom friction approach. The effects of 3-D simulations on the vertical velocity profile, maximum extractable energy, and volume flux reduction across the channel were investigated through a series of numerical experiments. 3-D model results indicate that the volume flux reduction at the maximum extractable power predicted by the 1-D analytical model or two-dimensional (2-D) depth-averaged numerical model may be overestimated. Maximum extractable energy strongly depends on the turbine hub height in the water column, and which reaches a maximum when turbine hub height is located at mid-water depth. Far-field effects of tidal turbines on the flushing time of the tidal bay were also investigated. Model results demonstrate that tidal energy extraction has a greater effect on the flushing time than volume flux reduction, which could negatively affect the biogeochemical processes in estuarine and coastal waters that support primary productivity and higher forms of marine life.

  15. Development of regional curves relating bankfull-channel geometry and discharge to drainage area for streams in Pennsylvania and selected areas of Maryland

    USGS Publications Warehouse

    Chaplin, Jeffrey J.

    2005-01-01

    Natural-stream designs are commonly based on the dimensions of the bankfull channel, which is capable of conveying discharges that transport sediment without excessive erosion or deposition. Regional curves relate bankfull-channel geometry and discharge to drainage area in watersheds with similar runoff characteristics and commonly are utilized by practitioners of natural-stream design to confirm or refute selection of the field-identified bankfull channel. Data collected from 66 streamflow-gaging stations and associated stream reaches between December 1999 and December 2003 were used in one-variable ordinary least-squares regression analyses to develop regional curves relating drainage area to cross-sectional area, discharge, width, and mean depth of the bankfull channel. Watersheds draining to these stations are predominantly within the Piedmont, Ridge and Valley, and Appalachian Plateaus Physiographic Provinces of Pennsylvania and northern Maryland. Statistical analyses of physiography, percentage of watershed area underlain by carbonate bedrock, and percentage of watershed area that is glaciated indicate that carbonate bedrock, not physiography or glaciation, has a controlling influence on the slope of regional curves. Regional curves developed from stations in watersheds underlain by 30 percent or less carbonate bedrock generally had steeper slopes than the corresponding relations developed from watersheds underlain by greater than 30 percent carbonate bedrock. In contrast, there is little evidence to suggest that regional curves developed from stations in the Piedmont or Ridge and Valley Physiographic Province are different from the corresponding relations developed from stations in the Appalachian Plateaus Physiographic Province. On the basis of these findings, regional curves are presented to represent two settings that are independent of physiography: (1) noncarbonate settings characterized by watersheds with carbonate bedrock underlying 30 percent or less

  16. Flow resistance dynamics in step-pool stream channels: 1. Large woody debris and controls on total resistance

    USGS Publications Warehouse

    Wilcox, A.C.; Wohl, E.E.

    2006-01-01

    Flow resistance dynamics in step-pool channels were investigated through physical modeling using a laboratory flume. Variables contributing to flow resistance in step-pool channels were manipulated in order to measure the effects of various large woody debris (LWD) configurations, steps, grains, discharge, and slope on total flow resistance. This entailed nearly 400 flume runs, organized into a series of factorial experiments. Factorial analyses of variance indicated significant two-way and three-way interaction effects between steps, grains, and LWD, illustrating the complexity of flow resistance in these channels. Interactions between steps and LWD resulted in substantially greater flow resistance for steps with LWD than for steps lacking LWD. LWD position contributed to these interactions, whereby LWD pieces located near the lip of steps, analogous to step-forming debris in natural channels, increased the effective height of steps and created substantially higher flow resistance than pieces located farther upstream on step treads. Step geometry and LWD density and orientation also had highly significant effects on flow resistance. Flow resistance dynamics and the resistance effect of bed roughness configurations were strongly discharge-dependent; discharge had both highly significant main effects on resistance and highly significant interactions with all other variables. Copyright 2006 by the American Geophysical Union.

  17. Quantifying N2 and N2O production in agricultural streams using open channel methods: a tool for finding missing watershed nitrogen

    NASA Astrophysics Data System (ADS)

    Gardner, J. R.; Jordan, T. E.; Knee, K.; Fisher, T. R.

    2013-12-01

    Anthropogenic nitrogen (N) inputs are altering biogeochemical cycles, impairing aquatic ecosystems, and contributing to climate change. Agricultural watersheds, such as those in our study area on the eastern shore of Maryland, play a significant role as one of the greatest sources of N to coastal waters and N2O to the atmosphere. Denitrification can permanently remove N from the landscape through conversion to N2 and N2O gases, and gaseous N loss from streams and rivers is thought to be an important loss term in watershed N budgets. However, denitrification and fluxes of biogenic gases in streams are poorly understood, especially at ecologically relevant scales. In this study, we applied open channel methods to quantify in-situ N2 and N2O production at the reach scale. We accounted for both in-stream N2 production and watershed-derived N2 delivered to the stream via groundwater influx, and used two naturally present gases, 222Rn and Ar, as tracers for gas transfer velocity (k). We conducted eleven studies, each lasting six hours and repeated approximately quarterly in three different stream branches within a small watershed. Ultimately, these data will be part of a watershed nitrogen budget to assess the role of streams in the fate of Net Anthropogenic Nitrogen Inputs (NANI). Gas transfer velocity using 222Rn was 9-98% greater than k derived from Ar. However, k 222Rn agreed better with previous estimates; thus, the presented rates were estimated using k 222Rn. Biogenic N2 production rates ranged from 0.5 to 63.0 mmol N2-N m-2hr-1 with an average of 12.8. Biogenic N2O production ranged from 1.8 to 484.4 μmol N2O-N m-2hr-1 with an average of 98.0. N2O emissions to the atmosphere varied from 1.2 to 464.9 μmol N2O-N m-2 hr-1. Rates generally increased with temperature and spatial variation was fairly consistent across seasons. N2O will not contribute significantly to the watershed N budget (<2% of NANI); however, N2O was always supersaturated (344-3110%) and

  18. Effects of streamflows on stream-channel morphology in the eastern Niobrara National Scenic River, Nebraska, 1988–2010

    USGS Publications Warehouse

    Schaepe, Nathaniel J.; Alexander, Jason S.; Folz-Donahue, Kiernan

    2016-01-01

    Changes in channel metrics generally corresponded to changes in streamflow conditions, but other than changes in incipient flood-plain area, these changes were small and were not measured in all three segments simultaneously. Increases in total channel width (except in segment 1) and incipient flood-plain area between 1993 and 1999 corresponded to increases in streamflow. Channel narrowing (except in segment 1) between 1999 and 2003 corresponded to lower summer streamflows and extended durations of very low summer streamflow. Although the pattern of low summer streamflow and extended durations of very low summer streamflow continued during the 2004–6 period and at the beginning of the 2007–10 period, no further narrowing was measured. Consistent tributary summer inflows help to explain the resistance of segments 2 and 3 to further narrowing. Because segment 1 is already much narrower than segments 2 and 3, its average current velocity is likely to be swifter and, therefore, competent to offset further effects of the processes that led to its narrowness.

  19. 25 CFR 248.8 - Abandoned property.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Abandoned property. 248.8 Section 248.8 Indians BUREAU OF... SITES § 248.8 Abandoned property. No vehicle, trailer, boat, or other personal property shall be abandoned on the sites. Property abandoned in violation of the regulations in this part may be...

  20. 18 CFR 157.216 - Abandonment.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... facilities to be abandoned. (5) For any abandonment resulting in earth disturbance, a USGS 71/2-minute-series... abandoned; (3) The accounting treatment of the facilities abandoned; and (4) The date earth disturbance, if... the agreements obtained pursuant to § 157.206(b)(3), if earth disturbance was involved....

  1. 18 CFR 157.216 - Abandonment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... facilities to be abandoned. (5) For any abandonment resulting in earth disturbance, a USGS 71/2-minute-series... abandoned; (3) The accounting treatment of the facilities abandoned; and (4) The date earth disturbance, if... the agreements obtained pursuant to § 157.206(b)(3), if earth disturbance was involved....

  2. 18 CFR 157.216 - Abandonment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... facilities to be abandoned. (5) For any abandonment resulting in earth disturbance, a USGS 71/2-minute-series... abandoned; (3) The accounting treatment of the facilities abandoned; and (4) The date earth disturbance, if... the agreements obtained pursuant to § 157.206(b)(3), if earth disturbance was involved....

  3. 18 CFR 157.216 - Abandonment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... facilities to be abandoned. (5) For any abandonment resulting in earth disturbance, a USGS 71/2-minute-series... abandoned; (3) The accounting treatment of the facilities abandoned; and (4) The date earth disturbance, if... the agreements obtained pursuant to § 157.206(b)(3), if earth disturbance was involved....

  4. 18 CFR 157.216 - Abandonment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... facilities to be abandoned. (5) For any abandonment resulting in earth disturbance, a USGS 71/2-minute-series... abandoned; (3) The accounting treatment of the facilities abandoned; and (4) The date earth disturbance, if... the agreements obtained pursuant to § 157.206(b)(3), if earth disturbance was involved....

  5. Stream bed organic carbon and biotic integrity.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Allochthonous organic matter provides a basis for some stream ecosystems. Channel incision, which is a common result of anthropogenic impacts on watersheds and stream channels, may deplete stream bed C stores due to erosion, less frequent hydrologic exchanges between stream and floodplain, and remov...

  6. Glacially-megalineated limestone terrain of Anticosti Island, Gulf of St. Lawrence, Canada; onset zone of the Laurentian Channel Ice Stream

    NASA Astrophysics Data System (ADS)

    Eyles, Nick; Putkinen, Niko

    2014-03-01

    postulated Laurentian Channel Ice Stream (LCIS) within the Gulf of St. Lawrence sector of the Laurentide Ice Sheet.

  7. Evaluation of irrigation canal networks to assess stream connectivity in a watershed

    USGS Publications Warehouse

    Colvin, M.E.; Moffitt, C.M.

    2009-01-01

    We used digital data sets, aerial photos and direct field observations in a geographical information system to evaluate the stream habitat in an Idaho watershed affected by agriculture. We found that the scale of the digital data sets affected the outcome of the assessment due to the presence of dewatered stream channels in the drainage. We analysed the spatial configuration of irrigation canals in the watershed to determine if the contemporary stream network connectivity could be attributed to human- caused or to natural hydrological processes. Many irrigation canals were significantly longer than would have been expected if these canals were constructed to capture water from the closest portion of the abandoned stream channels. Our findings provide evidence that some of these tributary streams had reaches that were likely ephemeral or intermittent at the time of canal construction. Our approach for assessing stream and irrigation network connectivity in pastoral and agricultural lands should aid managers in prioritizing the effective and appropriate reconnection efforts. Published in 2008 by John Wiley & Sons Ltd. ?? 2008 John Wiley & Sons, Ltd.

  8. Urban Stream Ecology

    EPA Science Inventory

    Urban watersheds characteristically have high impervious surface cover, resulting in high surface runoff and low infiltration following storms. In response, urban streams experience “flashy” stormflows, reduced baseflows, bank erosion, channel widening, and sedimentation. Urban ...

  9. Macroinvertebrate response to stream restoration by large wood addition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel incision processes resulting primarily from channel straightening/dredging and watershed deforestation have been among the most profound degradations in our streams. Physical changes to streams affected by channel incision processes have included significant increases in streambed degradatio...

  10. Experimental tests of priority effects and light availability on relative performance of Myriophyllum spicatum and Elodea nuttallii propagules in artificial stream channels.

    PubMed

    Zefferman, Emily P

    2015-01-01

    Submersed macrophytes have important ecological functions in many streams, but fostering growth of beneficial native species while suppressing weedy invasives may be challenging. Two approaches commonly used in management of terrestrial plant communities may be useful in this context: (1) altering resource availability and (2) establishing desirable species before weeds can invade (priority effects). However, these approaches are rarely used in aquatic systems, despite widespread need for sustainable solutions to aquatic weed problems. In artificial stream channels in California, USA, I conducted experiments with asexual propagules of non-native invasive Myriophyllum spicatum (Eurasian watermilfoil) and native Elodea nuttallii (western waterweed) to address the questions: (1) How does light availability affect relative performance of the two species?; (2) Does planting the native earlier than the invasive decrease survival or growth rate of the invasive?; and (3) Do light level and priority effects interact? The relative performance between E. nuttallii and M. spicatum had an interesting and unexpected pattern: M. spicatum had higher growth rates than E. nuttallii in the zero and medium shade levels, but had similar performance in the low and high shade levels. This pattern is most likely the result of E. nutallii's sensitivity to both very low and very high light, and M. spicatum's sensitivity to very low light only. Native priority did not significantly affect growth rate or survival of M. spicatum, possibly because of unexpectedly poor growth of the E. nuttallii planted early. This study suggests that altering light levels could be effective in reducing growth of an invasive macrophyte, and for changing the competitive balance between a native and a non-native species in the establishment phase. Further investigations into the use of priority effects and resource alteration for submersed macrophyte management are warranted, given their mixed results in other

  11. Effects of hatchery fish density on emigration, growth, survival, and predation risk of natural steelhead parr in an experimental stream channel

    USGS Publications Warehouse

    Tatara, Christopher P.; Riley, Stephen C.; Berejikian, Barry A.

    2011-01-01

    Hatchery supplementation of steelhead Oncorhynchus mykiss raises concerns about the impacts on natural populations, including reduced growth and survival, displacement, and increased predation. The potential risks may be density dependent.We examined how hatchery stocking density and the opportunity to emigrate affect the responses of natural steelhead parr in an experimental stream channel and after 15 d found no density-dependent effects on growth, emigration, or survival at densities ranging from 1-6 hatchery parr/m2. The opportunity for steelhead parr to emigrate reduced predation by coastal cutthroat trout O. clarkii clarkii on both hatchery and natural steelhead parr. The cutthroat trout exhibited a type-I functional response (constant predation rate with increased prey density) for the hatchery and composite populations. In contrast, the predation rate on natural parr decreased as hatchery stocking density increased. Supplementation with hatchery parr at any experimental stocking density reduced the final natural parr density. This decline was explained by increased emigration fromthe supplemented groups. Natural parr had higher mean instantaneous growth rates than hatchery parr. The proportion of parr emigrating decreased as parr size increased over successive experimental trials. Smaller parr had lower survival and suffered higher predation. The final density of the composite population, a measure of supplementation effectiveness, increased with the hatchery steelhead stocking rate. Our results indicate that stocking larger hatchery parr (over 50 d postemergence) at densities within the carrying capacity would have low short-term impact on the growth, survival, and emigration of natural parr while increasing the density of the composite population; in addition, a stocking density greater than 3 fish/m2 might be a good starting point for the evaluation of parr stocking in natural streams.

  12. Remediation of abandoned mine discharges in the Loyalhanna Creek watershed

    SciTech Connect

    Fish, C.L.; Fish, D.H.

    1999-07-01

    Abandoned deep mine discharges were responsible for high iron loadings into several streams in the Loyalhanna Creek watershed. A total of seven discharges with flow rates from 20 to 1240 gal/min were flowing into Four Mile Run near Latrobe, PA. The iron concentrations in these discharges averaged near 80 ppm. The pH, however, was near neutral due to contact with underground limestone deposits. The high iron concentrations had severely degraded the habitat of the streams including 22 miles of Loyalhanna Creek. Benthic macroinvertebrates are especially vulnerable to the deposition of iron in these streams. In 1993, the Loyalhanna Mine Drainage Coalition was formed to oversee the remediation of the AMD discharges affecting Loyalhanna Creek. During this time monthly monitoring of the discharges began. Then using the chemistry and flow data, passive wetland treatment systems were designed to remediate the mine drainage. The remediation process precipitates and collects the iron oxide in the wetlands, thus eliminating the iron precipitation from the stream. In 1997 and 1998 three wetland treatment systems were constructed. The three wetlands capture the flow from the seven discharges and during low flow periods remove 95--100% of the iron from these discharges. The affected streams have shown a significant decrease in the iron concentrations and a subsequent improvement in the habitat quality of the streams. Fish and macroinvertebrates have been found in the most polluted stream which was void of life before the treatment systems were in operation.

  13. Bearing the risk of abandonment

    SciTech Connect

    Attanasio, Donna M.

    2010-05-15

    In Order Nos. 679 and 679-A, FERC adopted a policy of authorizing rate incentives for new transmission early in the development process to encourage transmission investment. The abandoned-plant cost recovery incentive creates a tension between ratepayer and investor interests, which is increasingly reflected in FERC's orders. (author)

  14. 32 CFR 636.31 - Abandoned vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... vehicle which has been left unattended or abandoned on a street, road, highway, parking lot, or any other... impoundment procedures. (d) Civilian vehicles left abandoned on the reservation will be towed to...

  15. 32 CFR 636.31 - Abandoned vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... vehicle which has been left unattended or abandoned on a street, road, highway, parking lot, or any other... impoundment procedures. (d) Civilian vehicles left abandoned on the reservation will be towed to...

  16. Legacy soil contamination at abandoned mine sites: making a case for guidance on soil protection.

    PubMed

    Kostarelos, Konstantinos; Gavriel, Ifigenia; Stylianou, Marinos; Zissimos, Andreas M; Morisseau, Eleni; Dermatas, Dimitris

    2015-03-01

    Within the European Union, guidance in the form of a uniform Soil Directive does not exist and member states are left to enact their own legislation governing historic soil contamination. Several historic or "legacy" sites exist in Cyprus - an EU member state with a long history of mining and a significant number of abandoned mining sites. The gold-silver enrichment plant of Mitsero village was abandoned 70 years ago, yet soil samples inside and outside the plant were extremely low in pH, exhibited high leachability of heavy metals and high cyanide levels. Water samples collected from an ephemeral stream located down-gradient of the site contained high levels of heavy metals. Two abandoned open-pit mines (Kokkinopezoula and Mathiatis) were investigated, where elevated metal content in soil samples from the surrounding streams and spoil heaps, and extremely low pH and high metal content in water samples from the mine crater were measured. PMID:25600021

  17. Human impacts to mountain streams

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen

    2006-09-01

    Mountain streams are here defined as channel networks within mountainous regions of the world. This definition encompasses tremendous diversity of physical and biological conditions, as well as history of land use. Human effects on mountain streams may result from activities undertaken within the stream channel that directly alter channel geometry, the dynamics of water and sediment movement, contaminants in the stream, or aquatic and riparian communities. Examples include channelization, construction of grade-control structures or check dams, removal of beavers, and placer mining. Human effects can also result from activities within the watershed that indirectly affect streams by altering the movement of water, sediment, and contaminants into the channel. Deforestation, cropping, grazing, land drainage, and urbanization are among the land uses that indirectly alter stream processes. An overview of the relative intensity of human impacts to mountain streams is provided by a table summarizing human effects on each of the major mountainous regions with respect to five categories: flow regulation, biotic integrity, water pollution, channel alteration, and land use. This table indicates that very few mountains have streams not at least moderately affected by land use. The least affected mountainous regions are those at very high or very low latitudes, although our scientific ignorance of conditions in low-latitude mountains in particular means that streams in these mountains might be more altered than is widely recognized. Four case studies from northern Sweden (arctic region), Colorado Front Range (semiarid temperate region), Swiss Alps (humid temperate region), and Papua New Guinea (humid tropics) are also used to explore in detail the history and effects on rivers of human activities in mountainous regions. The overview and case studies indicate that mountain streams must be managed with particular attention to upstream/downstream connections, hillslope/channel

  18. Riparian deforestation, stream narrowing, and loss of stream ecosystem services.

    PubMed

    Sweeney, Bernard W; Bott, Thomas L; Jackson, John K; Kaplan, Louis A; Newbold, J Denis; Standley, Laurel J; Hession, W Cully; Horwitz, Richard J

    2004-09-28

    A study of 16 streams in eastern North America shows that riparian deforestation causes channel narrowing, which reduces the total amount of stream habitat and ecosystem per unit channel length and compromises in-stream processing of pollutants. Wide forest reaches had more macroinvertebrates, total ecosystem processing of organic matter, and nitrogen uptake per unit channel length than contiguous narrow deforested reaches. Stream narrowing nullified any potential advantages of deforestation regarding abundance of fish, quality of dissolved organic matter, and pesticide degradation. These findings show that forested stream channels have a wider and more natural configuration, which significantly affects the total in-stream amount and activity of the ecosystem, including the processing of pollutants. The results reinforce both current policy of the United States that endorses riparian forest buffers as best management practice and federal and state programs that subsidize riparian reforestation for stream restoration and water quality. Not only do forest buffers prevent nonpoint source pollutants from entering small streams, they also enhance the in-stream processing of both nonpoint and point source pollutants, thereby reducing their impact on downstream rivers and estuaries. PMID:15381768

  19. Riparian deforestation, stream narrowing, and loss of stream ecosystem services

    PubMed Central

    Sweeney, Bernard W.; Bott, Thomas L.; Jackson, John K.; Kaplan, Louis A.; Newbold, J. Denis; Standley, Laurel J.; Hession, W. Cully; Horwitz, Richard J.

    2004-01-01

    A study of 16 streams in eastern North America shows that riparian deforestation causes channel narrowing, which reduces the total amount of stream habitat and ecosystem per unit channel length and compromises in-stream processing of pollutants. Wide forest reaches had more macroinvertebrates, total ecosystem processing of organic matter, and nitrogen uptake per unit channel length than contiguous narrow deforested reaches. Stream narrowing nullified any potential advantages of deforestation regarding abundance of fish, quality of dissolved organic matter, and pesticide degradation. These findings show that forested stream channels have a wider and more natural configuration, which significantly affects the total in-stream amount and activity of the ecosystem, including the processing of pollutants. The results reinforce both current policy of the United States that endorses riparian forest buffers as best management practice and federal and state programs that subsidize riparian reforestation for stream restoration and water quality. Not only do forest buffers prevent nonpoint source pollutants from entering small streams, they also enhance the in-stream processing of both nonpoint and point source pollutants, thereby reducing their impact on downstream rivers and estuaries. PMID:15381768

  20. Semianalytical solutions for stream depletion in partially penetrating streams.

    PubMed

    Chen, Xunhong; Yin, Yanfeng

    2004-01-01

    In the analysis of streamflow depletion, the Hunt (1999) solution has an important advantage because it considers a partially penetrating stream. By extending the Hunt drawdown solution, this paper presents semianalytical solutions for gaining streams that evaluate the induced stream infiltration and base flow reduction separately. Simulation results show that for a given deltah (the initial hydraulic head difference between stream and aquifer beneath the channel), the base flow reduction is in direct proportion to the product of streambed leakage (lambda) and the distance between pumping well and stream (L), and the induced stream infiltration is in inverse proportion to lambdaL. Deltah has a significant effect on the ratio of stream infiltration to base flow reduction. The results from the semianalytical solutions agree well with those from MODFLOW simulations. The semianalytical solutions are useful in the verification of numerical simulations and in the analysis of stream-aquifer interactions where water quantity or quality is concerned. PMID:14763621

  1. Multiple factors drive regional agricultural abandonment.

    PubMed

    Osawa, Takeshi; Kohyama, Kazunori; Mitsuhashi, Hiromune

    2016-01-15

    An understanding of land-use change and its drivers in agroecosystems is important when developing adaptations to future environmental and socioeconomic pressures. Agricultural abandonment occurs worldwide with multiple potentially positive and negative consequences; however, the main factors causing agricultural abandonment in a country i.e., at the macro scale, have not been identified. We hypothesized that socio-environmental factors driving agricultural abandonment could be summarized comprehensively into two, namely "natural" and "social", and the relative importance of these differs among regions. To test this postulate, we analyzed the factors currently leading to agricultural abandonment considering ten natural environment variables (e.g., temperature) and five social variables (e.g., number of farmers) using the random forest machine learning method after dividing Japan into eight regions. Our results showed that agricultural abandonment was driven by various socio-environmental factors, and the main factors leading to agricultural abandonment differed among regions, especially in Hokkaido in northern Japan. Hokkaido has a relatively large area of concentrated farmland, and abandonment might have resulted from the effectiveness of cultivation under specific climate factors, whereas the other regions have relatively small areas of farmland with many elderly part-time farmers. In such regions, abandonment might have been caused by the decreasing numbers of potential farmers. Thus, two different drivers of agricultural abandonment were found: inefficient cultivation and decreasing numbers of farmers. Therefore, agricultural abandonment cannot be prevented by adopting a single method or policy. Agricultural abandonment is a significant problem not only for food production but also for several ecosystem services. Governments and decision-makers should develop effective strategies to prevent further abandonment to ensure sustainable future management of agro

  2. THE USE OF GEOMORPHOLOGICAL CLASSIFICATION FOR RISK MANAGEMENT OF STREAMS

    EPA Science Inventory

    Changes in the amount and types of land use in a watershed can destabilize stream channel structure, increase sediment loading and degrade in-stream habitat. Stream classification systems (e.g., Rosgen) may be useful for determining the susceptibility of stream channel segments t...

  3. Stream biogeochemical and suspended sediment responses to permafrost degradation in stream banks in Taylor Valley, Antarctica

    NASA Astrophysics Data System (ADS)

    Gooseff, Michael N.; Van Horn, David; Sudman, Zachary; McKnight, Diane M.; Welch, Kathleene A.; Lyons, William B.

    2016-03-01

    Stream channels in the McMurdo Dry Valleys are characteristically wide, incised, and stable. At typical flows, streams occupy a fraction of the oversized channels, providing habitat for algal mats. In January 2012, we discovered substantial channel erosion and subsurface thermomechanical erosion undercutting banks of the Crescent Stream. We sampled stream water along the impacted reach and compared concentrations of solutes to the long-term data from this stream ( ˜ 20 years of monitoring). Thermokarst-impacted stream water demonstrated higher electrical conductivity, and concentrations of chloride, sulfate, sodium, and nitrate than the long-term medians. These results suggest that this mode of lateral permafrost degradation may substantially impact stream solute loads and potentially fertilize stream and lake ecosystems. The potential for sediment to scour or bury stream algal mats is yet to be determined, though it may offset impacts of associated increased nutrient loads to streams.

  4. AN INTERREGIONAL COMPARISON OF CHANNEL STRUCTURE, TRANSIENT STORAGE, AND RIPARIAN COVER WITH COMMUNITY METABOLISM IN STREAMS DRAINING EARLY- AND MID-SUCCESSIONAL WATERSHEDS

    EPA Science Inventory

    The goal of this research was to evaluate stream ecosystem function in response to different forest harvest intensities and time since harvest. Research was conducted in North Carolina, Arkansas, Oregon, and California.

  5. STREAM WATER QUALITY MODEL

    EPA Science Inventory

    QUAL2K (or Q2K) is a river and stream water quality model that is intended to represent a modernized version of the QUAL2E (or Q2E) model (Brown and Barnwell 1987). Q2K is similar to Q2E in the following respects:

    • One dimensional. The channel is well-mixed vertically a...

    • 7 CFR 767.51 - Property abandonment.

      Code of Federal Regulations, 2010 CFR

      2010-01-01

      ... jeopardy, the Agency will take the above actions prior to completing servicing actions contained in 7 CFR... 7 Agriculture 7 2010-01-01 2010-01-01 false Property abandonment. 767.51 Section 767.51... AGRICULTURE SPECIAL PROGRAMS INVENTORY PROPERTY MANAGEMENT Property Abandonment and Personal Property...

    • 7 CFR 767.51 - Property abandonment.

      Code of Federal Regulations, 2011 CFR

      2011-01-01

      ... jeopardy, the Agency will take the above actions prior to completing servicing actions contained in 7 CFR... 7 Agriculture 7 2011-01-01 2011-01-01 false Property abandonment. 767.51 Section 767.51... AGRICULTURE SPECIAL PROGRAMS INVENTORY PROPERTY MANAGEMENT Property Abandonment and Personal Property...

    • 25 CFR 248.8 - Abandoned property.

      Code of Federal Regulations, 2010 CFR

      2010-04-01

      ... 25 Indians 1 2010-04-01 2010-04-01 false Abandoned property. 248.8 Section 248.8 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE USE OF COLUMBIA RIVER INDIAN IN-LIEU FISHING SITES § 248.8 Abandoned property. No vehicle, trailer, boat, or other personal property shall...

    • 25 CFR 248.8 - Abandoned property.

      Code of Federal Regulations, 2012 CFR

      2012-04-01

      ... 25 Indians 1 2012-04-01 2011-04-01 true Abandoned property. 248.8 Section 248.8 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE USE OF COLUMBIA RIVER INDIAN IN-LIEU FISHING SITES § 248.8 Abandoned property. No vehicle, trailer, boat, or other personal property shall...

    • 25 CFR 248.8 - Abandoned property.

      Code of Federal Regulations, 2014 CFR

      2014-04-01

      ... 25 Indians 1 2014-04-01 2014-04-01 false Abandoned property. 248.8 Section 248.8 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE USE OF COLUMBIA RIVER INDIAN IN-LIEU FISHING SITES § 248.8 Abandoned property. No vehicle, trailer, boat, or other personal property shall...

    • 25 CFR 248.8 - Abandoned property.

      Code of Federal Regulations, 2011 CFR

      2011-04-01

      ... 25 Indians 1 2011-04-01 2011-04-01 false Abandoned property. 248.8 Section 248.8 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE USE OF COLUMBIA RIVER INDIAN IN-LIEU FISHING SITES § 248.8 Abandoned property. No vehicle, trailer, boat, or other personal property shall...

    • 19 CFR 147.47 - Mandatory abandonment.

      Code of Federal Regulations, 2011 CFR

      2011-04-01

      ... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.47 Mandatory abandonment. Any article entered for a fair, and not disposed of under the provisions of this subpart prior to the expiration of 3 months after the close of the fair shall be regarded as abandoned to the Government,...

    • 19 CFR 147.47 - Mandatory abandonment.

      Code of Federal Regulations, 2013 CFR

      2013-04-01

      ... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.47 Mandatory abandonment. Any article entered for a fair, and not disposed of under the provisions of this subpart prior to the expiration of 3 months after the close of the fair shall be regarded as abandoned to the Government,...

    • 19 CFR 147.47 - Mandatory abandonment.

      Code of Federal Regulations, 2010 CFR

      2010-04-01

      ... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.47 Mandatory abandonment. Any article entered for a fair, and not disposed of under the provisions of this subpart prior to the expiration of 3 months after the close of the fair shall be regarded as abandoned to the Government,...

    • 19 CFR 147.47 - Mandatory abandonment.

      Code of Federal Regulations, 2012 CFR

      2012-04-01

      ... TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.47 Mandatory abandonment. Any article entered for a fair, and not disposed of under the provisions of this subpart prior to the expiration of 3 months after the close of the fair shall be regarded as abandoned to the Government,...

    • 32 CFR 636.31 - Abandoned vehicles.

      Code of Federal Regulations, 2013 CFR

      2013-07-01

      ... 32 National Defense 4 2013-07-01 2013-07-01 false Abandoned vehicles. 636.31 Section 636.31... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.31 Abandoned vehicles. (a) Any MP or DOD police officer who finds or has knowledge of a...

    • Evolution of abandoned underground hardrock mine closures by the Texas abandoned mine land reclamation program

      SciTech Connect

      Rhodes, M.J.

      1997-12-31

      The Texas Abandoned Mine Land (AML) Reclamation program began investigating, designing and implementing hard rock abandoned underground mine closures, after a young boy fell to his death in an abandoned mine opening in 1982. This paper discusses the evolution of abandoned hard rock mine closures in west Texas, by the Texas AML program in response to the development of abandoned underground mine resource information. Case histories are presented of the Texas AML program`s efforts in west Texas including: mine history summaries; site characterization, environmental assessment; design and construction planning considerations, and construction cost information.

    • REACH SPECIFIC CHANNEL STABILIZATION BASED ON COMPREHENSIVE EVALUATION OF VALLEY FILL HISTORY, ALLUVIAL ARCHITECTURE AND GROUNDWATER HYDROLOGY IN A MOUNTAIN STREAM IN THE CENTRAL GREAT BASIN, NEVADA

      EPA Science Inventory

      Kingston meadow, located in the Toiyabe Range, is one of many wet meadow complexes threatened by rapid channel incision in the mountain ranges of the central Great Basin. Channel incision can lower the baselevel for groundwater discharge and de-water meadow complexes resulting in...

    • Stream dynamics at pipeline river crossings

      SciTech Connect

      Beckstead, G.R.E.; Cavers, D.S.

      1996-12-31

      Pipeline crossings of streams, whether large or small, must consider the ability of the stream channel to scour its bed and erode its banks. Case studies are presented to illustrate the kinds of dynamic environments which must be considered in designing pipeline stream crossings. These characteristics may be determined through the use of comparative historical aerial photography and site photographs and surveys. The case studies presented as examples in this paper include gullies, bedrock-lined channels, entrenched meandering streams, multi-channel wandering streams, degrading channels, alluvial fans, and major channels affected by regulation and man-made structures. Natural hazards such as debris jams and beaver dams are also discussed. For each case study, the characteristics of the channels are described, the design approach discussed and site-specific constraints presented which affected the final design.

    • Application of electromagnetic techniques in survey of contaminated groundwater at an abandoned mine complex in southwestern Indiana, U.S.A.

      USGS Publications Warehouse

      Brooks, G.A.; Olyphant, G.A.; Harper, D.

      1991-01-01

      In part of a large abandoned mining complex, electromagnetic geophysical surveys were used along with data derived from cores and monitoring wells to infer sources of contamination and subsurface hydrologic connections between acidic refuse deposits and adjacent undisturbed geologic materials. Electrical resistivity increases sharply along the boundary of an elevated deposit of pyritic coarse refuse, which is highly contaminated and electrically conductive, indicating poor subsurface hydrologic connections with surrounding deposits of fine refuse and undisturbed glacial material. Groundwater chemistry, as reflected in values of specific conductance, also differs markedly across the deposit's boundary, indicating that a widespread contaminant plume has not developed around the coarse refuse in more than 40 yr since the deposit was created. Most acidic drainage from the coarse refuse is by surface runoff and is concentrated around stream channels. Although most of the contaminated groundwater within the study area is concentrated within the surficial refuse deposits, transects of apparent resistivity and phase angle indicate the existence of an anomalous conductive layer at depth (>4 m) in thick alluvial sediments along the northern boundary of the mining complex. Based on knowledge of local geology, the anomaly is interpreted to represent a subsurface connection between the alluvium and a flooded abandoned underground mine. ?? 1991 Springer-Verlag New York Inc.

  1. Influence of spatial resolution on assessing channelization impacts on fish and macroinvertebrate communities in a warmwater stream in the southeastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The choice of spatial and temporal scale in the design of environmental assessments may influence the observed results. One method of assessing the impact of stream habitat alterations involves the comparison of response variables among treatments (i.e., impacted and unimpacted sites). Yet, the infl...

  2. Continued distress among abandoned dogs in Fukushima.

    PubMed

    Nagasawa, Miho; Mogi, Kazutaka; Kikusui, Takefumi

    2012-01-01

    In Fukushima, Japan, a prolonged refugee situation caused by a major nuclear incident after the earthquake of March 11, 2011 has led to the unintentional abandonment of many pets. We received stray or abandoned dogs from rescue centers in Fukushima Prefecture. During re-socialization training and health care, we accessed the behavioral characteristics and the urine cortisol level of each dog and compared them with those of other abandoned dogs not involved in this earthquake. The dogs from Fukushima showed significantly lower aggression toward unfamiliar people, trainability, and attachment to their caretakers; also, urine cortisol levels in the dogs from Fukushima were 5-10-fold higher than those in abandoned dogs from another area of Japan. These results suggested that the dogs from Fukushima suffered through an extremely stressful crisis. PMID:23061007

  3. Weyl's Abandonment of Unified Field Theory

    NASA Astrophysics Data System (ADS)

    Sieroka, Norman

    2015-01-01

    In 1918, Hermann Weyl proposed a generalisation of Riemannian geometry, in order to unify general relativity and electrodynamics. This paper investigates the physical, mathematical and philosophical reasons for his subsequent abandonment of any such attempt towards a unified field theory.

  4. 7 CFR 767.51 - Property abandonment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... jeopardy, the Agency will take the above actions prior to completing servicing actions contained in 7 CFR..., manage, and operate the abandoned security property, including marketing perishable security property...

  5. Abandoned oil fields of Texas Gulf Coast

    SciTech Connect

    Dutton, S.P.

    1984-04-01

    One nonconventional oil target in Texas is the oil that remains in abandoned fields, defined as those fields that had no oil or gas production in 1977 and 1982. This target includes oil that has not been tapped by conventional field development because of reservoir heterogeneity and oil in reservoirs that have not been subjected to any secondary or tertiary recovery efforts. A total of 138 abandoned oil fields having individual cumulative production greater than 500,000 bbl are located in the Texas Gulf Coast (railroad Commission of Texas Districts 2, 3, and 4). These 138 onshore fields produced 276 million barrels of oil before being abandoned. Nongiant fields in the Texas Gulf Coast average about 40% ultimate recovery, so these fields probably originally contained about 700 million bbl of oil in place. Therefore, about 424 million bbl of oil remain unrecovered. Reservoirs in these abandoned fields are Tertiary sandstones. The 44 abandoned fields in the upper Texas Gulf Coast (District 3) produced from a wide range of plays; those plays with the largest number of abandoned fields are Yegua and Frio deep-seated domes, Eocene deltaic sandstone, and Frio barrier/strand-plain sandstone. The 19 abandoned fields in the middle Texas Gulf Coast (District 2) produced mainly from Wilcox and Frio fluvial/deltaic sandstones and from Frio and Jackson-Yegua barrier/strand-plain sandstones. The lower Texas Gulf Coast (District 4) contains 75 abandoned fields that produced from Frio fluvial/deltaic and barrier/strand-plain sandstones and from Jackson-Yegua barrier/strand-plain sandstones.

  6. The rail abandonment process: A southern perspective

    SciTech Connect

    Not Available

    1988-12-01

    One factor in evaluating the desirability of rail transport for high-level radioactive wastes or spent fuels is the frequency, or lack thereof, with which railroad and railroad lines have been, and are, abandoned. If DOE makes a decision to use the rail option and a line is subsequently abandoned, the choice results in increased cost, time delays and possibly safety problems: Information is therefore needed prior to the decision-making process to evaluate the desirability of the rail shipping option. One result of the abandonments mentioned herein, as well as other later abandonments, is the creation of a US rail system undergoing an evolutionary process in the 1980s as far-reaching as the changes that occurred when the industry was in its infancy a century and-a-half ago. The purpose of this paper is to examine the factors leading to some of these changes by tracing the historical development of the rail abandonment process, with particular emphasis on the rise of regional railroads, their problems in the modern era and current trends in rail abandonments as well as their effects on the southeastern United States.

  7. Sedimentological effects and stratigraphic implications of a rare, high-stage flow in an evolving, braided to anabranching stream with riparian woodland

    NASA Astrophysics Data System (ADS)

    Joeckel, R. M.; Tucker, S. T.; Fielding, C. R.

    2015-07-01

    Low-frequency (1 in 25 years) high-stage flows on the South Platte and upper Platte rivers in Nebraska (USA) during September-October 2013 produced sedimentary effects that are unaccounted for in depositional models of that fluvial system. Being superimposed on a historically recent trend of channel-belt abandonment and encroachment of woody vegetation, these outcomes are even more useful for comparison with the wider sedimentary record. Rooted vegetation, particularly riparian trees, played a major role in determining where erosion and sedimentation occurred outside of the main (perennially flowing) channels. Effects of the 2013 event include: (1) small pebble to cobble-sized gravel in various bar-top and flood-channel settings; (2) common current or sediment shadows, including streamlined sediment shadow bars, several meters or more in length, which formed downstream from rooted trees and logjams; (3) sand lobes that prograded into densely wooded abandoned parts of the historical channel belt at angles of as much as 85° from average downstream flow; (4) large scours, some approaching 2 m in depth, many of which formed behind trees near the diffluences of flood channels and the main channel; (5) deposits of sand that were baffled by nonwoody or shrubby vegetation in the abandoned channel belt; and (6) local accumulations of large woody debris in front of rooted trees, as cross-flood-channel dams, and rarely as walls alongside flood channels. In an aggrading system, these features should be preserved as a distinctive set of sedimentary structures, which may be interpretable as evidence for episodic major flows in a system in which woody vegetation has encroached widely onto the channel belt. Stream-gaging data (U.S. Geological Survey, undated) generally support the observation expressed by Clemens. During the period 1902-2013 at Julesburg, Colorado, 61% of all peak annual flows were less than 100 m3/s, or less than one-sixth the size

  8. Influence of riparian vegetation on channel widening and subsequent contraction on a sand-bed stream since European settlement: Widden Brook, Australia

    NASA Astrophysics Data System (ADS)

    Erskine, Wayne; Keene, Annabelle; Bush, Richard; Cheetham, Michael; Chalmers, Anita

    2012-04-01

    Widden Brook in the Hunter Valley, Australia, was first settled by Europeans in 1831 and had widened substantially by the 1870s due to frequent floods during a flood-dominated regime impacting on highly disturbed banks whose riparian trees had been either ringbarked or cleared, and whose understorey had been grazed. Catastrophic floods in 1950 (many), two in August 1952 and one in February 1955 effected the final phase of channel widening at the onset of a second flood-dominated regime more than half a century after the initial widening. Contraction has been active since 1963 by a combination of five biogeomorphic processes. Firstly, rapid channel widening, migration and cutoffs totally reworked the pre-European floodplain and were followed by active floodplain formation. Initial bar formation was replaced by sand splay and overbank deposition which constructed a new floodplain and narrower channel. Secondly, overwidened channel segments that were produced by the catastrophic 1955 flood have contracted since 1963 by the formation of up to four bank-attached, discontinuous benches below the floodplain. Each bench has a bar nucleus of pebbly coarse sand overlain by stratified fine-medium sand and mud. Colonisation by River Sheoaks (Casuarina cunninghamiana subsp. cunninghamiana) or grasses (Cynodon dactylon, Paspalum distichum, Pennisetum clandestinum) is important in converting bars to benches. Thirdly, narrower segments which developed since 1963 have contracted by small-scale accretion on both banks. These deposits are steeply dipping, interbedded sand and mud trapped by stoloniferous and rhizomatous grasses (C. dactylon, P. distichum, P. clandestinum) which also rapidly stabilise the deposits. Fourthly, rare laterally migrating, small radius bends have contracted by recent point bar formation greatly exceeding cutbank recession rates. Point bar formation is controlled by secondary currents producing inclined stratified coarse sands without the influence of

  9. A geostatistical framework for quantifying the reach-scale spatial structure of river morphology: 2. Application to restored and natural channels

    NASA Astrophysics Data System (ADS)

    Legleiter, Carl J.

    2014-01-01

    Alluvial rivers are shaped by interactions between the bed topography, the flow field, and the movement of sediment. To help refine our understanding of these connections between form and process, I developed a geostatistical framework for quantifying the reach-scale spatial structure of river morphology, described in a companion paper. In this study, I applied this approach to a restored channel and three disparate reaches of a dynamic, natural stream. Repeat topographic surveys of each site were used to examine relationships between channel change and the variability and organization of the topography. For the restored river, the development of point bars increased overall morphologic diversity, primarily because of greater cross-sectional asymmetry. The three natural reaches experienced a variety of adjustments ranging from 1) gradual bar growth and bank erosion to; 2) extensive deposition followed by channel abandonment; and 3) chute cutoff and incision of a new channel. In both the restored and natural streams, geostatistical analysis, which involved variogram modeling, calculation of integral metrics, and inspection of variogram maps, provided an effective, informative summary of the observed channel changes. The use of dimensionless variables accounted for channel size, highlighted differences in spatial structure, and enabled a comparison among sites — the restored reach had not yet achieved the same degree of heterogeneity as the more pristine channels. Emphasizing variability and spatial pattern via this geostatistical framework could yield insight on form-process interactions and help to quantify geomorphic complexity and habitat heterogeneity in the applied context of river restoration.

  10. Beaver dams and channel sediment dynamics on Odell Creek, Centennial Valley, Montana, USA

    NASA Astrophysics Data System (ADS)

    Levine, Rebekah; Meyer, Grant A.

    2014-01-01

    Beaver dams in streams are generally considered to increase bed elevation through in-channel sediment storage, thus, reintroductions of beaver are increasingly employed as a restoration tool to repair incised stream channels. Here we consider hydrologic and geomorphic characteristics of the study stream in relation to in-channel sediment storage promoted by beaver dams. We also document the persistence of sediment in the channel following breaching of dams. Nine reaches, containing 46 cross-sections, were investigated on Odell Creek at Red Rock Lakes National Wildlife Refuge, Centennial Valley, Montana. Odell Creek has a snowmelt-dominated hydrograph and peak flows between 2 and 10 m3 s- 1. Odell Creek flows down a fluvial fan with a decreasing gradient (0.018-0.004), but is confined between terraces along most of its length, and displays a mostly single-thread, variably sinuous channel. The study reaches represent the overall downstream decrease in gradient and sediment size, and include three stages of beaver damming: (1) active; (2) built and breached in the last decade; and (3) undammed. In-channel sediment characteristics and storage were investigated using pebble counts, fine-sediment depth measurements, sediment mapping and surveys of dam breaches. Upstream of dams, deposition of fine (≤ 2 mm) sediment is promoted by reduced water surface slope, shear stress and velocity, with volumes ranging from 48 to 182 m3. High flows, however, can readily transport suspended sediment over active dams. Variations in bed-sediment texture and channel morphology associated with active dams create substantial discontinuities in downstream trends and add to overall channel heterogeneity. Observations of abandoned dam sites and dam breaches revealed that most sediment stored above beaver dams is quickly evacuated following a breach. Nonetheless, dam remnants trap some sediment, promote meandering and facilitate floodplain development. Persistence of beaver dam sediment

  11. Key stream/sediment exchanges of water and heat near stream mouths

    NASA Astrophysics Data System (ADS)

    Constantz, J. E.; Naranjo, R. C.; Niswonger, R. G.; Neilson, B. T.; Allander, K.; Zamora, C.; Smith, D. W.; Stonestrom, D. A.

    2014-12-01

    The section of stream discharging to a lake or other surface-water body is referred to as the stream mouth, a stream reach with rapidly changing hydrologic conditions, leading to unique aquatic and benthic ecology, as well as a visibly active fishery habitat. Of environmental significance, bridges, control structures, channelization and foot traffic are common near stream mouths, warranting comparisons of natural and channelized stream mouths. The present work completes the first investigation focusing specifically on the hydrology of surface-water/sediment exchanges at stream-mouth reaches discharging to lakes and compares these exchanges to those measured along the nearby shoreline in both a qualitative and quantitative manner. Heat and water exchanges for two common types of stream mouths (a natural stream with a summer barrier bar and a channelized stream mouth) are compared with comparable exchanges along the nearby shoreline on the north shore of Lake Tahoe located in the Central Sierra Nevada Mountain Range (CA/NV, US). The study site was selected partially due the abundance of streams discharging into the lake of both a natural and channelized nature (~30 small streams with a large number of both types of stream mouths). Heat and water exchanges were both qualitatively and quantitatively distinct for the three types of hydrologic settings, with (1) cool, low velocity, longitudinal (hyporheic) flowpaths observed below the channelized stream mouth, discharging beneath the warmer, more buoyant lakeshore water, (2) the nearby shoreline receiving relatively warm, higher velocity discharge and (3) for the natural stream mouth, there was strong diurnal temperature pattern in groundwater discharging through the seasonal barrier beach to the lake. Impacts of strong 2013 wave action on exchanges were also distinct for the three settings, with (1) channelization allowing waves to extend well upstream, (2) a lesser invasive impact in the shoreline swash zone exchanges

  12. CONNECTICUT STREAMS

    EPA Science Inventory

    This is a 1:24,000-scale datalayer of named streams in Connecticut. It includes two Shapefiles with line and polygon features. Both Shapefiles should be used together. The polygon shapefile fills in open water streams such as the Connecticut River as well as Long Island Sound. T...

  13. Stream Processors

    NASA Astrophysics Data System (ADS)

    Erez, Mattan; Dally, William J.

    Stream processors, like other multi core architectures partition their functional units and storage into multiple processing elements. In contrast to typical architectures, which contain symmetric general-purpose cores and a cache hierarchy, stream processors have a significantly leaner design. Stream processors are specifically designed for the stream execution model, in which applications have large amounts of explicit parallel computation, structured and predictable control, and memory accesses that can be performed at a coarse granularity. Applications in the streaming model are expressed in a gather-compute-scatter form, yielding programs with explicit control over transferring data to and from on-chip memory. Relying on these characteristics, which are common to many media processing and scientific computing applications, stream architectures redefine the boundary between software and hardware responsibilities with software bearing much of the complexity required to manage concurrency, locality, and latency tolerance. Thus, stream processors have minimal control consisting of fetching medium- and coarse-grained instructions and executing them directly on the many ALUs. Moreover, the on-chip storage hierarchy of stream processors is under explicit software control, as is all communication, eliminating the need for complex reactive hardware mechanisms.

  14. Water availability controls on community structure of an ephemeral meltwater stream ecosystem in the McMurdo Dry Valleys

    NASA Astrophysics Data System (ADS)

    McKnight, D. M.; Simmons, B.; Stanish, L.

    2009-05-01

    The McMurdo Dry Valleys of Antarctica contain many glacial meltwater streams that flow during the summer into lakes on the valley floors. Many streams have thriving cyanobacterial mats that are freeze-dried in winter and begin photosynthesis when flow arrives. We studied the community structure in a formerly abandoned channel, which was reactivated by a flow diversion in 1994. Cyanobacterial mats became abundant in the reactivated channel within a week and have remained evident even through cold, low flow summers. We recently compared the abundance and species distribution of invertebrates and diatoms in the cyanobacterial mats and in hyporheic zone during cold (low flow) and warm (high flow) summers. During the warm summer, there were sites where the invertebrate abundance was greater in the mats than in the underlying hyporheic sediments. In contrast, during the cold summer the invertebrate biomass was lower in the mats than in the hyporheic sediments. These findings suggest that the optimal micro-habitat for invertebrates in these mats and sediments is partially driven by ephemeral stream hydrology. This limitation on potential invertebrate grazers (which are important nutrient transformers) may account for the accumulation of algal biomass and subsequent nutrient immobilization in the mats over many summers.

  15. Coevolution of hydrodynamics, vegetation and channel evolution in wetlands of a semi-arid floodplain

    NASA Astrophysics Data System (ADS)

    Seoane, Manuel; Rodriguez, Jose Fernando; Rojas, Steven Sandi; Saco, Patricia Mabel; Riccardi, Gerardo; Saintilan, Neil; Wen, Li

    2015-04-01

    The Macquarie Marshes are located in the semi-arid region in north western NSW, Australia, and constitute part of the northern Murray-Darling Basin. The Marshes are comprised of a system of permanent and semi-permanent marshes, swamps and lagoons interconnected by braided channels. The wetland complex serves as nesting place and habitat for many species of water birds, fish, frogs and crustaceans, and portions of the Marshes was listed as internationally important under the Ramsar Convention. Some of the wetlands have undergone degradation over the last four decades, which has been attributed to changes in flow management upstream of the marshes. Among the many characteristics that make this wetland system unique is the occurrence of channel breakdown and channel avulsion, which are associated with decline of river flow in the downstream direction typical of dryland streams. Decrease in river flow can lead to sediment deposition, decrease in channel capacity, vegetative invasion of the channel, overbank flows, and ultimately result in channel breakdown and changes in marsh formation. A similar process on established marshes may also lead to channel avulsion and marsh abandonment, with the subsequent invasion of terrestrial vegetation. All the previous geomorphological evolution processes have an effect on the established ecosystem, which will produce feedbacks on the hydrodynamics of the system and affect the geomorphology in return. In order to simulate the complex dynamics of the marshes we have developed an ecogeomorphological modelling framework that combines hydrodynamic, vegetation and channel evolution modules and in this presentation we provide an update on the status of the model. The hydrodynamic simulation provides spatially distributed values of inundation extent, duration, depth and recurrence to drive a vegetation model based on species preference to hydraulic conditions. It also provides velocities and shear stresses to assess geomorphological

  16. Modeling the Effects of Connecting Side Channels to the Long Tom River, Oregon

    NASA Astrophysics Data System (ADS)

    Appleby, C.; McDowell, P. F.

    2015-12-01

    The lower Long Tom River is a heavily managed, highly modified stream in the southwestern Willamette Valley with many opportunities for habitat improvements and river restoration. In the 1940s and 1950s, the US Army Corps of Engineers dramatically altered this river system by constructing the Fern Ridge Dam and three, large drop structures, converting the River from a highly sinuous channel to a straight, channelized stream that is interrupted by these grade control structures, and removed the majority of the riparian vegetation. As a result, juvenile spring Chinook salmon are no longer found in the Watershed and the local population of coastal cutthroat trout face limited aquatic habitat. When the river was channelized, long sections of the historical channel were left abandoned on the floodplain. Reconnecting these historical channels as side channels may improve the quality and quantity of aquatic habitat and could allow fish passage around current barriers. However, such construction may also lead to undesirable threats to infrastructure and farmland. This study uses multiple HEC-RAS models to determine the impact of reconnecting two historical channels to the lower Long Tom River by quantifying the change in area of flood inundation and identifying infrastructure in jeapordy given current and post-restoration conditions for 1.5, 5, 10, and 25-year flood discharges. Bathymetric data from ADCP and RTK-GPS surveys has been combined with LiDAR-derived topographic data to create continuous elevation models. Several types of side channel connections are modeled in order to determine which type of connection will result in both the greatest quantity of accessible habitat and the fewest threats to public and private property. In the future, this study will also consider the change in the quantity of physical salmonid habitat and map the areas prone to sedimentation and erosion using CEASAR and PHABSIM tools.

  17. Infanticide and illegal infant abandonment in Malaysia.

    PubMed

    Razali, Salmi; Kirkman, Maggie; Ahmad, S Hassan; Fisher, Jane

    2014-10-01

    Infant abandonment and infanticide are poorly understood in Malaysia. The information available in the public arena comes predominantly from anecdotal sources. The aim of this study was to describe the prevalence and characteristics of infanticide and illegal infant abandonment in Malaysia and to estimate annual rates for the most recent decade. Summaries of data about infanticide and illegal infant abandonment were gathered from police records; the annual number of live births was ascertained from the national registry. The estimated inferred infanticide rates for Malaysia were compared with the infanticide rates among countries of very high, high, medium, and low rankings on the Human Development, Gender Inequality, and Gini indices. From 1999 to 2011, 1,069 cases of illegal infant abandonment were recorded and 1,147 people were arrested as suspected perpetrators. The estimated inferred infanticide rate fluctuated between 4.82 and 9.11 per 100,000 live births, a moderate rate relative to the infanticide rates of other countries. There are substantial missing data, with details undocumented for about 78-87% of cases and suspected perpetrators. Of the documented cases, it appeared that more boys than girls were victims and that suspected perpetrators were predominantly Malays who were women, usually mothers of the victim; the possibility of arrest bias must be acknowledged. Economic and social inequality, particularly gender inequality, might contribute to the phenomena of infanticide and abandonment. Strategies to reduce rates of infanticide and illegal infant abandonment in Malaysia will require strengthening of the surveillance system and attention to the gender-based inequalities that underpin human development. PMID:25048164

  18. Multiphase Flow and Cavern Abandonment in Salt

    SciTech Connect

    Ehgartner, Brian; Tidwell, Vince

    2001-02-13

    This report will explore the hypothesis that an underground cavity in gassy salt will eventually be gas filled as is observed on a small scale in some naturally occurring salt inclusions. First, a summary is presented on what is known about gas occurrences, flow mechanisms, and cavern behavior after abandonment. Then, background information is synthesized into theory on how gas can fill a cavern and simultaneously displace cavern fluids into the surrounding salt. Lastly, two-phase (gas and brine) flow visualization experiments are presented that demonstrate some of the associated flow mechanisms and support the theory and hypothesis that a cavity in salt can become gas filled after plugging and abandonment

  19. GEOMORPHIC CONTROLS ON C AND N PROCESSING IN A RESTORED URBAN STREAM; POWER POINT PRESENTATION

    EPA Science Inventory

    Stream channel incision due to hydraulic alteration stemming from urbanization may cause a disconnection between the stream channel and the adjacent floodplain. This disconnection may inhibit removal of nitrate via denitrification and/or stimulate nitrate production through nitr...

  20. Nitrogen Dynamics in a Degraded Urban Stream: Can the Patient be Revived? (Balitmore, MD)

    EPA Science Inventory

    Urbanization degrades stream ecosystems by altering hydrology and nutrient dynamics. We investigated temporal and spatial patterns in biogeochemistry and hydrology in and near the stream channel of a geomorphically degraded urban stream of Baltimore County, Maryland, USA. Our o...

  1. Nitrogen dynamics at the ground water-surface water interface of a degraded urban stream

    EPA Science Inventory

    Urbanization degrades stream ecosystems by altering hydrology and nutrient dynamics. We investigated temporal and spatial patterns in biogeochemistry and hydrology in and near the stream channel of a geomorphically degraded urban stream of Baltimore County, Maryland, USA. Our o...

  2. Stream network expansion: a riparian water quality factor

    NASA Astrophysics Data System (ADS)

    Wigington, P. J., Jr.; Moser, T. J.; Lindeman, D. R.

    2005-05-01

    Little is known about how active stream network expansion during rainstorms influences the ability of riparian buffers to improve water quality. We used aerial photographs to quantify stream network expansion during the wet winter season in five agricultural catchments in western Oregon, USA. Winter stream drainage densities were nearly two orders of magnitude greater than summer stream densities, and agricultural land use was much more abundant along transient portions (e.g. swales, road ditches) of stream networks. Water moving from agricultural fields into expanded stream networks during large hydrologic events has the opportunity to bypass downstream riparian buffers along perennial streams and contribute nonpoint-source pollutants directly into perennial stream channels.

  3. Real time detection of lysozyme by pulsed streaming potentials using polyclonal antibodies immobilized on a renewable nonfouling surface inside plastic microfluidic channels.

    PubMed

    Luna-Vera, Fernando; Ferguson, Josephus D; Alvarez, Julio C

    2011-03-15

    A composite surface was prepared on cyclic olefin copolymer (COC) microchannels by UV-photografting of polyethylene glycol acrylate (PEGA) and poly(acrylic acid) (PAA) films. A PEGA layer of globular particles with average thickness of 60 nm was formed after 15 min of polymerization. Real time monitoring by pulsed streaming potentials demonstrated the ability of the PEGA layer to inhibit the adhesion of five different nonspecific adsorbing proteins when compared with pristine COC. Roughness determined by atomic force microscopy (AFM) after PAA grafting on COC-PEGA at different UV illumination times suggests that PAA formation is initiated at the free space in between the PEGA particles. Carboxylic groups activated with N-hydroxysuccinimide and N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide were used to bind anti-lysozyme polyclonal antibodies. The composite COC-PEGA-PAA-anti-lysozyme surface demonstrated its ability to detect lysozyme with a dynamic range between 140 and 860 nM. Linearity was maintained even when samples were spiked with 250 nM of cytochrome as interfering species. The equilibrium constant K(eq) for the adsorption of Ly on COC-PEGA-PAA-anti-Ly was estimated to be 2.7 × 10(6) M(-1), and it shows that this kinetic approach of monitoring the surface charge is also useful to estimate affinity interactions for proteins in label free fashion. The regeneration of the surface exhibited an average percentage of recovery of ∼97% for each of six adsorption-regeneration cycles. This feature enables curve calibration on a single microfluidic chip because each point of the curve has a reproducible and renewable surface. PMID:21322582

  4. GEOMORPHOLOGICAL STUDIES IN THE LITTLE MIAMI RIVER (INITIALLY, OTHER STREAM SYSTEMS TO BE ADDED LATER)

    EPA Science Inventory

    Changes in the amount and types of land use in a watershed can destabilize stream channel structure, increase sediment loading and degrade in-stream habitat. Stream classification systems (e.g., Rosgen) may be useful for determining the susceptibility of stream channel segments t...

  5. USUING STREAM MORPHOLOGY CLASSIFICATION TO MANAGE ECOLOGICAL RISKS FROM LAND USE CHANGES IN THE LMR WATERSHED

    EPA Science Inventory

    Changes in the amount and types of land use in a watershed can destabilize stream channel structure, increase sediment loading and degrade in-stream habitat. Stream classification systems (e.g. Rosgen) may be useful for determining the susceptibility of stream channel segments t...

  6. USING STREAM MORPHOLOGY CLASSIFICATION TO MANAGE ECOLOGICAL RISKS FROM LAND USE CHANGES IN THE LMR WATERSHED

    EPA Science Inventory

    Changes in the amount and types of land use in a watershed can destabilize stream channel structure, increase sediment loading and degrade in-stream habitat. Stream classification systems (e.g. Rosgen) may be useful for determining the susceptibility of stream channel segments t...

  7. 23 CFR 752.10 - Abandoned vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 23 Highways 1 2014-04-01 2014-04-01 false Abandoned vehicles. 752.10 Section 752.10 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY AND ENVIRONMENT LANDSCAPE AND..., or enhancement of scenic beauty as seen from the traveled way of the highway as a landscape...

  8. 23 CFR 752.10 - Abandoned vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 false Abandoned vehicles. 752.10 Section 752.10 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY AND ENVIRONMENT LANDSCAPE AND..., or enhancement of scenic beauty as seen from the traveled way of the highway as a landscape...

  9. 23 CFR 752.10 - Abandoned vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 23 Highways 1 2012-04-01 2012-04-01 false Abandoned vehicles. 752.10 Section 752.10 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY AND ENVIRONMENT LANDSCAPE AND..., or enhancement of scenic beauty as seen from the traveled way of the highway as a landscape...

  10. 23 CFR 752.10 - Abandoned vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 23 Highways 1 2013-04-01 2013-04-01 false Abandoned vehicles. 752.10 Section 752.10 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY AND ENVIRONMENT LANDSCAPE AND..., or enhancement of scenic beauty as seen from the traveled way of the highway as a landscape...

  11. LOCATION OF ABANDONED WELLS WITH GEOPHYSICAL METHODS

    EPA Science Inventory

    Abandoned wells are sometimes an important element in the contamination of fresh underground water supplies. If a well is not properly plugged and the casing is leaky, it may serve as a conduit for brines or other pollutants to reach a fresh water aquifer. This study was made to ...

  12. 36 CFR 13.122 - Abandonment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 13.122 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Cabins General Provisions § 13.122 Abandonment. (a) An existing cabin or... portion of a cabin or other structure and its contents from a park area, to the extent of his or...

  13. 36 CFR 13.122 - Abandonment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 13.122 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Cabins General Provisions § 13.122 Abandonment. (a) An existing cabin or... portion of a cabin or other structure and its contents from a park area, to the extent of his or...

  14. 37 CFR 1.138 - Express abandonment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Section 1.138 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES National Processing Provisions Time for Reply by... Patent and Trademark Office. Express abandonment of the application may not be recognized by the...

  15. 32 CFR 636.31 - Abandoned vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Abandoned vehicles. 636.31 Section 636.31 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart,...

  16. 23 CFR 752.10 - Abandoned vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Abandoned vehicles. 752.10 Section 752.10 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY AND ENVIRONMENT LANDSCAPE AND..., or enhancement of scenic beauty as seen from the traveled way of the highway as a landscape...

  17. 32 CFR 636.31 - Abandoned vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... § 636.31 Abandoned vehicles. (a) Any MP or DOD police officer who finds or has knowledge of a motor... MP or DOD police officer who, under the provisions of this section, causes any motor vehicle to be... motor vehicle by any MP or DOD police officer should not be within the scope of either that...

  18. Assessing vulnerability in stream channel evolution in relation with morphological transformations and hydrodynamic behavior. Case Study: the Subcarpathian Prahova Valley, Romania

    NASA Astrophysics Data System (ADS)

    Osaci-Costache, G.; Armas, I.; Gogoase Nistoran, D.; Gheorghe, D.

    2010-05-01

    The objective of the study is to analyze the relationship between morphological transformations observed during the last 200 years along a 20 km reach of Prahova river, and hydrodynamic behavior during high intensity flood periods, in the context of erosion-control works and environmental changes. Along this sub-Carpathian reach, Prahova is a typical mountain river, partially regulated, flowing under fluvial and torrential regime and having a mean thalweg slope of about 1%. Riverbed material consists in cobbles and boulders. Its valley has gradually been cut; therefore four terraces may clearly be identified in the subbasin areas of Breaza and Câmpina. The Holocene floodplain is asymmetrical, and during the last decades an incision of about 3-4 m has clearly been observed in the main channel. This also led to an evolution from an anabranching river aspect to a meandering one along the studied reach. Reasons to explain these changes are a positive neotectonic background coupled with an increased anthropic component (granular material extraction, channel regulation for construction purposes of roads, bridges, railways, layout of gas and oil pipelines, vegetation cutoff etc.). The data obtained from 1900-1980 topographical maps and 1997-2002 satellite images and orthophotos were coupled with topo-bathymetric surveys carried out in 57 cross-sections, in order to obtain the DTM of the studied area. These cross-sections were used to build up the geometry of a 1D hydraulic model by using the HEC-RAS software (USACE, version 3.1.3). Simulations were obtained under steady flow conditions for 1% and 2% return periods (360-400 mc/s and 450-500 mc/s). Calibration of Manning roughness factors was performed on stages measured at the two upstream and downstream gauging stations. High values of computed shear stresses and velocities show areas of potential erosion leading to morphological changes, bank collapsing and incision observed during the last decades and predicted for the

  19. 4. INTERIOR OF ABANDONED SANTA ANA CANAL TUNNEL, SHOWING CEMENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. INTERIOR OF ABANDONED SANTA ANA CANAL TUNNEL, SHOWING CEMENT TROUGH FLOOR AND UNFINISHED GRANITE ROOF. VIEW TO SOUTHWEST. - Santa Ana River Hydroelectric System, Abandoned Tunnel, Redlands, San Bernardino County, CA

  20. Analyzing indicators of stream health for Minnesota streams

    USGS Publications Warehouse

    Singh, U.; Kocian, M.; Wilson, B.; Bolton, A.; Nieber, J.; Vondracek, B.; Perry, J.; Magner, J.

    2005-01-01

    Recent research has emphasized the importance of using physical, chemical, and biological indicators of stream health for diagnosing impaired watersheds and their receiving water bodies. A multidisciplinary team at the University of Minnesota is carrying out research to develop a stream classification system for Total Maximum Daily Load (TMDL) assessment. Funding for this research is provided by the United States Environmental Protection Agency and the Minnesota Pollution Control Agency. One objective of the research study involves investigating the relationships between indicators of stream health and localized stream characteristics. Measured data from Minnesota streams collected by various government and non-government agencies and research institutions have been obtained for the research study. Innovative Geographic Information Systems tools developed by the Environmental Science Research Institute and the University of Texas are being utilized to combine and organize the data. Simple linear relationships between index of biological integrity (IBI) and channel slope, two-year stream flow, and drainage area are presented for the Redwood River and the Snake River Basins. Results suggest that more rigorous techniques are needed to successfully capture trends in IBI scores. Additional analyses will be done using multiple regression, principal component analysis, and clustering techniques. Uncovering key independent variables and understanding how they fit together to influence stream health are critical in the development of a stream classification for TMDL assessment.

  1. Geomorphic applications of stream-gage information

    USGS Publications Warehouse

    Juracek, K.E.; Fitzpatrick, F.A.

    2009-01-01

    In the United States, several thousand stream gages provide what typically is the only source of continuous, long-term streamflow and channel-geometry information for the locations being monitored. In this paper, the geomorphic content of stream-gage information, previous and potential applications of stream-gage information in fluvial geomorphic research and various possible limitations are described. Documented applications include studies of hydraulic geometry, channel bankfull characteristics, sediment transport and channel geomorphic response to various types of disturbance. Potential applications include studies to determine the geomorphic effectiveness of large floods and in-stream habitat change in response to disturbance. For certain applications, various spatial, temporal and data limitations may render the stream-gage information of limited use; however, such information often is of considerable value to enable or enhance geomorphic investigations.

  2. A comparative analysis of abandoned street children and formerly abandoned street children in La Paz, Bolivia

    PubMed Central

    Huang, C; Barreda, P; Mendoza, V; Guzman, L; Gilbert, P

    2004-01-01

    Aims and Methods: A comparative study of abandoned street children and formerly abandoned street children was conducted in La Paz, Bolivia, representing the first such comparative assessment. Between August and December 1997, all abandoned street children in La Paz, Bolivia, who were willing to participate (n = 124) were interviewed repeatedly at night using standardised questionnaires to collect information on family history, demographics, socioeconomics, drug use, and physical/sexual abuse. The same questionnaires were administered to all former abandoned street children who chose to enter a local orphanage (n = 35). Results: The persistent street children differed greatly from those who entered the orphanage, most markedly in their higher risk of police abuse (95% versus 38%), absence from school (84% versus 19%), engagement in robbery (26% versus 4%), paint thinner use (88% versus 41%), alcohol use (58% versus 12%), and a serious medical problem (53% versus 20%). The risks for street children increased rapidly with age. Conclusions: A cascade of adverse outcomes afflicts the vast majority of abandoned street children in La Paz, which cumulate with age and diminish the likelihood of successful rehabilitation through lasting placement in an orphanage or residential home. Informed by these findings, the investigators operate a home for abandoned street children in La Paz. PMID:15321856

  3. Working Models about Mother-Child Relationships in Abandoned Children.

    ERIC Educational Resources Information Center

    Garcia-Torres, Belen; Guerrero, Pilar Garcia-Calvo

    2000-01-01

    Sixty abandoned and 36 non-abandoned school-aged children were told six short stories about mother-child relationships. Abandoned children showed less positive affect attribution to the mother, more compliant behavior in the child, and more justification of the mother when her behaviors were unfair. (Contains references.) (Author/CR)

  4. 30 CFR 56.4011 - Abandoned electric circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Abandoned electric circuits. 56.4011 Section 56.4011 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Control § 56.4011 Abandoned electric circuits. Abandoned electric circuits shall be deenergized...

  5. 30 CFR 57.4011 - Abandoned electric circuits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Abandoned electric circuits. 57.4011 Section 57.4011 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... and Control § 57.4011 Abandoned electric circuits. Abandoned electric circuits shall be...

  6. 30 CFR 57.4011 - Abandoned electric circuits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Abandoned electric circuits. 57.4011 Section 57.4011 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... and Control § 57.4011 Abandoned electric circuits. Abandoned electric circuits shall be...

  7. 30 CFR 56.4011 - Abandoned electric circuits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Abandoned electric circuits. 56.4011 Section 56.4011 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Control § 56.4011 Abandoned electric circuits. Abandoned electric circuits shall be deenergized...

  8. 30 CFR 56.4011 - Abandoned electric circuits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Abandoned electric circuits. 56.4011 Section 56.4011 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Control § 56.4011 Abandoned electric circuits. Abandoned electric circuits shall be deenergized...

  9. 30 CFR 56.4011 - Abandoned electric circuits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Abandoned electric circuits. 56.4011 Section 56.4011 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Control § 56.4011 Abandoned electric circuits. Abandoned electric circuits shall be deenergized...

  10. 30 CFR 56.4011 - Abandoned electric circuits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Abandoned electric circuits. 56.4011 Section 56.4011 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Control § 56.4011 Abandoned electric circuits. Abandoned electric circuits shall be deenergized...

  11. 30 CFR 57.4011 - Abandoned electric circuits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Abandoned electric circuits. 57.4011 Section 57.4011 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... and Control § 57.4011 Abandoned electric circuits. Abandoned electric circuits shall be...

  12. 30 CFR 57.4011 - Abandoned electric circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Abandoned electric circuits. 57.4011 Section 57.4011 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... and Control § 57.4011 Abandoned electric circuits. Abandoned electric circuits shall be...

  13. 30 CFR 57.4011 - Abandoned electric circuits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Abandoned electric circuits. 57.4011 Section 57.4011 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... and Control § 57.4011 Abandoned electric circuits. Abandoned electric circuits shall be...

  14. Non-Abandonment as a Foundation for Inclusive School Practice

    ERIC Educational Resources Information Center

    Razer, Michal; Friedman, Victor J.

    2013-01-01

    The authors of this article describe an essential feature of inclusive educational practice: "non-abandonment". When students' needs and difficult behavior are overwhelming, teachers may abandon them emotionally as a defensive reaction to their own experience of emotional distress and helplessness. Non-abandonment represents a…

  15. 30 CFR 256.56 - Lease-specific abandonment accounts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Lease-specific abandonment accounts. 256.56... OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Bonding § 256.56 Lease-specific abandonment accounts. (a) The Regional Director may authorize you to establish a lease-specific abandonment account...

  16. 30 CFR 900.14 - Abandoned mine land programs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Abandoned mine land programs. 900.14 Section 900.14 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE... Abandoned mine land programs. Programs for reclamation of abandoned mine lands are codified under...

  17. 30 CFR 900.14 - Abandoned mine land programs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Abandoned mine land programs. 900.14 Section 900.14 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE... Abandoned mine land programs. Programs for reclamation of abandoned mine lands are codified under...

  18. 30 CFR 900.14 - Abandoned mine land programs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Abandoned mine land programs. 900.14 Section 900.14 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE... Abandoned mine land programs. Programs for reclamation of abandoned mine lands are codified under...

  19. 25 CFR 214.29 - Prospecting; abandonment of mines.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Prospecting; abandonment of mines. 214.29 Section 214.29... RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.29 Prospecting; abandonment of mines. All prospecting or mining operations or the abandonment of a well or mine shall be subject to the approval of...

  20. 25 CFR 214.29 - Prospecting; abandonment of mines.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Prospecting; abandonment of mines. 214.29 Section 214.29... RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.29 Prospecting; abandonment of mines. All prospecting or mining operations or the abandonment of a well or mine shall be subject to the approval of...

  1. 25 CFR 214.29 - Prospecting; abandonment of mines.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Prospecting; abandonment of mines. 214.29 Section 214.29... RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.29 Prospecting; abandonment of mines. All prospecting or mining operations or the abandonment of a well or mine shall be subject to the approval of...

  2. 30 CFR 900.14 - Abandoned mine land programs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Abandoned mine land programs. 900.14 Section 900.14 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE... Abandoned mine land programs. Programs for reclamation of abandoned mine lands are codified under...

  3. 30 CFR 900.14 - Abandoned mine land programs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Abandoned mine land programs. 900.14 Section 900.14 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE... Abandoned mine land programs. Programs for reclamation of abandoned mine lands are codified under...

  4. 25 CFR 214.29 - Prospecting; abandonment of mines.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Prospecting; abandonment of mines. 214.29 Section 214.29... RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.29 Prospecting; abandonment of mines. All prospecting or mining operations or the abandonment of a well or mine shall be subject to the approval of...

  5. 25 CFR 214.29 - Prospecting; abandonment of mines.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Prospecting; abandonment of mines. 214.29 Section 214.29... RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.29 Prospecting; abandonment of mines. All prospecting or mining operations or the abandonment of a well or mine shall be subject to the approval of...

  6. Stream salamanders as indicators of stream quality in Maryland, USA

    USGS Publications Warehouse

    Southerland, M.T.; Jung, R.E.; Baxter, D.P.; Chellman, I.C.; Mercurio, G.; Volstad, J.H.

    2004-01-01

    Biological indicators are critical to the protection of small, headwater streams and the ecological values they provide. Maryland and other state monitoring programs have determined that fish indicators are ineffective in small streams, where stream salamanders may replace fish as top predators. Because of their life history, physiology, abundance, and ubiquity, stream salamanders are likely representative of biological integrity in these streams. The goal of this study was to determine whether stream salamanders are effective indicators of ecological conditions across biogeographic regions and gradients of human disturbance. During the summers of 2001 and 2002, we intensively surveyed for stream salamanders at 76 stream sites located west of the Maryland Coastal Plain, sites also monitored by the Maryland Biological Stream Survey (MBSS) and City of Gaithersburg. We found 1,584 stream salamanders, including all eight species known in Maryland, using two 15 ? 2 m transects and two 4 m2 quadrats that spanned both stream bank and channel. We performed removal sampling on transects to estimate salamander species detection probabilities, which ranged from 0.67-0.85. Stepwise regressions identified 15 of 52 non-salamander variables, representing water quality, physical habitat, land use, and biological conditions, which best predicted salamander metrics. Indicator development involved (1) identifying reference (non-degraded) and degraded sites (using percent forest, shading, riparian buffer width, aesthetic rating, and benthic macroinvertebrate and fish indices of biotic integrity); (2) testing 12 candidate salamander metrics (representing species richness and composition, abundance, species tolerance, and reproductive function) for their ability to distinguish reference from degraded sites; and (3) combining metrics into an index that effectively discriminated sites according to known stream conditions. Final indices for Highlands, Piedmont, and Non-Coastal Plain

  7. A Study on the Thermal Characteristics of Space Abandoned Satellites

    NASA Astrophysics Data System (ADS)

    Shaohua, Zhang

    Abstract: Influenced by the limited space resources and the increased space debris, it is very exigent to clean the orbital abandoned satellite. The thermal characteristic of the abandoned satellite is a key parameter for the infrared radiation study, and it is also an important gist to estimate whether or not the satellite can be worked correctly. And this paper researched on the thermal analysis of the LEO and GEO abandoned satellite, and has been acquired the temperature variety law for the the space abandoned target, which is very significant for apperceiving the space situation and cleaning the space abandoned satellites and other debris initiatively.    

  8. Venus - Sinuous Channel

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This full resolution radar mosaic from Magellan at 49 degrees south latitude, 273 degrees east longitude of an area with dimensions of 130 by 190 kilometers (81 by 118 miles), shows a 200 kilometer (124 mile) segment of a sinuous channel on Venus. The channel is approximately 2 kilometers (1.2 miles) wide. These channel-like features are common on the plains of Venus. In some places they appear to have been formed by lava which may have melted or thermally eroded a path over the plains' surface. Most are 1 to 3 kilometers (0.6 to 2 miles) wide. They resemble terrestrial rivers in some respects, with meanders, cutoff oxbows, and abandoned channel segments. However, Venus channels are not as tightly sinuous as terrestrial rivers. Most are partly buried by younger lava plains, making their sources difficult to identify. A few have vast radar-dark plains units associated with them, suggesting large flow volumes. These channels appear to be older than other channel types on Venus, as they are crossed by fractures and wrinkle ridges, and are often buried by other volcanic materials. In addition, they appear to run both upslope and downslope, suggesting that the plains were warped by regional tectonism after channel formation. Resolution of the Magellan data is about 120 meters (400 feet).

  9. Stream Studies.

    ERIC Educational Resources Information Center

    Hamilton City Board of Education (Ontario).

    This manual provides teachers with some knowledge of ecological study methods and techniques used in collecting data when plants and animals are studied in the field. Most activities deal with the interrelatedness of plant and animal life to the structure and characteristics of a stream and pond. Also included in this unit plan designed for the…

  10. Stream Studies.

    ERIC Educational Resources Information Center

    Stein, Scott

    1997-01-01

    Outlines a science curriculum reform effort aimed at enabling students to collect original data concerning an environmental parameter such as water quality on a yearly basis. Students track the overall health of the stream by analyzing both biotic and abiotic factors. (DDR)

  11. Abandoned metal mine stability risk evaluation.

    PubMed

    Bétournay, Marc C

    2009-10-01

    The abandoned mine legacy is critical in many countries around the world, where mine cave-ins and surface subsidence disruptions are perpetual risks that can affect the population, infrastructure, historical legacies, land use, and the environment. This article establishes abandoned metal mine failure risk evaluation approaches and quantification techniques based on the Canadian mining experience. These utilize clear geomechanics considerations such as failure mechanisms, which are dependent on well-defined rock mass parameters. Quantified risk is computed using probability of failure (probabilistics using limit-equilibrium factors of safety or applicable numerical modeling factor of safety quantifications) times a consequence impact value. Semi-quantified risk can be based on failure-case-study-based empirical data used in calculating probability of failure, and personal experience can provide qualified hazard and impact consequence assessments. The article provides outlines for land use and selection of remediation measures based on risk. PMID:19645755

  12. Explosives remain preferred methods for platform abandonment

    SciTech Connect

    Pulsipher, A.; Daniel, W. IV; Kiesler, J.E.; Mackey, V. III

    1996-05-06

    Economics and safety concerns indicate that methods involving explosives remain the most practical and cost-effective means for abandoning oil and gas structures in the Gulf of Mexico. A decade has passed since 51 dead sea turtles, many endangered Kemp`s Ridleys, washed ashore on the Texas coast shortly after explosives helped remove several offshore platforms. Although no relationship between the explosions and the dead turtles was ever established, in response to widespread public concern, the US Minerals Management Service (MMS) and National Marine Fisheries Service (NMFS) implemented regulations limiting the size and timing of explosive charges. Also, more importantly, they required that operators pay for observers to survey waters surrounding platforms scheduled for removal for 48 hr before any detonations. If observers spot sea turtles or marine mammals within the danger zone, the platform abandonment is delayed until the turtles leave or are removed. However, concern about the effects of explosives on marine life remains.

  13. Detecting abandoned objects using interacting multiple models

    NASA Astrophysics Data System (ADS)

    Becker, Stefan; Münch, David; Kieritz, Hilke; Hübner, Wolfgang; Arens, Michael

    2015-10-01

    In recent years, the wide use of video surveillance systems has caused an enormous increase in the amount of data that has to be stored, monitored, and processed. As a consequence, it is crucial to support human operators with automated surveillance applications. Towards this end an intelligent video analysis module for real-time alerting in case of abandoned objects in public spaces is proposed. The overall processing pipeline consists of two major parts. First, person motion is modeled using an Interacting Multiple Model (IMM) filter. The IMM filter estimates the state of a person according to a finite-state, discrete-time Markov chain. Second, the location of persons that stay at a fixed position defines a region of interest, in which a nonparametric background model with dynamic per-pixel state variables identifies abandoned objects. In case of a detected abandoned object, an alarm event is triggered. The effectiveness of the proposed system is evaluated on the PETS 2006 dataset and the i-Lids dataset, both reflecting prototypical surveillance scenarios.

  14. Ecoregions and stream morphology in eastern Oklahoma

    USGS Publications Warehouse

    Splinter, D.K.; Dauwalter, D.C.; Marston, R.A.; Fisher, W.L.

    2010-01-01

    Broad-scale variables (i.e., geology, topography, climate, land use, vegetation, and soils) influence channel morphology. How and to what extent the longitudinal pattern of channel morphology is influenced by broad-scale variables is important to fluvial geomorphologists and stream ecologists. In the last couple of decades, there has been an increase in the amount of interdisciplinary research between fluvial geomorphologists and stream ecologists. In a historical context, fluvial geomorphologists are more apt to use physiographic regions to distinguish broad-scale variables, while stream ecologists are more apt to use the concept of an ecosystem to address the broad-scale variables that influence stream habitat. For this reason, we designed a study using ecoregions, which uses physical and biological variables to understand how landscapes influence channel processes. Ecoregions are delineated by similarities in geology, climate, soils, land use, and potential natural vegetation. In the fluvial system, stream form and function are dictated by processes observed throughout the fluvial hierarchy. Recognizing that stream form and function should differ by ecoregion, a study was designed to evaluate how the characteristics of stream channels differed longitudinally among three ecoregions in eastern Oklahoma, USA: Boston Mountains, Ozark Highlands, and Ouachita Mountains. Channel morphology of 149 stream reaches was surveyed in 1st- through 4th-order streams, and effects of drainage area and ecoregion on channel morphology was evaluated using multiple regressions. Differences existed (?????0.05) among ecoregions for particle size, bankfull width, and width/depth ratio. No differences existed among ecoregions for gradient or sinuosity. Particle size was smallest in the Ozark Highlands and largest in the Ouachita Mountains. Bankfull width was larger in the Ozark Highlands than in the Boston Mountains and Ouachita Mountains in larger streams. Width/depth ratios of the

  15. Macrophyte presence is an indicator of enhanced denitrification and nitrification in sediments of a temperate restored agricultural stream

    EPA Science Inventory

    Stream macrophytes are often removed with their sediments to deepen stream channels, stabilize channel banks, or provide habitat for target species. These sediments may support enhanced nitrogen processing. To evaluate sediment nitrogen processing, identify seasonal patterns, and...

  16. Incremental learning from stream data.

    PubMed

    He, Haibo; Chen, Sheng; Li, Kang; Xu, Xin

    2011-12-01

    Recent years have witnessed an incredibly increasing interest in the topic of incremental learning. Unlike conventional machine learning situations, data flow targeted by incremental learning becomes available continuously over time. Accordingly, it is desirable to be able to abandon the traditional assumption of the availability of representative training data during the training period to develop decision boundaries. Under scenarios of continuous data flow, the challenge is how to transform the vast amount of stream raw data into information and knowledge representation, and accumulate experience over time to support future decision-making process. In this paper, we propose a general adaptive incremental learning framework named ADAIN that is capable of learning from continuous raw data, accumulating experience over time, and using such knowledge to improve future learning and prediction performance. Detailed system level architecture and design strategies are presented in this paper. Simulation results over several real-world data sets are used to validate the effectiveness of this method. PMID:22057060

  17. Effects of urban stream burial on nitrogen uptake and ecosystem metabolism: implications for watershed nitrogen and carbon fluxes

    EPA Science Inventory

    Urbanization has resulted in extensive burial and channelization of headwater streams, yet little is known about impacts on stream ecosystem functions critical for reducing downstream nitrogen pollution. To characterize the biogeochemical impact of stream burial, we measured NO3...

  18. Biogeochemistry and Hydrology in Streams Impacted by Legacy Sediments and Urbanization: Implications for Stream Restoration

    EPA Science Inventory

    The groundwater–surface water interface, consisting of shallow groundwater adjacent to stream channels, is a hot spot for nitrogen removal processes, a storage zone for other solutes, and a target for restoration activities. Characterizing groundwater-surface water interac...

  19. The burial of headwater streams in drainage pipes reduces in-stream nitrate retention: results from two US metropolitan areas

    EPA Science Inventory

    Nitrogen (N) retention in stream networks is an important ecosystem service that may be affected by the widespread burial of headwater streams in urban watersheds. Stream burial occurs when segments of a channel are encased in drainage pipe and buried beneath the land surface to...

  20. Evaluation of reclaimed abandoned bentonite mine lands

    SciTech Connect

    Edinger, K.D.; Schuman, G.E.; Vance, G.F.

    1999-07-01

    In 1985, the Abandoned Mined Land Division of the Wyoming Department of Environmental Quality began reclamation of 4,148 ha of abandoned bentonite mined lands. Calcium amendments and sawmill wood wastes were applied to the regraded spoils to enhance water infiltration, displacement of Na on the clay spoil, and leaching of the displaced Na and other soluble salts. Revegetation of these lands was generally successful, but after several years small areas (0.1--0.2 ha) began to show signs of vegetation die-back and to prescribe corrective treatment options. A randomized block design was imposed on study areas near Upton, Colony, and Greybull, Wyoming to characterize spoil chemical properties of good, moderate, and dead vegetation zones, which were subjectively delineated by visual vegetation cover and density differences. Spoil analyses indicated exchangeable-sodium (Na) concentrations were high and the dead vegetation zones exhibited exchangeable-sodium-percentages (ESP) above 50%, while surrounding good vegetation zones exhibited ESP values <10%. This coupled with low soluble-Na concentrations (<2 cmol/kg) suggests insufficient calcium (Ca) amendments were initially applied to ameliorate the sodic conditions of the spoil. The sampling design used to determine Ca amendment rates, which consisted of a composite of 5 spoil cores taken from each 0.8 ha area, was apparently insufficient to account for the highly heterogeneous spoil material that occurred throughout these abandoned bentonite reclamation sites. To revegetate these small degraded sites, additional Ca amendment would be necessary and reseeding would be required. However, the authors recommend further monitoring of the affected sites to determine if unfavorable conditions continue to degrade the reclaimed landscape before any attempt is made to rehabilitate the affected sites. If the degraded sites are stable, further Remediation efforts are not warranted because small areas of little or no vegetation are

  1. 75 years after mining ends stream insect diversity is still affected by heavy metals.

    PubMed

    Lefcort, Hugh; Vancura, James; Lider, Edward L

    2010-11-01

    A century of heavy metal mining in the western United States has left a legacy of abandoned mines. While large operations have left a visible reminder, smaller one and two-man operations have been overgrown and largely forgotten. We revisited an area of northern Idaho that has not had active mining since at least 1932 and probably since 1910. At three sites along each of 10 mountain streams we sampled larval stream insects and correlated their community diversity to stream levels of arsenic, cadmium, lead, zinc, pH, temperature, oxygen content, and conductivity. Although the streams appear pristine, multivariate statistics indicated that cadmium and zinc levels were significantly correlated with fewer animals, fewer families, a smaller percentage of plecopterans (stoneflies), and lower Shannon H diversity values. After at least 75 years, abandoned mines appear to be still influencing stream communities. PMID:20680454

  2. Stream capture and piracy recorded by provenance in fluvial fan strata

    NASA Astrophysics Data System (ADS)

    Mikesell, Leslie R.; Weissmann, Gary S.; Karachewski, John A.

    2010-03-01

    Stream capture and piracy in tectonically active regions have been described in geomorphic systems worldwide; however, few studies show the influence stream capture has on the rock record. We present an analysis of fluvial fan stratigraphy that developed as a result of multiple stream capture events, building a complex stratigraphic succession beneath the Lawrence Livermore National Laboratory (LLNL), California. The LLNL site is located in the southeast portion of the tectonically active Livermore Basin, a transpressional basin in the California Coast Ranges. Geomorphic evidence for this stream capture include: (1) the Arroyo Seco enters the basin from the south through an uplifted fault block, (2) south of this fault block lies an abandoned Arroyo Seco fluvial fan, (3) north of the fault block, in the Livermore Basin, Arroyo Seco built a 7-km 2 fluvial fan, apparently forcing the Arroyo Las Positas, a smaller stream that enters the basin from the east, northward around the Arroyo Seco fan, and (4) a knickpoint exists near the point of capture on Arroyo Seco. Stratigraphic evidence reflecting this shift in the Arroyo Seco position into the Livermore Basin was evaluated through a provenance study of 215 gravel units from 34 boreholes spaced evenly over the 2.6 km 2 LLNL site. The Arroyo Seco derives its sediment from both the Jurassic-Cretaceous Franciscan Assemblage and the Altamont Hills (which are comprised of Mesozoic Great Valley Group and Tertiary continental sediments). The Arroyo Las Positas drains only the Altamont Hills and thus lacks the Franciscan Assemblage-derived clasts. The origin of the individual gravel units was determined by the percentage of Franciscan Assemblage indicator pebbles (red chert, green chert and blueschist) in the samples. Through this analysis, we determined that high-percentage Franciscan Assemblage-derived clasts were present below a depth of approximately 35 m below the surface, low-percentage Franciscan Assemblage

  3. Crimes and misdemeanours: the case of child abandonment

    PubMed Central

    Giordano, S

    2007-01-01

    In 2002, a child was abandoned in a Burger King restaurant in Amsterdam by a Chinese woman, who hoped that the baby would be picked up by someone able to give the child a better life. She was convicted for child abandonment and imprisoned. Whereas some forms of child abandonment are criminalised, others are socially accepted and not even on the ethics agenda. This paper is an invitation to reflect on the inconsistency in the ways in which we prosecute, punish or try to correct some forms of child abandonment and yet make allowances for others. PMID:17209107

  4. Crimes and misdemeanours: the case of child abandonment.

    PubMed

    Giordano, S

    2007-01-01

    In 2002, a child was abandoned in a Burger King restaurant in Amsterdam by a Chinese woman, who hoped that the baby would be picked up by someone able to give the child a better life. She was convicted for child abandonment and imprisoned. Whereas some forms of child abandonment are criminalised, others are socially accepted and not even on the ethics agenda. This paper is an invitation to reflect on the inconsistency in the ways in which we prosecute, punish or try to correct some forms of child abandonment and yet make allowances for others. PMID:17209107

  5. Stream, Inverted

    NASA Technical Reports Server (NTRS)

    2006-01-01

    27 July 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the inverted, eroded remains of a channel -- now standing as a complex ridge that runs across the middle of this scene -- in dust-mantled terrain west of Sinus Meridiani, Mars. The original channel might have been carved by running water, but too little detail remains today to provide any certainty as to whether water was the culprit.

    Location near: 5.6oN, 7.6oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Northern Spring

  6. Inner gorge-slot canyon system produced by repeated stream incision (eastern Alps): Significance for development of bedrock canyons

    NASA Astrophysics Data System (ADS)

    Sanders, Diethard; Wischounig, Lukas; Gruber, Alfred; Ostermann, Marc

    2014-06-01

    Many inner bedrock gorges of the Alps show abrupt downstream changes in gorge width, as well as channel type and gradient, as a result of epigenetic incision of slot canyons. Many slot canyons also are associated with older gorge reaches filled with Quaternary deposits. The age of slot canyons and inner bedrock gorges, however, commonly is difficult to constrain. For the inner-bedrock gorge system of the Steinberger Ache catchment (eastern Alps), active slot canyons as well as older, abandoned gorge reaches filled with upper Würmian proglacial deposits record three phases of gorge development and slot-canyon incision. A 234U/230Th age of cement of 29.7 ± 1.8 ka in fluvial conglomerates onlapping the flank of an inner gorge fits with late Würmian valley-bottom aggradation shortly before pleniglacial conditions; in addition, the age indicates that at least the corresponding canyon reach must be older. During advance of ice streams in the buildup of the Last Glacial Maximum (LGM), the catchment was blocked, and a proglacial lake formed. Bedrock gorges submerged in that lake were filled with fluviolacustrine deposits. During the LGM, the entire catchment was overridden by ice. During post-glacial reincision, streams largely found again their preexisting inner bedrock canyons. In some areas, however, the former stream course was 'missed', and a slot canyon formed. The distribution of Pleistocene deposits, the patterns of canyon incision, and the mentioned U/Th cementation age, however, together record a further discrete phase of base-level rise and stream incision well before the LGM. The present course of Steinberger Ache and its tributaries is a patchwork of (1) slot canyons incised during post-glacial incision; (2) vestiges of slot canyons cut upon an earlier (middle to late Würmian?) cycle of base-level rise and fall; (3) reactivated reaches up to ~ 200 m in width of inner bedrock gorge that are watershed at present, and more than at least ~ 30 ka in age; and (4

  7. Biogeochemical and suspended sediment responses to permafrost degradation in stream banks in Taylor Valley, Antarctica

    NASA Astrophysics Data System (ADS)

    Gooseff, M. N.; Van Horn, D.; Sudman, Z.; McKnight, D. M.; Welch, K. A.; Lyons, W. B.

    2015-09-01

    Stream channels in the McMurdo Dry Valleys are typically wide, incised, and stable. At typical flows, streams occupy a fraction of the oversized channels, providing habitat for algal mats. In January 2012, we discovered substantial channel erosion and subsurface thermomechanical erosion undercutting banks of Crescent Stream. We sampled stream water along the impacted reach and compared concentrations of solutes to the long-term data from this stream (~20 years of monitoring). Thermokarst-impacted stream water demonstrated higher electrical conductivity, and concentrations of chloride, sulfate, sodium, suspended sediments, and nitrate than the long-term medians. These results suggest that this mode of lateral permafrost degradation may substantially impact stream solute loads and potentially fertilize stream and lake ecosystems. The potential for sediment to scour or bury stream algal mats is yet to be determined, though it may offset impacts of associated increased nutrient loads to streams.

  8. Variability in stream flow and specific discharge along three headwater streams in central Montana, USA

    NASA Astrophysics Data System (ADS)

    Payn, R. A.; Gooseff, M. N.; Jencso, K.; McGlynn, B. L.

    2008-12-01

    Specific discharge is commonly used to quantify the runoff at a watershed outlet with respect to the watershed area. However, little is known about how specific discharge is distributed along stream valleys within watersheds. Analyses of stream flow and specific discharge distributions may provide insight into the interactions of runoff generating processes and stream-subsurface exchange. We compare longitudinal distributions of stream channel flow and specific discharge in 3 mountain headwater streams of the Tenderfoot Creek Experimental Forest in central Montana, comprising 2.6-, 1.4-, and 2.3-km valley lengths with 5.5, 4.0, and 4.5 km2 of total contributing area, respectively. We performed an instantaneous tracer release every 100 m along each valley, and used dilution gauging to estimate stream channel flow from each release. Multiple series of tracer tests were performed during the summer baseflow recession following snowmelt. We used topographic analysis of digital elevation models to quantify sub-basin contributing areas to each location where flow was measured. We then calculated specific discharges by normalizing each estimate of stream channel flow by its corresponding sub-basin contributing area. The study streams demonstrated substantial variability in specific discharge in both space and time. For example, a 1300-m upstream segment showed consistently lower specific discharges than an 800-m downstream segment in the same stream, where the ratio of specific discharges in the upstream segment to specific discharges in the downstream segment generally ranged from 0.7 at higher baseflows to 0.3 at lower baseflows. The differences in specific discharges over the segments were likely driven by both the variability in source water input from contributing areas and the variability in the importance of segment-scale stream-subsurface exchange relative to stream channel flow. We compare the stream flow and specific discharge distributions across space and time

  9. Biological and economic impact of stream alteration in the Virginia Piedmont

    USGS Publications Warehouse

    Whelan, James B.

    1981-01-01

    A 31 month (September 1974 - March 1977) study was conducted on warmwater streams located in the Roanoke Creek watershed of the Piedmont Region of Virginia. The purpose of the study was to determine the effects of stream channelization on the aquatic/riparian wildlife resource and agricultural land-use patterns associated with the altered streams. Three streams, which were channelized 3, 6, and 10 years prior to initiation of the study, and teo unaltered streams, were selected as representative streams for the study. Recently channelized streams lacked overstory cover but has an abundance of herbaceous and small woody plany cover, Conversely, control streams had significantly larger percentages of trees over 46 m tall. Plant species diversity, foliage height diversity, and evenness diversity increased as age since channelization increased. No major differences in water quality parameters were found for either channelized or control streams, although channelized streams had greater deposits of sand and lesser amount of rock, rubble, and gravel. These changes in substrate composition did not significantly modify actual stream flow rates. Fish species composition and species diversity among channelized and unchannelized streams were only slightly different, with most of the differences probably attributable to strays from adjacent habitats, However, evenness diversity for fish communities was lower in channelized streams. The benthic population showed greater changes than did the fish populations with an increase in Chironominae tolerant of unstable sand substrates in channelized streams. Evenness diversity of benthic populations was also higher and showed more consistency in the control stream than in channelized streams. Evenness diversity of benthic communities in control stream averaged between 0.5 to 0.6 and was quite consistent; whereas, the average in the two youngest channelized streams was 0.3 to 0.4. These data seem to indicate decreased stability of the

  10. 32 CFR 644.494 - Donation, abandonment or destruction.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Donation, abandonment or destruction. 644.494 Section 644.494 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL... Land) § 644.494 Donation, abandonment or destruction. (a) General. Improvements may be...

  11. 32 CFR 644.494 - Donation, abandonment or destruction.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Donation, abandonment or destruction. 644.494 Section 644.494 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL... Land) § 644.494 Donation, abandonment or destruction. (a) General. Improvements may be...

  12. 32 CFR 644.494 - Donation, abandonment or destruction.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Donation, abandonment or destruction. 644.494 Section 644.494 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL... Land) § 644.494 Donation, abandonment or destruction. (a) General. Improvements may be...

  13. 37 CFR 2.135 - Abandonment of application or mark.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... mark. 2.135 Section 2.135 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... Abandonment of application or mark. After the commencement of an opposition, concurrent use, or interference proceeding, if the applicant files a written abandonment of the application or of the mark without...

  14. 37 CFR 2.135 - Abandonment of application or mark.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... mark. 2.135 Section 2.135 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... Abandonment of application or mark. After the commencement of an opposition, concurrent use, or interference proceeding, if the applicant files a written abandonment of the application or of the mark without...

  15. 37 CFR 2.135 - Abandonment of application or mark.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... mark. 2.135 Section 2.135 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... Abandonment of application or mark. After the commencement of an opposition, concurrent use, or interference proceeding, if the applicant files a written abandonment of the application or of the mark without...

  16. 37 CFR 2.135 - Abandonment of application or mark.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... mark. 2.135 Section 2.135 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... Abandonment of application or mark. After the commencement of an opposition, concurrent use, or interference proceeding, if the applicant files a written abandonment of the application or of the mark without...

  17. 37 CFR 2.135 - Abandonment of application or mark.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... mark. 2.135 Section 2.135 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... Abandonment of application or mark. After the commencement of an opposition, concurrent use, or interference proceeding, if the applicant files a written abandonment of the application or of the mark without...

  18. 21 CFR 1315.27 - Abandonment of quota.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 9 2012-04-01 2012-04-01 false Abandonment of quota. 1315.27 Section 1315.27 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE IMPORTATION AND PRODUCTION QUOTAS FOR EPHEDRINE, PSEUDOEPHEDRINE, AND PHENYLPROPANOLAMINE Individual Manufacturing Quotas § 1315.27 Abandonment...

  19. 21 CFR 1315.27 - Abandonment of quota.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Abandonment of quota. 1315.27 Section 1315.27 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE IMPORTATION AND PRODUCTION QUOTAS FOR EPHEDRINE, PSEUDOEPHEDRINE, AND PHENYLPROPANOLAMINE Individual Manufacturing Quotas § 1315.27 Abandonment...

  20. 21 CFR 1315.27 - Abandonment of quota.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 9 2014-04-01 2014-04-01 false Abandonment of quota. 1315.27 Section 1315.27 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE IMPORTATION AND PRODUCTION QUOTAS FOR EPHEDRINE, PSEUDOEPHEDRINE, AND PHENYLPROPANOLAMINE Individual Manufacturing Quotas § 1315.27 Abandonment...

  1. 21 CFR 1315.27 - Abandonment of quota.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 9 2013-04-01 2013-04-01 false Abandonment of quota. 1315.27 Section 1315.27 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE IMPORTATION AND PRODUCTION QUOTAS FOR EPHEDRINE, PSEUDOEPHEDRINE, AND PHENYLPROPANOLAMINE Individual Manufacturing Quotas § 1315.27 Abandonment...

  2. 21 CFR 1315.27 - Abandonment of quota.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Abandonment of quota. 1315.27 Section 1315.27 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE IMPORTATION AND PRODUCTION QUOTAS FOR EPHEDRINE, PSEUDOEPHEDRINE, AND PHENYLPROPANOLAMINE Individual Manufacturing Quotas § 1315.27 Abandonment...

  3. 36 CFR 13.45 - Unattended or abandoned property.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Unattended or abandoned property. 13.45 Section 13.45 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA General Provisions § 13.45 Unattended or abandoned...

  4. 36 CFR 13.45 - Unattended or abandoned property.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Unattended or abandoned property. 13.45 Section 13.45 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA General Provisions § 13.45 Unattended or abandoned...

  5. 36 CFR 13.45 - Unattended or abandoned property.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Unattended or abandoned property. 13.45 Section 13.45 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA General Provisions § 13.45 Unattended or abandoned property. (a) This section applies to all...

  6. 49 CFR 195.59 - Abandonment or deactivation of facilities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....phmsa.dot.gov or contact the NPMS National Repository at 703-317-3073. A digital data format is... abandonment, and certification that, to the best of the operator's knowledge, all of the reasonably available information requested was provided and, to the best of the operator's knowledge, the abandonment was...

  7. 42 CFR 498.69 - Dismissal for abandonment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Dismissal for abandonment. 498.69 Section 498.69 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... IN THE MEDICAID PROGRAM Hearings § 498.69 Dismissal for abandonment. (a) The ALJ may dismiss...

  8. 32 CFR 644.494 - Donation, abandonment or destruction.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Donation, abandonment or destruction. 644.494 Section 644.494 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal Disposal of Buildings and Other Improvements (without the Related Land) § 644.494 Donation, abandonment...

  9. 49 CFR 192.727 - Abandonment or deactivation of facilities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... persons other than those authorized by the operator. (2) A mechanical device or fitting that will prevent... abandonment, diameter, method of abandonment, and certification that, to the best of the operator's knowledge, all of the reasonably available information requested was provided and, to the best of the...

  10. 49 CFR 192.727 - Abandonment or deactivation of facilities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... persons other than those authorized by the operator. (2) A mechanical device or fitting that will prevent... abandonment, diameter, method of abandonment, and certification that, to the best of the operator's knowledge, all of the reasonably available information requested was provided and, to the best of the...

  11. 49 CFR 192.727 - Abandonment or deactivation of facilities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... persons other than those authorized by the operator. (2) A mechanical device or fitting that will prevent... abandonment, diameter, method of abandonment, and certification that, to the best of the operator's knowledge, all of the reasonably available information requested was provided and, to the best of the...

  12. 28 CFR 104.35 - Claims deemed abandoned by claimants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Claims deemed abandoned by claimants. 104.35 Section 104.35 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) SEPTEMBER 11TH VICTIM COMPENSATION FUND Claim Intake, Assistance, and Review Procedures § 104.35 Claims deemed abandoned by...

  13. 28 CFR 104.35 - Claims deemed abandoned by claimants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Claims deemed abandoned by claimants. 104.35 Section 104.35 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) SEPTEMBER 11TH VICTIM COMPENSATION FUND Claim Intake, Assistance, and Review Procedures § 104.35 Claims deemed abandoned by...

  14. 28 CFR 104.35 - Claims deemed abandoned by claimants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Claims deemed abandoned by claimants. 104.35 Section 104.35 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) SEPTEMBER 11TH VICTIM COMPENSATION FUND OF 2001 Claim Intake, Assistance, and Review Procedures § 104.35 Claims deemed abandoned...

  15. 28 CFR 104.35 - Claims deemed abandoned by claimants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Claims deemed abandoned by claimants. 104.35 Section 104.35 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) SEPTEMBER 11TH VICTIM COMPENSATION FUND Claim Intake, Assistance, and Review Procedures § 104.35 Claims deemed abandoned by...

  16. 28 CFR 104.35 - Claims deemed abandoned by claimants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Claims deemed abandoned by claimants. 104.35 Section 104.35 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) SEPTEMBER 11TH VICTIM COMPENSATION FUND OF 2001 Claim Intake, Assistance, and Review Procedures § 104.35 Claims deemed abandoned...

  17. 17 CFR 230.155 - Integration of abandoned offerings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Integration of abandoned... GENERAL RULES AND REGULATIONS, SECURITIES ACT OF 1933 General § 230.155 Integration of abandoned offerings... from integration of private and registered offerings. Because of the objectives of Rule 155 and...

  18. 17 CFR 230.155 - Integration of abandoned offerings.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 3 2014-04-01 2014-04-01 false Integration of abandoned... GENERAL RULES AND REGULATIONS, SECURITIES ACT OF 1933 General § 230.155 Integration of abandoned offerings. Compliance with paragraph (b) or (c) of this section provides a non-exclusive safe harbor from integration...

  19. 17 CFR 230.155 - Integration of abandoned offerings.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Integration of abandoned... GENERAL RULES AND REGULATIONS, SECURITIES ACT OF 1933 General § 230.155 Integration of abandoned offerings... from integration of private and registered offerings. Because of the objectives of Rule 155 and...

  20. 17 CFR 230.155 - Integration of abandoned offerings.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 2 2012-04-01 2012-04-01 false Integration of abandoned... GENERAL RULES AND REGULATIONS, SECURITIES ACT OF 1933 General § 230.155 Integration of abandoned offerings... from integration of private and registered offerings. Because of the objectives of Rule 155 and...

  1. 17 CFR 230.155 - Integration of abandoned offerings.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 2 2013-04-01 2013-04-01 false Integration of abandoned... GENERAL RULES AND REGULATIONS, SECURITIES ACT OF 1933 General § 230.155 Integration of abandoned offerings... from integration of private and registered offerings. Because of the objectives of Rule 155 and...

  2. 37 CFR 2.66 - Revival of abandoned applications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Revival of abandoned applications. 2.66 Section 2.66 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... Applicants § 2.66 Revival of abandoned applications. (a) The applicant may file a petition to revive...

  3. 37 CFR 2.66 - Revival of abandoned applications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Revival of abandoned applications. 2.66 Section 2.66 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... Applicants § 2.66 Revival of abandoned applications. (a) The applicant may file a petition to revive...

  4. Book review: old fields: dynamics and restoration of abandoned farmland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 2007 volume, “Old Fields: Dynamics and Restoration of Abandoned Farmland”, edited by VA Cramer and RJ Hobbs and published by the Society for Ecological Restoration International (Island Press), is a valuable attempt to synthesize a dozen case studies on agricultural abandonment from all of the ...

  5. Transverse mixing of simulated piscicides in small montane streams

    USGS Publications Warehouse

    Brown, Peter J.; Ard, Jenifer L.; Zale, Alexander V.

    2012-01-01

    Thorough mixing of piscicides into receiving waters is important for efficient and effective fish eradication. However, no guidance exists for the placement of drip stations with respect to mixing. Salt (NaCl) was used as a tracer to measure the mixing rates of center versus edge applications in riffle–pool, straight, and meandering sections of montane streams. The tracer was applied at either the center or the edge of a channel and measured with a conductivity meter across a downstream grid to determine the distances at which transverse mixing was complete. No advantage was accrued by applying piscicides in different types of channels because transverse mixing distance did not differ among them. However, mixing distance was significantly shorter at center applications. Chemicals entering a stream at the center of the channel mixed thoroughly within 10 stream widths, whereas chemicals entering a stream channel at the edge mixed thoroughly within 20 stream widths.

  6. Drawdown and stream depletion produced by pumping in the vicinity of a partially penetrating stream

    USGS Publications Warehouse

    Butler, J.J., Jr.; Zlotnik, V.A.; Tsou, M.-S.

    2001-01-01

    Commonly used analytical approaches for estimation of pumping-induced drawdown and stream depletion are based on a series of idealistic assumptions about the stream-aquifer system. A new solution has been developed for estimation of drawdown and stream depletion under conditions that are more representative of those in natural systems (finite width stream of shallow penetration adjoining an aquifer of limited lateral extent). This solution shows that the conventional assumption of a fully penetrating stream will lead to a significant overestimation of stream depletion (> 100 %) in many practical applications. The degree of overestimation will depend on the value of the stream leakance parameter and the distance from the pumping well to the stream. Although leakance will increase with stream width, a very wide stream will not necessarily be well represented by a model of a fully penetrating stream. The impact of lateral boundaries depends upon the distance from the pumping well to the stream and the stream leakance parameter. In most cases, aquifer width must be on the order of hundreds of stream widths before the assumption of a laterally infinite aquifer is appropriate for stream-depletion calculations. An important assumption underlying this solution is that stream-channel penetration is negligible relative to aquifer thickness. However, an approximate extension to the case of nonnegligible penetration provides reasonable results for the range of relative penetrations found in most natural systems (up to 85%). Since this solution allows consideration of a much wider range of conditions than existing analytical approaches, it could prove to be a valuable new tool for water management design and water rights adjudication purposes.

  7. Toward strict liability for abandoned mine drainage

    SciTech Connect

    Bryan, M.D.

    1983-01-01

    This note examines ways to impose responsibility for abating the pollution caused by mine drainage. It describes coal mine drainage and control techniques, then examines abatement responsibility under the common law doctrine of public nuisance, the Surface Mining Control and Reclamation Act of 1977, the Federal Water Pollution Control Act, and the Resource Conservation and Recovery Act of 1976. More statutory and regulatory controls will probably be devised in the near future, given the serious problem such drainage poses and the lack of existing controls. It is also likely, given the trend apparent in the statutes and cases, that such controls will adopt rules of strict liability for abandoned mine drainage based on mere ownership of property. 175 references.

  8. A 12-year cavern abandonment test

    NASA Astrophysics Data System (ADS)

    Bérest, P.; Brouard, B.; Hévin, G.

    2010-06-01

    In 1997-1998, an abandonment test was performed in a 950-m deep, 8000-m3 salt cavern operated by GDF SUEZ at Etrez, France. In this relatively small brine-filled cavern, which had been kept idle for 15 years before the test, thermal equilibrium was reached. A special system was designed to monitor leaks, which proved to be exceedingly small. In these conditions, brine permeation and cavern creep closure are the only factors to play significant roles in pressure evolution. This test strongly suggested that obtaining an equilibrium pressure such that the effects of these two factors were exactly equal would be reached in the long term. Four years later, pressure monitoring in the closed cavern resumed. Pressure evolution during the 2002-2009 period confirmed that cavern brine pressure will remain constant and significantly smaller than geostatic pressure in the long term, precluding any risk of fracturing and brine seepage to the overburden layers.

  9. Ventures: Conoco abandons Iranian oil deal

    SciTech Connect

    Westervelt, R.

    1995-03-22

    Conoco (Houston), the oil and gas subsidiary of DuPont, has backed out of a deal to develop offshore oil fields for Iran as a result of a week of intense pressure from the Clinton Administration. Under the agreement, Conoco Iran, a Netherlands-based affiliate, would have developed two oil fields in the Persian Gulf. The deal, valued at $1 billion, would have been the first between Iran and a U.S. company since Washington severed relations with Teheran in 1980. Conoco says it operated within the law and with the knowledge of the U.S. government in the three years the deal was being negotiated. President Clinton announced an executive order barring such deals last Tuesday, after Conoco executives informed the Administration that the deal would be abandoned if an order was issued.

  10. Nitrogen Removal by Streams and Rivers of the Upper Mississippi River Basin

    EPA Science Inventory

    Our study, based on chemistry and channel dimensions data collected at 893 randomly-selected stream and river sites in the Mississippi River basin, demonstrated the interaction of stream chemistry, stream size, and NO3-N uptake metrics across a range of stream sizes and across re...

  11. Abandoning pipelines working group regulatory issues

    SciTech Connect

    1997-03-01

    The history of hydrocarbon development in Louisiana and off its coast is one of the interdependence of technological innovation, entrepreneurial risk-taking, resource management, judicial decisions, legislation, marketing, employee good will, infrastructure and support services, coupled with favorable geologic structures that made early exploration and development relatively easy. Mariners sailing off the coast of Louisiana and Texas in the 1600`s recorded one of the earliest known natural oil seeps. They shrugged it off as unimportant, as there was no market for the substance they witnessed. The seepage, however, provided a tiny clue to the vast storehouse of hydrocarbons trapped in the earth`s crust extending from the uplands, through Louisiana`s swamps and marshes, and into the subaqueous habitats of the Gulf of Mexico-the world`s ninth largest body of water. In all cases, each move into a new geographic province required considerable change in operation philosophy and in the science supporting the exploration and development activity. As technology changed, or was developed to meet the industry`s needs, new frontiers were explored. However, with time-as is the case with any nonrenewable resource-fields and wells lost their productive life. They had to be abandoned. In fact, the Minerals Management Service suggests that within the next 10 years the offshore industry will remove 150 platforms per year, or nearly half of the current number of production units. The industry will be asked to dispose of nearly one unit every 2.4 days. If this is the case, abandonment issues are going to continue to surface.

  12. Applying geomorphologic principles to restore streams impacted by surface mining

    SciTech Connect

    Ellison, M.S.

    1996-12-31

    The combination of geomorphic principles and native material restoration techniques provides a viable alternative to traditional engineering approaches to restore rivers and streams affected by surface mining. Channels can be designed to reflect ranges of stability known to occur in natural streams for measurable parameters such as bankfull width, depth, gradient, meander radius, sinuosity and entrenchment. Stable channel geometry reduces stresses on the stream bed and banks and eliminate the need for channel lining. Methods to utilize native materials have been developed and refined to stabilize stream channels constructed to appropriate dimensions until planted riparian vegetation develops mature root systems. These native materials include root wads, willow bundles, and boulders. These methods result in improved wildlife habitat in and around channels that maintain equilibria between sediment supply and sediment transport, and between erosional and depositional rates and patterns. Two streams in Baltimore County, Maryland were disturbed during mining operations and are being restored using this approach. Goodwin Run had been channelized to allow quarrying of the Cockeysville Marble. Approximately 1100 feet of stream were restored in the fall of 1992. White Marsh Run has been channelized and relocated several times to facilitate sand and gravel mining between an urbanized area and sensitive habitats of the Chesapeake Bay. The design of the White Marsh Run Restoration Project incorporated refinements to techniques used at Goodwin Run, and entails the restoration of over 5000 feet of stream and adjacent wetland habitat.

  13. Hydrogeochemical niches associated with hyporheic exchange beneath an acid mine drainage-contaminated stream

    NASA Astrophysics Data System (ADS)

    Larson, Lance N.; Fitzgerald, Michael; Singha, Kamini; Gooseff, Michael N.; Macalady, Jennifer L.; Burgos, William

    2013-09-01

    Biological low-pH Fe(II)-oxidation creates terraced iron formations (TIFs) that remove Fe(III) from solution. TIFs can be used for remediation of acid mine drainage (AMD), however, as sediment depth increases, Fe(III)-reduction in anoxic subsurface areas may compromise treatment effectiveness. In this study we used near-surface electrical resistivity imaging (ERI) and in situ pore-water samplers to spatially resolve bulk conductivity changes within a TIF formed in a stream emanating from a large abandoned deep clay mine in Cambria County, Pennsylvania, USA. Because of the high fluid electrical conductivity of the emergent AMD (1860 μS), fresh water (42 μS) was added as a dilution tracer to visualize the spatial and temporal extent of hyporheic exchange and to characterize subsurface flow paths. Distinct hydrogeochemical niches were identified in the shallow subsurface beneath the stream by overlaying relative groundwater velocities (derived from ERI) with pore-water chemistry profiles. Niches were classified based on relatively “fast” versus “slow” rates of hyporheic exchange and oxic versus anoxic conditions. Pore-water concentrations and speciation of iron, pH, and redox potential differed between subsurface flow regimes. The greatest extent of hyporheic exchange was beneath the center of the stream, where a shallower (<10 cm) Fe(II)-oxidizing zone was observed. Meanwhile, less hyporheic exchange was observed near the channel banks, concurrent with a more pronounced, deeper (>70 cm) Fe(II)-oxidizing zone. At these locations, relatively slower groundwater exchange may promote biotic Fe(II)-oxidation and improve the long-term stability of Fe sequestered in TIFs.

  14. Availability and distribution of low flow in Anahola Stream, Kauaʻi, Hawaiʻi

    USGS Publications Warehouse

    Cheng, Chui Ling; Wolff, Reuben H.

    2012-01-01

    Anahola Stream is a perennial stream in northeast Kauaʻi, Hawaiʻi, that supports agricultural, domestic, and cultural uses within its drainage basin. Beginning in the late 19th century, Anahola streamflow was diverted by Makee Sugar Company at altitudes of 840 feet (upper intake) and 280 feet (lower intake) for irrigating sugarcane in the Keālia area. When sugarcane cultivation in the Keālia area ceased in 1988, part of the Makee Sugar Company’s surface-water collection system (Makee diversion system) in the Anahola drainage basin was abandoned. In an effort to better manage available surface-water resources, the State of Hawaiʻi Department of Hawaiian Home Lands is considering using the existing ditches in the Anahola Stream drainage basin to provide irrigation water for Native Hawaiian farmers in the area. To provide information needed for successful management of the surface-water resources, the U.S. Geological Survey investigated the availability and distribution of natural low flow in Anahola Stream and also collected low-flow data in Goldfish Stream, a stream that discharges into Kaneha Reservoir, which served as a major collection point for the Makee diversion system. Biological surveys of Anahola Stream were conducted as part of a study to determine the distribution of native and nonnative aquatic stream fauna. Results of the biological surveys indicated the presence of the following native aquatic species in Anahola Stream: ʻoʻopu ʻakupa (Sandwich Island sleeper) and ʻoʻopu naniha (Tear-drop goby) in the lower stream reaches surveyed; and ʻoʻopu nākea (Pacific river goby), ʻoʻopu nōpili (Stimpson’s goby), and ʻōpae kalaʻole (Mountain shrimp) in the middle and upper stream reaches surveyed. Nonnative aquatic species were found in all of the surveyed stream reaches along Anahola Stream. The availability and distribution of natural low flow were determined using a combination of discharge measurements made from February 2011 to May 2012

  15. Stream-subsurface nutrient dynamics in a groundwater-fed stream

    NASA Astrophysics Data System (ADS)

    Rezanezhad, F.; Niederkorn, A.; Parsons, C. T.; Van Cappellen, P.

    2015-12-01

    The stream-riparian-aquifer interface plays a major role in the regional flow of nutrients and contaminants due to a strong physical-chemical gradient that promotes the transformation, retention, elimination or release of biogenic elements. To better understand the effect of the near-stream zones on stream biogeochemistry, we conducted a field study on a groundwater-fed stream located in the rare Charitable Research Reserve, Cambridge, Ontario, Canada. This study focused on monitoring the spatial and temporal distributions of nutrient elements within the riparian and hyporheic zones of the stream. Several piezometer nests and a series of passive (diffusion) water samplers, known as peepers, were installed along longitudinal and lateral transects centered on the stream to obtain data on the groundwater chemistry. Groundwater upwelling along the stream resulted in distinctly different groundwater types and associated nitrate concentrations between small distances in the riparian zone (<4m). After the upstream source of the stream surface water, concentrations of nutrients (NO3-, NH4+, SO42- and carbon) did not significantly change before the downstream outlet. Although reduction of nitrate and sulphate were found in the riparian zone of the stream, this did not significantly influence the chemistry of the adjacent stream water. Also, minimal retention in the hyporheic zones limited reduction of reactive compounds (NO3- and SO42-) within the stream channel. The results showed that the dissolved organic carbon (DOC) and residence time of water in the hyporheic zone and in surface water limited denitrification.

  16. Deforestation alters the hydraulic and biogeochemical characteristics of small lowland Amazonian streams

    NASA Astrophysics Data System (ADS)

    Neill, Christopher; Deegan, Linda A.; Thomas, Suzanne M.; Haupert, Christie L.; Krusche, Alex V.; Ballester, Victoria M.; Victoria, Reynaldo L.

    2006-08-01

    We investigated how clearing of the tropical rainforest for cattle pasture along small, terra firme lowland streams in the Brazilian Amazon influenced stream hydraulic characteristics, solute concentrations and uptake of dissolved inorganic nitrogen and phosphorus. Measurements of stream channel structure, hydraulic properties and nutrient uptake were obtained from short-term conservative and non-conservative solute injections and an in-stream transport model in two watersheds with pairs of similar-sized forest and pasture streams in Rondônia. The pasture stream channels were deeper and had a lower cover of sandy bottom habitat and a higher cover of aquatic grass habitat than the forest streams. The pasture streams had larger transient storage zones, higher ratios of transient to channel storage and a shorter hydraulic uptake length than the forest streams. The pasture streams had lower concentrations of dissolved oxygen and NO3- and higher concentrations of dissolved Fe2+. Forest streams exhibited no NO3- uptake, but one pasture stream took up NO3- while the other did not. Uptake of NH4+ was low and variable among streams. Uptake velocities and rates of PO43- were greater in pasture streams compared to those in forest streams. In all streams, uptake lengths for NO3-, NH4+ and PO43- were long and indicated generally lower rates of uptake than in most comparably sized temperate forest streams. Uptake lengths or velocities were not correlated with stream transient storage, suggesting that other factors, such as hypoxia in pasture streams, controlled nutrient uptake. The structural differences are typical for the region, suggesting that deforestation may be altering stream hydrology and biogeochemistry over many thousands of kilometres of primary and secondary stream channels in the Amazon Basin. A better understanding of the extent and distribution of altered hydraulic and biogeochemical function in small streams is required to assess the importance of these changes

  17. Biology in focus: better lives through better science: new hope for acid streams

    USGS Publications Warehouse

    Watten, Barnaby

    1998-01-01

    Across the nation, a toxic pollutant turns clean streams orange, kills fish and plant life, and smells like rotten eggs. The culprit is acid mine drainage, the poisonous water leaking from more than 500,000 abandoned and inactive mines in 32 states. The toxic discharge is a problem for operational mines as well. In the Appalachian coal region, for example, acid mine drainage has degraded more than 8,000 miles of streams and has left some aquatic habitats virtually lifeless.

  18. Prediction of mountain stream morphology

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen; Merritt, David

    2005-08-01

    We use a large and diverse data set from mountain streams around the world to explore relationships between reach-scale channel morphology and control variables. The data set includes 177 step-pool reaches, 44 plane-bed reaches, and 114 pool-riffle reaches from the western United States, Panama, and New Zealand. We performed several iterations of stepwise discriminant analysis on these data. A three-variable discriminant function using slope (S), D84, and channel width (w) produced an error rate of 24% for the entire data set. Seventy percent of plane-bed reaches were correctly classified (16% incorrectly classified as pool-riffle and 14% incorrectly classified as step-pool). Sixty-seven percent of pool-riffle channels were correctly classified (31% incorrectly classified as plane-bed and 2% as step-pool). Eighty-nine percent of step-pool reaches were correctly classified (9% incorrectly classified as plane-bed and 2% as pool-riffle). The partial R2 values and F tests indicate that S is by far the most significant single explanatory variable. Comparison of the eight discriminant functions developed using different data sets indicates that no single variable is present in all functions, suggesting that the discriminant functions are sensitive to the specific stream reaches being analyzed. However, the three-variable discriminant function developed from the entire data set correctly classified 69% of the 159 channels included in an independent validation data set. The ability to accurately classify channel type in other regions using the three-variable discriminant function developed from the entire data set has important implications for water resources management, such as facilitating prediction of channel morphology using regional S-w-D84 relations calibrated with minimal field work.

  19. On the dynamics of stream piracy

    NASA Astrophysics Data System (ADS)

    Goren, L.; Willett, S. D.

    2012-04-01

    Drainage network reorganization by stream piracy is invoked repeatedly to explain the morphology of unique drainage patterns and as a possible mechanism inducing abrupt variations of sediment accumulation rates. However, direct evidence of stream piracy is usually rare, and is highly interpretation dependent. As a first step in assessing how probable capture events are and establishing the conditions that favor stream piracy versus the those that favor stable landscapes, we formulate analytically the physics of divide migration and capture events and study this formulation from a dynamical system point of view. The formulation is based on a one-dimensional topographic cross section between two channels that share a water divide. Two hillslope profiles diverge from the divide and drain into two fluvial bedrock tributaries, whose erosion rate is controlled by a stream power law. The rate of erosion at the bounding channels is thus a function of the upstream drainage area and local slope. A tectonically induced downward perturbation of the elevation of one of the bounding channels lowers the channel slope but at the same time increases the drainage area due to outward migration of the water divide. The changes in slope and area have opposing effect on the erosion rate at the bounding channels, so that the perturbation may either grow or be damped. We define the geomorphic and tectonic parameters that control the behavior of the system and find the regimes that lead to stable landscapes and to capture events.

  20. Magnitude of Treatment Abandonment in Childhood Cancer

    PubMed Central

    Friedrich, Paola; Lam, Catherine G.; Itriago, Elena; Perez, Rafael; Ribeiro, Raul C.; Arora, Ramandeep S.

    2015-01-01

    Background Treatment abandonment (TxA) is recognized as a leading cause of treatment failure for children with cancer in low-and-middle-income countries (LMC). However, its global frequency and burden have remained elusive due to lack of global data. This study aimed to obtain an estimate using survey and population data. Methods Childhood cancer clinicians (medical oncologists, surgeons, and radiation therapists), nurses, social workers, and psychologists involved in care of children with cancer were approached through an online survey February-May 2012. Incidence and population data were obtained from public sources. Descriptive, univariable, and multivariable analyses were conducted. Results 602 responses from 101 countries were obtained from physicians (84%), practicing pediatric hematology/oncology (83%) in general or children’s hospitals (79%). Results suggested, 23,854 (15%) of 155,088 children <15 years old newly diagnosed with cancer annually in the countries analyzed, abandon therapy. Importantly, 83% of new childhood cancer cases and 99% of TxA were attributable to LMC. The annual number of cases of TxA expected in LMC worldwide (26,166) was nearly equivalent to the annual number of cancer cases in children <15 years expected in HIC (26,368). Approximately two thirds of LMC had median TxA≥6%, but TxA ≥6% was reported in high- (9%), upper-middle- (41%), lower-middle- (80%), and low-income countries (90%, p<0.001). Most LMC centers reporting TxA>6% were outside the capital. Lower national income category, higher reliance on out-of-pocket payments, and high prevalence of economic hardship at the center were independent contextual predictors for TxA ≥6% (p<0.001). Global survival data available for more developed and less developed regions suggests TxA may account for at least a third of the survival gap between HIC and LMC. Conclusion Results show TxA is prevalent (compromising cancer survival for 1 in 7 children globally), confirm the suspected

  1. Predicting Facies Patterns within Fluvial Channel Belts

    NASA Astrophysics Data System (ADS)

    Willis, B. J.; Sech, R.; Sun, T.; Pyrcz, M.

    2014-12-01

    Reservoirs (aquifers) in fluvial channel belt sandstones can have very different subsurface flow behavior depending on the degree and distribution of internal heterogeneities. Fluvial channel belts are composed of multiple "storeys" formed as individual channel segments increase in sinuosity and then are cut off and abandoned. Heterogeneities are defined by depositional variations across storeys and inter-story connectivity patterns along the channel belt. Although commonly inferred to reflect the formative river pattern (sinuosity & braiding), the spatial arrangement of facies depend most directly on the relative preservation of deposits formed within different areas of the migrating channels and the lateral stacking arrangement of storeys due to style of bend cutoff. Grains are poorly sorted across the inner bank along upstream parts of channel bends and become better sorted laterally in downstream areas adjacent to a deeper thalweg scour. If deposition occurs evenly along the entire inner bank (bar), this grain size pattern leads to an elliptical body in planview with weak vertical grain size trends upstream and more fining-upward trend downstream. As channel bend segments migrate to a greater extent downstream, preserved inner-bank-bar deposits are increasingly dominated by upward-fining deposits and more outer-bank-deposits are preserved ("concave bank" deposits). Although concave bank deposits have highly variable character in different systems, vertical-grainsize trends tend to be weaker in straighter systems dominated by downstream-accretion, and more strongly upward-fining in higher sinuosity systems where these deposits form by eddy accretion or low flow aggradation. River cutoffs of straighter channel segments abandon slowly, leading to more gradual vertical fining. Subsurface heterogeneity prediction requires documentation of shape and character of deposits preserved in different zones within the channel (upstream and downstream inner bank, concave bank

  2. Beaded streams of Arctic permafrost landscapes

    NASA Astrophysics Data System (ADS)

    Arp, C. D.; Whitman, M. S.; Jones, B. M.; Grosse, G.; Gaglioti, B. V.; Heim, K. C.

    2014-07-01

    Beaded streams are widespread in permafrost regions and are considered a common thermokarst landform. However, little is known about their distribution, how and under what conditions they form, and how their intriguing morphology translates to ecosystem functions and habitat. Here we report on a Circum-Arctic inventory of beaded streams and a watershed-scale analysis in northern Alaska using remote sensing and field studies. We mapped over 400 channel networks with beaded morphology throughout the continuous permafrost zone of northern Alaska, Canada, and Russia and found the highest abundance associated with medium- to high-ice content permafrost in moderately sloping terrain. In the Fish Creek watershed, beaded streams accounted for half of the drainage density, occurring primarily as low-order channels initiating from lakes and drained lake basins. Beaded streams predictably transition to alluvial channels with increasing drainage area and decreasing channel slope, although this transition is modified by local controls on water and sediment delivery. Comparison of one beaded channel using repeat photography between 1948 and 2013 indicate relatively stable form and 14C dating of basal sediments suggest channel formation may be as early as the Pleistocene-Holocene transition. Contemporary processes, such as deep snow accumulation in stream gulches effectively insulates river ice and allows for perennial liquid water below most beaded stream pools. Because of this, mean annual temperatures in pool beds are greater than 2 °C, leading to the development of perennial thaw bulbs or taliks underlying these thermokarst features. In the summer, some pools stratify thermally, which reduces permafrost thaw and maintains coldwater habitats. Snowmelt generated peak-flows decrease rapidly by two or more orders of magnitude to summer low flows with slow reach-scale velocity distributions ranging from 0.1 to 0.01 m s-1, yet channel runs still move water rapidly between pools

  3. Re-Meandering of Lowland Streams: Will Disobeying the Laws of Geomorphology Have Ecological Consequences?

    PubMed Central

    Pedersen, Morten Lauge; Kristensen, Klaus Kevin; Friberg, Nikolai

    2014-01-01

    We evaluated the restoration of physical habitats and its influence on macroinvertebrate community structure in 18 Danish lowland streams comprising six restored streams, six streams with little physical alteration and six channelized streams. We hypothesized that physical habitats and macroinvertebrate communities of restored streams would resemble those of natural streams, while those of the channelized streams would differ from both restored and near-natural streams. Physical habitats were surveyed for substrate composition, depth, width and current velocity. Macroinvertebrates were sampled along 100 m reaches in each stream, in edge habitats and in riffle/run habitats located in the center of the stream. Restoration significantly altered the physical conditions and affected the interactions between stream habitat heterogeneity and macroinvertebrate diversity. The substrate in the restored streams was dominated by pebble, whereas the substrate in the channelized and natural streams was dominated by sand. In the natural streams a relationship was identified between slope and pebble/gravel coverage, indicating a coupling of energy and substrate characteristics. Such a relationship did not occur in the channelized or in the restored streams where placement of large amounts of pebble/gravel distorted the natural relationship. The analyses revealed, a direct link between substrate heterogeneity and macroinvertebrate diversity in the natural streams. A similar relationship was not found in either the channelized or the restored streams, which we attribute to a de-coupling of the natural relationship between benthic community diversity and physical habitat diversity. Our study results suggest that restoration schemes should aim at restoring the natural physical structural complexity in the streams and at the same time enhance the possibility of re-generating the natural geomorphological processes sustaining the habitats in streams and rivers. Documentation of

  4. Re-meandering of lowland streams: will disobeying the laws of geomorphology have ecological consequences?

    PubMed

    Pedersen, Morten Lauge; Kristensen, Klaus Kevin; Friberg, Nikolai

    2014-01-01

    We evaluated the restoration of physical habitats and its influence on macroinvertebrate community structure in 18 Danish lowland streams comprising six restored streams, six streams with little physical alteration and six channelized streams. We hypothesized that physical habitats and macroinvertebrate communities of restored streams would resemble those of natural streams, while those of the channelized streams would differ from both restored and near-natural streams. Physical habitats were surveyed for substrate composition, depth, width and current velocity. Macroinvertebrates were sampled along 100 m reaches in each stream, in edge habitats and in riffle/run habitats located in the center of the stream. Restoration significantly altered the physical conditions and affected the interactions between stream habitat heterogeneity and macroinvertebrate diversity. The substrate in the restored streams was dominated by pebble, whereas the substrate in the channelized and natural streams was dominated by sand. In the natural streams a relationship was identified between slope and pebble/gravel coverage, indicating a coupling of energy and substrate characteristics. Such a relationship did not occur in the channelized or in the restored streams where placement of large amounts of pebble/gravel distorted the natural relationship. The analyses revealed, a direct link between substrate heterogeneity and macroinvertebrate diversity in the natural streams. A similar relationship was not found in either the channelized or the restored streams, which we attribute to a de-coupling of the natural relationship between benthic community diversity and physical habitat diversity. Our study results suggest that restoration schemes should aim at restoring the natural physical structural complexity in the streams and at the same time enhance the possibility of re-generating the natural geomorphological processes sustaining the habitats in streams and rivers. Documentation of

  5. Stream geomorphology, bank vegetation, and three-dimensional habitat hydraulics for fish in midwestern agricultural streams

    NASA Astrophysics Data System (ADS)

    Rhoads, Bruce L.; Schwartz, John S.; Porter, Stacey

    2003-08-01

    Past work on physical habitat in streams has not explicitly considered how differences in channel planform and bank vegetation influence the three-dimensionality of habitat hydraulics. This study statistically compares frequency distributions of bed elevations, a stage-independent index of variability in flow depth, and three-dimensional velocity components for four stream reaches in east central Illinois that have different geomorphological conditions and types of bank vegetation. The analysis shows that bed elevations in a straight channelized reach are significantly less variable than bed elevations in the other three reaches. Distributions of downstream velocities do not differ significantly for two reaches with similar bank vegetation but substantially different channel morphologies, whereas distributions of cross-stream and vertical velocities are sensitive to differences both in channel planform and bank vegetation. Channel curvature enhances the variance of cross-stream and vertical velocity distributions through the production of large-scale helical motion. Conditions that result in net cross-stream flow, such as abrupt changes in curvature or deflection of the flow laterally, systematically influence the mean of cross-stream velocity distributions. Corresponding fish studies indicate that the straight, channelized reach has the lowest biotic integrity of the four sites. A detailed comparison of fish population characteristics between this reach and an unmodified reach immediately upstream reveals that the unmodified reach has significantly greater species richness, species diversity, and total biomass than the channelized reach. Thus geomorphological complexity, through its influence on the three-dimensionality of habitat hydraulics, appears to significantly influence fish community characteristics.

  6. Beaver Activity, Holocene Climate and Riparian Landscape Change Across Stream Scales in the Greater Yellowstone Ecosystem

    NASA Astrophysics Data System (ADS)

    Levine, R.; Meyer, G. A.

    2013-12-01

    Beaver (Castor canadensis) have been part of the fluvial and riparian landscape across much of North America since the Pleistocene, increasing channel habitat complexity and expanding riparian landscapes. The fur trade, however, decimated beaver populations by the 1840s, and other human activities have limited beaver in many areas, including parts of the Greater Yellowstone Ecosystem (GYE). Understanding fluctuations in beaver occupation through the Holocene will aid in understanding the natural range of variability in beaver activity as well as climatic and anthropogenic impacts to fluvial systems. We are developing a detailed chronology of beaver-assisted sedimentation and overall fluvial activity for Odell and Red Rock Creeks (basin areas 83 and 99 km2) in Centennial Valley (CV), Montana, to augment related studies on the long-term effects of beaver on smaller GYE fluvial systems (basin areas 0.1-50 km2). In developing the CV chronology, we use the presence of concentrations of beaver-chewed sticks as a proxy for beaver occupancy. Beaver-stick deposits are found in paleochannel and fluvial terrace exposures. The relative ages of exposures were determined by elevation data from airborne LiDAR and ground surveys. Numerical ages were obtained from 36 14C ages (~30 more are pending) of beaver-stick wood collected during investigation of the stratigraphy. Most beaver-stick deposits are associated with ~ 1 meter of fine-grained sediment, interpreted as overbank deposits, commonly overlying gravelly sand or pebble gravel channel deposits which is consistent with enhanced overbank sedimentation associated with active beaver dams in CV streams. The CV deposits differ from those on smaller GYE streams where beaver-stick deposits are associated with abandoned dams (berms), infilled ponds and laminated sediments. The lack of pond-related deposition associated with CV beaver-stick deposits is consistent with frequent dam breaching (≤ 5 years) in the modern channel of Odell

  7. 67. View of old, abandoned vehicular bridge near entrance to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    67. View of old, abandoned vehicular bridge near entrance to Lake Trapps. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  8. 19 CFR 147.46 - Voluntary abandonment or destruction.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...; DEPARTMENT OF THE TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.46... fair any article entered for a fair may be abandoned to the Government or destroyed under...

  9. 19 CFR 147.46 - Voluntary abandonment or destruction.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...; DEPARTMENT OF THE TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.46... fair any article entered for a fair may be abandoned to the Government or destroyed under...

  10. 19 CFR 147.46 - Voluntary abandonment or destruction.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...; DEPARTMENT OF THE TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.46... fair any article entered for a fair may be abandoned to the Government or destroyed under...

  11. 19 CFR 147.46 - Voluntary abandonment or destruction.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...; DEPARTMENT OF THE TREASURY (CONTINUED) TRADE FAIRS Disposition of Articles Entered for Fairs § 147.46... fair any article entered for a fair may be abandoned to the Government or destroyed under...

  12. 11. Remains of Douglasfir cordwood abandoned when kilns ceased operation, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Remains of Douglas-fir cordwood abandoned when kilns ceased operation, looking northeast. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID

  13. 32 CFR 644.494 - Donation, abandonment or destruction.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., destroyed or donated to a public body, upon a finding in writing by the DE (but in no event shall such... justify the decision to donate, abandon, or destroy the property proposed, without outside reference....

  14. 7 CFR 97.104 - Application or certificate abandoned.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 97.104 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) COMMODITY... abandoned certificates shall be published in the Official Journal, indicating that the variety has...

  15. 6. ANGLE VIEW OF ABANDONED INCINERATOR, INTERIOR OF BUILDING, 499 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. ANGLE VIEW OF ABANDONED INCINERATOR, INTERIOR OF BUILDING, 499 FACING NORTHWEST. - U.S. Naval Base, Pearl Harbor, Fleet Accounting & Dispersing Center, 178 Main Street, Pearl City, Honolulu County, HI

  16. BOILING HOUSE, GROUND FLOOR, ABANDONED SUGAR BIN IN CENTER. IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BOILING HOUSE, GROUND FLOOR, ABANDONED SUGAR BIN IN CENTER. IN BACKGROUND, THE ELEVATOR AND STAIRS GOING UP. VIEW FROM SOUTHWEST - Lihue Plantation Company, Sugar Mill Building, Haleko Road, Lihue, Kauai County, HI

  17. 7 CFR 97.104 - Application or certificate abandoned.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... abandoned certificates shall be published in the Official Journal, indicating that the variety has become... of such notice, the Commissioner shall publish a notice in the Official Journal that the variety...

  18. View of abandoned Yosemite Valley Railroad track grade and trestle ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of abandoned Yosemite Valley Railroad track grade and trestle remain. Seen from same camera location as HAER CA-150-39. Looking northwest - All Year Highway, Between Arch Rock & Yosemite Valley, El Portal, Mariposa County, CA

  19. The Whiteside Run restoration project: Wetlands and stream mitigation and restoration of a previously polluted stream

    SciTech Connect

    Bigatel, A.; Hellier, W.W.; Forman, J.G.; Kepler, S.

    1998-12-31

    An 841,000 m{sup 3} coal refuse pile from the operation of a now abandoned Lower Kitanning (B) coal deep mine had been the source of over 95% of the mine drainage pollution in Whiteside Run, a tributary of Moshannon Creek in Gulich and Woodward Townships, Clearfield County, Pennsylvania. Representative water quality upstream of the refuse pile was: pH = 6.9; alkalinity = 31 and acidity = 0 mg/L as CaCO{sub 3} equivalent; [Fe] = 0.85 mg/L; [Mn] = 0.31 mg/L; and [Al] = 0.25 mg/L. Representative water quality downstream of the refuse pile before th project was: pH = 3.0; alkalinity = 0 and acidity = 358 mg/L as CaCO{sub 3} equivalent; [Fe] = 7.08 mg/L; [Mn] = 0.81 mg/L; and [Al] = 46.86 mg/L. Present downstream water quality is: pH = 5.9; alkalinity = 14.3 and acidity = 8.1 mg/L as CaCO{sub 3} equivalent; [Fe] = 1.57 mg/L; [Mn] = 0.92 mg/L; and [Al] = 0.97 mg/L. There has been a significant improvement in the diversity of aquatic life since the project was undertaken. Power Operating Co., Inc., a local coal mining company, applied for authorization to conduct coal mining activities which would affect a wetland with an area of 1.7 ha and 790 m of an unnamed tributary of Moshannon Creek. Although part of this wetland was anthropogenic, having developed because earlier mining activities by others had affected the channel of the unnamed tributary of Moshannon Creek, the major portion of the area was a natural wetland. Power Operating developed 2.6 ha (6.5 ac) of constructed wetlands to replace the wetland disturbed by mining. The refuse pile was removed and placed in the backfilled area of Power`s adjacent surface mine permit, and the mitigation wetland was constructed on the area formerly occupied by the refuse pile. As a result, 6.4 km (4 mi) of formerly polluted stream are now capable of supporting fish.

  20. Lessons learned from the U.S. Geological Survey abandoned mine lands initiative: 1997-2002

    USGS Publications Warehouse

    Kimball, Briant A.; Church, Stanley E.; Besser, John M.

    2006-01-01

    Growth of the United States has been facilitated, in part, by hard-rock mining in the Rocky Mountains. Abandoned and inactive mines cause many significant environmental concerns in hundreds of watersheds. Those who have responsibility to address these environmental concerns must have a basic level of scientific information about mining and mine wastes in a watershed prior to initiating remediation activities. To demonstrate what information is needed and how to obtain that information, the U.S. Geological Survey implemented the Abandoned Mine Lands (AML) Initiative from 1997 to 2002 with demonstration studies in the Boulder River watershed in Montana and the Animas River watershed in Colorado. The AML Initiative included collection and analysis of geologic, hydrologic, geochemical, geophysical, and biological data. The synergy of this interdisciplinary analysis produced a perspective of the environmental concerns that could not have come from a single discipline. Two examples of these perspectives include (1) the combination of hydrological tracer techniques, structural geology, and geophysics help to understand the spatial distribution of loading to the streams in a way that cannot be evaluated by monitoring at a catchment outlet, and (2) the combination of toxicology and hydrology combine to illustrate that seasonal variability of toxicity conditions occurs. Lessons have been learned by listening to and collaborating with land-management agencies to understand their needs and by applying interdisciplinary methods to answer their questions.

  1. Roughness characteristics of natural channels

    USGS Publications Warehouse

    Barnes, Harry Hawthorne

    1967-01-01

    Color photographs and descriptive data are presented for 50 stream channels for which roughness coefficients have been determined. All hydraulic computations involving flow in open channels require an evaluation of the roughness characteristics of the channel. In the absence of a satisfactory quantitative procedure this evaluation remains chiefly an art. The ability to evaluate roughness coefficients must be developed through experience. One means of gaining this experience is by examining and becoming acquainted with the appearance of some typical channels whose roughness coefficients are known. The photographs and data contained in this report represent a wide range of channel conditions. Familiarity with the appearance, geometry, and roughness characteristics of these channels will improve the engineer's ability to select roughness coefficients for other channels .

  2. Water budgets and groundwater volumes for abandoned underground mines in the Western Middle Anthracite Coalfield, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania-Preliminary estimates with identification of data needs

    USGS Publications Warehouse

    Goode, Daniel J.; Cravotta, Charles A., III; Hornberger, Roger J.; Hewitt, Michael A.; Hughes, Robert E.; Koury, Daniel J.; Eicholtz, Lee W.

    2011-01-01

    This report, prepared in cooperation with the Pennsylvania Department of Environmental Protection (PaDEP), the Eastern Pennsylvania Coalition for Abandoned Mine Reclamation, and the Dauphin County Conservation District, provides estimates of water budgets and groundwater volumes stored in abandoned underground mines in the Western Middle Anthracite Coalfield, which encompasses an area of 120 square miles in eastern Pennsylvania. The estimates are based on preliminary simulations using a groundwater-flow model and an associated geographic information system that integrates data on the mining features, hydrogeology, and streamflow in the study area. The Mahanoy and Shamokin Creek Basins were the focus of the study because these basins exhibit extensive hydrologic effects and water-quality degradation from the abandoned mines in their headwaters in the Western Middle Anthracite Coalfield. Proposed groundwater withdrawals from the flooded parts of the mines and stream-channel modifications in selected areas have the potential for altering the distribution of groundwater and the interaction between the groundwater and streams in the area. Preliminary three-dimensional, steady-state simulations of groundwater flow by the use of MODFLOW are presented to summarize information on the exchange of groundwater among adjacent mines and to help guide the management of ongoing data collection, reclamation activities, and water-use planning. The conceptual model includes high-permeability mine voids that are connected vertically and horizontally within multicolliery units (MCUs). MCUs were identified on the basis of mine maps, locations of mine discharges, and groundwater levels in the mines measured by PaDEP. The locations and integrity of mine barriers were determined from mine maps and groundwater levels. The permeability of intact barriers is low, reflecting the hydraulic characteristics of unmined host rock and coal. A steady-state model was calibrated to measured groundwater

  3. Nurses' Attitudes and Knowledge of Their Roles in Newborn Abandonment

    PubMed Central

    Cesario, Sandra K.

    2003-01-01

    The practice of abandoning newborns shortly after birth has always existed. Occurring in primitive and contemporary societies, the motivations for newborn abandonment are varied and dependent upon the social norms of a specific geographic region at a given point in time. Because the desire to abandon an infant has had no support system in American society, such unwanted infants have been abandoned in a manner leading to their deaths. In response, many states have passed safe-haven legislation to save the lives of unwanted newborns. The laws typically specify a mother's ability to “abandon” her child to a medical service provider. However, judgmental attitudes and a lack of accurate information may impede a health care provider's ability to carry out a safe-haven law. The study described here examines a sample of nurses in a state with a safe-haven law. The study revealed no significant correlation between a nurse's knowledge, attitude, and self-perception of preparedness to manage a newborn abandonment event. owever, the outcomes highlight the negative attitudes and lack of knowledge many nurses possess regarding newborn abandonment and the women who commit this act. Educational programs for all health care providers and the community are essential to the efficacy of the legislation that currently exists. Continued multidisciplinary strategizing and general awareness are needed to serve as catalysts to build supports for unwanted newborns and their safe assimilation into the community. PMID:17273338

  4. 30 CFR 934.20 - Approval of North Dakota abandoned mine plan.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Approval of North Dakota abandoned mine plan... DAKOTA § 934.20 Approval of North Dakota abandoned mine plan. The North Dakota Abandoned Mine Plan as... 82601-1918; Telephone: (307) 261-5776. North Dakota Public Service Commission, Abandoned Mine...

  5. 30 CFR 934.20 - Approval of North Dakota abandoned mine plan.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Approval of North Dakota abandoned mine plan... DAKOTA § 934.20 Approval of North Dakota abandoned mine plan. The North Dakota Abandoned Mine Plan as... 82601-1918; Telephone: (307) 261-5776. North Dakota Public Service Commission, Abandoned Mine...

  6. 30 CFR 934.20 - Approval of North Dakota abandoned mine plan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Approval of North Dakota abandoned mine plan... DAKOTA § 934.20 Approval of North Dakota abandoned mine plan. The North Dakota Abandoned Mine Plan as... 82601-1918; Telephone: (307) 261-5776. North Dakota Public Service Commission, Abandoned Mine...

  7. 30 CFR 934.20 - Approval of North Dakota abandoned mine plan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Approval of North Dakota abandoned mine plan... DAKOTA § 934.20 Approval of North Dakota abandoned mine plan. The North Dakota Abandoned Mine Plan as... 82601-1918; Telephone: (307) 261-5776. North Dakota Public Service Commission, Abandoned Mine...

  8. Fish Community Responses to Stream Restoration

    NASA Astrophysics Data System (ADS)

    Daniel, W.; Jack, J.; Kelley, R.

    2005-05-01

    Stream restoration projects are often justified based on expected improvements in habitat and ecosystem services, but few of these restorations have been systematically studied to assess their "success." A channelized section of Wilson Creek (Kentucky, USA) was relocated to a new, meandering channel using a natural channel design approach. Fish communities were sampled before and after the restoration and compared to an upstream site in Wilson and two control streams that were not restored. There were no consistent taxa changes among sites at Wilson Creek between the pre- and post restoration samples. Wilson Creek fish communities were always more diverse than either of the control streams. Kentucky Fish Index of Biotic Integrity (IBI) scores in Wilson were Excellent for the pre-restoration fish community and 4 out of 5 reaches sampled after the restoration retained that classification. The reference streams' IBIs were classified as Good and remained unchanged throughout the study period. We are also conducting a stable isotope analysis of representative trophic groups in Wilson to assess if there have been any changes in food web dynamics post- restoration. More pre- and post restoration studies are needed to help develop success criteria and incorporate "lessons learned" in stream restorations.

  9. QUANTIFYING STREAM STRUCTURAL PHYSICAL HABITAT ATTRIBUTES USING LIDAR AND HYPERSPECTRAL IMAGERY

    EPA Science Inventory

    Structural physical habitat attributes include indices of stream size, channel gradient, substrate size, habitat complexity and cover, riparian vegetation cover and structure, anthropogenic disturbances and channel-riparian interaction.

  10. HEADWATER INTERMITTENT STREAMS STUDY: COLLABORATION ACROSS THE NATION

    EPA Science Inventory

    Headwater streams are the most abundant and widespread of our nation's surface waters, yet little guidance is available specific to these resources. Headwater streams lie at the terrestrial-aquatic interface, both spatially because of their narrow channels and landscape position ...

  11. ENHANCING HSPF MODEL CHANNEL HYDRAULIC REPRESENTATION

    EPA Science Inventory

    The Hydrological Simulation Program - FORTRAN (HSPF) is a comprehensive watershed model, which employs depth-area-volume-flow relationships known as hydraulic function table (FTABLE) to represent stream channel cross-sections and reservoirs. An accurate FTABLE determination for a...

  12. Log Distribution, Persistence, and Geomorphic Function in Streams and Rivers, in the Northeastern U.S.

    NASA Astrophysics Data System (ADS)

    St Pierre, L.; Burchsted, D.; Warren, D.

    2015-12-01

    Large wood provides critical ecosystem services such as fish habitat, temperature regulation and bank stabilization. In the northeastern U.S., the distribution of large wood is documented; however, there is little understanding of the movement, longevity and geomorphic function. This research examines the hypothesis that tree species control the persistence and geomorphic function of instream wood in the Appalachian region of the northeastern U.S. To do this, we assessed size, location, and species of logs in New Hampshire rivers, including locations in the White Mountain National Forest (WMNF) where these data were collected ten years ago. We expanded the previous dataset to include assessment of geomorphic function, including creation of diversion channels, pool formation, and sediment storage, among others. We also added new sites in the WMNF and sites on a large rural river in southwestern NH to increase the range of geomorphic variables to now include: confined and unconfined channels; 1st to 4th order streams; low to high gradient; meandering, multithreaded, and straight channels; and land use such as historic logging, modern agriculture, and post-agricultural abandonment. At each study site, we located all large logs (>10cm diameter, > 1m length) and log jams (>3 accumulated logs that provide a geomorphic function) along 100m-700m reaches. We marked each identified log with a numbered tag and recorded species, diameter, length, orientation, GPS location, tag number, and photographs. We assessed function and accumulation, decay, stability, and source classes for each log. Along each reach we measured riparian forest composition and structure and channel width. Preliminary analysis suggests that tree species significantly affects the function of logs: yellow birch and American sycamore are highly represented. Additionally, geomorphic setting also plays a primary role, where unconfined reaches have large logs that provide important functions; those functions

  13. Active channel for Fanno Creek, Oregon

    USGS Publications Warehouse

    Sobieszczyk, Steven

    2011-01-01

    Fanno Creek is a tributary to the Tualatin River and flows though parts of the southwest Portland metropolitan area. The stream is heavily influenced by urban runoff and shows characteristic flashy streamflow and poor water quality commonly associated with urban streams. This data set represents the active, wetted channel as derived from light detection and ranging (LiDAR) data and aerial photographic imagery. The wetted channel boundary is equivalent to the extent of water observed during a 2-yr high flow event.

  14. Low-flow characteristics of Alabama streams

    USGS Publications Warehouse

    Bingham, Roy H.

    1982-01-01

    A new procedure for estimating the 7-day, 2-year and the 7-day, 10-year low flow of ungaged Alabama streams is based on geology, drainage area, and mean annual precipitation. One equation for each of the two low-flow frequencies applies statewide to all natural flow streams; the equations do not apply to streams where flow is significantly altered by activities of man. The standard error of estimate of each equation based on map values is 40 percent for 7-day, 2-year low flow and 44 percent for 7-day, 10-year low flow. The rate of streamflow recession is used to account for the effects of geology on low flow. Streamflow recession rate depends primarily on transmissivity and storage characteristics of the aquifers, and average distance from stream channels to divides. Relations of low-flow discharge to geology, drainage area, and mean annual precipitation were analyzed by multiple regression techniques.

  15. Flood-frequency characteristics of Wisconsin streams

    USGS Publications Warehouse

    Walker, John F.; Krug, William R.

    2003-01-01

    Flood-frequency characteristics for 312 gaged sites on Wisconsin streams are presented for recurrence intervals of 2 to 100 years using flood-peak data collected through water year 2000. Equations of the relations between flood-frequency and drainage-basin characteristics were developed by multiple-regression analyses. Flood-frequency characteristics for ungaged sites on unregulated, rural streams can be estimated by use of these equations. The state was divided into five areas with similar physiographic characteristics. The most significant basin characteristics are drainage area, main-channel slope, soil permeability, storage, rainfall intensity, and forest cover. The standard error of prediction for the equation for the 100-year flood discharge ranges from 22 to 44 percent in the state. A graphical method for estimating flood-frequency characteristics of regulated streams was developed from the relation of discharge and drainage area. Graphs for the major regulated streams are presented.

  16. Inventory of miscellaneous streams

    SciTech Connect

    Haggard, R.D.

    1998-08-14

    Miscellaneous streams discharging to the soil column on the Hanford Site are subject to requirements of several milestones identified in Consent Order No. DE 9INM-177 (Ecology and DOE 1991). The Plan and Schedule for Disposition and Regulatory Compliance for Miscellaneous Stream (DOE/RL-93-94) provides a plan and schedule for the disposition of miscellaneous streams to satisfy one of the Section 6.0 requirements of the Consent Order. One of the commitments (Activity 6-2.2) established in the plan and schedule is to annually update, the miscellaneous streams inventory. This document constitutes the 1998 revision of the miscellaneous streams inventory. Miscellaneous stream discharges were grouped into four permitting categories (Table 1). The first miscellaneous streams Permit (ST 4508) was issued May 30, 1997, to cover wastewater discharges from hydrotesting, maintenance, and construction activities. The second miscellaneous streams Permit (ST4509) covers discharges from cooling water and condensate discharges. The third permit application for category three waste streams was eliminated by recategorizing waste streams into an existing miscellaneous streams permit or eliminating stream discharges. Elimination of the third categorical permit application was approved by Ecology in January 1997 (Ecology 1997). The fourth permit application, to cover storm water, is due to Ecology in September 1998. Table 1 provides a history of the miscellaneous streams permitting activities.

  17. Who Says There Is No Life after Abandonment? A Grounded Theory on the Coping of Abandoned Filipino Elderly in Nursing Homes

    ERIC Educational Resources Information Center

    de Guzman, Allan B.; Lacorte, Jeremy C.; Lacsamana, Andrea Keith G.; Lagac, Mark Lawrence M.; Laguador, Jobel M.; Lapid, Jazminn Jessica R.; Lee, Lyndcie Miriele C.

    2012-01-01

    Cases of abandoned elderly are increasing worldwide. By and large, this group struggles with the sudden change in living arrangement as well as abandonment by their families. Consequently, many elderly are forced into living in nursing homes for the remainder of their lives. Abandonment among these elderly negatively affects how they view…

  18. Prioritized Contact Transport Stream

    NASA Technical Reports Server (NTRS)

    Hunt, Walter Lee, Jr. (Inventor)

    2015-01-01

    A detection process, contact recognition process, classification process, and identification process are applied to raw sensor data to produce an identified contact record set containing one or more identified contact records. A prioritization process is applied to the identified contact record set to assign a contact priority to each contact record in the identified contact record set. Data are removed from the contact records in the identified contact record set based on the contact priorities assigned to those contact records. A first contact stream is produced from the resulting contact records. The first contact stream is streamed in a contact transport stream. The contact transport stream may include and stream additional contact streams. The contact transport stream may be varied dynamically over time based on parameters such as available bandwidth, contact priority, presence/absence of contacts, system state, and configuration parameters.

  19. Regex-Stream

    2012-09-01

    Log files are typically semi-or un-structured. To be useable, they need to be parsed into a standard, structured format. Regex-Stream facilitates parsing text files into structured data (JSON) in streams of data.

  20. Sulfur hexafluoride gas tracer studies in streams

    SciTech Connect

    Hibbs, D.E.; Gulliver, J.S.; Parkhill, K.L.

    1998-08-01

    Gas tracers are useful investigative tools in the study of reaeration and the fate of volatile organic contaminants in many natural streams. They enable the direct measurement of a variety of stream parameters, including the gas exchange rates between the stream and the atmosphere, as well as the spreading rate for dissolved pollutants downstream of a discharge point or spill site. The air-water mass transfer coefficients, dispersion coefficients, and mean residence times in two experimental streams and one natural stream are measured using a variation of the standard volatile tracer-dye technique. Sulfur hexafluoride (SF{sub 6}) is used as the volatile tracer and rhodamine WT is used as the conservative tracer. The low limit of quantification of SF{sub 6} makes it possible to inject SF{sub 6}-rich water into many streams and avoid complications with dosing a stream with a gaseous tracer. The experimental methods are described in detail. The SF{sub 6} measurements were extremely precise, producing smooth concentration time curves. The SF{sub 6} measurements collected in side-by-side experimental channels yielded similar values of the gas transfer coefficient.

  1. Seasonal energy storage using bioenergy production from abandoned croplands

    NASA Astrophysics Data System (ADS)

    Campbell, J. Elliott; Lobell, David B.; Genova, Robert C.; Zumkehr, Andrew; Field, Christopher B.

    2013-09-01

    Bioenergy has the unique potential to provide a dispatchable and carbon-negative component to renewable energy portfolios. However, the sustainability, spatial distribution, and capacity for bioenergy are critically dependent on highly uncertain land-use impacts of biomass agriculture. Biomass cultivation on abandoned agriculture lands is thought to reduce land-use impacts relative to biomass production on currently used croplands. While coarse global estimates of abandoned agriculture lands have been used for large-scale bioenergy assessments, more practical technological and policy applications will require regional, high-resolution information on land availability. Here, we present US county-level estimates of the magnitude and distribution of abandoned cropland and potential bioenergy production on this land using remote sensing data, agriculture inventories, and land-use modeling. These abandoned land estimates are 61% larger than previous estimates for the US, mainly due to the coarse resolution of data applied in previous studies. We apply the land availability results to consider the capacity of biomass electricity to meet the seasonal energy storage requirement in a national energy system that is dominated by wind and solar electricity production. Bioenergy from abandoned croplands can supply most of the seasonal storage needs for a range of energy production scenarios, regions, and biomass yield estimates. These data provide the basis for further down-scaling using models of spatially gridded land-use areas as well as a range of applications for the exploration of bioenergy sustainability.

  2. Abandoned pastoral settlements provide concentrations of resources for savanna birds

    NASA Astrophysics Data System (ADS)

    Söderström, Bo; Reid, Robin S.

    2010-03-01

    Knowledge is poor of how fertilization affects birds in grasslands. We investigated the impact on birds of abandoned pastoral settlements that historically received very high levels of livestock dung. A total of 28 abandoned settlements and 74 landscape controls - in Koyake Group Ranch and Maasai Mara National Reserve in Kenya - were surveyed for birds during the wet and/or dry season. Our results showed that bird species richness and total abundance increased within 200 m of abandoned pastoral settlements, particularly during the dry season when foraging resources on the savanna are limited. The high concentrations of nutrients inside abandoned settlements favoured the abundance of Diptera and Coleoptera, as shown by invertebrate surveys performed during the dry season on a subset of 32 sites. Both total numbers and dry biomass of these two invertebrate orders were higher on abandoned settlements in comparison with the surrounding landscape. We conclude that higher fertilization levels cause a temporal and spatial redistribution of birds on the savanna. Livestock fertilization and bird abundance are probably linked through an increase in abundance of invertebrate food upon which birds feed in an opportunistic fashion.

  3. Classification of stream basins in southeastern Ohio according to extent of surface coal mining

    USGS Publications Warehouse

    Childress, C.J.

    1985-01-01

    Water-quality data were collected from streams grenadine 35 basins in the southeaster-Ohio coal region to evaluate and categorize the effect of surface coal mining on stream quality. The study area is underlain by rocks of Pennsylvanian age, the most important coal-producing formations of which are the Allegheny and Monogahela Formations. The study area contains 276 data-collection sites, each of which was sampled four times over a 3-year period. Water and bed-material samples were collected. Each site was classified as 'abandoned,' reclaimed,' unmined,' or mixed,' depending on the proportion of the drainage basin disturbed by mining, and if mined, on the present condition of the mine. Of the 130 sites in the Monogahela Formation, 18 percent were classified as abandoned, 2 percent as reclaimed, 10 percent as unmined, and 70 percent as mixed. Of the 146 sites in the Allegheny Formation, 14 percent were classified as abandoned, 11 percent as unmined, and 75 percent as mixed. Streams draining the carbonate-bearing Monogahela Formation have a significantly greater buffering capacity than streams draining the Allegheny Formation. THere are significant differences in specific conductance; pH; alkalinity; acidity; hardness; total and dissolve manganese, and aluminum; dissolved nickel, zinc, and sulfate; and dissolved solids among mining-disturbance types in the Allegheny Formation. However, in stream draining the Monogahela Formation, only hardness, sulfur, dissolved solids, and dissolved manganese are significantly different among mining-disturbance types. Discriminant-function analysis of water-quality data was used to classify each 'mixed' site into one of four categories: Abandoned, reclaimed, unmined, or uncertain. In addition, observations in each of the first three categories were classified as strongly, moderately, or weakly characteristic of that category. The discriminant function was based on specific conductance, pH, acidity, dissolved sulfate, dissolved

  4. Potential stream density in Mid-Atlantic US watersheds.

    PubMed

    Elmore, Andrew J; Julian, Jason P; Guinn, Steven M; Fitzpatrick, Matthew C

    2013-01-01

    Stream network density exerts a strong influence on ecohydrologic processes in watersheds, yet existing stream maps fail to capture most headwater streams and therefore underestimate stream density. Furthermore, discrepancies between mapped and actual stream length vary between watersheds, confounding efforts to understand the impacts of land use on stream ecosystems. Here we report on research that predicts stream presence from coupled field observations of headwater stream channels and terrain variables that were calculated both locally and as an average across the watershed upstream of any location on the landscape. Our approach used maximum entropy modeling (MaxEnt), a robust method commonly implemented to model species distributions that requires information only on the presence of the entity of interest. In validation, the method correctly predicts the presence of 86% of all 10-m stream segments and errors are low (<1%) for catchments larger than 10 ha. We apply this model to the entire Potomac River watershed (37,800 km(2)) and several adjacent watersheds to map stream density and compare our results with the National Hydrography Dataset (NHD). We find that NHD underestimates stream density by up to 250%, with errors being greatest in the densely urbanized cities of Washington, DC and Baltimore, MD and in regions where the NHD has never been updated from its original, coarse-grain mapping. This work is the most ambitious attempt yet to map stream networks over a large region and will have lasting implications for modeling and conservation efforts. PMID:24023704

  5. MANAGING RISKS USING MEASUREMENTS OF STREAM COMMUNITY METABOLISM, NUTRIENT AND SEDIMENT DYNAMICS AND GEOMORPHOLOGY IN THE LITTLE MIAMI RIVER WATERSHED

    EPA Science Inventory

    Understanding the ecological response of stream communities to land use stressors requires coordinated measurement of physical, chemical and biological parameters. The physical structure of stream channels (i.e. geomorphology) provides a foundation for ecological health, but res...

  6. Relative importance of water chemistry and habitat to fish communities in headwater streams influenced by agricultural land use

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channelized headwater streams are common throughout agricultural watersheds in the Midwestern United States. Understanding the relative impacts of agricultural contaminants and habitat degradation on the aquatic biota within agricultural headwater streams will provide information that can assist wi...

  7. RFI channels

    NASA Technical Reports Server (NTRS)

    Mceliece, R. J.

    1980-01-01

    A class of channel models is presented which exhibit varying burst error severity much like channels encountered in practice. An information-theoretic analysis of these channel models is made, and conclusions are drawn that may aid in the design of coded communication systems for realistic noisy channels.

  8. FATE AND BIOLOGICAL EFFECTS OF MERCURY INTRODUCED INTO ARTIFICIAL STREAMS

    EPA Science Inventory

    Mercuric ion was continuously input to artificial stream channels to provide water concentrations of 0.01, 1.0, and 5.0 micrograms/l. Channel components were periodically sampled for total mercury analyses. The effects of mercury on the algal components of the periphyton communit...

  9. Modeling the Evolution of Incised Streams: III. Model Application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incision and ensuing widening of alluvial stream channels is widespread in the midsouth and midwestern United States and represents an important form of channel adjustment. Two accompanying papers have presented a robust computational model for simulating the long-term evolution of incised and resto...

  10. Use of Unchannelized Agricultural Streams as a Guiding Image for Restoring Agricultural Drainage Ditches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural drainage ditches or channelized headwater streams are a common landscape feature in the Midwestern United States. These streams have been channelized and maintained for removal of excess water from agricultural fields without regard for the aquatic biota. The use of pristine forested wa...

  11. Downstream variation in bankfull width of wadeable streams across the conterminous United States

    EPA Science Inventory

    Bankfull channel width is a fundamental measure of stream size and a key parameter of interest for many applications in hydrology, fluvial geomorphology, and stream ecology. We developed downstream hydraulic geometry relationships for bankfull channel width w as a function of dra...

  12. Geophysical methods for locating abandoned wells

    USGS Publications Warehouse

    Frischknecht, Frank C.; Muth, L.; Grette, R.; Buckley, T.; Kornegay, B.

    1983-01-01

    A preliminary study of the feasibility of using geophysical exploration methods to locate abandoned wells containing steel casing indicated that magnetic methods promise to be effective and that some electrical techniques might be useful as auxiliary methods. Ground magnetic measurements made in the vicinity of several known cased wells yielded total field anomalies with peak values ranging from about 1,500 to 6,000 gammas. The anomalies measured on the ground are very narrow and, considering noise due to other cultural and geologic sources, a line spacing on the order of 50 feet (15.2 m) would be necessary to locate all casings in the test area. The mathematical model used to represent a casing was a set of magnetic pole pairs. By use of a non-linear least squares curve fitting (inversion) program, model parameters which characterize each test casing were determined. The position and strength of the uppermost pole was usually well resolved. The parameters of lower poles were not as well resolved but it appears that the results are adequate for predicting the anomalies which would be observed at aircraft altitudes. Modeling based on the parameters determined from the ground data indicates that all of the test casings could be detected by airborne measurements made at heights of 150 to 200 feet (45.7-61.0 m) above the ground, provided lines spaced as closely as 330 feet (100 m) were used and provided noise due to other cultural and geologic sources is not very large. Given the noise levels of currently available equipment and assuming very low magnetic gradients due to geologic sources, the detection range for total field measurements is greater than that for measurements of the horizontal or vertical gradient of the total intensity. Electrical self-potential anomalies were found to be associated with most of the casings where measurements were made. However, the anomalies tend to be very narrow and, in several cases, they are comparable in magnitude to other small

  13. Influence of Riparian Habitat and Nutrients on Aquatic Communities Within Riparian Zones of Headwater Streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Headwater streams are the smallest streams in a watershed. Their small size and high frequency of occurrence make them susceptible to anthropogenic habitat alterations. Many headwater streams in the Midwestern United States have been channelized to drain agricultural fields. Aquatic macroinvertebrat...

  14. Abandoned Mine Detection in Western Pennsylvania Using Surface Wave Data

    NASA Astrophysics Data System (ADS)

    Miller, B.

    2015-12-01

    Abandoned mines throughout the Appalachian region of the United States have been recognized as problematic. Resource extraction from these mines has long ceased and few, if any, documents pertaining to these operations exist. Over time support structures internal to the mines may collapse and lead to subsidence, potentially damaging surface structures. A non-invasive, surface deployed seismic method to detect undisclosed, abandoned near-surface mines would be beneficial as a first step to remediation. The use of seismic surface waves to analyze the upper several tens of meters of the subsurface has become an important technique for near-surface investigations and may provide a method for detection of near-surface, abandoned mine shafts. While there are many undocumented abandoned mines throughout the Appalachians one known example exists within Butler County, Pennsylvania. Although little is known about the overall operation there is limited documentation which provides information as to the location of the mine tunnels. Currently there is no recognized surface subsidence associated with the mine however documents indicate that the abandoned mining operations have an estimated depth ranging from twenty to fifty feet. To assist with acquisition a seismic land streamer was constructed. Use of a land streamer increases the speed, ease and efficiency required to perform a seismic survey. Additionally the land streamer allows for the acquisition of seismic surface waves which were analyzed using the Multichannel Analysis of Surface Waves (MASW) method. Data were acquired by conducting multiple, adjacent surveys perpendicular to the suspected location of abandoned mine tunnels. Throughout the survey area to a depth of approximately 15 meters, shear wave velocities range between approximately 200-1200 m/s. Based upon shear wave velocity changes within the profile anomalies have been identified corresponding to the contrast between the suspected mined, and unmined, areas.

  15. Comparison of Stream Restoration and Vegetation Restoration on Stream Temperature in the Middle Fork John Day River, Oregon

    NASA Astrophysics Data System (ADS)

    Diabat, M.; Wondzell, S. M.; Haggerty, R.

    2013-12-01

    Stream temperature is an important component of aquatic ecosystems. During the past century, various anthropogenic activities (such as timber harvest, mining, and agriculture) reduced riparian vegetation and channel complexity along many streams around the world. As a result, stream temperature increased and suitable habitat for cool- and cold-water organisms declined. Stream temperatures are expected to increase even more under future climate. The effects of warmer climate and anthropogenic activities are proposed to be mitigated by restoration projects aimed to reduce stream temperatures. Common restoration practices are replanting natural vegetation along stream banks and restoring channel complexity. The Middle Fork John Day River, in northeastern Oregon, USA is an example of such a process. We modeled stream temperature along a 37-km section of the Middle Fork John Day River for current and projected conditions of climate, restored riparian vegetation along 6.6-km, and restored channel meanders along 1.5 km. Preliminary simulations suggest that if current riparian vegetation remains unchanged, an average summertime air warming of 4°C increased the 7-day average daily maximum (7DADM) by about 1.3°C. However, restored riparian vegetation reduced the 7DADM by about 0.7°C relative to the current temperature. Restored channel meanders reduced the 7DADM by less than 0.05°C relative to the current temperature. These preliminary simulations assume no hyporheic exchange and riparian vegetation that is 10 m tall and has 30% canopy density.

  16. Simulation of fluid, heat transport to estimate desert stream infiltration.

    PubMed

    Kulongoski, Justin T; Izbicki, John A

    2008-01-01

    In semiarid regions, the contribution of infiltration from intermittent streamflow to ground water recharge may be quantified by comparing simulations of fluid and heat transport beneath stream channels to observed ground temperatures. In addition to quantifying natural recharge, streamflow infiltration estimates provide a means to characterize the physical properties of stream channel sediments and to identify suitable locations for artificial recharge sites. Rates of winter streamflow infiltration along stream channels are estimated based on the cooling effect of infiltrated water on streambed sediments, combined with the simulation of two-dimensional fluid and heat transport using the computer program VS2DH. The cooling effect of ground water is determined by measuring ground temperatures at regular intervals beneath stream channels and nearby channel banks in order to calculate temperature-depth profiles. Additional data inputs included the physical, hydraulic, and thermal properties of unsaturated alluvium, and monthly ground temperatures measurements over an annual cycle. Observed temperatures and simulation results can provide estimates of the minimum threshold for deep infiltration, the variability of infiltration along stream channels, and also the frequency of infiltration events. PMID:18194325

  17. Simulation of fluid, heat transport to estimate desert stream infiltration

    USGS Publications Warehouse

    Kulongoski, J.T.; Izbicki, J.A.

    2008-01-01

    In semiarid regions, the contribution of infiltration from intermittent streamflow to ground water recharge may be quantified by comparing simulations of fluid and heat transport beneath stream channels to observed ground temperatures. In addition to quantifying natural recharge, streamflow infiltration estimates provide a means to characterize the physical properties of stream channel sediments and to identify suitable locations for artificial recharge sites. Rates of winter streamflow infiltration along stream channels are estimated based on the cooling effect of infiltrated water on streambed sediments, combined with the simulation of two-dimensional fluid and heat transport using the computer program VS2DH. The cooling effect of ground water is determined by measuring ground temperatures at regular intervals beneath stream channels and nearby channel banks in order to calculate temperature-depth profiles. Additional data inputs included the physical, hydraulic, and thermal properties of unsaturated alluvium, and monthly ground temperatures measurements over an annual cycle. Observed temperatures and simulation results can provide estimates of the minimum threshold for deep infiltration, the variability of infiltration along stream channels, and also the frequency of infiltration events.

  18. How wide is a stream? Spatial extent of the potential "stream signature" in terrestrial food webs using meta-analysis.

    PubMed

    Muehlbauer, Jeffrey D; Collins, Scott F; Doyle, Martin W; Tockner, Klement

    2014-01-01

    The magnitude of cross-ecosystem resource subsidies is increasingly well recognized; however, less is known about the distance these subsidies travel into the recipient landscape. In streams and rivers, this distance can delimit the "biological stream width," complementary to hydro-geomorphic measures (e.g., channel banks) that have typically defined stream ecosystem boundaries. In this study we used meta-analysis to define a "stream signature" on land that relates the stream-to-land subsidy to distance. The 50% stream signature, for example, identifies the point on the landscape where subsidy resources are still at half of their maximum (in- or near-stream) level. The decay curve for these data was best fit by a negative power function in which the 50% stream signature was concentrated near stream banks (1.5 m), but a non-trivial (10%) portion of the maximum subsidy level was still found > 0.5 km from the water's edge. The meta-analysis also identified explanatory variables that affect the stream signature. This improves our understanding of ecosystem conditions that permit spatially extensive subsidy transmission, such as in highly productive, middle-order streams and rivers. Resultant multivariate models from this analysis may be useful to managers implementing buffer rules and conservation strategies for stream and riparian function, as they facilitate prediction of the extent of subsidies. Our results stress that much of the subsidy remains near the stream, but also that subsidies (and aquatic organisms) are capable of long-distance dispersal into adjacent environments, and that the effective "biological stream width" of stream and river ecosystems is often much larger than has been defined by hydro-geomorphic metrics alone. Limited data available from marine and lake sources overlap well with the stream signature data, indicating that the "signature" approach may also be applicable to subsidy spatial dynamics across other ecosystems. PMID:24649645

  19. Risk Assessment of Heavy Metals in Abandoned Mine Lands as Signifcant Contamination Problem in Romania

    NASA Astrophysics Data System (ADS)

    Horvath, E.; Jordan, G.; Fugedi, U.; Bartha, A.; Kuti, L.; Heltai, G.; Kalmar, J.; Waldmann, I.; Napradean, I.; Damian, G.

    2009-04-01

    INTRODUCTION Wide-spread environmental contamination associated with historic mining in Europe has triggered social responses to improve related environmental legislation, the environmental assessment and management methods for the mining industry. Pollution by acid mine drainage (AMD) from ore and coal mining is the outstanding and most important source of mining-induced environmental pollution. Younger et al. (2002) estimates that watercourses polluted by coal mine drainage could be in the order of 2,000 to 3,000 km, and 1,000 to 1,500 km polluted by metal mine discharges for the EU 15 Member States (Younger et al. 2002). Significance of contamination risk posed by mining is also highlighted by mine accidents such as those in Baia Mare, Romania in 2002 and in Aznalcollar, Spain in 1999 (Jordan and D'Alessandro 2004). The new EU Mine Waste Directive (Directive 2006/21/EC) requires the risk-based inventory of abandoned mines in the EU. The cost-effective implementation of the inventory is especially demanding in countries with extensive historic mining and great number of abandoned mine sites, like Romania. The problem is further complicated in areas with trans-boundary effects. The objective of this investigation to carry out the risk-based contamination assessment of a mine site with possible trans-boundary effects in Romania. Assessment follows the source-pathway-receptor chain with a special attention to heavy metal leaching from waste dumps as sources and to transport modelling along surface water pathways. STUDY AREA In this paper the Baiut mine catchment located in the Gutai Mts., Romania, close to the Hungarian border is studied. The polymetallic deposites in the Tertiary Inner-Carpathian Volcanic Arc are exposed by a series of abandoned Zn and Pb mines first operated in the 14th century. Elevation in the high relief catchment ranges from 449m to 1044m. Geology is characterised by andesites hosting the ore deposits and paleogene sediments dominating at the

  20. Roles of Benthic Algae in the Structure, Function, and Assessment of Stream Ecosystems Affected by Acid Mine Drainage

    EPA Science Inventory

    Tens of thousands of stream kilometers around the world are degraded by a legacy of environmental impacts and acid mine drainage (AMD) caused by abandoned underground and surface mines, piles of discarded coal wastes, and tailings. Increased acidity, high concentrations of metals...