Science.gov

Sample records for adjacent tidal creek

  1. A long-term monitoring study of chlorophyll, microbial contaminants, and pesticides in a coastal residential stormwater pond and its adjacent tidal creek.

    PubMed

    DeLorenzo, Marie E; Thompson, Brian; Cooper, Emily; Moore, Janet; Fulton, Michael H

    2012-01-01

    Stormwater ponds are commonly used in residential and commercial areas to control flooding. The accumulation of urban contaminants in stormwater ponds can lead to water-quality problems including nutrient enrichment, chemical contamination, and bacterial contamination. This study presents 5 years of monitoring data assessing water quality of a residential subdivision pond and adjacent tidal creek in coastal South Carolina, USA. The stormwater pond is eutrophic, as described by elevated concentrations of chlorophyll and phosphorus, and experiences periodic cyanobacterial blooms. A maximum monthly average chlorophyll concentration of 318.75 μg/L was measured in the stormwater pond and 227.63 μg/L in the tidal creek. Fecal coliform bacteria (FCB) levels were measured in both the pond and the tidal creek that exceeded health and safety standards for safe recreational use. A maximum monthly average FCB level of 1,247 CFU/100 mL was measured in the stormwater pond and 12,850 CFU/100 mL in the tidal creek. In addition, the presence of antibiotic resistant bacteria and pathogenic bacteria were detected. Low concentrations of herbicides (atrazine and 2,4-D: ), a fungicide (chlorothalonil), and insecticides (pyrethroids and imidacloprid) were measured. Seasonal trends were identified, with the winter months having the lowest concentrations of chlorophyll and FCB. Statistical differences between the stormwater pond and the tidal creek were also noted within seasons. The tidal creek had higher FCB levels than the stormwater pond in the spring and summer, whereas the stormwater pond had higher chlorophyll levels than the tidal creek in the summer and fall seasons. Chlorophyll and FCB levels in the stormwater pond were significantly correlated with monthly average temperature and total rainfall. Pesticide concentrations were also significantly correlated with temperature and rainfall. Pesticide concentrations in the stormwater pond were significantly correlated with

  2. Tidal creek changes at the Sonoma Baylands restoration site

    USGS Publications Warehouse

    Dingler, John R.; Cacchione, David A.; ,

    1998-01-01

    Over the past 150 years, human activity has had a major impact on tidal wetlands adjoining the San Francisco Bay-Delta estuary Growing concern about the effect of this change on the ecology of the estuary has prompted Bay area managers to attempt to reclaim tidal wetlands. The Sonoma Baylands Restoration Project is designed to use dredge material to convert 348 acres from farmland to wetland. This paper describes changes to a tidal creek that flows from that restoration site to San Pablo Bay (north San Francisco Bay) through an existing tidal wetland during different phases of the project. Hydrologic measurements near the bottom of the creek and cross-creek profiles show how the creek responded to non-tidal flow conditions introduced by filling the site with dredge materials. At the time of this study, the creek had deepened by approximately 40 cm but had not widened.

  3. Hydrodynamics of a small trained tidal inlet (Currumbin Creek, Australia)

    NASA Astrophysics Data System (ADS)

    Shaeri, S.; Tomlinson, R. B.; Etemad-Shahidi, A.; Strauss, D.; Hughes, L. P.

    2014-04-01

    Small tidal inlets are important features of coastal areas, in terms of provision of access from a back barrier water-body to the ocean as well as periodic circulation of fresh nutrients for the local ecology. Usually, dimensional and geometrical characteristics contribute significantly to morphological stability or instability of a particular inlet and necessitate an individual investigation of any desired location. In other words, generalized usage of previous empirical and experimental research of a different position can hardly be used for other places. In this regard, one of the powerful tools to understand the physical processes of a particular region is to collect as much field data as possible. Such a dataset is used to further analyse and explore the governing processes and can also be used for building a numerical computer model for supplementary studies. In this research, the results of a comprehensive field measurement at Currumbin Creek, Queensland, Australia are presented. This study is part of broader research to investigate the long term evolution of the Currumbin entrance and its adjacent beaches. Currently, an annual dredging campaign is needed to reduce the risk of flooding due to excess rainfall inundations and to maintain water quality. The majority of data were collected over a three month period consistent with the time of the 2012 dredging operation. However, due to the loss of some instrumentation, data collection for some of the parameters was repeated till the middle of May 2013. All collected data included: (1) nearshore waves and tide; (2) creek tidal variation; (3) creek flow discharge and velocity; (4) bathymetric survey of the creek; (5) beach profile evolution survey; and (6) sediment sampling. The measurement showed that the creek entrance is tidally dominated, with flood events having a major role in sediment transport into the creek. The nearshore stations' wave data illustrated the marginal effect of the beach curvature between

  4. Tidally influenced alongshore circulation at an inlet-adjacent shoreline

    USGS Publications Warehouse

    Hansen, Jeff E.; Elias, Edwin P.L.; List, Jeffrey H.; Erikson, Li H.; Barnard, Patrick L.

    2013-01-01

    The contribution of tidal forcing to alongshore circulation inside the surfzone is investigated at a 7 km long sandy beach adjacent to a large tidal inlet. Ocean Beach in San Francisco, CA (USA) is onshore of a ∼150 km2 ebb-tidal delta and directly south of the Golden Gate, the sole entrance to San Francisco Bay. Using a coupled flow-wave numerical model, we find that the tides modulate, and in some cases can reverse the direction of, surfzone alongshore flows through two separate mechanisms. First, tidal flow through the inlet results in a barotropic tidal pressure gradient that, when integrated across the surfzone, represents an important contribution to the surfzone alongshore force balance. Even during energetic wave conditions, the tidal pressure gradient can account for more than 30% of the total alongshore pressure gradient (wave and tidal components) and up to 55% during small waves. The wave driven component of the alongshore pressure gradient results from alongshore wave height and corresponding setup gradients induced by refraction over the ebb-tidal delta. Second, wave refraction patterns over the inner shelf are tidally modulated as a result of both tidal water depth changes and strong tidal flows (∼1 m/s), with the effect from currents being larger. These tidally induced changes in wave refraction result in corresponding variability of the alongshore radiation stress and pressure gradients within the surfzone. Our results indicate that tidal contributions to the surfzone force balance can be significant and important in determining the direction and magnitude of alongshore flow.

  5. The Influence of Tidal Forcing and Groundwater Flow on Nutrient Exchange Between Salt Marsh Sediments and Adjacent Estuaries

    NASA Astrophysics Data System (ADS)

    Wilson, A. M.; Morris, J. T.

    2008-12-01

    Unlike freshwater wetlands, tidal salt marshes export significant dissolved reactive phosphorus (DRP) and ammonium to adjacent surface waters. Here we used long-term nutrient and salinity records from porewaters and tidal creeks collected at North Inlet, SC and numerical models of tidally-driven groundwater flow to investigate the role of tidal forcing in nutrient export. Long-term nutrient and salinity records were found to be highly correlated with variations in the tidal signal over a wide range of time scales. Numerical models of tidally-driven groundwater flow were then developed to independently estimate the impact of variations in mean water level (MWL) and tidal amplitude on porewater discharge to tidal creeks. Simulation results are consistent with observed trends and suggest that an increase in MWL of as little as 5 cm can increase groundwater flushing, and hence nutrient export, by more than 40 percent when marsh platforms are equilibrated near mean high water. Should MWL continue to increase faster than the marsh surface can accrete, however, the rate of flushing decreases steadily with increasing MWL. Increases in tidal amplitude also increase groundwater flushing, particularly when increasing the tidal amplitude causes the marsh platform to be inundated at high tide. Mass balance calculations based on these simulations suggest that the total DRP and ammonium discharged from salt marsh sediments at North Inlet are in excess of that needed to support observed exports to the coastal ocean. Results have important implications for marsh restoration, estuarine nutrient budgets, and sea level rise.

  6. A method for using shoreline morphology to predict suspended sediment concentration in tidal creeks

    NASA Astrophysics Data System (ADS)

    Ensign, Scott; Currin, Carolyn; Piehler, Michael; Tobias, Craig

    2017-01-01

    Improving mechanistic prediction of shoreline response to sea level rise is currently limited by 1) morphologic complexity of tidal creek shorelines that confounds application of mechanistic models, and 2) availability of suspended sediment measurements to parameterize mechanistic models. To address these challenges we developed a metric to distinguish two morphodynamic classes of tidal creek and tested whether this metric could be used to predict suspended sediment concentration. We studied three small tidal creeks in North Carolina, U.S.A. We collected suspended sediment at one non-tidal and two tidal sites in each creek and measured the wetland and channel width using a geographic information system. In each creek, tidal harmonics were measured for one year, sediment accretion on the salt marsh was measured for three years, and shoreline erosion was measured from aerial photographs spanning 50 years. Additional total suspended solids measurements from seven creeks reported in a national database supplemented our analysis. Among the three intensively studied creeks, shoreline erosion was highest in the most embayed creek (having a wider channel than the width of adjoining wetlands) and lowest in the wetland-dominated creek (having a channel narrower than the width of adjoining wetlands). Wetland sediment accretion rate in the wetland-dominated creek was four times higher than the accretion in the embayed creek. The wetland-dominated tidal creek had over twice the suspended sediment as the most embayed creek. Based on these results, we conclude that our metric of embayed and contrasting wetland-dominated creek morphology provides a guide for choosing between two types of morphodynamic models that are widely used to predict wetland shoreline change. This metric also allowed us to parse the 10 tidal creeks studied into two groups with different suspended sediment concentrations. This relationship between suspended sediment concentration and creek morphology provides

  7. Salt transport in a tidal canal, West Neck Creek, Virginia

    USGS Publications Warehouse

    Bales, Jerad D.; Skrobialowski, Stanley C.; ,

    1993-01-01

    Flow and stability were monitored during 1989-92 in West Neck Creek, Virginia, which provides a direct hydraulic connection between the saline waters of Chesapeake Bay and the relatively fresh waters of Currituck Sound, North Carolina. Flow in the tidal creek was to the south 64 percent of the time, but 80 percent of the southward flows were less than 40 cubic feet per second. The highest flows were associated with rain storms. Salinity ranged from 0.1 parts per thousand to 24.5 per thousand, and the highest salinities were observed during periods of sustained, strong northerly winds. Salt loads ranged from 302 tons per day to the north to 4,500 tons per day to the south.

  8. Fish communities of a disturbed mangrove wetland and an adjacent tidal river in Palmar, Ecuador

    NASA Astrophysics Data System (ADS)

    Shervette, V. R.; Aguirre, W. E.; Blacio, E.; Cevallos, Rodrigo; Gonzalez, Marcelo; Pozo, Francisco; Gelwick, F.

    2007-03-01

    Coastal Ecuador has lost 20-30% of mangrove wetlands over the past 30 years. Such habitat loss can impair the ecological functions of wetlands. A paucity of information exists concerning mangrove fish communities of Ecuador. In this study we identify the fish community of the remaining mangrove wetland in Palmar, Ecuador. Fish were sampled in the dry season of 2003 and the wet season of 2004 by seining in mangrove creeks and Main channel of Rio Palmar. For comparison, an adjacent tidal river without mangroves, Rio Javita, was also sampled. We collected a total of 12,231 individuals comprising 36 species in 16 families from Rios Palmar and Javita. Gobiidae (7 species) was the most diverse family for mangrove sites followed by Gerreidae (5 species) and Engraulidae (4 species). A total of 34 species were collected in the mangrove wetland, 21 of which were exclusive to the mangroves including three species of juvenile snook (Centropomidae), indicating that the mangrove habitat of Palmar may provide nursery habitat for these economically valued species. In Rio Javita, Carangidae (3 species) was the most diverse family followed by Engraulidae and Gerreidae (2 species each). A total of 14 species were collected in the tidal river, only two of which were exclusive to the river. Multivariate analyses of fish community data indicated significant differences in community composition between the mangrove creeks and the tidal river and between seasons in both. Juvenile white mullet, Mugil curema, were collected in high relative abundance in both Rios Palmar and Javita, as was the tropical silverside Atherinella serrivomer an ecologically important species. Although Rios Palmar and Javita are characterized by relatively low fish species richness compared to other tropical estuarine systems, they appear to provide an important habitat for several economically and ecologically valued species.

  9. Rapid evolution of a marsh tidal creek network in response to sea level rise.

    NASA Astrophysics Data System (ADS)

    Hughes, Z. J.; Fitzgerald, D. M.; Mahadevan, A.; Wilson, C. A.; Pennings, S. C.

    2008-12-01

    In the Santee River Delta (SRD), South Carolina, tidal creeks are extending rapidly onto the marsh platform. A time-series of aerial photographs establishes that these channels were initiated in the 1950's and are headward eroding at a rate of 1.9 m /yr. Short-term trends in sea level show an average relative sea level rise (RSLR) of 4.6 mm/yr over a 20-year tide gauge record from nearby Winyah Bay and Charleston Harbor (1975-1995). Longer-term (85-year) records in Charleston suggest a rate of 3.2 mm/yr. RSLR in the SRD is likely even higher as sediment cores reveal that the marsh is predominantly composed of fine-grained sediment, making it highly susceptible to compaction and subsidence. Furthermore, loss in elevation will have been exacerbated by the decrease in sediment supply due to the damming of the Santee River in 1939. The rapid rate of headward erosion indicates that the marsh platform is in disequilibrium; unable to keep pace with RSLR through accretionary processes and responding to an increased volume and frequency of inundation through the extension of the drainage network. The observed tidal creeks show no sinuosity and a distinctive morphology associated with their young age and biological mediation during their evolution. Feedbacks between tidal flow, vegetation and infauna play a strong role in the morphological development of the creeks. The creek heads are characterized by a region denuded of vegetation, the edges of which are densely populated and burrowed by Uca Pugnax (fiddler crab). Crab burrowing destabilizes sediment, destroys rooting and impacts drainage. Measured infiltration rates are three orders of magnitude higher in the burrowed regions than in a control area (1000 ml/min and 0.6 ml/min respectively). Infiltration of oxygenated water enhances decomposition of organic matter and root biomass is reduced within the creek head (marsh=4.3 kg/m3, head=0.6 kg/m3). These processes lead to the removal and collapse of the soils, producing

  10. Tidal Flooding and Vegetation Patterns in a Salt Marsh Tidal Creek Imaged by Low-altitude Balloon Aerial Photography

    NASA Astrophysics Data System (ADS)

    White, S. M.; Madsen, E.

    2013-12-01

    Inundation of marsh surfaces by tidal creek flooding has implications for the headward erosion of salt marsh creeks, effect of rising sea levels, biological zonation, and marsh ecosystem services. The hydroperiod; as the frequency, duration, depth and flux of water across the marsh surface; is a key factor in salt marsh ecology, but remains poorly understood due to lack of data at spatial scales relevant to tracking the spatial movement of water across the marsh. This study examines how hydroperiod, drainage networks, and tidal creek geomorphology on the vegetation at Crab Haul Creek. Crab Haul Creek is the farthest landward tidal basin in North Inlet, a bar-built estuary in South Carolina. This study measures the hydroperiod in the headwaters Crab Haul Creek with normal and near-IR photos from a helium balloon Helikite at 75-100 m altitude. Photos provide detail necessary to resolve the waterline and delineate the hydroperiod during half tidal cycles by capturing the waterline hourly from the headwaters to a piezometer transect 260 meters north. The Helikite is an ideal instrument for local investigations of surface hydrology due to its maneuverability, low cost, ability to remain aloft for extended time over a fixed point, and ability to capture high-resolution images. Photographs taken from aircraft do not provide the detail necessary to determine the waterline on the marsh surface. The near-IR images make the waterline more distinct by increasing the difference between wet and dry ground. In the headwaters of Crab Haul Creek, individual crab burrows are detected by automated image classification and the number of crab burrows and their spatial density is tracked from January-August. Crab burrows are associated with the unvegetated region at the creek head, and we relate their change over time to the propagation of the creek farther into the tidal basin. Plant zonation is influenced by the hydroperiod, but also may be affected by salinity, water table depth, and

  11. The Effect of Oyster Reef Morphology on Particulate Transfer in a North Carolina Tidal Creek

    NASA Astrophysics Data System (ADS)

    Lemon, M. G.; Posey, M.; Mallin, M.; Alphin, T.

    2014-12-01

    The eastern oyster (Crassostrea virginica) is a vital ecosystem engineer species, providing a number of ecosystem services that structure and maintain estuarine environments through the construction of large, hard-bottom reef complexes. Through suspension feeding, oysters clear the water column of particulates, leading to decreased suspended material and enhanced benthic pelagic coupling. Past field studies have indicated the potential importance of the physical reef structure in regulating the transfer of particulate material in the seston. In order to directly assess the existence of the physical reef effect, multiple field experiments were performed in a small tidal creek estuary along the south eastern coast of North Carolina. Comparison of clearance rates derived from two different in situ methods, one accounting for the physical structure of the oyster reef in addition to oyster filtration and one looking at oyster filtration alone, indicate that the reef structure may increase the amount of particulate removal performed by the reef by more than 4 times the removal performed by oyster filtration alone. A defaunation experiment was performed by eliminating the live component of the oyster reef and comparing particulate transfer of this defaunated transect to that of an adjacent faunated transect. The defaunated transect had reduced but not significantly lower material removal when compared to the faunated transect prior to defaunation. Results from short and long term sediment collection and flow velocity measurements indicate that the physical effect of oyster reefs is strong over short temporal scales (days) but is much smaller when evaluated over longer time periods (months). Generally, large silt and small sand sized material is permanently removed from the seston due to the interaction of oyster reef structure and tidal flows, however the transfer of small and medium sized silt grains is only slowed down by the presence of large reef complexes. This

  12. Assessment and monitoring of nutrient loading in the sediments of tidal creeks receiving shrimp farm effluent in Quang Ninh, Vietnam.

    PubMed

    Bui, Thuyet D; Luong-Van, Jim; Maier, Stefan W; Austin, Chris M

    2013-10-01

    Coastal shrimp farming may lead to the contamination of sediments of surrounding estuarine and marine ecosystems as shrimp farm effluent often contains high levels of pollutants including a range of organic compounds (from uneaten feed, shrimp feces, and living and dead organisms) which can accumulate in the sediments of receiving waterways. The assessment and monitoring of sediment quality in tidal creeks receiving shrimp farm effluent can support environmental protection and decision making for sustainable development in coastal areas since sediment quality often shows essential information on long-term aquatic ecosystem health. Within this context, this paper investigates nutrient loadings in the sediments of tidal creeks receiving shrimp farm effluent in Quang Ninh, Vietnam, which now have a high concentration of intensive and semi-intensive shrimp farms. Sediment samples taken from inside creek sections directly receiving effluent from concentrated shrimp farms (IEC), from main creeks adjacent to points of effluent discharge outside concentrated shrimp farms (OEC), and few kilometers away from shrimp farms (ASF) as reference sites were collected and analyzed before and after shrimp crops to investigate spatial and temporal variation. The results showed that there were statistically significant differences in the concentrations of total nitrogen, total phosphorus, and total organic carbon among IEC, OEC, and ASF sites while the seasonal variation being limited over study times. A sediment nutrient index (SNI) computed from coefficient scores of the factor analysis efficiently summarizes sediment nutrient loads, which are high, albeit quite variable, in canals directly receiving effluents from farms but then decline sharply with distance from shrimp farms. The visualization and monitoring of sediment quality data including SNI on maps can strongly support managers to manage eutrophication at concentrated shrimp farming areas, contributing to sustainable

  13. Tidal reversal and flow velocities using temperature and specific conductance in a small wetland creek

    NASA Astrophysics Data System (ADS)

    Eaton, Timothy T.

    2016-11-01

    Characterizing flow dynamics in very small tidal creeks is complicated and not well suited to methods developed for upland streams or coastal estuaries, due to low flows, bidirectionality and shallow waters. Simple instrumentation enables thermal and salinity signals to be used to observe flow directions and estimate velocities in these settings. Using multiple inexpensive sensors over 500 m along a tidally influenced wetland creek, I demonstrate how advection of temperature and specific conductance pulses reveal flood and ebb tides and the temporary reversal of flow by warmer, estuarine water from the receiving embayment. The sequential rise of temperature upstream was most evident under hot and dry conditions, after daily peak air temperatures of 25 °C or above, and was subdued or disrupted under cooler or rainy conditions in summertime. Changes in specific conductance at successive sites upstream were less susceptible to environmental influences and confirm tidal flood velocity of between 0.07 and 0.37 m/s. The tidally-induced flow reversal suggests that periodic high tide conditions can interfere with rapid dispersal of pollution discharges, such as from the combined sewer overflow (CSO) located upstream of the studied creek reach. This low-cost approach of temperature and specific conductance sensing in vegetated coastal wetlands where access, precise elevation control and creek discharge measurements are difficult, provides a simple way of tracking water masses when sufficient contrast exists between water sources.

  14. Utilization by fishes of the Alviso Island ponds and adjacent waters in south san francisco bay following restoration to tidal influence

    USGS Publications Warehouse

    Saiki, M.K.; Mejia, F.H.

    2009-01-01

    Earthen levees of three isolated salt ponds known locally as the Alviso Island Ponds were intentionally breached in March 2006 to allow tidal exchange of the ponds with water from Coyote Creek. The water exchange transformed the previously fishless hypersaline ponds into lower salinity habitats suitable for fish life. This study documented fish utilization of the ponds, adjacent reaches of Coyote Creek, and an upstream reach in nearby Artesian Slough during May-July 2006. By the time the study was initiated, water quality conditions in the ponds were similar to conditions in adjacent reaches of Coyote Creek. The only variable exhibiting a strong gradient within the study area was salinity, which increased progressively from upstream to downstream in Coyote Creek. A total of 4,034 fish represented by 18 species from 14 families was caught during the study. Judging from cluster analysis of presence-absence data that excluded rare fish species, the 10 sampling units (3 ponds, 6 reaches in Coyote Creek, and 1 reach in Artesian Slough) formed two clusters or groups, suggesting two species assemblages. The existence of two groups was also suggested by ordination with non-metric multidimensional scaling (NMS). One group, which was composed of the three ponds and four of the lowermost reaches of Coyote Creek, was characterized by mostly estuarine or marine species (e.g., topsmelt, Atherinops affinis; northern anchovy, Engraulis mordax; and longjaw mudsucker, Gillichthys mirabilis). The second group, which was composed of the two uppermost reaches of Coyote Creek and the one reach of Artesian Slough, was characterized by freshwater species (e.g., Sacramento sucker, Catostomus occidentalis) and by an absence of the estuarine/marine species noted in the first assemblage. Judging from a joint plot of selected water quality variables overlaying the ordination results, salinity was the only important variable associated with spatial distribution of fish species. Water

  15. Saltmarsh pool and tidal creek morphodynamics: Dynamic equilibrium of northern latitude saltmarshes?

    NASA Astrophysics Data System (ADS)

    Wilson, Carol A.; Hughes, Zoe J.; FitzGerald, Duncan M.; Hopkinson, Charles S.; Valentine, Vinton; Kolker, Alexander S.

    2014-05-01

    Many saltmarsh platforms in New England and other northern climates (e.g. Canada, northern Europe) exhibit poor drainage, creating waterlogged regions where short-form Spartina alterniflora dominates and stagnant pools that experience tidal exchange only during spring tides and storm-induced flooding events. The processes related to pool formation and tidal creek incision (via headward erosion) that may eventually drain these features are poorly understood, however it has been suggested that an increase in pool occurrence in recent decades is due to waterlogging stress from sea-level rise. We present evidence here that saltmarshes in Plum Island Estuary of Massachusetts are keeping pace with sea-level rise, and that the recent increase in saltmarsh pool area coincides with changes in drainage density from a legacy of anthropogenic ditching (reversion to natural drainage conditions). Gradients, in addition to elevation and hydroperiod, are critical for saltmarsh pool formation. Additionally, elevation and vegetative changes associated with pool formation, creek incision, subsequent drainage of pools, and recolonization by S. alterniflora are quantified. Pool and creek dynamics were found to be cyclic in nature, and represent platform elevation in dynamic equilibrium with sea level whereby saltmarsh elevation may be lowered (due to degradation of organic matter and formation of a pool), however may be regained on short timescales (101-2 yr) with creek incision into pools and restoration of tidal exchange. Rapid vertical accretion is associated with sedimentation and S. alterniflora plant recolonization.

  16. Water use patterns of estuarine vegetation in a tidal creek system.

    PubMed

    Wei, Lili; Lockington, David A; Poh, Seng-Chee; Gasparon, Massimo; Lovelock, Catherine E

    2013-06-01

    Water availability is a key determinant of the zonation patterns in estuarine vegetation, but water availability and the use of different water sources over space and time are not well understood. We have determined the seasonal water use patterns of riparian vegetation over an estuarine ecotone. Our aim was to investigate how the water use patterns of estuarine vegetation respond to variations in the availability of tidal creek water and rain-derived freshwater. The levels of natural stable isotopes of oxygen and hydrogen were assessed in the stem of the mangrove Avicennia marina (tall and scrub growth forms), Casuarina glauca and Melaleuca quinquenervia that were distributed along transects from river/creek-front towards inland habitats. The isotopic composition of plant tissues and the potential water sources were assessed in both the wet season, when freshwater from rainfall is present, and the dry season, when mangrove trees are expected to be more dependent on tidal water, and when Casuarina and Melaleuca are expected to be dependent on groundwater. Our results indicate that rainwater during the wet season contributes significantly to estuarine vegetation, even to creek-side mangroves which are inundated by tidal creek water daily, and that estuarine vegetation depends primarily on freshwater throughout the year. In contrast, high intertidal scrub mangroves were found to use the greatest proportion of tidal creek water, supplemented by groundwater in the dry season. Contrary to prediction, inland trees C. glauca and M. quinquenervia were found also to rely predominantly on rainwater--even in the dry season. The results of this study reveal a high level of complexity in vegetation water use in estuarine settings.

  17. Evaluation of the impacts of dock structures and land use on tidal creek ecosystems in South Carolina estuarine environments.

    PubMed

    Sanger, Denise M; Holland, A Fredrick; Hernandez, Debra L

    2004-03-01

    Tidal creeks and their associated salt marshes are the primary link between uplands and estuaries in the southeastern region. They are also critical nursery and feeding grounds. In addition, the uplands surrounding creeks are preferred sites for homebuilding because of their natural beauty and the ability to access the estuary from a personal dock structure. The objective of this study was to evaluate the cumulative impacts of docks on tidal creek nursery habitats for both small and large tidal creeks. The number of docks was associated with the amount of impervious cover in both small and large creeks. The presence of docks had little measurable effect on sediment metal concentrations at the scale of small and large creeks. In small and large creeks, sediment polycyclic aromatic hydrocarbon (PAH) concentrations were related to the human activity in the upland that includes the presence of docks at the scale of small and large creeks. Some impacts on the benthic community were associated with docks and human activity in small creeks but not in large creeks. Suburban development may reduce fish and crustacean abundances, but the dock may potentially mediate the development effect. Individually, the harm to the marine environment resulting from dock shading, chrominated copper arsenate leachates, and PAH contamination was small at the scale of tidal creeks. However, impacts from dock structures could not be separated from anthropogenic watershed-scale effects. These results demonstrate that suburban development with its accompanying dock construction does represent a major source of environmental degradation to tidal creeks and associated salt marsh habitats.

  18. Influence of moon phase on fish assemblages in estuarine mangrove tidal creeks.

    PubMed

    Ramos, J A A; Barletta, M; Dantas, D V; Lima, A R A; Costa, M F

    2011-01-01

    Significant differences in the composition of fish assemblages during different moon phases were detected in mangrove tidal creeks of the Goiana Estuary. The numbers of Zabaleta anchovy Anchovia clupeoides, Tarpon snook Centropomus pectinatus and Guavina Guavina guavina as well as at least 15 other species showed significant changes according to moon phase and were higher in terms of individuals (32%) and mass (34%) during the new moon.

  19. Development of a data management framework in support of southeastern tidal creek research.

    PubMed

    White, David L; Wolf, Danna; Porter, Dwayne E; Sanger, Denise M; Riekerk, George H M; DiDonato, Guy; Holland, A Fred; Dabney, David

    2009-03-01

    The NOAA Center of Excellence for Oceans and Human Health Initiative (OHHI) at the Hollings Marine Laboratory (HML) is developing a data management framework that supports an integrated research program across scientific disciplines. The primary focus of the database is to support environmental research focused on tidal creek watershed systems. Specifically, the current data holdings include physical water quality parameters, nutrients, pathogens, chemical contaminants, benthic and nekton species abundances and human dimensions data from Georgia, North Carolina and South Carolina dating to 1994. These data are not from a single long-term research project but are derived from several state and federal research programs and integrated into a common database model to support current research being conducted under the OHHI program at HML. The Tidal Creek database was developed with the intent to support a well documented and open system, thus metadata elements from common metadata standards including the Dublin Core ISO 15836:2003 and Federal Geographic Data Committee (FGDC-STD-001-1998) are components of the database model. The result is a semantic database framework with descriptive ancillary data at the record level including methods, investigator names, date, locations and other descriptive elements. The primary users of the database are project personnel to meet analytical needs. The database is also available through a number of web-based applications that are designed to give users the necessary information to evaluate and access data. In addition, data can be accessed with Open Geospatial Consortium (OGC) standards, and species records and abundances are being made available to the Ocean Biogeographic Information System (OBIS). Overall, the Tidal Creek database summarizes the response of tidal creeks and watersheds to coastal development, and serves as a repository for environmental, demographic, and socioeconomic data in the Southeast.

  20. Benthic macroinvertebrate communities affected by multiple stressors within tidal creeks in northeastern USA harbors

    SciTech Connect

    Papageorgis, C.; Murray, M.; Danis, C.; Yates, L.

    1995-12-31

    Surveys of water quality, substrate quality and benthic macroinvertebrates were conducted in a variety of tidal creeks located in the vicinity of a municipal solid waste landfill prior to the construction of a leachate collection system. In-Situ water quality data indicated high water temperatures and low dissolved oxygen values along with high turbidites. Sediment chemistry data indicated that all sediment within the study area exceed USEPA heavy metal criteria. Grain size and salinity data indicate that the study area lies within the Mesohaline Mud habitat class. Water quality data remained within similar concentrations with respect to indicators of leachate. The benthic macroinvertebrate community was consistently dominated by opportunistic Polychaete and Oligochaete worms. Both Shannon diversity and Rarefaction curves were used to evaluate trends in species diversity over time. The study includes a comparison to data obtained by USEPA R-EMAP monitoring programs. While large scale biomonitoring programs do not focus on small tidal creeks this study provides useful data regarding baseline benthic communities within tidal creeks affected by multiple stressors to include previous exposure and potential exposure to oil spills, continued point and non-point municipal and industrial wastewater discharges and physical stressors such as elevated water temperatures, homogeneous silt/clay substrate, and depressed dissolved oxygen values.

  1. Nocturnal Fish Use of New Jersey Marsh Creek and Adjacent Bay Shoal Habitats

    NASA Astrophysics Data System (ADS)

    Rountree, R. A.; Able, K. W.

    1997-06-01

    Night-time sampling with gill nets in the Little Egg Harbor estuary revealed a component of the estuarine fish fauna, hitherto poorly documented, which is comprised of relatively large size classes of juvenile and adult life history stages. The fishesMustelus canis, Pomatomus saltatrix, Paralichthys dentatus, Brevoortia tyrannus, Prionotus evolansandAlosa mediocriswere the most abundant fishes captured. These observations suggest that Mid-Atlantic Bight estuaries are important nurseries for juvenile stages beyond the first year, as well as for the young of the year (YOY). Although many other studies emphasise the importance of estuaries as nurseries for YOY stages, the importance of estuaries to later juvenile life stages has been largely overlooked. This component of estuarine fish fauna has been poorly represented in previous North American studies because of probable gear avoidance, and because most studies are conducted primarily during the day. The authors hypothesise that these later juvenile stages are likely to be important estuarine faunal components in other geographic regions, as well as in the Mid-Atlantic Bight. A descriptive comparison of catches between ebb and flood tide stages, and between bay shoal and tidal marsh creek habitats, suggests that later juvenile and adult stages of several species make tidal migrations into shallow estuarine habitats, such as shoals and marsh creeks, during the night hours.

  2. Marsh Pool and Tidal Creek Morphodynamics: Dynamic Equilibrium of New England Saltmarshes?

    NASA Astrophysics Data System (ADS)

    Wilson, C.; FitzGerald, D. M.; Hughes, Z. J.

    2012-12-01

    Under natural conditions, high saltmarsh platforms in New England exhibit poor drainage, creating waterlogged pannes (where short-form Spartina alterniflora dominates) and stagnant pools that experience tidal exchange only during spring tides and storm-induced flooding events. It is well accepted that a legacy of ditching practices (either for agriculture or mosquito control purposes) provide "overdrainage" of saltmarshes (after Redfield, 1972) and a shift in biogeochemical conditions: lowering of groundwater tables, aeration of soil, and decrease in preserved belowground biomass. Analysis of historical imagery in the Plum Island Estuary of Massachusetts reveals closure and decrease in length of anthropogenic ditches in recent decades is closely linked to marsh pool evolution. Field analyses including stratigraphic transects and elevation surveys suggest these marshes are reverting to natural drainage conditions. Further, an important dynamic interaction exists between saltmarsh pools and natural tidal creeks: creeks incise into pool areas, causing drainage of the pools, and formation of an unvegetated mudflat which can be rapidly recolonized by halophytic Spartina alterniflora vegetation. It was determined that pool and creek dynamics are cyclic in nature. The marsh platform is in dynamic equilibrium with respect to elevation and sea-level whereby marsh elevation may be lost (due to degradation of organic matter and formation of a pool) however may be regained (by creek incision into pools, restoration of tidal exchange, and rapid vertical accretion with Spartina alterniflora recolonization. Since vertical accretion in saltmarshes is a function of both organic and inorganic contributions to the marsh subsurface, it is hypothesized that cannibalization of existing muds is supplying inorganic material in this sediment starved system.

  3. Temperature anomalies in the Lower Suwannee River and tidal creeks, Florida, 2005

    USGS Publications Warehouse

    Raabe, Ellen A.; Bialkowska-Jelinska, Elzbieta

    2007-01-01

    Temperature anomalies in coastal waters were detected with Thermal Infrared imagery of the Lower Suwannee River (LSR) and nearshore tidal marshes on Florida’s Gulf Coast. Imagery included 1.5-m-resolution day and night Thermal Infrared (TIR) and 0.75-m-resolution Color Infrared (CIR) imagery acquired on 2-3 March 2005. Coincident temperature readings were collected on the ground and used to calibrate the imagery. The Floridan aquifer is at or near the land surface in this area and bears a constant temperature signature of ~ 22 degrees Celsius. This consistent temperature contrasts sharply with ambient temperatures during winter and summer months. Temperature anomalies identified in the imagery during a late-winter cold spell may be correlated with aquifer seeps. Hot spots were identified as those areas exceeding ambient water temperature by 4 degrees Celsius or more. Warm-water plumes were also mapped for both day and night imagery. The plume from Manatee Spring, a first-order magnitude spring, influenced water temperature in the lower river. Numerous temperature anomalies were identified in small tributaries and tidal creeks from Shired Island to Cedar Key and were confirmed with field reconnaissance. Abundant warm-water features were identified along tidal creeks south of the Suwannee River and near Waccasassa Bay. Features were mapped in the tidal creeks north of the river but appear to be less common or have lower associated discharge. The imagery shows considerable promise in mapping coastal-aquifer seeps and understanding the underlying geology of the region. Detection of seep locations may aid research in groundwater/surface-water interactions and water quality, and in the management of coastal habitats.

  4. Nonlinear Tidal Distortion and Low Frequency Residual Effects in a Coastal Creek

    NASA Astrophysics Data System (ADS)

    Jachec, S. M.; Hansell, H. C.

    2012-12-01

    A 62 day observational campaign in the spring 2011, recorded free surface and meteorological observations used to determine hydrodynamic conditions of an area in the northern region of Mosquito Lagoon, FL. Mean water level ranges at instrument locations decrease from 0.35 to 0.22 m moving further from the primary inlet. A harmonic analysis revealed mean extracted tidal ranges at the former stations decreasing from 0.34 to 0.21 m. Nonlinear distortion increases with distance into the system, with a maximum tidal range decrease of 0.13 m and high tide time lag of 0.89 hrs between extreme stations. Ebb durations averaged 1 hr longer than flood, indicating a flood-dominant system. Spectral and cross-spectral analyses showed significant coherence between wind and non-tidal fluctuations in the low frequency regime. Using a modified conservation of mass equation, flow calculations reveal a partitioning of the flow between tides and winds.; Study site: Mosquito Lagoon, FL. ; Tidal amplitude attenuation of M2 and M4 tides through creek.

  5. Hydrographic characterization of two tidal creeks with implications for watershed land use, flushing times, and benthic production

    USGS Publications Warehouse

    Buzzelli, C.; Holland, Austin F.; Sanger, D.M.; Conrads, P.C.

    2007-01-01

    Many coastal ecosystems are undergoing anthropogenic stress from large increases in population and urbanization. In many regions changes in freshwater and material inputs to the coastal zone are altering the biogeochemical and biological capacities of ecosystems. Despite increased watershed inputs, large tidal volumes and flushing indicative of macrotidal estuaries can modulate the fate of introduced materials masking some of the symptoms of eutrophication. The Land Use Coastal Ecosystem Study (LU-CES) examined linkages between land use and environmental properties of Malind and Okatee Creeks in South Carolina from 2001 to 2004. The objectives of this particular study were to assess the hydrography of the two macrotidal creek ecosystems, explore differences in dissolved oxygen (DO), and develop a better understanding of the variations in primary and benthic secondary production in southeastern creek ecosystems. Depth, pH, salinity, and DO were reduced and more variable in Malind Creek than in Okatee Creek, although both creeks had strong semidiurnal frequencies in salinity time signatures. While time series analyses of DO saturation in Malind Creek revealed a dominant semidiurnal pattern, Okatee Creek had a distinctly diel DO pattern. The strongly semidiurnal fluctuations in DO and reduced flushing time indicated that biological processes were not fast enough to influence DO in Malind Creek. The Okatee Creek system had a much greater storage volume, a wider marsh, and a dominant 25-h DO frequency. These attributes contributed to an estimated 8-10 times more phytoplankton-based carbon in Okatee Creek and twice the annual benthic production. As expected from their proximity to the upland, low surface area, and high organic content, both ecosystems were net heterotrophic. This fundamental understanding of tidal creek hydrography is being used to help define linkages among differential watershed land uses, flushing characteristics, and levels of biological production

  6. Impact of roadside ditch dredging on bacterial communities and biological contamination of a tidal creek

    NASA Astrophysics Data System (ADS)

    Jones, Chance E.; Barkovskii, Andrei L.

    2017-03-01

    Tidal creek networks form the primary hydrologic link between estuaries and land-based activities on barrier islands. A possible impact from the excavation of drainage ditch systems on bacterial communities and biological contamination was studied in the water column and sediments of headwater, mid-stream, and mouth sites of the intertidal Oakdale Creek on Sapelo Island, GA. Community analysis was performed using the MiSeq Illumina platform and revealed that dredging was the cause of a significant rise in Proteobacteria, especially γ-proteobacteria. Targeted biological contaminants included fecal indicator bacteria, Enterococcus spp. (Entero-1), pathogens, Shigella spp. (ipaH), and Salmonella spp (invA), virulence associated genes (VG's) of pathogenic E. coli (eaeA, hlyD, stx1, stx2, and set1B), integrons (intI1, intI2), and tetracycline resistance genes (TRGs). Incidence and gene concentrations of Shigella spp., eaeA and set1B, and of TRGs increased 3-20 folds after the onset of dredging, and followed the dredging schedule. Principal Component Analysis suggested possible common carriers for Shigella spp., some TRGs, and the pathogenic E. coli eaeA gene. At the site of dredging, all of the above contaminants were detected at high concentrations. We concluded that excavation of roadside ditches caused significant changes in bacterial composition and a rise in incidence and concentrations of biological contaminants in the creek. The authors suggest a different approach for the maintenance of this material be explored.

  7. Soil chemistry adjacent to roads treated with dust control products at Squaw Creek National Wildlife Refuge

    USGS Publications Warehouse

    Kunz, Bethany K.

    2016-01-01

    The health of soils along roadways is critical for maximizing habitat quality and minimizing negative ecological effects of roads. Adjacent to unpaved roads, soil chemistry may be altered by the deposition of dust, as well as by road treatment with dust suppressants or soil stabilizer products. If present in roadside soils, these product residues may be available to plants, terrestrial invertebrates, or small mammals. Unfortunately, very few studies have attempted to track the transport of dust suppressants after application. As part of a larger ongoing study on the environmental effects of dust suppressant products on roadside plants and animals, we sampled roadside soils at Squaw Creek National Wildlife Refuge (NWR). Replicated road sections at Squaw Creek NWR had been previously treated with two road products—calcium chloride-based durablend-C™ and synthetic iso-alkane EnviroKleen®. In order to quantify the effect of dust suppressant treatment on roadside soils, we took replicated composite soil samples one year after treatment at 1m and 4m from the road’s edge, and analyzed samples for a suite of soil chemistry variables (pH, conductivity, NO3-N, P, K, Ca, Mg, Na and S). We also assessed dust suppressant product residues in the soil. For durablend-C™, we used soil conductivity as an indicator. For EnviroKleen®, we developed a method for extraction and isolation, followed by analysis with gas chromatography/mass spectrometry to look for a specific EnviroKleen® signature. Surprisingly, soil conductivity was not elevated adjacent to road sections treated with durablend-C™, relative to other sections. EnviroKleen® was detectable at both 1m and 4m from treated sections at concentrations from 1 to 1500 mg/kg, and was non-detectable in soils adjacent to the untreated section. The most notable characteristic of soils across all treated and untreated sections at 1m was elevated calcium (up to 30,000 mg/kg), likely as a result of dust deposition from the

  8. METHODS OF EXPLORING METABOLIC STRUCTURE AND TAXONOMIC DIVERSITY RELATIONSHIPS BETWEEN BACTERIOPLANKTON AND PHYTOPLANKTON IN SALT MARSH TIDAL CREEKS

    EPA Science Inventory

    Bacterial metabolic diversity and phytoplankton community diversity were examined in eight shallow tidal creeks over a two-year period (1997-1998) within North Inlet estuary, South Carolina. The BIOLOG 96-well microplate method was used to assess metabolic diversity of bacteria, ...

  9. Hydrogeologic characteristics of the alluvial aquifer and adjacent deposits of the Fountain Creek valley, El Paso County, Colorado

    USGS Publications Warehouse

    Radell, Mary Jo; Lewis, Michael E.; Watts, Kenneth R.

    1994-01-01

    The alluvial aquifer in Fountain Creek Valley between Colorado Springs and Widefield is the source for several public-supply systems. Because of the importance of this aquifer, defining aquifer boundaries, areas where underflow occurs, and where Fountain Creek is hydraulically connected to the aquifer will greatly add to the understanding of the alluvial aquifer and management of the public- supply systems. Bedrock altitude, water-table altitude for October 1991, saturated thickness for October 1991, selected hydrogeologic sections in the alluvial aquifer and adjacent deposits of the Fountain Creek Valley, and estimated underflow rates are mapped or tabulated for the area between Colorado Springs and Widefield, Colorado. Results from test drilling indicate that the bedrock surface is highly irregular and that several ridges and buried channels exist in the study area. These features affect the direction of ground-water flow on a local scale. In places, a shale ridge prevents exchange of water between Fountain Creek and the aquifer. Generally, ground water flowed toward Fountain Creek during the study (June 1991 to September 1992) in response to relatively high hydraulic heads in the aquifer and the steep gradients on the boundaries of the study area. Water levels, which were measured monthly, varied little during the study, except in areas near pumping wells or adjacent to Fountain Creek. Hydraulic-conductivity values, estimated from 30 bail tests in wells completed in the alluvial aquifer, were used to determine underflow across the saturated boundaries of the alluvial aquifer. Estimated hydraulic-conductivity values range from 1 to about 1,300 feet per day; the larger values occur in the buried channel of the alluvial aquifer and the smaller values occur near the boundaries of the saturated alluvium. Estimated underflow into the study area exceeded underflow out of the study area by about 10 times. Gain-loss investigations along Fountain Creek indicated that the

  10. Altered mangrove wetlands as habitat for estuarine nekton: are dredged channels and tidal creeks equivalent?

    USGS Publications Warehouse

    Krebs, Justin M.; Brame, Adam B.; McIvor, Carole C.

    2007-01-01

    Hasty decisions are often made regarding the restoration of "altered" habitats, when in fact the ecological value of these habitats may be comparable to natural ones. To assess the "value" of altered mangrove-lined habitats for nekton, we sampled for 1 yr within three Tampa Bay wetlands. Species composition, abundance, and spatial distribution of nekton assemblages in permanent subtidal portions of natural tidal creeks and wetlands altered by construction of mosquito-control ditches and stormwater-drainage ditches were quantified through seasonal seine sampling. Results of repeated-measures analysis of variance and ordination of nekton community data suggested differences in species composition and abundance between natural and altered habitat, though not consistently among the three wetlands. In many cases, mosquito ditches were more similar in assemblage structure to tidal creeks than to stormwater ditches. In general, mosquito ditches and stormwater ditches were the most dissimilar in terms of nekton community structure. These dissimilarities were likely due to differences in design between the two types of ditches. Mosquito ditches tend to fill in over time and are thus more ephemeral features in the landscape. In contrast, stormwater ditches are a more permanent altered habitat that remain open due to periodic flushing from heavy runoff. Results indicate that environmental conditions (e.g., salinity, current velocity, vegetative structure) may provide a more useful indication of potential habitat "value" for nekton than whether the habitat has been altered. The type of ditching is therefore more important than ditching per se when judging the habitat quality of these altered channels for fishes, shrimps and crabs. Planning should entail careful consideration of environmental conditions rather than simply restoring for restoration's sake.

  11. Apogean-perigean signals encoded in tidal flats at the fluvio-estuarine transition of Glacier Creek, Turnagain Arm, Alaska; implications for ancient tidal rhythmites

    USGS Publications Warehouse

    Greb, S.F.; Archer, A.W.; Deboer, D.G.

    2011-01-01

    Turnagain Arm is a macrotidal fjord-style estuary. Glacier Creek is a small, glacially fed stream which enters the estuary tangentially near Girdwood, Alaska. Trenches and daily sedimentation measurements were made in a mudflat along the fluvio-estuarine transition of Glacier Creek during several summers since 2003. Each year, the flats appear to erode during the winter and then accrete vertically in the spring and summer. In each of the years studied, tidal laminae in vertically thickening and thinning laminae bundles were deposited by twice daily tides in neap-spring tidal cycles. In 2004, bundles of thickening and thinning laminae couplets were noted in trenches cut into the flats. Five laminae bundles alternated between thicker and thinner bundles, corresponding to the perigean (high spring) and apogean (low spring) tides. Well-preserved apogean-perigean cycles have rarely been documented in modern tidal flat sediments. At this location, vertical accretion of tidal rhythmites with well-developed neap-spring cyclicity is possible because of the near-complete removal of the flat from the previous year, which creates accommodation space for vertical accretion without significant reworking. Macrotidal conditions, no reworking by infaunal invertebrates, protection from the main tidal channel by a gravel bar and protection from storm waves and fluvial erosion by a recess in the sedge marsh that surrounds the flats all aid in preservation of rhythmites during aggradation. The position of the flats relative to tidal range allows for accumulation of complete spring cycles and incomplete neap cycles. In the summer of 2004, apogee and perigee were closely aligned with the new and full moons, resulting in successive strong perigee and apogee tides which probably aided in the accumulation of successive thick-thin spring cycles encoding the apogean and perigean tidal cycle. The apogean-perigean signal was not observed in subsequent years. ?? 2011 The Authors.

  12. Tidal, diel and semi-lunar changes in the faunal assemblage of an intertidal salt marsh creek

    NASA Astrophysics Data System (ADS)

    Hampel, Henrietta; Cattrijsse, Andre; Vincx, Magda

    2003-03-01

    The utilisation of a brackish estuarine marsh by nekton was investigated over a semi-lunar cycle in August 1994. Nekton migrating in and out of the intertidal creeks of the marsh 'Het Verdronken Land van Saeftinghe' in the Westerschelde estuary, SW Netherlands, was sampled passively during seven complete tidal cycles. Sampling one tidal cycle yielded three consecutive flood samples and four consecutive ebb samples. Sampling occurred every 2-3 days, covering diel, tidal and semi-lunar situations, thus allowing comparison of tidal, diel and semi-lunar influences on the composition of the intertidal fauna. Two different tidal-migration modes were observed. The mysid shrimp, Mesopodopsis slabberi, showed maximum abundance around high tide. For the remaining common species, the mysid ( Neomysis integer), the shrimp ( Palaemonetes varians), the crab ( Carcinus maenas) and the goby ( Pomatoschistus microps) and the amphipod ( Corophium volutator), highest densities were recorded during lower water heights. The faunal assemblage shifts between the different tidal stages. On two occasions, consecutive day and night samples were taken. Total densities were higher during the night samples. During spring tide, difference in community composition was noticed between the night and the day samples. During neap tide, day-night differences were less clear. Recorded total densities were highest during spring tide and lowest during neap tide. At maximum water levels, a drop in total density was observed. A shift in community composition occurred between spring and neap tides.

  13. Effect of water quality indices on phytoplankton of a sluggish tidal creek in Lagos, Nigeria.

    PubMed

    Adesalu, T A; Nwankwo, D I

    2008-03-15

    The phytoplankton of a tidal creek in Lagos was investigated for six months (September 1998-February 1999). The physico-chemical environment was essentially neutral (pH 7.00-7.30), relatively more transparent (> 0.23 m), expressed higher conductivity (> 0.10 mS cm(-1)), higher chloride values (> 23.48 mg L(-1)), lower nitrate content (< 0.70 mg L(-1)), lower sulphate values (< 0.45 mg L(-1)) and phosphate values (< 0.12 mg L(-1)) in the dry months. In the wet months, September to November 1998, conductivity (< 0.16 mS cm(-1)), transparency (< 0.80 m), salinity (< 0.04%), dissolved oxygen (< 24.00 mg L(-1)), chloride (< 24.21 mg L(-1)) and phosphate (< 0.21 mg L(-1)) were recorded. The phytoplankton was dominated by diatoms (48 pennate forms and 23 centric forms). The other algal groups comprised six blue- green algae and six green algae. Species richness (d) was high in stations nearer the Lagos lagoon for the six sampling periods. Shannon-Weaver index (H1) was lowest in November 1998 and highest in October 1998 and February 1999 while evenness of species J was low (< 0.71) throughout the period. Higher phytoplankton biomass was recorded in the dry months than wet months.

  14. Dynamics of Rainfall-mobilized Suspended Particulate Organic Carbon in Salt Marsh Tidal Creeks

    NASA Astrophysics Data System (ADS)

    Chen, S.; Torres, R.; Goni, M. A.

    2011-12-01

    Climate models have projected a trend of more frequent and more intense rainfall events in many coastal landscapes due to goble climate change. Rainfall kinetic energy and runoff from severe thunderstorms have the ability to do a substantial amount of work on intertidal landscapes. For instance, low tide rainfall events can produce a 2-3 order of magnitude increase in suspended sediment concentration in subtidal channels. Moreover, low tide rainfall affects the bulk composition of carbon and other nutrients in surface sediments and in the water column. We sampled rainfall-mobilized suspended sediment in two intertidal creeks in North Inlet (South Carolina) salt marsh, examined their elemental (carbon and nitrogen), isotopic (δ13C and δ15N), CuO oxidation product (COP) compositions, Chlorophyll a content, and use upscaling methods, to analyze the biogeochemical composition of rainfall-entrained suspended particulate organic carbon (RSPOC) and quantify the flux of RSPOC between marsh platform and subtidal channel. The concentrations and compositions of RSPOC varied widely but were significantly different from no-rain samples and salt marsh surface sediment. COP parameters such as lignin contents are higher in RSPOC, indicating a preferential transportation of terrestrial materials. Acid/aldehyde ratios of vanillyl and syringyl phenols, cinnamyl/vanillyl ratios and syringyl/vanillyl ratios indicate that RSPOC is more degraded and from distinct terrigenous sources. Chla/TSS ratio indicates that rainfall-entrained sediment contains less biotic material. Preliminary results indicated that 7-12 tons/km2 of POC can be mobilized in a single rain event. Therefore, low tide rainfall-runoff processes likely detach and transport organic matter which is compositionally distinct from tidally-resuspended particulate matter. The RSPOC is more degraded, with more of a terrestrial contribution and a higher abundance of abiotic materials. The significant input of these specific

  15. Water quality assessment of Malad Creek, Mumbai, India: an impact of sewage and tidal water.

    PubMed

    Sardar, V K; Vijay, R; Sohony, R A

    2010-01-01

    The aim of the study was to carry out water quality assessment and to identify sources responsible for deterioration of quality in the Malad creek, Mumbai, India. Creek receives sewage and wastewater from various drains and partially treated effluent from Malad and Versova treatment facilities. To assess the water quality, sampling locations were identified in the creek based on discharges of wastewater and sewage. Identified locations were traced in physical space by a global positioning system. Samples were collected during low and high tides and analyzed for physical, chemical and bacteriological parameters such as pH, Turbidity, DO, BOD, NH(3)-N, PO(4) and FC and compared with SW-II Standards. Parameters were also analyzed statistically and correlated to determine the relationship amongst the parameters using SPSS software. The idea was to determine the probable causes contributing to the pollution in the creek. Various options were suggested for improvement in the creek quality based on water quality assessment.

  16. Loading of fecal indicator bacteria in North Carolina tidal creek headwaters: hydrographic patterns and terrestrial runoff relationships.

    PubMed

    Stumpf, Curtis H; Piehler, Michael F; Thompson, Suzanne; Noble, Rachel T

    2010-09-01

    In the New River Estuary (NRE) in eastern North Carolina (NC), fecal indicator bacteria (FIB) levels exceed water quality standards, leading to closure of estuarine waters for shellfishing and classification of parts of the estuary as "impaired" per the Clean Water Act section 303(d) list. As a means to investigate fecal contamination and loading of FIB to the NRE, a continuous automated sampler (ISCO) outfitted with flow modules and water quality probes was placed in four first-order tidal creek headwaters. Total storm discharge and bacterial load for Escherichia coli (EC) and Enterococcus spp. (ENT) were calculated using graphical volumetric flow calculations and interpolation of FIB measurements over each storm's duration for 10 storms. Mean total load of 10(9)-10(12) EC and ENT cells (MPN) occurred over the course of each storm. Total storm loading, averaged across all storms, was as much as 30 and 37 times greater than equivalent duration of baseflow loading for EC and ENT, respectively. Within the first 30% of creek storm volume for all storms and all creeks combined, a mean cumulative load of only 37% and 44% of the total EC and ENT cells, respectively, was discharged, indicating these creeks are not demonstrating a 'first flush' scenario for FIB. The median storm Event Mean Concentrations (EMCs) were 6.37 × 10(2) and 2.03 × 10(2) MPN/100 mL, for EC and ENT, respectively, compared with median baseflow concentrations of 1.48 × 10(2) and 4.84 × 10(1) for EC and ENT, respectively, and were significantly different between base and storm flow events. FIB was correlated with TSS (weak), flow rate (strong), and different stages (base, rising, peak, and falling) of the hydrograph (strong). Pollutographs indicate large intra-storm variability of FIB, and the need for more intensive sampling throughout a storm in order to attain accurate FIB contaminant estimates. Instream sediment concentrations ranged from 5 to 478 (MPN/g) and 13 to 776 (MPN/g) for EC and ENT

  17. Long-term stability of tidal and diel-related patterns in mangrove creek fish assemblages in North Brazil

    NASA Astrophysics Data System (ADS)

    Castellanos-Galindo, G. A.; Krumme, U.

    2014-08-01

    Intertidal fish assemblages are thought to respond to tidal and diel rhythms although the assumption that these patterns are stable over long time scales (>1 year) is largely untested. Testing the validity of this assumption is necessary to assess whether short-term temporal patterns, once established, can be extrapolated over time and give a better understanding of the temporal dynamics of fish assemblages in coastal habitats. Here, we compare the fish assemblage structure from two intertidal mangrove creeks in North Brazil (Bragança Peninsula, Caeté estuary) sampled with the same sampling methodology (block nets), effort (two lunar cycles) and design (accounting for the combination of tidal and diel cycle) in the rainy seasons of 1999 and 2012 to evaluate the persistence, stability and recurrence of short-term patterns in the fish community organization. The interaction of tidal and diel cycles (inundations at spring tide-night, spring tide-day, neap tide-night, neap tide-day), found to be stable after 13 years, resulted in recurrent and stable intertidal mangrove fish assemblage compositions. The intertidal mangrove creek fish assemblage consisted of a persistent number of dominant species (seven). However, there were notable changes in fish catch mass, abundance and species dominance between 1999 and 2012. The most severe drought in North Brazil in 30 years, linked to lower precipitation and river runoff in the rainy season of 2012, may have resulted in (1) lower abundance of small juveniles of several dominant species in this assemblage (especially Ariidae - Cathorops agassizii and Sciades herzbergii) and (2) increased dominance of large-sized specimens of the tetraodontid Colomesus psittacus. Our findings highlight: (1) the overriding importance and stability of the interactive pulse of the tidal and diel cycles in determining short-term temporal patterns in intertidal mangrove fish assemblages in neotropical macrotidal estuaries despite the occurrence of

  18. Delineation of tidal scour through marine geophysical techniques at Sloop Channel and Goose Creek bridges, Jones Beach State Park, Long Island, New York

    USGS Publications Warehouse

    Stumm, Frederick; Chu, Anthony; Reynolds, Richard J.

    2001-01-01

    Inspection of the Goose Creek Bridge in southeastern Nassau County in April 1998 by the New York State Department of Transportation (NYSDOT) indicated a separation of bridge piers from the road bed as a result of pier instability due to apparent seabed scouring by tidal currents. This prompted a cooperative study by the U.S. Geological Survey with the NYSDOT to delineate the extent of tidal scour at this bridge and at the Sloop Channel Bridge, about 0.5 mile to the south, through several marine- geophysical techniques. These techniques included use of a narrow-beam, 200-kilohertz, research-grade fathometer, a global positioning system accurate to within 3 feet, a 3.5 to 7-kilohertz seismic-reflection profiler, and an acoustic Doppler current profiler (ADCP). The ADCP was used only at the Sloop Channel Bridge; the other techniques were used at both bridges.Results indicate extensive tidal scour at both bridges. The fathometer data indicate two major scour holes nearly parallel to the Sloop Channel Bridge—one along the east side, and one along the west side (bridge is oriented north-south). The scour-hole depths are as much as 47 feet below sea level and average more than 40 feet below sea level; these scour holes also appear to have begun to connect beneath the bridge. The deepest scour is at the north end of the bridge beneath the westernmost piers. The east-west symmetry of scour at Sloop Channel Bridge suggests that flood and ebb tides produce extensive scour.The thickness of sediment that has settled within scour holes could not be interpreted from fathometer data alone because fathometer frequencies cannot penetrate beneath the sea-floor surface. The lower frequencies used in seismic-reflection profiling can penetrate the sea floor and underlying sediments, and indicate the amount of infilling of scour holes, the extent of riprap under the bridge, and the assemblages of clay, sand, and silt beneath the sea floor. The seismic- reflection surveys detected 2 to

  19. Delineation of tidal scour through marine geophysical techniques at Sloop Channel and Goose Creek bridges, Jones Beach State Park, Long Island, New York

    USGS Publications Warehouse

    Stumm, Frederick; Chu, Anthony; Reynolds, Richard J.

    2001-01-01

    Inspection of the Goose Creek Bridge in southeastern Nassau County in April 1998 by the New York State Department of Transportation (NYSDOT) indicated a separation of bridge piers from the road bed as a result of pier instability due to apparent seabed scouring by tidal currents. This prompted a cooperative study by the U.S. Geological Survey with the NYSDOT to delineate the extent of tidal scour at this bridge and at the Sloop Channel Bridge, about 0.5 mile to the south, through several marine- geophysical techniques. These techniques included use of a narrow-beam, 200-kilohertz, research-grade fathometer, a global positioning system accurate to within 3 feet, a 3.5 to 7-kilohertz seismic-reflection profiler, and an acoustic Doppler current profiler (ADCP). The ADCP was used only at the Sloop Channel Bridge; the other techniques were used at both bridges. Results indicate extensive tidal scour at both bridges. The fathometer data indicate two major scour holes nearly parallel to the Sloop Channel Bridge -- one along the east side, and one along the west side (bridge is oriented north-south). The scour-hole depths are as much as 47 feet below sea level and average more than 40 feet below sea level; these scour holes also appear to have begun to connect beneath the bridge. The deepest scour is at the north end of the bridge beneath the westernmost piers. The east-west symmetry of scour at Sloop Channel Bridge suggests that flood and ebb tides produce extensive scour. The thickness of sediment that has settled within scour holes could not be interpreted from fathometer data alone because fathometer frequencies cannot penetrate beneath the sea-floor surface. The lower frequencies used in seismic-reflection profiling can penetrate the sea floor and underlying sediments, and indicate the amount of infilling of scour holes, the extent of riprap under the bridge, and the assemblages of clay, sand, and silt beneath the sea floor. The seismic- reflection surveys detected 2

  20. A tidal creek water budget: Estimation of groundwater discharge and overland flow using hydrologic modeling in the Southern Everglades

    NASA Astrophysics Data System (ADS)

    Michot, Béatrice; Meselhe, Ehab A.; Rivera-Monroy, Victor H.; Coronado-Molina, Carlos; Twilley, Robert R.

    2011-07-01

    Taylor Slough is one of the natural freshwater contributors to Florida Bay through a network of microtidal creeks crossing the Everglades Mangrove Ecotone Region (EMER). The EMER ecological function is critical since it mediates freshwater and nutrient inputs and controls the water quality in Eastern Florida Bay. Furthermore, this region is vulnerable to changing hydrodynamics and nutrient loadings as a result of upstream freshwater management practices proposed by the Comprehensive Everglades Restoration Program (CERP), currently the largest wetland restoration project in the USA. Despite the hydrological importance of Taylor Slough in the water budget of Florida Bay, there are no fine scale (˜1 km 2) hydrodynamic models of this system that can be utilized as a tool to evaluate potential changes in water flow, salinity, and water quality. Taylor River is one of the major creeks draining Taylor Slough freshwater into Florida Bay. We performed a water budget analysis for the Taylor River area, based on long-term hydrologic data (1999-2007) and supplemented by hydrodynamic modeling using a MIKE FLOOD (DHI, http://dhigroup.com/) model to evaluate groundwater and overland water discharges. The seasonal hydrologic characteristics are very distinctive (average Taylor River wet vs. dry season outflow was 6 to 1 during 1999-2006) with a pronounced interannual variability of flow. The water budget shows a net dominance of through flow in the tidal mixing zone, while local precipitation and evapotranspiration play only a secondary role, at least in the wet season. During the dry season, the tidal flood reaches the upstream boundary of the study area during approximately 80 days per year on average. The groundwater field measurements indicate a mostly upwards-oriented leakage, which possibly equals the evapotranspiration term. The model results suggest a high importance of groundwater contribution to the water salinity in the EMER. The model performance is satisfactory

  1. Cycle of Vertical and Horizontal Mixing in a Shallow Tidal Creek

    DTIC Science & Technology

    2010-01-14

    not NRL !*«« - nto intended to olfef IKtepaper to the ’.n, -:r...v..-;• seas ??,; •.«nv5«.’*i?’A (Name of ConferenooJ > -ma< ’t— ^. 1:." ?5»’j5...inundation in the estuary through Ekman transport from a drought in 2001 and 2002. Some of the decrease in processes (as will be seen in the residual sea ...scales: from turbulent to tidal and fortnightly scales. The interaction between estuarine tides, bathymetry and irregularities at the channel edge can

  2. Engineering and Environmental Study of DDT Contamination of Huntsville Spring Branch, Indian Creek and Adjacent Lands and Waters, Wheeler Reservoir, Alabama. Revision,

    DTIC Science & Technology

    1984-04-01

    AD-A142 517 ENGINEERING AND ENVIRONMENTAL STUDY OF DDT CONTAMINATION OF HUNTSVILLE SP..(U) WATER AND AIR RESEARCH INC GAINESVILLE FL d H...DDT Con- tamination of Huntsville Spring Branch, Indian Creek and Adjacent Lands and Waters , Wheeler Reservoir, Alabama a. i irk ut iPOR...Pruitt and J. C. Nichols 8. CONTRACT OR GRANT NUMBER)» DACW01-79-C-0224 9. PERFORMING ORGANIZATION NAME AND ADDRESS Water and Air Research

  3. Sedimentological characterization of flood-tidal delta deposits in the Sego Sandstone, subsidence analysis in the Piceance Creek Basin, and uranium-lead geochronology (NW Colorado, USA)

    NASA Astrophysics Data System (ADS)

    York, Carly C.

    The Sego Sandstone located in western Colorado is a member of the Upper Cretaceous Mesaverde Group and is considered an analogue of the Canadian heavy oil sands. Deposition of the Sego Sandstone occurred during the Upper Campanian (~78 Ma) at the end of the Sevier Orogeny and the beginning of the Laramide Orogeny on the western edge of the Cretaceous Interior Seaway. Although regional studies have detailed time equivalent deposits in the Book Cliffs, UT, the tidally influenced and marginal marine lithofacies observed north of Rangely, CO are distinctly different from the dominately fluvial and tidally-influenced delta facies of Book Cliff outcrops to the southwest. This study characterized flood-tidal delta deposits within the Sego Sandstone, the subsidence history of the Upper Cretaceous sedimentary rocks within the present day Piceance Creek Basin in NW Colorado, and the detrital zircon signal and oldest depositional age of the Sego Sandstone. The goals of this study are to (i) identify relative controls on reservoir characteristics of marginal marine deposits, specifically in flood-tidal delta deposits; (ii) identify the possible mechanisms responsible for subsidence within the present day Piceance Creek Basin during the Late Cretaceous; and (iii) better constrain the provenance and maximum depositional age of the Sego Sandstone. In this study I compared grain size diameter, grain and cement composition, and the ratio of pore space/cement from thin sections collected in tidal, shoreface, and flood-tidal delta facies recognized along detailed measured stratigraphic sections. This analysis provides a detailed comparison between different depositional environments and resultant data showed that grain size diameter is different between tidal, shoreface, and flood-tidal delta facies. Identifying the subsidence mechanisms affecting the Piceance Creek Basin and sediment source of the Late Cretaceous sediments, on the other hand, is important for evaluation of controls

  4. Spatial trends in marsh sediment deposition within a microtidal creek system, Waccasassa Bay, Florida

    USGS Publications Warehouse

    Wood, Nathan; Hine, Albert C.

    2007-01-01

    Marsh surface deposition, suspended sediment concentrations, tidal hydrodynamics, and marsh surface characteristics were measured within a tidal creek system of a west-central Florida, microtidal, open marine Juncus roemerianus marsh to examine the depositional relationship between a creek system and the surrounding marsh during nonstorm conditions. Results suggest that short-term marsh deposition is highly episodic with deposition showing an inverse relationship with marsh surface inundation. Deposition was greatest at marsh sites adjacent to secondary creek segments over all examined timescales. Variations in hydroperiod, time–velocity asymmetry, vegetation density, and sediment availability could not explain the observed differences in short-term deposition.

  5. Subsurface-controlled geological maps for the Y-12 plant and adjacent areas of Bear Creek Valley

    SciTech Connect

    King, H.L.; Haase, C.S.

    1987-04-01

    Bear Creek Valley in the vicinity of the US Department of Energy Y-12 Plant is underlain by Middle to Late Cambrian strata of the Conasauga Group. The group consists of interbedded limestones, shales, mudstones, and siltstones, and it can be divided into six discrete formations. Bear Creek Valley is bordered on the north by Pine Ridge, which is underlain by sandstones, siltstones, and shales of the Rome Formation, and on the south by Chestnut Ridge, which is underlain by dolostones of the Knox Group. Subsurface-controlled geological maps illustrating stratigraphic data and formational contacts for the formations within the Conasauga Group have been prepared for the Y-12 Plant vicinity and selected areas in Bear Creek Valley westward from the plant. The maps are consistent with all available surface and subsurface data for areas where sufficient data exist to make map construction feasible. 13 refs.

  6. Process-Based Evidence of Coastal Accretion Adjacent to a Natural Inlet and Ebb-Tidal Delta on the North Florida Atlantic Coast

    NASA Astrophysics Data System (ADS)

    Adams, P. N.; Olabarrieta, M.; Keough, K. M.

    2015-12-01

    Physical mechanisms of tidal inlet accretion are difficult to document because of the episodic nature of sediment delivery to the coast from fluvial sources and the complex patterns of current magnitudes and directions arising from the interaction of nearshore waves with ebb-tidal delta bathymetry. Using monthly RTK-GPS field measurements of beach topography adjacent to a natural inlet, we document a shoreline change time series that illustrates a bi-directional, alongshore spreading pattern of accretion following an exceptionally high rainfall-discharge event in May 2009. Numerical modeling of wave set-up and nearshore currents in the vicinity of the inlet and ebb tidal delta produces depth-averaged flow velocity patterns consistent with our field observations of coastal accretion. Our results are in agreement with an accretion mechanism, proposed by other researchers, that involves sediment delivery to the margins of the ebb tidal delta during high velocity ebb flows that accompany large rainfall-discharge events, followed by onshore migration of swash bars during subsequent days to months, at a rate dependent upon the timing of nearshore wave energy delivery to the site.

  7. 76 FR 44602 - Notice of Temporary Closure of Roads and Trails on Public Lands Adjacent to Big Willow Creek in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-26

    ... Willow Creek in Payette County, ID AGENCY: Bureau of Land Management, Interior. ACTION: Notice of Temporary Closure. SUMMARY: Notice is hereby given that the Big Willow closure to motorized vehicle use is...\\1/4\\NW\\1/4\\ north and west of Big Willow Road. T. 8 N., R. 3 W., Sec. 1, lots 1, 3, 4,...

  8. Analyzing the Modeled Tidal Signal in the Bab El Mandeb Strait and Adjacent Red Sea and Gulf of Aden Waters

    NASA Astrophysics Data System (ADS)

    Guillory, R. N. B.

    2014-12-01

    The tidal forces that dominate the Bab el Mandeb region are influenced by both the generally semi-diurnal tides in the Red Sea and mixed tides in the Gulf of Aden. Also, the tidal ranges are much greater in the Gulf of Aden (~ 2 m) than in the Red Sea (< 1m), which further complicates the tidal signal in Bab el Mandeb Strait. The Red Sea Regional Navy Coastal Model (NCOM), which includes the entire Red Sea, and the western part of the Gulf of Aden at a 1 km resolution, will be evaluated on how well it replicates the tidal signal described in literature and historical observations. In addition, the model will be compared to available temperature/salinity in situ profiles. NCOM incorporates the Oregon State University Tide Model, which should allow the ocean model to accurately reflect the transitional tides in the Bab el Mandeb Strait. Preliminary estimates indicate that the model replicates the overall circulation pattern seen in literature and the fact that there are higher tidal amplitudes in the Gulf of Aden than in the Red Sea. Approved for Public Release, Distribution Unlimited

  9. Continuous tidal streamflow, water level, and specific conductance data for Union Creek and the Little Back, Middle, and Front Rivers, Savannah River Estuary, November 2008 to March 2009

    USGS Publications Warehouse

    Lanier, Timothy H.; Conrads, Paul A.

    2010-01-01

    In the Water Resource Development Act of 1999, the U.S. Congress authorized the deepening of the Savannah Harbor. Additional studies were then identified by the Georgia Ports Authority and other local and regional stakeholders to determine and fully describe the potential environmental effects of deepening the channel. One need that was identified was the validation of a three-dimensional hydrodynamic model developed to evaluate mitigation scenarios for a potential harbor deepening and the effects on the Savannah River estuary. The streamflow in the estuary is very complex due to reversing tidal flows, interconnections of streams and tidal creeks, and the daily flooding and draining of the marshes. The model was calibrated using very limited streamflow data and no continuous streamflow measurements. To better characterize the streamflow dynamics and mass transport of the estuary, two index-velocity sites were instrumented with continuous acoustic velocity, water level, and specific conductance sensors on the Little Back and Middle Rivers for the 5-month period of November 2008 through March 2009. During the same period, a third acoustic velocity meter was installed on the Front River just downstream from U.S. Geological Survey streamgaging station 02198920 (Savannah River at GA 25, at Port Wentworth, Georgia) where water level and specific conductance data were being collected. A fourth index-velocity site was instrumented with continuous acoustic velocity, water level, and specific conductance sensors on Union Creek for a 2-month period starting in November 2008. In addition to monitoring the tidal cycles, streamflow measurements were made at the four index-velocity sites to develop ratings to compute continuous discharge for each site. The maximum flood (incoming) and ebb (outgoing) tides measured on Little Back River were –4,570 and 7,990 cubic feet per second, respectively. On Middle River, the maximum flood and ebb tides measured were –9,630 and 13

  10. Observations of tidal flux between a submersed aquatic plant stand and the adjacent channel in the Potomac River near Washington, D.C.

    USGS Publications Warehouse

    Rybicki, N.B.; Jenter, H.L.; Carter, V.; Baltzer, R.A.; Turtora, M.

    1997-01-01

    Dye injection studies and direct velocity and water-level measurements were made in macrophyte stands and adjacent channels in order to observe the effects of the macrophyte stand on flow and mass exchange in the tidal Potomac River. During the summer, dense stands of submersed aquatic plants cover most shoals <2 m deep. Continuous summertime water-level records within a submersed aquatic plant stand and in the adjacent channel revealed time-varying gradients in water-surface elevation between the two areas. Water-level gradients are created by differing rates of tidal water-level change in vegetated and unvegetated areas. Results were consistent with the idea that on a rising tide the water was slower to enter a macrophyte stand, and on a falling tide it was slower to leave it. Differences in water elevation between the stand and the open channel generated components of velocity in the stand that were at right angles to the line of flow in the channel. Seasonal differences in flow speed and direction over the shoals indicate substantial differences in resistance to flow as a result of the vegetation.

  11. Vertical distribution, composition profiles, sources and toxicity assessment of PAH residues in the reclaimed mudflat sediments from the adjacent Thane Creek of Mumbai.

    PubMed

    Basavaiah, N; Mohite, R D; Singare, P U; Reddy, A V R; Singhal, R K; Blaha, U

    2017-02-23

    A study on vertical distribution of magnetic susceptibility, carcinogenic and endocrine disrupting PAHs was performed in the reclaimed mudflat sediments adjacent to the Thane Creek of Mumbai. The 5-rings PAHs and ΣC-PAHs were more dominant at 120cm depth contributing 52.23% and 60.19% respectively to ∑PAHs. The average ratio values of LMW/HMW PAHs (0.58); Fla/(Fla+Pyr) (0.50); Ant/(Ant+Phe) (0.50); BaA/(Chry+BaA) (0.48); BaP/BghiP (2.06), Phe/Ant (1.03) and BaA/Chr (0.93) indicate that the PAH contamination might have raised due to inefficient combustion and pyrogenic emissions during the open burning of solid waste in the vicinity. This was further supported by the anthropogenic ferri(o)magnetic loading over the last 100years influencing the Creek sediments. The PAHs toxicity estimation was performed by calculating the toxic equivalent quantity (TEQ) value of 8.62ng TEQ/g which was below the safe level (600ng TEQ/g) suggested by the Canadian risk-based soil criterion for protection of human health.

  12. NITROGEN CONCENTRATIONS IN LOADING SOURCES FOR THREE COASTAL LAGOONS FROM ATMOSPHERIC AND WATERSHED SOURCES, ADJACENT COASTAL MARSHES, TIDAL EXCHANGES

    EPA Science Inventory

    Abstract and Oral Presentation Gulf Estuarine Research Society.

    Standing stocks and inputs of total dissolved nitrogen (TDN) to three coastal lagoons, hereafter referred to as Kee's Bayou, Gongora, and State Park, with varying adjacent land-use, geomorphology, and water re...

  13. Sulfide variation in the pore and surface waters of artificial salt-marsh ditches and a natural tidal creek

    SciTech Connect

    Rey, J.R.; Shaffer, J.; Kain, T.; Stahl, R.; Crossman, R. )

    1992-09-01

    Pore and surface water sulfide variation near artificial ditches and a natural creek are examined in salt marshes bordering the Indian River Lagoon in east-central Florida. Pore water sulfide concentrations ranged from 0 [mu]g-at l[sup [minus]1] to 1,640 [mu]g-at l[sup [minus]1]. On average, the natural creek had the lowest sulfide concentrations (mean < 1.0 [mu]g-at l[sup [minus]1]) and the perimeter ditch of a managed salt marsh impoundment the highest (436.5 [mu]g-at l[sup [minus]1]). There was a trend of increasing sulfide concentration in the summer, and sharp peaks in late fall-early winter which correspond with peak litter input into the sediments. Significant differences in sulfide concentration between sites are attributed to differences in water flow and in organic matter content. Delaying the seasonal opening of culverts (which connect impounded marshes with the lagoon) until lagoon water levels rise in fall may prevent massive fish kills that have been associated with high sulfide levels in the impoundment perimeter ditches. 35 refs., 7 figs., 5 tabs.

  14. Selenium and Other Elements in Water and Adjacent Rock and Sediment of Toll Gate Creek, Aurora, Arapahoe County, Colorado, December 2003 through March 2004

    USGS Publications Warehouse

    Herring, J.R.; Walton-Day, Katherine

    2007-01-01

    Streamwater and solid samples (rock, unconsolidated sediment, stream sediment, and efflorescent material) in the Toll Gate Creek watershed, Colorado, were collected and analyzed for major and trace elements to determine trace-element concentrations and stream loads from December 2003 through March 2004, a period of seasonally low flow. Special emphasis was given to selenium (Se) concentrations because historic Se concentrations exceeded current (2004) stream standards. The goal of the project was to assess the distribution of Se concentration and loads in Toll Gate Creek and to determine the potential for rock and unconsolidated sediment in the basin to be sources of Se to the streamwater. Streamwater samples and discharge measurements were collected during December 2003 and March 2004 along Toll Gate Creek and its two primary tributaries - West Toll Gate Creek and East Toll Gate Creek. During both sampling periods, discharge ranged from 2.5 liters per second to 138 liters per second in the watershed. Discharge was greater in March 2004 than December 2003, but both periods represent low flow in Toll Gate Creek, and results of this study should not be extended to periods of higher flow. Discharge decreased moving downstream in East Toll Gate Creek but increased moving downstream along West Toll Gate Creek and the main stem of Toll Gate Creek, indicating that these two streams gain flow from ground water. Se concentrations in streamwater samples ranged from 7 to 70 micrograms per liter, were elevated in the upstream-most samples, and were greater than the State stream standard of 4.6 micrograms per liter. Se loads ranged from 6 grams per day to 250 grams per day, decreased in a downstream direction along East Toll Gate Creek, and increased in a downstream direction along West Toll Gate Creek and Toll Gate Creek. The largest Se-load increases occurred between two sampling locations on West Toll Gate Creek during both sampling periods and between the two sampling

  15. [Spatial distribution and pollution assessment of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area, China ].

    PubMed

    Zhang, Lei; Qin, Yan-wen; Ma, Ying-qun; Zhao, Yan-min; Shi, Yao

    2014-09-01

    The aim of this article was to explore the pollution level of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area. The contents and spatial distribution of As, Cd, Cr, Cu, Ph and Zn in surface water, suspended solids and surface sediments were analyzed respectively. The integrated pollution index and geoaccumulation index were used to evaluate the contamination degree of heavy metals in surface water and surface sediments respectively. The results indicated that the contents of heavy metals in surface water was in the order of Pb < Cu < Cd < Cr < As < Zn. The heavy metal contents in surface water increased from river to sea. Compared with the contents of heavy metals in surface water of the typical domestic estuary in China, the overall contents of heavy metals in surface water were at a higher level. The contents of heavy metals in suspended solids was in the order of Cd < Cu < As < Cr

  16. Meiobenthic gradients with special reference to Plathelminthes and Polychaeta in an estuarine salt marsh creek—a small-scale model for boreal tidal coasts?

    NASA Astrophysics Data System (ADS)

    Hellwig-Armonies, Monika; Armonies, Werner

    1987-06-01

    Environmental conditions in salt marsh creeks are intermediate between the open tidal coast and estuaries. A large salt marsh creek at the island of Sylt (North Sea) was studied in order to test whether its fauna is more similar to that of the open tidal coast or to that of estuaries. Because of a sandy bar at the seaward opening, the tidal range is only 10 cm in the creek, and the water level never drops below the level of the sand bar. Zoobenthos in the sandy bottom and on the sandy shores was studied at both ends and in the middle of the creek. Polychaeta and Plathelminthes were determined to species level. On an average, 2115 metazoans were found below 10 cm2 of surface area. At the seaward end of the creek, abundance and taxonomic composition are similar to that of the adjoining Wadden area. Nematoda are the dominant taxon, followed by Copepoda, Plathelminthes and Oligochaeta. Taxonomic composition is different at the landward end. Plathelminthes and Nematoda are most abundant followed by Copepoda. Both Oligochaeta and Polychaeta are scarce at these newly eroded sites. Plathelminth abundance at the landward end of the creek is exceptionally high (770 935·10 cm-2). Contrary to what is generally found in estuaries, the species density of Plathelminthes shows a significant increase toward the land. The species composition of Polychaeta and Plathelminthes indicates that the sites below mean high tide level of the creek correspond to the adjacent eulittoral Wadden area while the fauna of the supralittoral sites of the creek is similar to the fauna of supralittoral tidal coasts. Typical sublittoral species did not occur in the salt marsh creek. Thus, salt marsh creeks may be regarded as a small-scale model for the tidal coast. In context with the results obtained, the definition of estuaries is discussed.

  17. The regional structural setting of the 2008 Wells earthquake and Town Creek Flat Basin: implications for the Wells earthquake fault and adjacent structures

    USGS Publications Warehouse

    Henry, Christopher S.; Colgan, Joseph P.

    2011-01-01

    The 2008 Wells earthquake occurred on a northeast-striking, southeast-dipping fault that is clearly delineated by the aftershock swarm to a depth of 10-12 km below sea level. However, Cenozoic rocks and structures around Wells primarily record east-west extension along north- to north-northeast-striking, west-dipping normal faults that formed during the middle Miocene. These faults are responsible for the strong eastward tilt of most basins and ranges in the area, including the Town Creek Flat basin (the location of the earthquake) and the adjacent Snake Mountains and western Windermere Hills. These older west-dipping faults are locally overprinted by a younger generation of east-dipping, high-angle normal faults that formed as early as the late Miocene and have remained active into the Quaternary. The most prominent of these east-dipping faults is the set of en-échelon, north-striking faults that bounds the east sides of the Ruby Mountains, East Humboldt Range, and Clover Hill (about 5 km southwest of Wells). The northeastern-most of these faults, the Clover Hill fault, projects northward along strike toward the Snake Mountains and the approximately located surface projection of the Wells earthquake fault as defined by aftershock locations. The Clover Hill fault also projects toward a previously unrecognized, east-facing Quaternary fault scarp and line of springs that appear to mark a significant east-dipping normal fault along the western edge of Town Creek Flat. Both western and eastern projections may be northern continuations of the Clover Hill fault. The Wells earthquake occurred along this east-dipping fault system. Two possible alternatives to rupture of a northern continuation of the Clover Hill fault are that the earthquake fault (1) is antithetic to an active west-dipping fault or (2) reactivated a Mesozoic thrust fault that dips east as a result of tilting by the west-dipping faults along the west side of the Snake Mountains. Both alternatives are

  18. Effects of brush management on the hydrologic budget and water quality in and adjacent to Honey Creek State Natural Area, Comal County, Texas, 2001-10

    USGS Publications Warehouse

    Banta, J. Ryan; Slattery, Richard N.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture Natural Resources Conservation Service, the Edwards Region Grazing Lands Conservation Initiative, the Texas State Soil and Water Conservation Board, the San Antonio River Authority, the Edwards Aquifer Authority, Texas Parks and Wildlife, the Guadalupe Blanco River Authority, and the San Antonio Water System, evaluated the hydrologic effects of ashe juniper (Juniperus ashei) removal as a brush management conservation practice in and adjacent to the Honey Creek State Natural Area in Comal County, Tex. By removing the ashe juniper and allowing native grasses to reestablish in the area as a brush management conservation practice, the hydrology in the watershed might change. Using a simplified mass balance approach of the hydrologic cycle, the incoming rainfall was distributed to surface water runoff, evapotranspiration, or groundwater recharge. After hydrologic data were collected in adjacent watersheds for 3 years, brush management occurred on the treatment watershed while the reference watershed was left in its original condition. Hydrologic data were collected for another 6 years. Hydrologic data include rainfall, streamflow, evapotranspiration, and water quality. Groundwater recharge was not directly measured but potential groundwater recharge was calculated using a simplified mass balance approach. The resulting hydrologic datasets were examined for differences between the watersheds and between pre- and post-treatment periods to assess the effects of brush management. The streamflow to rainfall relation (expressed as event unit runoff to event rainfall relation) did not change between the watersheds during pre- and post-treatment periods. The daily evapotranspiration rates at the reference watershed and treatment watershed sites exhibited a seasonal cycle during the pre- and post-treatment periods, with intra- and interannual variability. Statistical analyses indicate the mean

  19. Benthic community structure and biomarker responses of the clam Scrobicularia plana in a shallow tidal creek affected by fish farm effluents (Rio San Pedro, SW Spain).

    PubMed

    Silva, Claudio; Mattioli, Mattia; Fabbri, Elena; Yáñez, Eleuterio; Delvalls, T Angel; Martín-Díaz, M Laura

    2012-10-15

    The effects of solid organic wastes from a marine fish farm on sediments were tested using benthic community as ecological indicators and biomarkers in native clam (Scrobicularia plana) as biochemical indicators. The benthic fauna and clam samples were collected in the intertidal sediment in October 2010 from five sites of the Rio San Pedro (RSP) creek, following a gradient of contamination from the aquaculture effluent to the control site. Numbers of species, abundance, richness and Shannon diversity were the biodiversity indicators measured in benthic fauna. Morphological and reproduction status of clams were assessed using the condition factor and gonado-somatic index, respectively. Phase I and Phase II detoxification enzymatic activities (ethoxyresorufin O-deethylase (EROD), glutathione S-transferase (GST)), antioxidant enzymatic activities (glutathione peroxidase (GPX), glutathione reductase (GR)) and oxidative stress parameters (Lipid Peroxidation (LPO) and DNA strand breaks) were measured in clams' digestive gland tissues. In parallel, temperature and salinity in the adjacent water, redox potential, pH and organic matter in sediment, and dissolved oxygen in the interstitial water were measured. The results suggested that RSP showed a spatial gradient characterised by hypoxia/anoxia, reduced potential, acidic conditions and high organic enrichment in sediments at the most contaminated sites. Significant (p<0.05) decrease of biodiversity indicators were observed in the areas impacted by the aquaculture discharges. Biomarkers did not show a clear pattern and of all biochemical responses tested, GPX, DNA damage and LPO were the most sensitive ones and showed significant (p<0.05) increase in the polluted sites. Benthic biodiversity indicators were significantly (p<0.05) positively correlated with pH, redox potential and dissolved oxygen and negatively correlated with organic matter. On the contrary, antioxidant enzymatic responses (GPX) and oxidative stress

  20. Hydrogeologic and geochemical characterization of groundwater resources in Deep Creek Valley and adjacent areas, Juab and Tooele Counties, Utah, and Elko and White Pine Counties, Nevada

    USGS Publications Warehouse

    Gardner, Philip M.; Masbruch, Melissa D.

    2015-09-18

    Water-level altitude contours and groundwater ages indicate the potential for a long flow path from southwest to northeast between northern Spring and Deep Creek Valleys through Tippett Valley. Although information gathered during this study is insufficient to conclude whether or not groundwater travels along this interbasin flow path, dissolved sulfate and chloride data indicate that a small fraction of the lower altitude, northern Deep Creek Valley discharge may be sourced from these areas. Despite the uncertainty due to limited data collection points, a hydraulic connection between northern Spring Valley, Tippett Valley, and Deep Creek Valley appears likely, and potential regional effects resulting from future groundwater withdrawals in northern Spring Valley warrant ongoing monitoring of groundwater levels across this area.

  1. Design and analysis of a natural-gradient ground-water tracer test in a freshwater tidal wetland, West Branch Canal Creek, Aberdeen Proving Ground, Maryland

    USGS Publications Warehouse

    Olsen, Lisa D.; Tenbus, Frederick J.

    2005-01-01

    A natural-gradient ground-water tracer test was designed and conducted in a tidal freshwater wetland at West Branch Canal Creek, Aberdeen Proving Ground, Maryland. The objectives of the test were to characterize solute transport at the site, obtain data to more accurately determine the ground-water velocity in the upper wetland sediments, and to compare a conservative, ionic tracer (bromide) to a volatile tracer (sulfur hexafluoride) to ascertain whether volatilization could be an important process in attenuating volatile organic compounds in the ground water. The tracer test was conducted within the upper peat unit of a layer of wetland sediments that also includes a lower clayey unit; the combined layer overlies an aquifer. The area selected for the test was thought to have an above-average rate of ground-water discharge based on ground-water head distributions and near-surface detections of volatile organic compounds measured in previous studies. Because ground-water velocities in the wetland sediments were expected to be slow compared to the underlying aquifer, the test was designed to be conducted on a small scale. Ninety-seven ?-inch-diameter inverted-screen stainless-steel piezometers were installed in a cylindrical array within approximately 25 cubic feet (2.3 cubic meters) of wetland sediments, in an area with a vertically upward hydraulic gradient. Fluorescein dye was used to qualitatively evaluate the hydrologic integrity of the tracer array before the start of the tracer test, including verifying the absence of hydraulic short-circuiting due to nonnatural vertical conduits potentially created during piezometer installation. Bromide and sulfur hexafluoride tracers (0.139 liter of solution containing 100,000 milligrams per liter of bromide ion and 23.3 milligrams per liter of sulfur hexafluoride) were co-injected and monitored to generate a dataset that could be used to evaluate solute transport in three dimensions. Piezometers were sampled 2 to 15 times

  2. Design and Performance of an Enhanced Bioremediation Pilot Test in a Tidal Wetland Seep, West Branch Canal Creek, Aberdeen Proving Ground, Maryland

    USGS Publications Warehouse

    Majcher, Emily H.; Lorah, Michelle M.; Phelan, Daniel J.; McGinty, Angela L.

    2009-01-01

    Because of a lack of available in situ remediation methods for sensitive wetland environments where contaminated groundwater discharges, the U.S. Geological Survey, in cooperation with the U.S. Army Garrison, Aberdeen Proving Ground, Maryland, conceived, designed, and pilot tested a permeable reactive mat that can be placed horizontally at the groundwater/surface-water interface. Development of the reactive mat was part of an enhanced bioremediation study in a tidal wetland area along West Branch Canal Creek at Aberdeen Proving Ground, where localized areas of preferential discharge (seeps) transport groundwater contaminated with carbon tetrachloride, chloroform, tetrachloroethene, trichloroethene, and 1,1,2,2-tetrachloroethane from the Canal Creek aquifer to land surface. The reactive mat consisted of a mixture of commercially available organic- and nutrient-rich peat and compost that was bioaugmented with a dechlorinating microbial consortium, WBC-2, developed for this study. Due to elevated chlorinated methane concentrations in the pilot test site, a layer of zero-valent iron mixed with the peat and compost was added at the base of the reactive mat to promote simultaneous abiotic and biotic degradation. The reactive mat for the pilot test area was designed to optimize chlorinated volatile organic compound degradation efficiency without altering the geotechnical and hydraulic characteristics, or creating undesirable water quality in the surrounding wetland area, which is referred to in this report as achieving geotechnical, hydraulic, and water-quality compatibility. Optimization of degradation efficiency was achieved through the selection of a sustainable organic reactive matrix, electron donor, and bioaugmentation method. Consideration of geotechnical compatibility through design calculations of bearing capacity, settlement, and geotextile selection showed that a 2- to 3-feet tolerable thickness of the mat was possible, with 0.17 feet settlement predicted for

  3. 1. A BRICK AND CONCRETE FAN HOUSING ADJACENT TO ONE ...

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

    1. A BRICK AND CONCRETE FAN HOUSING ADJACENT TO ONE OF THE ADIT OPENINGS (VIEW TO THE NORTH). - Foster Gulch Mine, Fan Housing, Bear Creek 1 mile Southwest of Town of Bear Creek, Red Lodge, Carbon County, MT

  4. Effects of brush management on the hydrologic budget and water quality in and adjacent to Honey Creek State Natural Area, Comal County, Texas, 2001--10

    USGS Publications Warehouse

    Banta, J. Ryan; Slattery, Richard N.

    2012-01-01

    Woody vegetation, including ashe juniper (Juniperus ashei), has encroached on some areas in central Texas that were historically oak grassland savannah. Encroachment of woody vegetation is generally attributed to overgrazing and fire suppression. Removing the ashe juniper and allowing native grasses to reestablish in the area as a brush management conservation practice (hereinafter referred to as "brush management") might change the hydrology in the watershed. These hydrologic changes might include changes to surface-water runoff, evapotranspiration, or groundwater recharge. The U.S. Geological Survey (USGS), in cooperation with Federal, State, and local partners, examined the hydrologic effects of brush management in two adjacent watersheds in Comal County, Tex. Hydrologic data were collected in the watersheds for 3-4 years (pre-treatment) depending on the type of data, after which brush management occurred on one watershed (treatment watershed) and the other was left in its original condition (reference watershed). Hydrologic data were collected in the study area for another 6 years (post-treatment). These hydrologic data included rainfall, streamflow, evapotranspiration, and water quality. Groundwater recharge was not directly measured, but potential groundwater recharge was calculated by using a simplified mass balance approach. This fact sheet summarizes highlights of the study from the USGS Scientific Investigations Report on which it is based.

  5. Prevalence of the bopyrid isopod Probopyrus pandalicola in the grass shrimp, Palaemonetes pugio, in four tidal creeks on the South Carolina-Georgia coast.

    PubMed

    Chaplin-Ebanks, Sue A; Curran, Mary Carla

    2007-02-01

    The grass shrimp, Palaemonetes pugio, is an important food source for many invertebrate and fish species, including several of commercial importance. The bopyrid Probopyrus pandalicola prevents reproduction in P. pugio by sexual sterilization. The purpose of our research was to determine bopyrid prevalence in grass shrimp over the course of a year. Shrimp were collected from 2 estuarine systems in South Carolina and 2 estuarine systems in Georgia and examined for parasite presence, sex, and gravidity. Site-specific monthly prevalence ranged from 0 to 6.3%. Country Club Creek had the maximum mean +/- SE prevalence of 3.1 +/- 0.3%, and Harbour Town had the minimum of 1.3 +/- 0.3%. Maximum prevalence was concurrent with peak gravidity for Moon River; thus, at this site the negative effect of this parasite on reproductive output may be greater. Reduced egg production may affect grass shrimp abundance and ultimately the recruitment success of its predators.

  6. Laboratory Observations on Tidal Network Growth and Development

    NASA Astrophysics Data System (ADS)

    Stefanon, L.; Carniello, L.; D'Alpaos, A.

    2011-12-01

    We present the results of laboratory experiments carried out in a large experimental apparatus aimed at reproducing a typical lagoonal environment subject to tidal forcings. The experiments were designed in order to improve our understanding of the main processes governing tidal network initiation and its progressive morphodynamic evolution. In particular, the experiments summarized herein aimed at understanding the physical processes, as well as boundary and initial conditions, which lead to the initiation and subsequent development of a tidal channel network, starting from a plane horizontal tidal flat located behind a barrier island and connected through the sea by a single inlet. During the experiments we observed the growth and development of tidal networks and analyzed their most relevant geomorphic features, taking into account the role played by the characteristics of the tidal forcing in driving the development of channelled patterns. The experimental evidence suggests that general network evolution is substantially characterized by three processes: (1) channel elongation via headward growth, driven by the exceedance of a critical bottom shear stress; (2) incision and sinuosity gradually increasing with channels age; (3) formation of new lateral creeks and tributaries. The lack of external sediment supply, the absence of vegetation, and the prevalence of bedload transport prevented any deposition processes and lateral surface accretion, attributing a purely erosive character to the experimental lagoon. Nevertheless, the morphodynamic feedbacks occurring in the erosional case are essentially the same that occur under depositional conditions. In fact, in both cases, channel excavation is closely connected to concentration of tidal fluxes within the channel network during maximum ebb phase when maximum velocities and shear stresses are reached. In this experimental lagoon the main morphodynamic process responsible for tidal network initiation and development

  7. Benthic macroinvertebrate populations of urban freshwater tidal wetlands in the Anacostia River, Washington D.C.

    NASA Astrophysics Data System (ADS)

    Brittingham, K. D.

    2005-05-01

    This study characterizes the benthic communities establishing themselves on recently reconstructed urban freshwater tidal wetlands along the Anacostia River in Washington, D.C. in comparison to a similar relic wetland as well as to a reference wetland in the adjacent Patuxent River watershed. The study's focus is the two main areas of Kingman Marsh, which were reconstructed from Anacostia dredge material by the U.S. Army Corps of Engineers in 2000. Populations from this 'new' marsh are compared to those of similarly reconstructed Kenilworth Marsh (1993), as well as to the relic Dueling Creek Marsh on the Anacostia and the outside reference Patuxent Marsh in an adjacent watershed. Benthic organisms were collected using selected techniques including the Ekman bottom grab sampler, sediment corer, D-net and Hester-Dendy sampler. Samples were collected seasonally from tidal channels, tidal mudflats, three vegetation zones (low, middle and high marsh), and pools. Data collected from this study can provide valuable information on the extent that benthic macroinvertebrate communities can serve as an indicator of the relative success of freshwater tidal marsh reconstruction.

  8. Wetlands: Tidal

    USGS Publications Warehouse

    Conner, William H.; Krauss, Ken W.; Baldwin, Andrew H.; Hutchinson, Stephen

    2014-01-01

    Tidal wetlands are some of the most dynamic areas of the Earth and are found at the interface between the land and sea. Salinity, regular tidal flooding, and infrequent catastrophic flooding due to storm events result in complex interactions among biotic and abiotic factors. The complexity of these interactions, along with the uncertainty of where one draws the line between tidal and nontidal, makes characterizing tidal wetlands a difficult task. The three primary types of tidal wetlands are tidal marshes, mangroves, and freshwater forested wetlands. Tidal marshes are dominated by herbaceous plants and are generally found at middle to high latitudes of both hemispheres. Mangrove forests dominate tropical coastlines around the world while tidal freshwater forests are global in distribution. All three wetland types are highly productive ecosystems, supporting abundant and diverse faunal communities. Unfortunately, these wetlands are subject to alteration and loss from both natural and anthropogenic causes.

  9. Natural and anthropogenic change in the morphology and connectivity of tidal channels of southwest Bangladesh

    NASA Astrophysics Data System (ADS)

    Wilson, C.; Goodbred, S. L., Jr.; Wallace Auerbach, L.; Ahmed, K. R.; Small, C.; Sams, S. E.

    2014-12-01

    Over the last century, land use changes in the Ganges-Brahmaputra tidal delta have transformed >5000 km2 of intertidal mangrove forest to densely inhabited, agricultural islands that have been embanked to protect against tides and storm surges (i.e., polders). More recently, the conversion of rice paddies to profitable shrimp aquaculture has become increasingly widespread. Recent field studies documented that poldering in southwest Bangladesh has resulted in an elevation deficit relative to that of the natural mangrove forests and mean high water (MHW). The offset is a function of lost sedimentation, enhanced compaction, and an effective rise in MHW from tidal amplification. The morphologic adjustment of the tidal channel network to these perturbations, however, has gone largely undocumented. One effect has been the shoaling of many channels due to decreases in fluvial discharge and tidal prism. We document a previously unrecognized anthropogenic component: the widespread closure of large conduit tidal channels for land reclamation and shrimp farming. GIS analysis of historical Landsat and Google Earth imagery within six 1000 km2 study areas reveals that the tidal network in the natural Sundarbans mangrove forest has remained relatively constant since the 1970s, while significant changes are observed in human-modified areas. Construction of the original embankments removed >1000 km of primary tidal creeks, and >80 km2 of land has been reclaimed outside of polders through the closure of formerly active tidal channels (decrease in mean channel width from 256±91 m to 25±10 m). Tidal restriction by large sluice gates is prevalent, favoring local channel siltation. Furthermore, severing the intertidal platform and large conduit channels from the tidal network has had serious repercussions, such as increased lateral migration and straightening of the remaining channels. Where banklines have eroded, the adjacent embankments appear to be more vulnerable to failure, as

  10. The mangrove pump: The tidal flushing of animal burrows in a tropical mangrove forest determined from radionuclide budgets

    NASA Astrophysics Data System (ADS)

    Stieglitz, Thomas C.; Clark, Jordan F.; Hancock, Gary J.

    2013-02-01

    Intertidal mangrove forests contribute significantly to biogeochemical solute budgets of tropical and subtropical coastlines. A significant part of the biogeochemical cycling in mangrove ecosystems occurs within the subsurface of the forest floor. This subsurface source and the 'offshore' sink are linked by the tidally-driven movement of water through the mangrove forest floor. The tidal circulation through animal macro-burrows in the Coral Creek mangrove forest (area 3 km2) on Hinchinbrook Island (Australia) is documented by constructing mass balances of isotopes of radium and radon measured in the creek in 1997 and 2005 respectively. Isotope activities in burrows were found to be significantly greater than in the adjacent mangrove creek (e.g. for 222Rn, 680-1750 and 30-170 Bq m-3 in burrows and creek respectively). From isotope mass balances, a daily water circulation flux through burrows of 30.4 ± 4.7 L m-2 of forest floor is calculated. This study quantifies the underlying physical process, i.e. the tidal flushing of burrows, that supports significant and continuous exports of soluble organic and inorganic matter from mangrove forest floors to the coastal ocean. The potential significance of the circulation flux estimate is illustrated by up-scaling of the forest-scale estimates to the mangrove forests in the entire central Great Barrier Reef. This extrapolation indicates that the annual water flux circulated by this tidally-driven 'mangrove pump' is equivalent to as much as 20% (16-22%) of the total annual river discharge along the ca. 400 km long coastline of this region.

  11. Coastal saltmarsh managed realignment drives rapid breach inlet and external creek evolution, Freiston Shore (UK)

    NASA Astrophysics Data System (ADS)

    Friess, Daniel A.; Möller, Iris; Spencer, Thomas; Smith, Geoffrey M.; Thomson, Andrew G.; Hill, Ross A.

    2014-03-01

    The creation of saltmarsh through the managed realignment of sea defences, implemented in NW Europe as a sustainable coastal defence option, represents a substantial hydrodynamic perturbation to the local coastal system. The impact of a significantly increased tidal prism on hydromorphological features was investigated at Freiston Shore, Lincolnshire UK. Local tidal conditions and inadequate drainage at this realignment trial contributed to significant channel erosion due to the establishment of water surface slopes and pooling between the newly realigned site and the adjacent intertidal zone. Very high spatial resolution aerial photography and blimp photography were used to monitor inlet evolution from breaching in August 2002 to March 2008, showing a highly non-linear response with breach channels increasing in width by up to 960% within 2.5 months. Airborne laser scanning/LiDAR and terrestrial laser scanning quantified breach channel volume increases, showing a similar pattern. Breach channel evolution did not follow established tidal prism-channel width/cross-sectional area relationships that are often used to guide realignment design. Pre- and post-breach rates of external creek morphology change between 1999 and 2006 were also quantified, with intertidal creeks attached to the breach channels increasing significantly after realignment in both width and depth. This study highlights the physical processes affected by managed realignment, and the importance of understanding the causes of complex water surface slopes at multiple scales.

  12. View of viaduct, looking SE from roof of adjacent parking ...

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

    View of viaduct, looking SE from roof of adjacent parking garage. - Mulberry Street Viaduct, Spanning Paxton Creek & Cameron Street (State Route 230) at Mulberry Street (State Route 3012), Harrisburg, Dauphin County, PA

  13. Quantifying vegetation and nekton response to tidal restoration of a New England salt marsh

    USGS Publications Warehouse

    Roman, C.T.; Raposa, K.B.; Adamowicz, S.C.; James-Pirri, M.J.; Catena, J.G.

    2002-01-01

    Tidal flow to salt marshes throughout the northeastern United States is often restricted by roads, dikes, impoundments, and inadequately sized culverts or bridge openings, resulting in altered ecological structure and function. In this study we evaluated the response of vegetation and nekton (fishes and decapod crustaceans) to restoration of full tidal flow to a portion of the Sachuest Point salt marsh, Middletown, Rhode Island. A before, after, control, impact study design was used, including evaluations of the tide-restricted marsh, the same marsh after reintroduction of tidal flow (i.e., tide-restored marsh), and an unrestricted control marsh. Before tidal restoration vegetation of the 3.7-ha tide-restricted marsh was dominated by Phragmites australis and was significantly different from the adjacent 6.3-ha Spartina -dominated unrestricted control marsh (analysis of similarities randomization test, p < 0.001). After one growing season vegetation of the tide-restored marsh had changed from its pre-restoration condition (analysis of similarities randomization test, p < 0.005). Although not similar to the unrestricted control marsh, Spartina patens and S. alterniflora abundance increased and abundance and height of Phragmites significantly declined, suggesting a convergence toward typical New England salt marsh vegetation. Before restoration shallow water habitat (creeks and pools) of the unrestricted control marsh supported a greater density of nekton compared with the tide-restricted marsh (analysis of variance, p < 0.001), but after one season of restored tidal flow nekton density was equivalent. A similar trend was documented for nekton species richness. Nekton density and species richness from marsh surface samples were similar between the tide-restored marsh and unrestricted control marsh. Fundulus heteroclitus and Palaemonetes pugio were the numerically dominant fish and decapod species in all sampled habitats. This study provides an example of a

  14. 10. Detail and contextual view of bridge and adjacent farmstead ...

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

    10. Detail and contextual view of bridge and adjacent farmstead setting. Note laced vertical compression members, latticed portal strut, decorative strut bracing, and lightness of diagonal and lateral tension members. View to southeast through southeast portal from truss mid-span. - Red Bank Creek Bridge, Spanning Red Bank Creek at Rawson Road, Red Bluff, Tehama County, CA

  15. Tidal Energy.

    ERIC Educational Resources Information Center

    Impact of Science on Society, 1987

    1987-01-01

    States that tidal power projects are feasible in a relatively limited number of locations around the world. Claims that together they could theoretically produce the energy equivalent to more than one million barrels of oil per year. (TW)

  16. Are historical pollution events on the Delaware River recorded as geochemical marker horizons in adjacent marsh sediments

    SciTech Connect

    Walsh, R.; Yemane, K. . Dept. of Geology Bryn Mawr Coll., PA . Geology Dept.)

    1993-03-01

    In the last two hundred years of massive population and industrial growth, the Delaware River has been subjected to several minor and major pollutions. For example, as recently as June 1989 the tanker Presidente Rivera spilled an estimated hundred thousand to million gallons of oil into the river. In the Lower Delaware Basin tides affect the river and its tributaries up to a hundred kilometers inland. The freshwater marshes adjacent to the creeks that empty into the Delaware River experience diurnal tidal sedimentation. It is thus expected that the pollutants in the waterway would be transported via the tidal channels into the adjacent wetlands. The high sedimentation rate, clay-rich sediments, accumulation of terrestrial organic matter, and the low energy environments in these marshes should ensure rapid burial which may preserve some of the contaminants transported into the marshes. To test this hypothesis the authors selected a freshwater marsh along the Raccoon Creek just south of Philadelphia in New Jersey, and collected a 2 m core from a relatively undisturbed portion of the marsh, about 15 m away from the tidal channels. The pH averages around 6.2, ranges from 5.5--6.8, but, is slightly higher in the middle part of the core. The bulk mineralogy comprises chlorite, illite, kaolinite, feldspars and quartz. Vivianite and vermiculite were observed at places lower in the core. Graminae dominates the pollen/spore taxa. The organic debris is unaltered throughout the core. The authors will measure heavy metals and toxic chemicals on < 2[mu]m clay fractions. Also pristane/phytane ratios, indicative of hydrocarbons (crude oils), will be determined on organic matter extracts. The authors will compare and correlate the results to historically documented events of chemical and petroleum spills on the Delaware River.

  17. Final report (2002-2004): Benthic macroinvertebrate communities of reconstructed freshwater tidal wetlands in the Anacostia River, Washington, D.C

    USGS Publications Warehouse

    Brittingham, K.D.; Hammerschlag, R.S.

    2006-01-01

    Considerable work has been conducted on the benthic communities of inland aquatic systems, but there remains a paucity of effort on freshwater tidal wetlands. This study characterized the benthic macroinvertebrate communities of recently reconstructed urban freshwater tidal wetlands along the Anacostia River in Washington, D.C. The focus of the study was on the two main areas of Kingman Marsh, which were reconstructed by the U.S. Army Corps of Engineers in 2000 using Anacostia dredge material. Populations from this 'new' marsh were compared to those of similarly reconstructed Kenilworth Marsh (1993) just one half mile upstream, the relic reference Dueling Creek Marsh in the upper Anacostia estuary and the outside reference Patuxent freshwater tidal marsh in an adjacent watershed. Benthic macro invertebrate organisms were collected using selected techniques for evaluation including the Ekman bottom grab sampler, sediment corer, D-net and Hester-Dendy sampler. Samples were collected at least seasonally from tidal channels, tidal mudflats, three vegetation/sediment zones (low, middle and high marsh), and pools over a 3-year period (late 2001-2004). The macroinvertebrate communities present at the marsh sites proved to be good indicators of disturbance and stress (Kingman Marsh), pollution, urban vs. rural location (Kenilworth and Patuxent), and similarities between reconstructed and remnant wetlands (Kenilworth and Dueling Creek). Macroinvertebrate density was significantly greater at Kingman Marsh than Kenilworth Marsh due to more numerous chironomids and oligochaetes. This may reflect an increase in unvegetated sediments at Kingman (even at elevations above natural mudflat) due to grazing pressure from over-abundant resident Canada geese. Unvegetated sediments yielded greater macroinvertebrate abundance but lower richness than vegetated marsh sites. Data collected from this study provides information on the extent that benthic macroinvertebrate communities can serve

  18. LUSK CREEK ROADLESS AREA, ILLINOIS.

    USGS Publications Warehouse

    Klasner, John S.; Thompson, Robert M.

    1984-01-01

    Geologic mapping and geochemical sampling show that the eastern third of the Lusk Creek Roadless Area in Illinois has a substantiated resource potential for fluorspar, lead, zinc, and barite, and other parts of the area have a probable resource potential for fluorspar. Fluorspar, which occurs along fault zones in the eastern part of the area, has been produced in the adjacent Illinois-Kentucky fluorspar district. There is little promise for the occurrence of other mineral or energy resources.

  19. Tidal Meanders

    NASA Astrophysics Data System (ADS)

    Marani, M.; Lanzoni, S.; Zandolin, D.; Seminara, S.; Rinaldo, A.

    Observational evidence is presented on the geometry of meandering tidal channels evolved within coastal wetlands characterized by different tidal, hydrodynamic, to- pographic, vegetational and ecological features. New insight is provided on the ge- ometrical properties of tidal meanders, with possible dynamic implications on their evolution. In particular, it is shown that large spatial gradients of leading flow rates induce important spatial variabilities of meander wavelengths and widths, while their ratio remains remarkably constant in the range of scales of observation. This holds regardless of changes in width and wavelength up to two orders of magnitude. This suggests a locally adapted evolution, involving the morphological adjustment to the chief landforming events driven by local hydrodynamics. The spectral analysis of lo- cal curvatures reveals that Kinoshita's model curve does not fit tidal meanders due to the presence of even harmonics, in particular the second mode. Geometric parameters are constructed that are suitable to detect possible geomorphic signatures of the tran- sitions from ebb- to flood-dominated hydrodynamics, here related to the skewness of the tidal meander. Trends in skewness, however, prove elusive to measure and fail to show detectable patterns. We also study comparatively the spatial patterns of evolu- tion of the ratios of channel width to depth, and the ratio of width to local radius of curvature. Interestingly, the latter ratio exhibits consistency despite sharp differences in channel incision. Since the degree of incision, epitomized by the width-to-depth ratio, responds to the relevant erosion and migrations mechanisms and is much sen- sitive to vegetation and sediment properties, it is noticeable that we observe a great variety of landscape carving modes and yet recurrent planar features like constant width/curvature and wavelength/width ratios.

  20. Electrical Resistivity Imaging of Tidal Fluctuations in the Water Table at Inwood Hill Park, Manhattan

    NASA Astrophysics Data System (ADS)

    Kenyon, P. M.; Kassem, D.; Olin, A.; Nunez, J.; Smalling, A.

    2005-05-01

    Inwood Hill Park is located on the northern tip of Manhattan and has been extensively modified over the years by human activities. In its current form, it has a backbone of exposed or lightly covered bedrock along the Hudson River, adjacent to a flat area with two tidal inlets along the northern shore of Manhattan. The tidal motions in the inlets are expected to drive corresponding fluctuations in the water table along the borders of the inlets. In the Fall of 2002, a group of students from the Department of Earth and Atmospheric Sciences at the City College of New York studied these fluctuations. Electrical resistivity cross sections were obtained with a Syscal Kid Switch 24 resistivity meter during the course of a tidal cycle at three locations surrounding the westernmost inlet in the park. No change was seen over a tidal cycle at Site 1, possibly due to the effect of concrete erosion barriers which were located between the land and the water surrounding this site. Measurements at Site 2 revealed a small, regular change in the water table elevation of approximately 5 cm over the course of a tidal cycle. This site is inferred to rest on alluvial sediments deposited by a small creek. The cross sections taken at different times during a tidal cycle at Site 3 were the most interesting. They show a very heterogeneous subsurface, with water spurting between blocks of high resistivity materials during the rising portion of the cycle. A small sinkhole was observed on the surface of the ground directly above an obvious plume of water in the cross section. Park personnel confirmed that this sinkhole, like others scattered around this site, is natural and not due to recent construction activity. They also indicated that debris from the construction of the New York City subways may have been dumped in the area in the past. Our conclusion is that the tidal fluctuations at Site 3 are being channeled by solid blocks in the construction debris, and that the sinkholes currently

  1. On funneling of tidal channels

    NASA Astrophysics Data System (ADS)

    Lanzoni, S.; D'Alpaos, A.

    2015-03-01

    Tidal channels dissect the tidal landscape and exert a crucial control on the morphodynamic evolution of these landscapes. Improving our understanding of channel equilibrium morphology is therefore an important issue for both theoretical and practical reasons. We analyze the case of a tidal channel dissecting a relatively short, unvegetated tidal flat characterized by microtidal conditions and a negligible external sediment supply. The three-dimensional equilibrium configuration of the channel is determined on the basis of a hydrodynamic model, describing the cross-sectional distribution of the longitudinal bed shear stresses, coupled with a morphodynamic model retaining the description of the main physical processes shaping the channel and the adjacent intertidal platform. Both channel bed and width are allowed to adapt to the flow field so that an equilibrium altimetric and planimetric configuration is eventually obtained, when erosion becomes negligibly small, and asymptotically constant elevations are reached everywhere within the domain. Model results reproduce several observed channel characteristics of geomorphic relevance, such as the relationship between channel cross-sectional area and the flowing tidal prism, the scaling of the width-to-depth ratio with channel width, and the longitudinal distributions of bed elevations and channel widths. In analogy with empirical evidence from estuaries, tidal channel funneling is usually assumed to be described by an exponential trend. Our theoretical analyses, modeling results, and observational evidence suggest that a linear relationship also provides a good approximation to describe longitudinal variations in channel width for short tidal channels. Longitudinal bed profiles characterized by a strong planform funneling tend to attain an upward concavity, whereas a low degree of convergence implies an almost linear profile. Finally, the model allows one to analyze the influence of environmental conditions (sediment

  2. Ecosystem engineers drive creek formation in salt marshes.

    PubMed

    Vu, Huy D; Wie Ski, Kazimierz; Pennings, Steven C

    2017-01-01

    Ecosystem engineers affect different organisms and processes in multiple ways at different spatial scales. Moreover, similar species may differ in their engineering effects for reasons that are not always clear. We examined the role of four species of burrowing crabs (Sesarma reticulatum, Eurytium limosum, Panopeus herbstii, Uca pugnax) in engineering tidal creek networks in salt marshes experiencing sea level rise. In the field, crab burrows were associated with heads of eroding creeks and the loss of plant (Spartina alterniflora) stems. S. reticulatum was closely associated with creek heads, but densities of the other crab species did not vary across marsh zones. In mesocosm experiments, S. reticulatum excavated the most soil and strongly reduced S. alterniflora biomass. The other three species excavated less and did not affect S. alterniflora. Creek heads with vegetation removed to simulate crab herbivory grew significantly faster than controls. Percolation rates of water into marsh sediments were 10 times faster at creek heads than on the marsh platform. Biomass decomposed two times faster at creek heads than on the marsh platform. Our results indicate that S. reticulatum increases creek growth by excavating sediments and by consuming plants, thereby increasing water flow and erosion at creek heads. Moreover, it is possible that S. reticulatum burrows also increase creek growth by increasing surface and subsurface erosion, and by increasing decomposition of organic matter at creek heads. Our results show that the interaction between crab and plant ecosystem engineers can have both positive and negative effects. At a small scale, in contrast to other marsh crabs, S. reticulatum harms rather than benefits plants, and increases erosion rather than marsh growth. At a large scale, however, S. reticulatum facilitates the drainage efficiency of the marsh through the expansion of tidal creek networks, and promotes marsh health.

  3. Seasonal Variation in the Quality of Dissolved and Particulate Organic Matter Exchanged Between a Salt Marsh and Its Adjacent Estuary

    NASA Astrophysics Data System (ADS)

    Osburn, C. L.; Mikan, M.; Etheridge, J. R.; Burchell, M. R.; Birgand, F.

    2015-12-01

    Salt marshes are transitional ecosystems between terrestrial and marine environments. Along with mangroves and other vegetated coastal habitats, salt marshes rank among the most productive ecosystems on Earth, with critical global importance for the planet's carbon cycle. Fluorescence was used to examine the quality of dissolved and particulate organic matter (DOM and POM) exchanging between a tidal creek in a created salt marsh and its adjacent estuary in eastern North Carolina, USA. Samples from the creek were collected hourly over four tidal cycles in May, July, August, and October of 2011. Absorbance and fluorescence of chromophoric DOM (CDOM) and of base-extracted POM (BEPOM) served as the tracers for organic matter quality while dissolved organic carbon (DOC) and base-extracted particulate organic carbon (BEPOC) were used to compute fluxes. Fluorescence was modeled using parallel factor analysis (PARAFAC) and principle components analysis (PCA) of the PARAFAC results. Of nine PARAFAC components modeled, we used multiple linear regression to identify tracers for recalcitrant DOM; labile soil-derived source DOM; detrital POM; and planktonic POM. Based on mass balance, recalcitrant DOC export was 86 g C m-2 yr-1 and labile DOC export was 49 g C m-2 yr-1. The marsh also exported 41 g C m-2 yr-1 of detrital terrestrial POC, which likely originated from lands adjacent to the North River estuary. Planktonic POC export from the marsh was 6 g C m-2 yr-1. Using the DOM and POM quality results obtained via fluorescence measurements and scaling up to global salt marsh area, we estimated that the potential release of CO2 from the respiration of salt marsh DOC and POC transported to estuaries could be 11 Tg C yr-1, roughly 4% of the recently estimated CO2 release for marshes and estuaries globally.

  4. Tidal Inlet Morphology Classification and Empirical Determination of Seaward and Down-Drift Extents of Tidal Inlets

    DTIC Science & Technology

    2012-05-01

    original Hayes (1979) diagram were not typical barrier island inlets. Some of them were fjords, and Bristol Bay and the Copper River Delta in Alaska included...shore that allows exchange of water between the ocean and bays , lagoons, and marsh and tidal creek systems, and for which the tidal current maintains...wave- dominated (Plum Island Sound, Essex Bay Inlet, and Newbury Port Harbor, all in Massachusetts) but lying close to the original line demarking tide

  5. The impact of organic pollution on the macrobenthic fauna of Dubai Creek (UAE).

    PubMed

    Saunders, James E; Al Zahed, Khalid Mohammed; Paterson, David M

    2007-11-01

    Dubai Creek is a tidal marine intrusion bisecting Dubai within the United Arab Emirates (UAE). The creek extends 14km inland from its opening into the Arabian Gulf, with a narrow lower creek channel leading to a lagoon section in the upper creek. The creek contains numerous sources of organic pollution including sewage outlet flows and boat waste. A survey of the creek was performed, assessing organic pollution, water properties, and the benthic macrofaunal community. The upper creek was heavily polluted with macrofauna communities commonly associated with organic pollution and eutrophication, while the lower creek contained low pollution and relatively healthy macrofauna communities. There is little net tidal flow of water within the creek and residence time in the lagoon is high, which may account for the high organic pollution levels. However, some evidence of the pollution effect moving into the lower creek was found. The results are considered in light of current and historic organic loading within the creek and future developments in the area.

  6. Geologic map of the Skull Creek Quadrangle, Moffat County Colorado

    USGS Publications Warehouse

    Van Loenen, R. E.; Selner, Gary; Bryant, W.A.

    1999-01-01

    The Skull Creek quadrangle is in northwestern Colorado a few miles north of Rangely. The prominent structural feature of the Skull Creek quadrangle is the Skull Creek monocline. Pennsylvanian rocks are exposed along the axis of the monocline while hogbacks along its southern flank expose rocks that are from Permian to Upper Cretaceous in age. The Wolf Creek monocline and the Wolf Creek thrust fault, which dissects the monocline, are salient structural features in the northern part of the quadrangle. Little or no mineral potential exists within the quadrangle. A geologic map of the Lazy Y Point quadrangle, which is adjacent to the Skull Creek quadrangle on the west, is also available (Geologic Investigations Series I-2646). This companian map shows similar geologic features, including the western half of the Skull Creek monocline. The geology of this quadrangle was mapped because of its proximity to Dinosaur National Monument. It is adjacent to quadrangles previously mapped to display the geology of this very scenic and popular National Monument. The Skull Creek quadrangle includes parts of the Skull Creek Wilderness Study Area, which was assessed for its mineral resource potential.

  7. Hydrodynamics and sediment suspension in shallow tidal channels intersecting a tidal flat

    NASA Astrophysics Data System (ADS)

    Pieterse, Aline; Puleo, Jack A.; McKenna, Thomas E.

    2016-05-01

    A field study was conducted on a tidal flat intersected by small tidal channels (depth <0.1 m, width <2 m) within a tidal marsh. Data were collected in the channels, and on the adjacent tidal flat that encompasses approximately 1600 m2 in planform area. Hydrodynamic processes and sediment suspension between the channels and adjacent flat were compared. Shear stress and turbulent kinetic energy were computed from high frequency velocity measurements. Maximum water depth at the field site varied from 0.11 m during the lowest neap high tide to 0.58 m during a storm event. In the channel intersecting the tidal flat, the shear stress, turbulence and along-channel velocity were ebb dominant; e.g. 0.33 m/s peak velocity for ebb compared to 0.19 m/s peak velocity for flood. Distinct pulses in velocity occurred when the water level was near the tidal flat level. The velocity pulse during flood tide occurred at a higher water level than during ebb tide. No corresponding velocity pulse on the tidal flat was observed. Sediment concentrations peaked at the beginning and end of each tidal cycle, and often had a secondary peak close to high tide, assumed to be related to sediment advection. The influence of wind waves on bed shear stress and sediment suspension was negligible. Water levels were elevated during a storm event such that the tidal flat remained inundated for 4 tidal cycles. The water did not drain from the tidal flat into the channels during the storm, and no velocity pulses occurred. Along-channel velocities, turbulent kinetic energy, and shear stresses were therefore smaller in the channels during storm conditions than during non-storm conditions.

  8. Hydrodynamic and geomorphological controls on suspended sediment transport in mangrove creek systems, a case study: Cocoa Creek, Townsville, Australia

    NASA Astrophysics Data System (ADS)

    Bryce, S.; Larcombe, P.; Ridd, P. V.

    2003-03-01

    In tide-dominated sedimentary systems, close relationships exist between tidal hydrodynamics, sediment transport and geomorphology. Tropical coastlines contain many tide-dominated mangrove creeks, yet few studies to date have examined the detail of such relationships for these environments. Time-series observations of tidal height, currents and suspended sediment concentrations were taken between 1992 and 1996 in Cocoa Creek, a mangrove creek system near Townsville, NE Australia. The creek and surrounding mangrove swamps and salt flats were surveyed with an echo-sounder and total survey station, respectively. For 'within-channel' tides, the flood tide is always the fastest, at up to 0.5 m s -1. In contrast, for overbank tides (i.e. tidal height > + 1.5 m Australian Height Datum, AHD) ebb currents are fastest in July, December and January, but flood currents are fastest in August and September, at up to 1 m s -1 in both cases. The tidal asymmetry of overbank tides in Cocoa Creek is controlled by the interaction between offshore tidal forcing and the intertidal storage effect of the mangrove swamps and salt flats, with the result being that during certain periods of the year there tends to be a predominance of either faster flood or ebb velocities on overbank tides. Significant tidal suspended sediment transport in the channel is only initiated at overbank height. On overbank tides, measured net suspended sediment fluxes in the channel are mostly seaward-directed (up to 180 t per tidal cycle). However, the net flux measured over a neap-spring period may be either landwards or seawards (up to 465 and 60 t, respectively). Furthermore, on the larger overbank tides (where the maximum tidal height >+1.85 m AHD) net sediment fluxes may be reduced because of a limited supply of available material. Thus hydrodynamic and sediment sampling durations of up to a month may not be representative of long-term trends. Given that our large dataset has not identified a clear long

  9. 1. EAGLE CREEK RECREATION AREA, VIEW OF EAGLE CREEK TRAIL ...

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

    1. EAGLE CREEK RECREATION AREA, VIEW OF EAGLE CREEK TRAIL REGISTRY BOOTH. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  10. Tidal changes in a heavily modified coastal wetland

    NASA Astrophysics Data System (ADS)

    Ferrarin, Christian; Tomasin, Alberto; Bajo, Marco; Petrizzo, Antonio; Umgiesser, Georg

    2015-06-01

    Changes in tidal regime in the heavily modified Venice Lagoon, Italy, are investigated using long-term observations and numerical modelling. The amplitudes of the major tidal constituents exhibit a significant increase over the last century. Analysis of tide gauge data in the adjacent Adriatic Sea reveals that these changes could be only partially attributed to the rise of the mean sea level. Numerical experiments confirm that natural and anthropogenic morphological changes are responsible for the alteration of tidal regime inside the lagoon. Temporal and spatial changes in tidal asymmetry highlight the complex impacts of human interventions on tidal changes and long-term morphodynamics. Our results suggest that over time the lagoon became more and more an ebb-dominant system. Moreover, in Venice the tidal modulations are significantly impacting the frequency with which high water level thresholds are exceeded. Occurrence of flooding events is therefore influenced by sea level rise and secondarily by the increase in amplitude of principal tidal waves.

  11. KANAB CREEK ROADLESS AREA, ARIZONA.

    USGS Publications Warehouse

    Billingsley, George H.; Ellis, Clarence E.

    1984-01-01

    On the basis of a mineral survey, the Kanab Creek Roadless Area in north-central Arizona has a probable mineral-resource potential for uranium and copper in four small areas around five collapse structures. Gypsum is abundant in layers along the canyon rim of Snake Gulch, but it is a fairly common mineral in the region outside the roadless area. There is little promise for the occurence of fossil fuels in the area. Studies of collapse structures in surrounding adjacent areas might reveal significant mineralization at depth, such as the recent discovery of the uranium ore body at depth in the Pigeon Pipe.

  12. Tidal power in Argentina

    SciTech Connect

    Aisiks, E.G.

    1993-03-01

    This presentation describes the tidal power potential of Argentina and the current status of its utilization. The topics of the presentation include tidal power potential, electric production of the region and the Argentine share of production and consumption, conventional hydroelectric potential, economic feasibility of tidal power production, and the general design and feasibility of a tidal power plant planned for the San Jose Gulf.

  13. Tidal Asteroseismology

    NASA Astrophysics Data System (ADS)

    Burkart, Joshua

    2012-01-01

    The recently discovered Kepler system KOI-54 is a face-on eccentric binary consisting of two similar A stars. Its lightcurve exhibits 20 tidally excited pulsations at perfect harmonics of the orbital frequency, and another 10 nonharmonic pulsations. Analysis of such data is a new form of asteroseismology in which oscillation amplitudes and phases rather than frequencies contain information that can be mined to constrain stellar properties. I will discuss the physics of mode excitation and the range of harmonics expected to be observed. I will then show the results of numerical modeling of the pulsation spectrum, using a nonadiabatic stellar oscillation code including rotation in the "traditional approximation", which qualitatively reproduce the observations. I will discuss the evolutionary history of the KOI-54 system, and will show that the system is likely in a state of stochastic dynamical pseudosynchronization with stellar spin periods of 1.5 days, significantly faster than the classical theoretical prediction of 2.5 days. Time permitting, I will also address the nonharmonic pulsations observed in KOI-54, and show that they can be produced by nonlinear three-mode coupling.

  14. Restoring Fossil Creek

    ERIC Educational Resources Information Center

    Flaccus, Kathleen; Vlieg, Julie; Marks, Jane C.; LeRoy, Carri J.

    2004-01-01

    Fossil Creek had been dammed for the past 90 years, and plans were underway to restore the stream. The creek runs through Central Arizona and flows from the high plateaus to the desert, cutting through the same formations that form the Grand Canyon. This article discusses the Fossil Creek monitoring project. In this project, students and teachers…

  15. Cache Creek ocean: Closure or enclosure?

    NASA Astrophysics Data System (ADS)

    Nelson, Joanne; Mihalynuk, Mitch

    1993-02-01

    Exotic Tethyan faunas within the Cache Creek terrane contrast markedly with faunas and lithologic associations in the adjacent Quesnel and Stikine terranes. In northern British Columbia and southeast Yukon, all three terranes are enveloped in the north by pericontinental rocks of the Yukon-Tanana terrane, a geometry that imposes severe constraints on terrane assembly models for the northern Canadian Cordillera. Our solution to the problem invokes a northern join between the Stikinia and Quesnellia arcs through the Yukon-Tanana terrane, forming an orocline that encloses the Cache Creek terrane. This model involves (1) collision of a linear oceanic plateau at the cusp between Quesnellia and Stikinia, (2) anticlockwise rotation of Stikinia about an axis in the Yukon-Tanana terrane, (3) simultaneous enclosure of the Cache Creek ocean, and (4) emplacement of Quesnellia onto the margin of ancestral North America and the Cache Creek terrane onto Stikinia during final closure of the orocline. Early Mesozoic Paleomagnetic declinations in Stikinia are permissive of the large anticlockwise rotations predicted by the model. Similar large-scale rotations and ocean-basin enclosure are common features in the southwest Pacific. This model accounts for Paleozoic and younger linkages between Yukon-Tanana and both northern Stikinia and Quesnellia, the striking similarity between Triassic-Jurassic arcs east and west of the Cache Creek terrane, and the profound early Mesozoic deformational event in the Yukon-Tanana terrane.

  16. Estimating pothole wetland connectivity to Pipestem Creek ...

    EPA Pesticide Factsheets

    Understanding hydrologic connectivity between wetlands and perennial streams is critical to understanding how reliant stream flow is on wetlands within their watershed. We used the isotopic evaporation signal in water to examine hydrologic connectivity within Pipestem Creek, North Dakota, with a watershed dominated by prairie potholes. During a decadal period of wet conditions, Pipestem Creek contained evaporated water that had approximately half the isotopic evaporative enrichment signal found in most evaporated permanent wetlands. If evaporation was mainly occurring within the stream, we expected the evaporation signal to increase from the headwaters with distance downstream. However, the signal either remained similar or decreased downstream over the two years of sampling. Groundwater measured at the water table adjacent to Pipestem Creek had isotopic values that indicated recharge from winter precipitation and had no significant evaporation. Using isotopic theory and discharge data, we estimated the surface area of open water necessary to generate the evaporation signal found within Pipestem Creek over time. The range of evaporating surface-area estimates was highly dynamic, spanning from 43 to 2653 ha and varying primarily with discharge. The average value (just over 600 ha) was well above the surface area of Pipestem Creek network (245 ha). This estimate of contributing area indicated that Prairie Pothole wetlands were important sources of stream fl

  17. Aeration for plant root respiration in a tidal marsh

    NASA Astrophysics Data System (ADS)

    Li, Hailong; Li, Ling; Lockington, David

    2005-06-01

    This paper investigates the tidal effects on aeration conditions for plant root respiration in a tidal marsh. We extend the work of Ursino et al. (2004) by using a two-phase model for air and water flows in the marsh. Simulations have been conducted to examine directly the link between the airflow dynamics and the aeration condition in the marsh soil. The results show that the effects of entrapped air on water movement in the vadose zone are significant in certain circumstances. Single-phase models based on Richards' equation, which neglect such effects, may not be adequate for quantifying the aeration condition in tidal marsh. The optimal aeration condition, represented by the maximum of the integral magnitude of tidally advected air mass (TAAM) flux, is found to occur near the tidal creek for the four soil textures simulated. This may explain the observation that some salt marsh plant species grow better near tidal creeks than in the inner marsh areas. Our analyses, based on the two-phase model and predicted TAAM flux magnitude, provide further insight into the "positive feedback" mechanism proposed by Ursino et al. (2004). That is, pioneer plants may grow successfully near the creek where the root aeration condition is optimal. The roots of the pioneer plants can soften and loosen the rhizosphere soil, which increases the evapotranspiration rate, the soil porosity, and absolute permeability and weakens the capillary effects. These, in turn, improve further the root aeration conditions and may lead to colonization by plants less resistant to anaerobic conditions.

  18. Aeration for plant root respiration in a tidal marsh

    NASA Astrophysics Data System (ADS)

    Li, Hailong; Li, Ling; Lockington, David

    2005-06-01

    This paper investigates the tidal effects on aeration conditions for plant root respiration in a tidal marsh. We extend the work of Ursino et al. (2004) by using a two-phase model for air and water flows in the marsh. Simulations have been conducted to examine directly the link between the airflow dynamics and the aeration condition in the marsh soil. The results show that the effects of entrapped air on water movement in the vadose zone are significant in certain circumstances. Single-phase models based on Richards' equation, which neglect such effects, may not be adequate for quantifying the aeration condition in tidal marsh. The optimal aeration condition, represented by the maximum of the integral magnitude of tidally advected air mass (TAAM) flux, is found to occur near the tidal creek for the four soil textures simulated. This may explain the observation that some salt marsh plant species grow better near tidal creeks than in the inner marsh areas. Our analyses, based on the two-phase model and predicted TAAM flux magnitude, provide further insight into the ``positive feedback'' mechanism proposed by Ursino et al. (2004). That is, pioneer plants may grow successfully near the creek where the root aeration condition is optimal. The roots of the pioneer plants can soften and loosen the rhizosphere soil, which increases the evapotranspiration rate, the soil porosity, and absolute permeability and weakens the capillary effects. These, in turn, improve further the root aeration conditions and may lead to colonization by plants less resistant to anaerobic conditions.

  19. Principal components granulometric analysis of tidally dominated depositional environments

    SciTech Connect

    Mitchell, S.W. ); Long, W.T. ); Friedrich, N.E. )

    1991-02-01

    Sediments often are investigated by using mechanical sieve analysis (at 1/4 or 1/2{phi} intervals) to identify differences in weight-percent distributions between related samples, and thereby, to deduce variations in sediment sources and depositional processes. Similar granulometric data from groups of surface samples from two siliciclastic estuaries and one carbonate tidal creek have been clustered using principal components analysis. Subtle geographic trends in tidally dominated depositional processes and in sediment sources can be inferred from the clusters. In Barnstable Harbor, Cape Cod, Massachusetts, the estuary can be subdivided into five major subenvironments, with tidal current intensities/directions and sediment sources (longshore transport or sediments weathering from the Sandwich Moraine) as controls. In Morro Bay, San Luis Obispo county, California, all major environments (beach, dune, bay, delta, and fluvial) can be easily distinguished; a wide variety of subenvironments can be recognized. On Pigeon Creek, San Salvador Island, Bahamas, twelve subenvironments can be recognized. Biogenic (Halimeda, Peneroplios, mixed skeletal), chemogenic (pelopids, aggregates), and detrital (lithoclastis skeletal), chemogenic (pelopids, aggregates), and detrital (lithoclastis of eroding Pleistocene limestone) are grain types which dominate. When combined with tidal current intensities/directions, grain sources produce subenvironments distributed parallel to tidal channels. The investigation of the three modern environments indicates that principal components granulometric analysis is potentially a useful tool in recognizing subtle changes in transport processes and sediment sources preserved in ancient depositional sequences.

  20. Shell Creek Summers

    ERIC Educational Resources Information Center

    Seier, Mark; Goedeken, Suzy

    2005-01-01

    In 2002 Shell Creek Watershed Improvement Group turned to the Newman Grove Public Schools' science department to help educate the public on water quality in the watershed and to establish a monitoring system that would be used to improve surface and groundwater quality in the creek's watershed. Nebraska Department of Environmental Quality provided…

  1. Variability of Polychaete Secondary Production in Intertidal Creek Networks along a Stream-Order Gradient

    PubMed Central

    Chu, Tianjiang; Sheng, Qiang; Wang, Sikai; Wu, Jihua

    2014-01-01

    Dendritic tidal creek networks are important habitats for sustaining biodiversity and ecosystem functioning in salt marsh wetlands. To evaluate the importance of creek heterogeneity in supporting benthic secondary production, we assess the spatial distribution and secondary production of a representative polychaete species (Dentinephtys glabra) in creek networks along a stream-order gradient in a Yangtze River estuarine marsh. Density, biomass, and secondary production of polychaetes were found to be highest in intermediate order creeks. In high order (3rd and 4th) creeks, the density and biomass of D. glabra were higher in creek edge sites than in creek bottom sites, whereas the reverse was true for low order (1st and 2nd) creeks. Secondary production was highest in 2nd order creeks (559.7 mg AFDM m−2 year−1) and was ca. 2 folds higher than in 1st and 4th order creeks. Top fitting AIC models indicated that the secondary production of D. glabra was mainly associated with geomorphological characters including cross-sectional area and bank slope. This suggests that hydrodynamic forces are essential factors influencing secondary production of macrobenthos in salt marshes. This study emphasizes the importance of microhabitat variability when evaluating secondary production and ecosystem functions. PMID:24817092

  2. Tidal Marsh Outwelling of Dissolved Organic Matter and Resulting Temporal Variability in Coastal Water Optical and Biogeochemical Properties

    NASA Technical Reports Server (NTRS)

    Tzortziou, Maria; Neale, Patrick J.; Megonigal, J. Patrick; Butterworth, Megan; Jaffe, Rudolf; Yamashita, Youhei

    2010-01-01

    Coastal wetlands are highly dynamic environments at the land-ocean interface where human activities, short-term physical forcings and intense episodic events result in high biological and chemical variability. Long being recognized as among the most productive ecosystems in the world, tidally-influenced coastal marshes are hot spots of biogeochemical transformation and exchange. High temporal resolution observations that we performed in several marsh-estuarine systems of the Chesapeake Bay revealed significant variability in water optical and biogeochemical characteristics at hourly time scales, associated with tidally-driven hydrology. Water in the tidal creek draining each marsh was sampled every hour during several semi-diurnal tidal cycles using ISCO automated samplers. Measurements showed that water leaving the marsh during ebbing tide was consistently enriched in dissolved organic carbon (DOC), frequently by more than a factor of two, compared to water entering the marsh during flooding tide. Estimates of DOC fluxes showed a net DOC export from the marsh to the estuary during seasons of both low and high biomass of marsh vegetation. Chlorophyll amounts were typically lower in the water draining the marsh, compared to that entering the marsh during flooding tide, suggesting that marshes act as transformers of particulate to dissolved organic matter. Moreover, detailed optical and compositional analyses demonstrated that marshes are important sources of optically and chemically distinctive, relatively complex, high molecular weight, aromatic-rich and highly colored dissolved organic compounds. Compared to adjacent estuarine waters, marsh-exported colored dissolved organic matter (CDOM) was characterized by considerably stronger absorption (more than a factor of three in some cases), larger DOC-specific absorption, lower exponential spectral slope, larger fluorescence signal, lower fluorescence per unit absorbance, and higher fluorescence at visible wavelengths

  3. Changing tidal hydrodynamics during different stages of eco-geomorphological development of a tidal marsh: A numerical modeling study

    NASA Astrophysics Data System (ADS)

    Stark, J.; Meire, P.; Temmerman, S.

    2017-03-01

    The eco-geomorphological development of tidal marshes, from initially low-elevated bare tidal flats up to a high-elevated marsh and its typical network of channels and creeks, induces long-term changes in tidal hydrodynamics in a marsh, which will have feedback effects on the marsh development. We use a two-dimensional hydrodynamic model of the Saeftinghe marsh (Netherlands) to study tidal hydrodynamics, and tidal asymmetry in particular, for model scenarios with different input bathymetries and vegetation coverages that represent different stages of eco-geomorphological marsh development, from a low elevation stage with low vegetation coverage to a high and fully vegetated marsh platform. Tidal asymmetry is quantified along a 4 km marsh channel by (1) the difference in peak flood and peak ebb velocities, (2) the ratio between duration of the rising tide and the falling tide and (3) the time-integrated dimensionless bed shear stress during flood and ebb. Although spatial variations in tidal asymmetry are large and the different indicators for tidal asymmetry do not always respond similarly to eco-geomorphological changes, some general trends can be obtained. Flood-dominance prevails during the initial bare stage of a low-lying tidal flat. Vegetation establishment and platform expansion lead to marsh-scale flow concentration to the bare channels, causing an increase in tidal prism in the channels along with a less flood-dominant asymmetry of the horizontal tide. The decrease in flood-dominance continues as the platform grows vertically and the sediment-demand of the platform decreases. However, when the platform elevation gets sufficiently high in the tidal frame and part of the spring-neap cycle is confined to the channels, the discharge in the channels decreases and tidal asymmetry becomes more flood-dominant again, indicating an infilling of the marsh channels. Furthermore, model results suggest that hydro-morphodynamic feedbacks based on tidal prism to channel

  4. Origin of water that discharges from Calf Creek Spring, Garfield County, Utah

    USGS Publications Warehouse

    Wilberg, Dale E.

    1995-01-01

    -term, sustainable source of water is the Navajo aquifer and not precipitation-derived runoff. Ground-water leakage from adjacent drainages could contribute to perennial flow in Calf Creek. Fractures modify the movement of ground water to discharge areas, such as Calf Creek Spring.

  5. Dynamics of suspended sediment exchange and transport in a degraded mangrove creek in Kenya.

    PubMed

    Kitheka, Johnson U; Ongwenyi, George S; Mavuti, Kenneth M

    2002-12-01

    This study focuses on sediment exchange dynamics in Mwache Creek, a shallow tidal mangrove wetland in Kenya. The surface area of the creek is 17 km2 at high water spring. The creek experiences semidiurnal tides with tidal ranges of 3.2 m and 1.4 m during spring and neap tides, respectively. The creek is ebb dominant in the frontwater zone main channel and is flood dominant in the backwater zone main channel. During rainy season, the creek receives freshwater and terrigenous sediments from the seasonal Mwache River. Heavy supply of terrigenous sediments during the El Niño of 1997-1998 led to the huge deposition of sediments (10(60 tonnes) in the wetland that caused massive destruction of the mangrove forest in the upper region. In this study, sea level, tidal discharges, tidal current velocities, salinity, total suspended sediment concentrations (TSSC) and particulate organic sediment concentrations (POSC) measured in stations established within the main channel and also within the mangrove forests, were used to determine the dynamics of sediment exchange between the frontwater and backwater zones of the main channel including also the exchange with mangrove forests. The results showed that during wet seasons, the high suspended sediment concentration associated with river discharge and tidal resuspension of fine channel-bed sediment accounts for the inflow of highly turbid water into the degraded mangrove forest. Despite the degradation of the mangrove forest, sediment outflow from the mangrove forest was considerably less than the inflow. This caused a net trapping of sediment in the wetland. The net import of the sediment dominated in spring tide during both wet and dry season and during neap tide in the wet season. However, as compared to heavily vegetated mangrove wetlands, the generally degraded Mwache Creek mangrove wetland sediment trapping efficiency is low as the average is about 30% for the highly degraded backwater zone mangrove forest and 65% in the

  6. San Mateo Creek Basin

    EPA Pesticide Factsheets

    The San Mateo Creek Basin comprises approximately 321 square miles within the Rio San Jose drainage basin in McKinley and Cibola counties, New Mexico. This basin is located within the Grants Mining District (GMD).

  7. Partridge Creek Diversion Project

    EPA Pesticide Factsheets

    Goal: prevent mercury contamination by keeping the creek from flowing through a mine pit. The project improved brook trout habitat, green infrastructure, the local economy, and decreased human health risks. Includes before-and-after photos.

  8. TIDEV: Tidal Evolution package

    NASA Astrophysics Data System (ADS)

    Cuartas-Restrepo, P.; Melita, M.; Zuluaga, J.; Portilla, B.; Sucerquia, M.; Miloni, O.

    2016-09-01

    TIDEV (Tidal Evolution package) calculates the evolution of rotation for tidally interacting bodies using Efroimsky-Makarov-Williams (EMW) formalism. The package integrates tidal evolution equations and computes the rotational and dynamical evolution of a planet under tidal and triaxial torques. TIDEV accounts for the perturbative effects due to the presence of the other planets in the system, especially the secular variations of the eccentricity. Bulk parameters include the mass and radius of the planet (and those of the other planets involved in the integration), the size and mass of the host star, the Maxwell time and Andrade's parameter. TIDEV also calculates the time scale that a planet takes to be tidally locked as well as the periods of rotation reached at the end of the spin-orbit evolution.

  9. Creation Of Constructed Tidal Flats Using Ocean Dredged Sediment

    NASA Astrophysics Data System (ADS)

    Park, S.; Yi, B.; Lee, I.; Sung, K.

    2007-12-01

    The enforcement of London dumping convention (1972) and protocols (1996) which are comprehensive assessment system for ocean dumping wastes needs environmentally sound treatment and/or reuse of dredged sediment. Creation of constructed tidal flats using dredged sediments could be one of the useful alternatives among other dredged sediment treatments. In this study, the pilot-scale constructed tidal flats with 4 different mixing ratio of ocean dredged sediment were constructed in Nakdong river estuary, Korea. The reed was transplanted from the adjacent reed community after construction, and then the survival and growth rate of the planted reed was measured. Also the changes of Chemical Oxygen Demand (COD), Ignition loss (IL), and the heterotrophic microbial numbers were monitored. The survival rate of the planted reed decreased as the mixing ratio of dredged sediment increased. The survival rate of reed in the constructed tidal flat with 100% dredged sediment was 54% while that in the tidal flat with 0% dredged sediment (original soil of Nakdong river estuary) was 90%. There was little difference of length and diameter of the reed shoot among the 4 different constructed tidal flats. 30% of COD and 9% of IL in the tidal flat with 100% dredged sediment decreased after 202 day, however, the consistent tendency in the change of COD and IL in the other tidal flats was not found possibly due to the open system. It was suggested that the construction of tidal flats using ocean dredged sediment can be possible considering the growth rate of transplanted reeds and the contaminated ocean dredged sediment might be biologically remediated considering the results of decrease of organic matter and increased heterotrophic microbial number in the tidal flat with 100% dredged sediment. However, the continuous monitoring on the vegetation and various environmental factors in the constructed tidal flats should be necessary to evaluate the success of creation of constructed flats using

  10. SF6 Tracer Release Study: A Contaminant Fate Study in Newtown Creek

    NASA Astrophysics Data System (ADS)

    Schmieder, P. J.; Ho, D. T.; Peter, S.; Simpson, H. J.; Flores, S.; Dugan, W. A.

    2004-12-01

    Newtown Creek is a 5.5km creek that discharges into the East River, a 25km strait connecting Long Island Sound to the north and the New York Harbor to the south. Surface runoff dominates the freshwater input into the creek, for natural tributaries no longer exist. The areas directly adjacent to the creek are highly industrialized, and New York City's largest Water Pollution Control Plant (WPCP) discharges directly into creek. In August 2004, we injected sulfur hexafluoride (SF6) into Newtown creek to study the fate of oil seeping into the creek from an underground oil spill and the fate of nutrient rich effluent from the WPCP. We monitored SF6 in Newtown Creek, the East River, and the Upper Bay of New York Harbor for 7 consecutive days following the injection in order to investigate the spreading patterns and transport mechanics of waters exiting the creek, and to determine the ultimate fate of the contaminants/solutes originating in Newtown Creek. Dissolved oxygen (DO) measurements were collected simultaneously with SF6 measurements. A strong DO gradient exists in the creek, where waters in the upper reaches are anoxic. We use SF6 data to calculate mean residence times for Newtown Creek waters. SF6 was detected above background concentrations approximately 15km to the south of the creek at the Verrazano Bridge only 1 day after the tracer injection. By combining the movements of the SF6 distribution, the position of the oxygen gradient, and the residence time of Newtown Creek water, we can determine a lower boundary for oxygen consumption rates.

  11. Relationships between sedimentation, plant species, and the proximity to tidal channels in coastal salt marshes

    NASA Astrophysics Data System (ADS)

    Mudd, S. M.; Howell, S. M.; Furbish, D. J.; Morris, J. T.

    2006-12-01

    Deposition of sediment on vegetated salt marshes enables these marshes to maintain their elevation relative to rising sea level. It has been found that deposition rates of suspended sediment on vegetated salt marshes are highest near tidal channels. This is due to the reduction in turbulence as flows from the tidal channel encounter the stems of the macrophytes that live on the marsh. Despite the presence of levees along some tidal channels, many marsh surfaces paradoxically slope gently upward away from tidal creeks, despite the reduction of deposition of suspended sediment distal from the salt marsh creek. We explore the effect of different marsh species on deposition rates in order to explain this apparent paradox. In the Beaufort Inlet, North Carolina, Spartina alterniflora tends to grow at low elevations near tidal channels, whereas Juncus roemerianus occupies higher elevations distal from the tidal channels. Juncus roemerianus tends to have greater biomass and stem density; this causes it to be more effective at trapping suspended sediment, and may lead Juncus roemerianus to have a higher rate of organogenic sedimentation compared to Spartina alterniflora. We explore how these two effects may allow the portion of the marsh populated by Juncus roemerianus to remain at a higher elevation than the portion of the marsh occupied by Spartina alterniflora, despite the greater rate of deposition due to the settling of suspended sediment in portions of the marsh near the tidal channels.

  12. Glaciotectonism and landsliding in Little Sandhill Creek, Alberta

    NASA Astrophysics Data System (ADS)

    Campbell, Ian A.; Evans, David J. A.

    1990-11-01

    Slope failure and gully erosion along Little Sandhill Creek, a tributary of the Red Deer River, Alberta, Canada, has exposed large stratigraphic sections in which the effects of glaciotectonism and landsliding are clearly revealed. Six main units are identified ranging from a deposit of coarse fluvial sands, through various glacial diamictons and gravels and sands, to postglacial fluvial and lacustrine (pond) and aeolian sediments. Incision by Little Sandhill Creek since late Wisconsinan deglaciation ca. 12,500 B.P., resulted in periodic landslides culminating in the main slope failure which occurred post ca. 5400 B.P. The slide was reactivated by irrigation water return flow from the adjacent prairie surface.

  13. Conservation of Thane Creek and Ulhas River Estuary, India.

    PubMed

    Nikam, Vinay S; Kumar, Arun; Lalla, Kamal; Gupta, Kapil

    2009-07-01

    There has been a steady decrease in the area occupied by wetlands in creeks and estuaries adjacent urban areas due to unprecedented urban growth in coastal cities, for example, Thane Creek and Ulhas River Estuary near Mumbai, India. Urban cities serve as centres of employment and attract a large number of migrants from other places. In case of coastal cities, due to inadequate infrastructure, wastewater and solid waste are disposed of into wetlands and estuary. Discharge of sediments and solid waste into the creeks from drains and construction activities has resulted in decreased flow depth in the coastal waters of Thane Creek and Ulhas River Estuary. Various researchers have studied individual elements of Thane Creek and Ulhas River Estuary at micro level. However, a holistic approach for restoration and conservation of the creek and estuary is required. This paper presents the details of an integrated approach incorporating different conservation measures such as sewerage and sewage treatment, urban drainage management, solid waste management, mangrove plantation and dredging.

  14. Soap Creek Associates NPDES Permit

    EPA Pesticide Factsheets

    Under National Pollutant Discharge Elimination System permit number MT-0023183, Soap Creek Associates, Inc. is authorized to discharge from its wastewater treatment facility located in West, Bighorn County, Montana, to Soap Creek.

  15. Methodology for classification of geographical features with remote sensing images: Application to tidal flats

    NASA Astrophysics Data System (ADS)

    Revollo Sarmiento, G. N.; Cipolletti, M. P.; Perillo, M. M.; Delrieux, C. A.; Perillo, Gerardo M. E.

    2016-03-01

    Tidal flats generally exhibit ponds of diverse size, shape, orientation and origin. Studying the genesis, evolution, stability and erosive mechanisms of these geographic features is critical to understand the dynamics of coastal wetlands. However, monitoring these locations through direct access is hard and expensive, not always feasible, and environmentally damaging. Processing remote sensing images is a natural alternative for the extraction of qualitative and quantitative data due to their non-invasive nature. In this work, a robust methodology for automatic classification of ponds and tidal creeks in tidal flats using Google Earth images is proposed. The applicability of our method is tested in nine zones with different morphological settings. Each zone is processed by a segmentation stage, where ponds and tidal creeks are identified. Next, each geographical feature is measured and a set of shape descriptors is calculated. This dataset, together with a-priori classification of each geographical feature, is used to define a regression model, which allows an extensive automatic classification of large volumes of data discriminating ponds and tidal creeks against other various geographical features. In all cases, we identified and automatically classified different geographic features with an average accuracy over 90% (89.7% in the worst case, and 99.4% in the best case). These results show the feasibility of using freely available Google Earth imagery for the automatic identification and classification of complex geographical features. Also, the presented methodology may be easily applied in other wetlands of the world and perhaps employing other remote sensing imagery.

  16. Tidal alignment of galaxies

    SciTech Connect

    Blazek, Jonathan; Vlah, Zvonimir; Seljak, Uroš

    2015-08-01

    We develop an analytic model for galaxy intrinsic alignments (IA) based on the theory of tidal alignment. We calculate all relevant nonlinear corrections at one-loop order, including effects from nonlinear density evolution, galaxy biasing, and source density weighting. Contributions from density weighting are found to be particularly important and lead to bias dependence of the IA amplitude, even on large scales. This effect may be responsible for much of the luminosity dependence in IA observations. The increase in IA amplitude for more highly biased galaxies reflects their locations in regions with large tidal fields. We also consider the impact of smoothing the tidal field on halo scales. We compare the performance of this consistent nonlinear model in describing the observed alignment of luminous red galaxies with the linear model as well as the frequently used "nonlinear alignment model," finding a significant improvement on small and intermediate scales. We also show that the cross-correlation between density and IA (the "GI" term) can be effectively separated into source alignment and source clustering, and we accurately model the observed alignment down to the one-halo regime using the tidal field from the fully nonlinear halo-matter cross correlation. Inside the one-halo regime, the average alignment of galaxies with density tracers no longer follows the tidal alignment prediction, likely reflecting nonlinear processes that must be considered when modeling IA on these scales. Finally, we discuss tidal alignment in the context of cosmic shear measurements.

  17. Tidal alignment of galaxies

    SciTech Connect

    Blazek, Jonathan; Vlah, Zvonimir; Seljak, Uroš E-mail: zvlah@stanford.edu

    2015-08-01

    We develop an analytic model for galaxy intrinsic alignments (IA) based on the theory of tidal alignment. We calculate all relevant nonlinear corrections at one-loop order, including effects from nonlinear density evolution, galaxy biasing, and source density weighting. Contributions from density weighting are found to be particularly important and lead to bias dependence of the IA amplitude, even on large scales. This effect may be responsible for much of the luminosity dependence in IA observations. The increase in IA amplitude for more highly biased galaxies reflects their locations in regions with large tidal fields. We also consider the impact of smoothing the tidal field on halo scales. We compare the performance of this consistent nonlinear model in describing the observed alignment of luminous red galaxies with the linear model as well as the frequently used 'nonlinear alignment model,' finding a significant improvement on small and intermediate scales. We also show that the cross-correlation between density and IA (the 'GI' term) can be effectively separated into source alignment and source clustering, and we accurately model the observed alignment down to the one-halo regime using the tidal field from the fully nonlinear halo-matter cross correlation. Inside the one-halo regime, the average alignment of galaxies with density tracers no longer follows the tidal alignment prediction, likely reflecting nonlinear processes that must be considered when modeling IA on these scales. Finally, we discuss tidal alignment in the context of cosmic shear measurements.

  18. Eocene tidal deposits, northern San Diego County, California

    SciTech Connect

    Eisenberg, L.I.; Abbott, P.L.

    1985-02-01

    A transgressive-regressive sedimentation sequence is recorded in a band of middle Eocene strata a few miles wide. An abundance of primary sedimentary structures, along with interfingering relationships and paleontology, define 12 lithofacies representing depositional environments including nearshore shelf, outer and inner barrier island, tidal flats and channels, lagoon and lagoonal delta. Tide-influenced sedimentary features are well defined and include meandering and abandoned tidal channels, oppositely inclined superimposed cross-strata, interlaminated mud and sand along the basal and lateral accretion surfaces of migrating tidal channels, flaser and wavy bedding, and storm-deposited strata. The first sedimentary half cycle was transgressive and documents the compression of dominantly tidal-flat and lagoonal environments against a steep, hilly coastline by the overall rising sea level of early and medial middle Eocene time. The inboard tidal-flat and lagoonal mudstones (Delmar and Friars Formations) and outboard tidal flat, channel and bar sandstones (Torrey Sandstone and Scripps Formation) interfinger in a landward-climbing, 3-dimensional sedimentary mass that parallels and meets the basement with a pronounced unconformity. The second half cycle was regressive and occurred in the medial and late middle Eocene. It formed due to the influx of coarser, more angular sediment from the adjacent basement into the narrowed paralic zone. This westward (seaward) progradation of lagoonal delta and inner tidal-flat sandy sediments occurred despite the still-rising sea level.

  19. Boulder Creek Study

    ERIC Educational Resources Information Center

    Bingaman, Deirdre; Eitel, Karla Bradley

    2010-01-01

    Boulder Creek runs literally in the backyard of Donnelly Elementary School and happens to be on the EPA list of impaired water bodies. Therefore, a unique opportunity for problem solving opened the door to an exciting chance for students to become scientists, while also becoming active in their community. With the help of the Idaho Department of…

  20. Channel stability of Turkey Creek, Nebraska

    USGS Publications Warehouse

    Rus, David L.; Soenksen, Philip J.

    1998-01-01

    Channelization on Turkey Creek and its receiving stream, the South Fork Big Nemaha River, has disturbed the equilibrium of Turkey Creek and has led to channel-stability problems, such as degradation and channel widening, which pose a threat to bridges and land adjacent to the stream. As part of a multiagency study, the U.S. Geological Survey assessed channel stability at two bridge sites on upper and middle portions of Turkey Creek by analyzing streambed-elevation data for gradation changes, comparing recent cross-section surveys and historic accounts, identifying bank-failure blocks, and analyzing tree-ring samples. These results were compared to gradation data and trend results for a U.S. Geological Survey streamflow-gaging station near the mouth of Turkey Creek from a previous study. Examination of data on streambed elevations reveals that degradation has occurred. The streambed elevation declined 0.5 m at the upper site from 1967-97. The streambed elevation declined by 3.2 m at the middle site from 1948-97 and exposed 2 m of the pilings of the Nebraska Highway 8 bridge. Channel widening could not be verified at the two sites from 1967-97, but a historic account indicates widening at the middle site to be two to three times that of the 1949 channel width. Small bank failures were evident at the upper site and a 4-m-wide bank failure occurred at the middle site in 1987 according to tree ring analyses. Examination of streambed-elevation data from a previous study at the lower site reveals a statistically significant aggrading trend from 1958-93. Further examination of these data suggests minor degradation occurred until 1975, followed by aggradation.

  1. Modeling pesticide fate in a small tidal estuary

    USGS Publications Warehouse

    McCarthy, A.M.; Bales, J.D.; Cope, W.G.; Shea, D.

    2007-01-01

    The exposure analysis modeling system (EXAMS), a pesticide fate model developed by the U.S. Environmental Protection Agency, was modified to model the fate of the herbicides atrazine and metolachlor in a small tidally dominated estuary (Bath Creek) in North Carolina, USA where freshwater inflow accounts for only 3% of the total flow. The modifications simulated the changes that occur during the tidal cycle in the estuary, scenarios that are not possible with the original EXAMS model. Two models were created within EXAMS, a steady-state model and a time-variant tidally driven model. The steady-state model accounted for tidal flushing by simply altering freshwater input to yield an estuary residence time equal to that measured in Bath Creek. The tidal EXAMS model explicitly incorporated tidal flushing by modifying the EXAMS code to allow for temporal changes in estuary physical attributes (e.g., volume). The models were validated with empirical measurements of atrazine and metolachlor concentrations in the estuary shortly after herbicide application in nearby fields and immediately following a rain event. Both models provided excellent agreement with measured concentrations. The steady-state EXAMS model accurately predicted atrazine concentrations in the middle of the estuary over the first 3 days and under-predicted metolachlor by a factor of 2-3. The time-variant, tidally driven EXAMS model accurately predicted the rise and plateau of both herbicides over the 6-day measurement period. We have demonstrated the ability of these modified EXAMS models to be useful in predicting pesticide fate and exposure in small tidal estuaries. This is a significant improvement and expansion of the application of EXAMS, and given the wide use of EXAMS for surface water quality modeling by both researchers and regulators and the ability of EXAMS to interface with terrestrial models (e.g., pesticide root zone model) and bioaccumulation models, we now have an easily-accessible and

  2. AN APPROACH FOR CLASSIFYING TIDAL REGIMES BASED ON TIDAL CONSTITUENTS

    EPA Science Inventory

    Tidal fluctuations can be one of the dominant physical processes in estuaries. This paper presents a numerical classification of tidal regimes that can be used to summarize local conditions and facilitate comparisons among locations. Tide predictions are customarily calculated ...

  3. Marine ecological habitat: a case study on projected thermal power plant around Dharamtar Creek, India.

    PubMed

    Kulkarni, Vikrant A; Naidu, Velamala S; Jagtap, Tanaji G

    2011-03-01

    Estuaries and tidal creeks, harboring mangroves particularly, face tremendous anthropogenic pressures. Expansion of mega cities and the thermal power plants are generally proposed in the vicinity of estuaries and creek, due to the feasibility of intake and discharge of water for cooling. Discharges from such developments remain constant threat of increasing thermal pollution and affecting the quality of environment. The baseline information on prevailing quality of aquatic environment comes handy for understanding alterations due to such activities. Principle component analysis (PCA) revealed that temperature, pH, salinity, suspended solids, DO, BOD and phaeophytins are major parameters influencing the creek system. Heated effluents may have direct and adverse impacts on these parameters, altering biotic constituents. Hence, periodic and detailed observations are necessary to estimate exact response of biotic communities to changing environment. The present paper is based on case study, projecting a power plant in the vicinity of major mangrove habitats of Dharamtar creek.

  4. Tidal propagation and dissipation in the Taiwan Strait

    NASA Astrophysics Data System (ADS)

    Yu, Haiqing; Yu, Huaming; Wang, Lu; Kuang, Liang; Wang, Hui; Ding, Yang; Ito, Shin-ichi; Lawen, Johannes

    2017-03-01

    Previous research on tides and tidal dynamics in the Taiwan Strait (TS) is reviewed in this paper. Tidal dynamics, which is the basic and dominant hydrodynamics in this area, attracts much interest in the last 30 years and till now its physical mechanism is still in debate. In this study, the major research methods and findings of previous works on barotropic tides in the TS are summarized. Based on Finite Volume Coastal Ocean Model (FVCOM), the main tidal constituents (M2, S2, K1, O1) are well simulated with the mean root-mean-square (RMS) errors of 4.7, 2.0, 1.3 and 0.7 cm between the observed and simulated tidal constants, respectively. It has been proved that semi-diurnal tidal movement is mainly determined by the waves from the East China Sea (ECS), while waves from the ECS and the Luzon Strait (LS) play comparable roles in diurnal tidal movement in the TS by linear superposition and the interaction of these two waves is the main cause for the progressive diurnal tidal waves in the TS. Furthermore, energy analysis revealed that the M2 tidal wave system in the TS and its adjacent area south to the shoal is an standing wave system and the anti-node appears in the central TS while the wave node locates in the shoal area, which can be contributed to the interaction of the incident waves from the ECS and the topography step south to Taiwan island, while the shoal also has an impact on the whole semi-diurnal tidal wave system in the TS. This standing wave system is consistent with the little energy dissipation in the central TS and much energy dissipation in the southern TS, where the shallow water effect also contributes to the local dissipation to some extent.

  5. Special Flood Hazard Report. Greater Anchorage Area. Campbell Creek

    DTIC Science & Technology

    1975-05-01

    PI ’Lu ~ ~o 1919 LW CONTENTS / :Page PREFACE BACKGROUND INFORMATION 1 Settlement 1 The Stream and Its Valley 1 Development in F d Plain ..... 2...population. As the community grew from its early beginnings to the modern city that ii is today, people began to develop the outlying areas, primarily for...residential pur- poses. Today, the areas adjacent to Campbell Creek are in a state of rapid develop - ment. Land is continually being subdivided and

  6. WELCOME CREEK WILDERNESS, MONTANA.

    USGS Publications Warehouse

    Lidke, D.J.; Close, T.J.

    1984-01-01

    Mineral-resource surveys indicate probable or substantiated mineral-resource potential for small amounts of gold and other metals. Areas of alluvium in Welcome Creek and in part of Rock Creek are classed as having probable and substantiated mineral-resource potential for small quantities of gold in small and scattered placers and in placer tailings. A small area which contains the Cleveland mine, on Cleveland Mountain, near the west border of the wilderness was classed as having probable mineral-resource potential for silver and gold in veins. Although green mudstone strata that often are favorable hosts for stratabound copper occurrences were found in the northeast part of the wilderness, no copper deposits were found and these studies indicate little likelihood for the occurrence of copper resources. The nature of the geologic terrain indicates that there is little likelihood of the occurrence of energy resources.

  7. Topographic heterogeneity influences fish use of an experimentally restored tidal marsh.

    PubMed

    Larkin, Daniel J; Madon, Sharook P; West, Janelle M; Zedler, Joy B

    2008-03-01

    Ecological theory predicts that incorporating habitat heterogeneity into restoration sites should enhance diversity and key functions, yet research is limited on how topographic heterogeneity affects higher trophic levels. Our large (8-ha) southern California restoration experiment tested effects of tidal creek networks and pools on trophic structure of salt marsh habitat and high-tide use by two regionally dominant fish species, California killifish (Fundulus parvipinnis) and longjaw mudsucker (Gillichthys mirabilis). We expected tidal creeks to function as "conduits" that would enhance connectivity between subtidal and intertidal habitat and pools to serve as microhabitat "oases" for fishes. Pools did provide abundant invertebrate prey and were a preferred microhabitat for F. parvipinnis, even when the entire marsh was inundated (catch rates were 61% higher in pools). However, G. mirabilis showed no preference for pools. At a larger scale, effects of tidal creek networks were also mixed. Areas containing creeks had 12% higher catch rates of G. mirabilis, but lower catch rates and feeding rates of F. parvipinnis. Collectively, the results indicate that restoring multiple forms of heterogeneity is required to provide opportunities for multiple target consumers.

  8. Final Report: Five years of monitoring reconstructed freshwater tidal wetlands in the urban Anacostia River (2000-2004)

    USGS Publications Warehouse

    Hammerschlag, R.S.; Baldwin, A.H.; Krafft, C.C.; Neff, K.P.; Paul, M.M.; Brittingham, K.D.; Rusello, K.; Hatfield, J.S.

    2006-01-01

    The Anacostia River in Washington, D.C. USA consisted of over 809 hectares (2000 acres) of freshwater tidal wetlands before mandatory dredging removed most of them in the first half of the 20th century. Much of this13 kilometer (8 mile) reach was transferred to the National Park Service (NPS). Planning processes in the 1980?s envisioned a restoration (rejuvenation) of some wetlands for habitat, aesthetics, water quality and interpretative purposes. Subsequently, the U.S. Army Corps of Engineers in a cost share agreement with the District of Columbia reconstructed wetlands on NPS lands at Kenilworth - 12.5 hectares (1993), Kingman - 27 hectares (2000), a Fringe Marsh - 6.5 hectares (2003) and is currently constructing Heritage Marsh - 2.5 hectares (2005/2006). The USGS Patuxent Wildlife Research Center in conjunction with the University of Maryland Biological Engineering Department was contracted to conduct post-reconstruction monitoring (2000-2004) to document the relative success and progress of the Kingman Marsh reconstruction primarily based on vegetative response but also in conjunction with seed bank and soil characteristics. Results from Kingman were compared to Kenilworth Marsh (reconstructed 7 years prior), Dueling Creek Marsh (last best remaining freshwater tidal wetland bench in the urbanized Anacostia watershed) and Patuxent River Marsh (in a more natural adjacent watershed). Vegetation establishment was initially strong at Kingman, but declined rapidly as measured by cover, richness, diversity , etc. under grazing pressure from resident Canada geese and associated reduction in sediment levels. This decline did not occur at the other wetlands. The decline occurred despite a substantial seed bank that was sustained primarily be water born propagules. Soil development, as true for most juvenile wetlands, was slow with almost no organic matter accumulation. By 2004 only two of 7 planted species remained (mostly Peltandra virginica) at Kingman which did

  9. Anthropogenic changes to the tidal channel network, sediment rerouting, and social implications in southwest Bangladesh

    NASA Astrophysics Data System (ADS)

    Wilson, C.; Goodbred, S. L., Jr.; Sams, S.; Small, C.

    2015-12-01

    The tidal channel network in southwest Bangladesh has been undergoing major adjustment in response to anthropogenic modification over the past few decades. Densely inhabited, agricultural islands that have been embanked to protect against inundation by tides, river flooding, and storm surges (i.e., polders) preclude tidal exchange and sedimentation. Studies reveal this results in elevation deficits relative to mean high water, endangering local communities when embankment failures occur (e.g., during storms, lateral channel erosion). In addition, many studies suggest that the decrease in tidal prism and associated change in hydrodynamics from poldering causes shoaling in remaining tidal channels, which can cause a disruption in transportation. The widespread closure and conversion of tidal channel areas to profitable shrimp aquaculture is also prevalent in this region. In this study, we quantify the direct closure of tidal channels due to poldering and shrimp aquaculture using historical Landsat and Google Earth imagery, and analyze the morphologic adjustment of the tidal channel network due to these perturbations. In the natural Sundarbans mangrove forest, the tidal channel network has remained relatively constant since the 1970s. In contrast, construction of polders removed >1000 km of primary tidal creeks and >90 km2 has been reclaimed outside of polders through infilling and closure of formerly-active, higher order conduit channels now used for shrimp aquaculture. Field validation confirm tidal restriction by large sluice gates is prevalent, favoring local channel siltation at rates up to 20cm/yr. With the impoundment of primary creeks and closure of 30-60% of conduit channels in the study area, an estimated 1,400 x 106 m3 of water has been removed from the tidal prism and potentially redirected within remaining channels. This has significant implications for tidal amplification in this region. Further, we estimate that 12.3 x 106 MT of sediment annually

  10. Tidal radius estimates for three open clusters

    NASA Astrophysics Data System (ADS)

    Danilov, V. M.; Loktin, A. V.

    2015-10-01

    A new method is developed for estimating tidal radii and masses of open star clusters (OCL) based on the sky-plane coordinates and proper motions and/or radial velocities of cluster member stars. To this end, we perform the correlation and spectral analysis of oscillations of absolute values of stellar velocity components relative to the cluster mass center along three coordinate planes and along each coordinate axis in five OCL models. Mutual correlation functions for fluctuations of absolute values of velocity field components are computed. The spatial Fourier transform of the mutual correlation functions in the case of zero time offset is used to compute wavenumber spectra of oscillations of absolute values of stellar velocity components. The oscillation spectra of these quantities contain series of local maxima at equidistant wavenumber k values. The ratio of the tidal radius of the cluster to the wavenumber difference Δ k of adjacent local maxima in the oscillation spectra of absolute values of velocity field components is found to be the same for all five OCL models. This ratio is used to estimate the tidal radii and masses of the Pleiades, Praesepe, and M67 based on the proper motions and sky-plane coordinates of the member stars of these clusters. The radial dependences of the absolute values of the tangential and radial projections of cluster star velocities computed using the proper motions relative to the cluster center are determined, along with the corresponding autocorrelation functions and wavenumber spectra of oscillations of absolute values of velocity field components. The Pleiades virial mass is estimated assuming that the cluster is either isolated or non-isolated. Also derived are the estimates of the Pleiades dynamical mass assuming that it is non-stationary and non-isolated. The inferred Pleiades tidal radii corresponding to these masses are reported.

  11. Developments in tidal power

    NASA Astrophysics Data System (ADS)

    Charlier, R. H.

    Successful, planned, and potential tidal power plants and sites are discussed. Units are in operation in France and Russia, with the French plant using reversible blade turbines being used as a design guide for plants in Argentina and Australia. The U.S. is studying the feasibility of a plant in Passamaquaddy Bay, and Canada is pursuing construction of a plant in the Bay of Fundy. The Severn River in Great Britain is receiving a site study, and over a hundred plants have been built as local power systems in China. Bulb-type turbines, which enhance the volume emptying and filling the retaining basin, are considered as the highest performing power unit. Simpler one-way flow turbines have been suggested as more economical to install. Governmental, institutional, and investor impediments to tidal power plant are explored.

  12. Water-Quality Characteristics of Cottonwood Creek, Taggart Creek, Lake Creek, and Granite Creek, Grand Teton National Park, Wyoming, 2006

    USGS Publications Warehouse

    Clark, Melanie L.; Wheeler, Jerrod D.; O'Ney, Susan E.

    2007-01-01

    To address water-resource management objectives of the National Park Service in Grand Teton National Park, the U.S. Geological Survey in cooperation with the National Park Service has conducted water-quality sampling on streams in the Snake River headwaters area. A synoptic study of streams in the western part of the headwaters area was conducted during 2006. Sampling sites were located on Cottonwood Creek, Taggart Creek, Lake Creek, and Granite Creek. Sampling events in June, July, August, and October were selected to characterize different hydrologic conditions and different recreational-use periods. Stream samples were collected and analyzed for field measurements, major-ion chemistry, nutrients, selected trace elements, pesticides, and suspended sediment. Water types of Cottonwood Creek, Taggart Creek, Lake Creek, and Granite Creek were calcium bicarbonate. Dissolved-solids concentrations were dilute in Cottonwood Creek and Taggart Creek, which drain Precambrian-era rocks and materials derived from these rocks. Dissolved-solids concentrations ranged from 11 to 31 milligrams per liter for samples collected from Cottonwood Creek and Taggart Creek. Dissolved-solids concentrations ranged from 55 to 130 milligrams per liter for samples collected from Lake Creek and Granite Creek, which drain Precambrian-era rocks and Paleozoic-era rocks and materials derived from these rocks. Nutrient concentrations generally were small in samples collected from Cottonwood Creek, Taggart Creek, Lake Creek, and Granite Creek. Dissolved-nitrate concentrations were the largest in Taggart Creek. The Taggart Creek drainage basin has the largest percentage of barren land cover of the basins, and subsurface waters of talus slopes may contribute to dissolved-nitrate concentrations in Taggart Creek. Pesticide concentrations, trace-element concentrations, and suspended-sediment concentrations generally were less than laboratory reporting levels or were small for all samples. Water

  13. The Beaver Creek story

    USGS Publications Warehouse

    Doyle, W.H.; Whitworth, B.G.; Smith, G.F.; Byl, T.D.

    1996-01-01

    Beaver Creek watershed in West Tennessee includes about 95,000 acres of the Nation's most productive farmland and most highly erodible soils. In 1989 the U.S. Geological Survey, in cooperation with the Tennessee Department of Agriculture, began a study to evaluate the effect of agricultural activities on water quality in the watershed and for best management practices designed to reduce agricultural nonpoint-source pollution. Agrichemical monitoring included testing the soils, ground water, and streams at four farm sites ranging from 27 to 420 acres. Monitoring stations were operated downstream to gain a better understanding of the water chemistry as runoff moved from small ditches into larger streams to the outlet of the Beaver Creek watershed. Prior to the implementation of best management practices at one of the farm study sites, some storms produced an average suspended-sediment concentration of 70,000 milligrams per liter. After the implementation of BMP's, however, the average value never exceeded 7,000 milligrams per liter. No-till crop production was the most effective best management practice for conserving soil on the farm fields tested. A natural bottomland hardwood wetland and a constructed wetland were evaluated as instream resource-management systems. The wetlands improved water quality downstream by acting as a filter and removing a significant amount of nonpoint-source pollution from the agricultural runoff. The constructed wetland reduced the sediment, pesticide, and nutrient load by approximately 50 percent over a 4-month period. The results of the Beaver Creek watershed study have increased the understanding of the effects of agriculture on water resources. Study results also demonstrated that BMP's do protect and improve water quality.

  14. 75 FR 27332 - AER NY-Gen, LLC; Eagle Creek Hydro Power, LLC; Eagle Creek Water Resources, LLC; Eagle Creek Land...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-14

    ... Energy Regulatory Commission AER NY-Gen, LLC; Eagle Creek Hydro Power, LLC; Eagle Creek Water Resources... Creek Hydro Power, LLC, Eagle Creek Water Resources, LLC, and Eagle Creek Land Resources, LLC.... For the transferee: Mr. Paul Ho, Eagle Creek Hydro Power, LLC, Eagle Creek Water Resources, LLC,...

  15. Tidal Heating in Enceladus

    NASA Astrophysics Data System (ADS)

    Meyer, Jennifer; Wisdom, J.

    2007-07-01

    The heating in Enceladus in an equilibrium resonant configuration with other saturnian satellites can be estimated independently of the physical properties of Enceladus. Our results update the values obtained for the equilibrium tidal heating found by Lissauer et al. (1984) and Peale (2003). We find that equilibrium tidal heating cannot account for the heat that is observed to be coming from Enceladus, and current heating rates are even less for conventional estimates of the Love number for Enceladus. Even allowing for a much larger dynamic Love number, as can occur in viscoelastic models (Ross and Schubert, 1989), the equilibrium tidal heating is less than the heat observed to be coming from Enceladus. One resolution is that the tidal equilibrium is unstable and that the system oscillates about equilibrium. Yoder (1981) suggested that Enceladus might oscillate about equilibrium if the Q of Enceladus is stress dependent. An alternate suggestion was made by Ojakangas and Stevenson (1986), who emphasized the possible temperature dependence of Q. In these models Enceladus would now be releasing heat stored during a recent high eccentricity phase. However, we have shown that the Ojakangas and Stevenson model does not produce oscillations for parameters appropriate for Enceladus. Other low-order resonance configurations are possible for the saturnian satellites in the past. These include the 3:2 Mimas-Enceladus and the 3:4 Enceladus-Tethys resonances. The latter resonance has no equilibrium because the orbits are diverging, and the former has an equilibrium heating rate of only 0.48 GW. So equilibrium heating at past resonances is no more successful at explaining past resurfacing events than equilibrium heating is at explaining the present activity.

  16. Line Creek improves efficiency

    SciTech Connect

    Harder, P.

    1988-04-01

    Boosting coal recovery rate by 8% and reducing fuel expense $18,000 annually by replacing two tractors, are two tangible benefits that Crows Nest Resources of British Columbia has achieved since overseas coal markets weakened in 1985. Though coal production at the 4-million tpy Line Creek open pit mine has been cut 25% from its 1984 level, morale among the pit crew remains high. More efficient pit equipment, innovative use of existing equipment, and encouragement of multiple skill development among workers - so people can be assigned to different jobs in the operation as situations demand - contribute to a successful operation.

  17. Relativistic tidal disruption events

    NASA Astrophysics Data System (ADS)

    Levan, A.

    2012-12-01

    In March 2011 Swift detected an extremely luminous and long-lived outburst from the nucleus of an otherwise quiescent, low luminosity (LMC-like) galaxy. Named Swift J1644+57, its combination of high-energy luminosity (1048 ergs s-1 at peak), rapid X-ray variability (factors of >100 on timescales of 100 seconds) and luminous, rising radio emission suggested that we were witnessing the birth of a moderately relativistic jet (Γ ˜ 2 - 5), created when a star is tidally disrupted by the supermassive black hole in the centre of the galaxy. A second event, Swift J2058+0516, detected two months later, with broadly similar properties lends further weight to this interpretation. Taken together this suggests that a fraction of tidal disruption events do indeed create relativistic outflows, demonstrates their detectability, and also implies that low mass galaxies can host massive black holes. Here, I briefly outline the observational properties of these relativistic tidal flares observed last year, and their evolution over the first year since their discovery.

  18. Overland Tidal Power Generation Using Modular Tidal Prism

    SciTech Connect

    Khangaonkar, Tarang; Yang, Zhaoqing; Geerlofs, Simon H.; Copping, Andrea

    2010-03-01

    Naturally occurring sites with sufficient kinetic energy suitable for tidal power generation with sustained currents > 1 to 2 m/s are relatively rare. Yet sites with greater than 3 to 4 m of tidal range are relatively common around the U.S. coastline. Tidal potential does exist along the shoreline but is mostly distributed, and requires an approach which allows trapping and collection to also be conducted in a distributed manner. In this paper we examine the feasibility of generating sustainable tidal power using multiple nearshore tidal energy collection units and present the Modular Tidal Prism (MTP) basin concept. The proposed approach utilizes available tidal potential by conversion into tidal kinetic energy through cyclic expansion and drainage from shallow modular manufactured overland tidal prisms. A preliminary design and configuration of the modular tidal prism basin including inlet channel configuration and basin dimensions was developed. The unique design was shown to sustain momentum in the penstocks during flooding as well as ebbing tidal cycles. The unstructured-grid finite volume coastal ocean model (FVCOM) was used to subject the proposed design to a number of sensitivity tests and to optimize the size, shape and configuration of MTP basin for peak power generation capacity. The results show that an artificial modular basin with a reasonable footprint (≈ 300 acres) has the potential to generate 10 to 20 kw average energy through the operation of a small turbine located near the basin outlet. The potential of generating a total of 500 kw to 1 MW of power through a 20 to 40 MTP basin tidal power farms distributed along the coastline of Puget Sound, Washington, is explored.

  19. Tidal Venuses: triggering a climate catastrophe via tidal heating.

    PubMed

    Barnes, Rory; Mullins, Kristina; Goldblatt, Colin; Meadows, Victoria S; Kasting, James F; Heller, René

    2013-03-01

    Traditionally, stellar radiation has been the only heat source considered capable of determining global climate on long timescales. Here, we show that terrestrial exoplanets orbiting low-mass stars may be tidally heated at high-enough levels to induce a runaway greenhouse for a long-enough duration for all the hydrogen to escape. Without hydrogen, the planet no longer has water and cannot support life. We call these planets "Tidal Venuses" and the phenomenon a "tidal greenhouse." Tidal effects also circularize the orbit, which decreases tidal heating. Hence, some planets may form with large eccentricity, with its accompanying large tidal heating, and lose their water, but eventually settle into nearly circular orbits (i.e., with negligible tidal heating) in the habitable zone (HZ). However, these planets are not habitable, as past tidal heating desiccated them, and hence should not be ranked highly for detailed follow-up observations aimed at detecting biosignatures. We simulated the evolution of hypothetical planetary systems in a quasi-continuous parameter distribution and found that we could constrain the history of the system by statistical arguments. Planets orbiting stars with masses<0.3 MSun may be in danger of desiccation via tidal heating. We have applied these concepts to Gl 667C c, a ∼4.5 MEarth planet orbiting a 0.3 MSun star at 0.12 AU. We found that it probably did not lose its water via tidal heating, as orbital stability is unlikely for the high eccentricities required for the tidal greenhouse. As the inner edge of the HZ is defined by the onset of a runaway or moist greenhouse powered by radiation, our results represent a fundamental revision to the HZ for noncircular orbits. In the appendices we review (a) the moist and runaway greenhouses, (b) hydrogen escape, (c) stellar mass-radius and mass-luminosity relations, (d) terrestrial planet mass-radius relations, and (e) linear tidal theories.

  20. Recognition of synodic and tropical tidal periodicities in tidal rhythmites

    SciTech Connect

    Archer, A.W. ); Kvale, E.P. ); Johnson, H.P. )

    1990-05-01

    Tidal processes are capable of producing bedding that records individual tidal events; however, only within the last decade have tidal cycles, such as neap-spring periodicities become widely recognized. Such cycles have been documented within thinly laminated, vertically accreted siltstones. The laminae exhibit systematic patterns of thickening and thinning that have been equated to the lunar orbital period (synodic month). However, modem tides are subject to periodicities other than the synodic month and such additional periods can be the causative mechanism for neap-spring tidal periods. Gravitational interactions of the earth, moon, and sun generate tides that fluctuate with periods that correspond to the phases of the moon (synodic month), declination of the moon (tropical month), and distance of the moon from the earth (anomalistic month). Although harmonic analyses of semidiurnal tidal data indicate that such systems are controlled by synodic factors, there are also indications that diurnal systems can be controlled by tropical factors. Thus neap-spring periods are not only related to lunar phase (synodic month), but can be related to tropical month (lunar declination) in diurnal systems. Analysis of laminae-thickness periodicities in a variety of Pennsylvanian tidal rhythmites, which include apparent examples of diurnal as well as semidiurnal tidal patterns, indicates similarities to modern tidal systems. For example, semidiurnal tidal rhythmites exhibit not only synodic periodicities but also exhibit a weaker, tropical periodicity. Conversely, within rhythmites that exhibit a diurnal pattern, it is not completely clear whether tropical or synodic periodicities are being expressed.

  1. Dissipation of Tidal Energy

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The moon's gravity imparts tremendous energy to the Earth, raising tides throughout the global oceans. What happens to all this energy? This question has been pondered by scientists for over 200 years, and has consequences ranging from the history of the moon to the mixing of the oceans. Richard Ray at NASA's Goddard Space Flight Center, Greenbelt, Md. and Gary Egbert of the College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Ore. studied six years of altimeter data from the TOPEX/Poseidon satellite to address this question. According to their report in the June 15 issue of Nature, about 1 terawatt, or 25 to 30 percent of the total tidal energy dissipation, occurs in the deep ocean. The remainder occurs in shallow seas, such as on the Patagonian Shelf. 'By measuring sea level with the TOPEX/Poseidon satellite altimeter, our knowledge of the tides in the global ocean has been remarkably improved,' said Richard Ray, a geophysicist at Goddard. The accuracies are now so high that this data can be used to map empirically the tidal energy dissipation. (Red areas, above) The deep-water tidal dissipation occurs generally near rugged bottom topography (seamounts and mid-ocean ridges). 'The observed pattern of deep-ocean dissipation is consistent with topographic scattering of tidal energy into internal motions within the water column, resulting in localized turbulence and mixing', said Gary Egbert an associate professor at OSU. One important implication of this finding concerns the possible energy sources needed to maintain the ocean's large-scale 'conveyor-belt' circulation and to mix upper ocean heat into the abyssal depths. It is thought that 2 terawatts are required for this process. The winds supply about 1 terawatt, and there has been speculation that the tides, by pumping energy into vertical water motions, supply the remainder. However, all current general circulation models of the oceans ignore the tides. 'It is possible that properly

  2. Kiowa Creek Switching Station

    SciTech Connect

    Not Available

    1990-03-01

    The Western Area Power Administration (Western) proposes to construct, operate, and maintain a new Kiowa Creek Switching Station near Orchard in Morgan County, Colorado. Kiowa Creek Switching Station would consist of a fenced area of approximately 300 by 300 feet and contain various electrical equipment typical for a switching station. As part of this new construction, approximately one mile of an existing 115-kilovolt (kV) transmission line will be removed and replaced with a double circuit overhead line. The project will also include a short (one-third mile) realignment of an existing line to permit connection with the new switching station. In accordance with the Council on Environmental Quality (CEQ) regulations for implementing the procedural provisions of the National Environmental Policy Act of 1969 (NEPA), 40 CFR Parts 1500--1508, the Department of Energy (DOE) has determined that an environmental impact statement (EIS) is not required for the proposed project. This determination is based on the information contained in this environmental assessment (EA) prepared by Western. The EA identifies and evaluates the environmental and socioeconomic effects of the proposed action, and concludes that the advance impacts on the human environment resulting from the proposed project would not be significant. 8 refs., 3 figs., 1 tab.

  3. Ship Creek bioassessment investigations

    SciTech Connect

    Cushing, C.E.; Mueller, R.P.; Murphy, M.T.

    1995-06-01

    Pacific Northwest Laboratory (PNL) was asked by Elmendorf Air Force Base (EAFB) personnel to conduct a series of collections of macroinvertebrates and sediments from Ship Creek to (1) establish baseline data on these populations for reference in evaluating possible impacts from Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) activities at two operable units, (2) compare current population indices with those found by previous investigations in Ship Creek, and (3) determine baseline levels of concentrations of any contaminants in the sediments associated with the macroinvertebrates. A specific suite of indices established by the US Environmental Protection Agency (EPA) was requested for the macroinvertebrate analyses; these follow the Rapid Bioassessment Protocol developed by Plafkin et al. (1989) and will be described. Sediment sample analyses included a Microtox bioassay and chemical analysis for contaminants of concern. These analyses included, volatile organic compounds, total gasoline and diesel hydrocarbons (EPA method 8015, CA modified), total organic carbon, and an inductive-coupled plasma/mass spectrometry (ICP/MS) metals scan. Appendix A reports on the sediment analyses. The Work Plan is attached as Appendix B.

  4. Preliminary simulated tidal flow and circulation patterns in Hillsborough Bay, Florida

    USGS Publications Warehouse

    Goodwin, Carl R.

    1980-01-01

    The effect of channel dredging and island construction on tidal flow and circulation in Hillsborough Bay, Fla., due to the Tampa Harbor Deepening Project is being investigated using a two-dimensional, finite-difference numerical model. Preliminary model results are presented as a series of maps showing tidal flood, tidal ebb, and circulation patterns in the bay for predredging and postdredging conditions. Complex circulation patterns occur near the bay mouth in an area where there is (1) a change in thalweg alinement of the bay, (2) an intersection of three major ship channels, and (3) submergent and emergent dredged material located adjacent to each of the channels. (USGS)

  5. Carbon and Nitrogen Cycling in a Shallow Coastal Tidal Basin

    NASA Astrophysics Data System (ADS)

    Hohn, S.; Voelker, C. D.; van Beusekom, J.; Schartau, M.

    2008-12-01

    The biogeochemical fluxes of carbon and nitrogen are tightly coupled via the production of biomass. The degree of this coupling is known to vary under different environmental conditions. Nitrogen limitation of phytoplankton organisms leads to increased C:N biomass ratios whereas light limitation at nutrient replete conditions causes a decrease in intracellular C:N ratios. The biogeochemical fluxes of carbon and nitrogen within and between a shallow coastal tidal basin in the danish-german Wadden Sea, the List tidal basin, and the adjacent North Sea are calculated with an ecosystem model that allows for variable C:N ratios in phytoplankton biomass. Differences in plankton C:N biomass ratios between both water boxes affect the net transport budgets of carbon and nitrogen between the North Sea and the List tidal basin and may also change the sign of the C:N ratio of biomass exchange, i.e. leading to net nitrogen export and net import of carbon into the tidal basin over an annual cycle. Benthic filterfeeding organisms consume phytoplankton biomass and release fresh nutrients to the water column. In the List tidal basin, the promoting effect on primary production due to nutrient release by benthic filterfeeders is found to outweigh the limiting effect due to grazing pressure on phytoplankton biomass.

  6. Tidal Flushing Restores the Physiological Condition of Fish Residing in Degraded Salt Marshes

    PubMed Central

    Dibble, Kimberly L.; Meyerson, Laura A.

    2012-01-01

    Roads, bridges, and dikes constructed across salt marshes can restrict tidal flow, degrade habitat quality for nekton, and facilitate invasion by non-native plants including Phragmites australis. Introduced P. australis contributes to marsh accretion and eliminates marsh surface pools thereby adversely affecting fish by reducing access to intertidal habitats essential for feeding, reproduction, and refuge. Our study assessed the condition of resident fish populations (Fundulus heteroclitus) at four tidally restricted and four tidally restored marshes in New England invaded by P. australis relative to adjacent reference salt marshes. We used physiological and morphological indicators of fish condition, including proximate body composition (% lipid, % lean dry, % water), recent daily growth rate, age class distributions, parasite prevalence, female gravidity status, length-weight regressions, and a common morphological indicator (Fulton’s K) to assess impacts to fish health. We detected a significant increase in the quantity of parasites infecting fish in tidally restricted marshes but not in those where tidal flow was restored to reduce P. australis cover. Using fish length as a covariate, we found that unparasitized, non-gravid F. heteroclitus in tidally restricted marshes had significantly reduced lipid reserves and increased lean dry (structural) mass relative to fish residing in reference marshes. Fish in tidally restored marshes were equivalent across all metrics relative to those in reference marshes indicating that habitat quality was restored via increased tidal flushing. Reference marshes adjacent to tidally restored sites contained the highest abundance of young fish (ages 0–1) while tidally restricted marshes contained the lowest. Results indicate that F. heteroclitus residing in physically and hydrologically altered marshes are at a disadvantage relative to fish in reference marshes but the effects can be reversed through ecological restoration. PMID

  7. Tidal flushing restores the physiological condition of fish residing in degraded salt marshes.

    PubMed

    Dibble, Kimberly L; Meyerson, Laura A

    2012-01-01

    Roads, bridges, and dikes constructed across salt marshes can restrict tidal flow, degrade habitat quality for nekton, and facilitate invasion by non-native plants including Phragmites australis. Introduced P. australis contributes to marsh accretion and eliminates marsh surface pools thereby adversely affecting fish by reducing access to intertidal habitats essential for feeding, reproduction, and refuge. Our study assessed the condition of resident fish populations (Fundulus heteroclitus) at four tidally restricted and four tidally restored marshes in New England invaded by P. australis relative to adjacent reference salt marshes. We used physiological and morphological indicators of fish condition, including proximate body composition (% lipid, % lean dry, % water), recent daily growth rate, age class distributions, parasite prevalence, female gravidity status, length-weight regressions, and a common morphological indicator (Fulton's K) to assess impacts to fish health. We detected a significant increase in the quantity of parasites infecting fish in tidally restricted marshes but not in those where tidal flow was restored to reduce P. australis cover. Using fish length as a covariate, we found that unparasitized, non-gravid F. heteroclitus in tidally restricted marshes had significantly reduced lipid reserves and increased lean dry (structural) mass relative to fish residing in reference marshes. Fish in tidally restored marshes were equivalent across all metrics relative to those in reference marshes indicating that habitat quality was restored via increased tidal flushing. Reference marshes adjacent to tidally restored sites contained the highest abundance of young fish (ages 0-1) while tidally restricted marshes contained the lowest. Results indicate that F. heteroclitus residing in physically and hydrologically altered marshes are at a disadvantage relative to fish in reference marshes but the effects can be reversed through ecological restoration.

  8. Suspended-sediment trapping in the tidal reach of an estuarine tributary channel

    USGS Publications Warehouse

    Downing-Kunz, Maureen; Schoellhamer, David H.

    2015-01-01

    Evidence of decreasing sediment supply to estuaries and coastal oceans worldwide illustrates the need for accurate and updated estimates. In the San Francisco Estuary (Estuary), recent research suggests a decrease in supply from its largest tributaries, implying the increasing role of smaller, local tributaries in sediment supply to this estuary. Common techniques for estimating supply from tributaries are based on gages located above head of tide, which do not account for trapping processes within the tidal reach. We investigated the effect of a tidal reach on suspended-sediment discharge for Corte Madera Creek, a small tributary of the Estuary. Discharge of water (Q) and suspended-sediment (SSD) were observed for 3 years at two locations along the creek: upstream of tidal influence and at the mouth. Comparison of upstream and mouth gages showed nearly 50 % trapping of upstream SSD input within the tidal reach over this period. At the storm time scale, suspended-sediment trapping efficiency varied greatly (range −31 to 93 %); storms were classified as low- or high-yield based on upstream SSD. As upstream peak Q increased, high-yield storms exhibited significantly decreased trapping. Tidal conditions at the mouth—ebb duration and peak ebb velocity—during storms had a minor effect on sediment trapping, suggesting fluvial processes dominate. Comparison of characteristic fluvial and tidal discharges at the storm time scale demonstrated longitudinal differences in the regulating process for SSD. These results suggest that SSD from gages situated above head of tide overestimate sediment supply to the open waters beyond tributary mouths and thus trapping processes within the tidal reach should be considered.

  9. 75 FR 40034 - Northeastern Tributary Reservoirs Land Management Plan, Beaver Creek, Clear Creek, Boone, Fort...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-13

    ... Northeastern Tributary Reservoirs Land Management Plan, Beaver Creek, Clear Creek, Boone, Fort Patrick Henry... Land Management Plan (NTRLMP) for the 4,933 acres of TVA-managed public land on Beaver Creek, Clear... the Watauga River. Beaver Creek and Clear Creek reservoirs are on tributaries within the South...

  10. Water table fluctuations near an incised stream, Walnut Creek, Iowa

    USGS Publications Warehouse

    Schilling, K.E.; Zhang, Y.-K.; Drobney, P.

    2004-01-01

    Incised channels are common features in many agricultural watersheds, but the effects of channel incision on riparian water table conditions have been poorly documented. In this study, we evaluate the water table fluctuations in the floodplain near an incised stream (Walnut Creek, Iowa) and investigate the roles that channel incision and variable recharge play in modifying the water table configuration in the floodplain. Groundwater flows from higher landscape positions towards Walnut Creek under hydraulic gradients that were steepest near the upland/floodplain contact and in the near-stream riparian zone. Annually, water table fluctuations on the floodplain were greatest in wells located 30 m from the creek, midway between the creek and upland. Water levels monitored continuously during a runoff event indicated that bank storage was confined to a narrow zone adjacent to the channel. A steady-state, one-dimensional analytical model was developed to describe the shape of the water table surface near an incised stream and evaluate how variable groundwater recharge and channel bed lowering has affected the shape of the water table surface. Results from this study have implications for managing the riparian buffers of incised streams with successful establishment dependent upon matching buffer vegetation to riparian water table conditions. ?? 2003 Elsevier B.V. All rights reserved.

  11. Conservation of tidal marshes

    SciTech Connect

    Daiber, F.C.

    1986-01-01

    This book is the first attempt to examine collectively the various uses and the consequences of marsh conservation efforts. Author Franklin Daiber emphasizes tidal marsh conservation from a holistic perspective rather than from the perspective of a single purpose or special economic interest. He addresses a topic receiving increasing attention, namely the concept of open marsh management as a means of controlling mosquito production without harmful effects on other marsh organisms. Topics considered include: water management; dikes, impoundments, ponds and ditches; reclaimed land and impoundments; ditching and ponding for mosquito control; sewage disposal and waste treatment; dredge material for wetland restoration; insecticides; oil pollution; and petroleum hydrocarbon interactions.

  12. Tidal heating of Ariel

    NASA Astrophysics Data System (ADS)

    Tittemore, William C.

    1990-09-01

    During evolution through the 4:1 commensurability early in the history of the Uranian system, over 3.8 billion years ago, tidal heating may have raised the internal temperature of Ariel by up to about 20 K; the internal temperature of Ariel may already have been high in virtue of both accretional and radiogenic heating. The additional increase in Ariel's temperature could then have triggered the geological activity that led to a late resurfacing, by decreasing lithospheric thickness and exacerbating thermal stresses on it to the point where observed cracks and faults formed.

  13. Tidal Energy Research

    SciTech Connect

    Stelzenmuller, Nickolas; Aliseda, Alberto; Palodichuk, Michael; Polagye, Brian; Thomson, James; Chime, Arshiya; Malte, Philip

    2014-03-31

    This technical report contains results on the following topics: 1) Testing and analysis of sub-scale hydro-kinetic turbines in a flume, including the design and fabrication of the instrumented turbines. 2) Field measurements and analysis of the tidal energy resource and at a site in northern Puget Sound, that is being examined for turbine installation. 3) Conceptual design and performance analysis of hydro-kinetic turbines operating at high blockage ratio, for use for power generation and flow control in open channel flows.

  14. Tidal heating of Ariel

    NASA Technical Reports Server (NTRS)

    Tittemore, William C.

    1990-01-01

    During evolution through the 4:1 commensurability early in the history of the Uranian system, over 3.8 billion years ago, tidal heating may have raised the internal temperature of Ariel by up to about 20 K; the internal temperature of Ariel may already have been high in virtue of both accretional and radiogenic heating. The additional increase in Ariel's temperature could then have triggered the geological activity that led to a late resurfacing, by decreasing lithospheric thickness and exacerbating thermal stresses on it to the point where observed cracks and faults formed.

  15. Nekton community structure varies in response to coastal urbanization near mangrove tidal tributaries

    USGS Publications Warehouse

    Krebs, Justin M.; McIvor, Carole C.; Bell, Susan S.

    2014-01-01

    To assess the potential influence of coastal development on estuarine-habitat quality, we characterized land use and the intensity of land development surrounding small tidal tributaries in Tampa Bay. Based on this characterization, we classified tributaries as undeveloped, industrial, urban, or man-made (i.e., mosquito-control ditches). Over one third (37 %) of the tributaries have been heavily developed based on landscape development intensity (LDI) index values >5.0, while fewer than one third (28 %) remain relatively undeveloped (LDI < 3.0). We then examined the nekton community from 11 tributaries in watersheds representing the four defined land-use classes. Whereas mean nekton density was independent of land use, species richness and nekton-community structure were significantly different between urban and non-urban (i.e., undeveloped, industrial, man-made) tributaries. In urban creeks, the community was species-poor and dominated by high densities of poeciliid fishes, Poecilia latipinna and Gambusia holbrooki, while typically dominant estuarine taxa including Menidia spp., Fundulus grandis, and Adinia xenica were in low abundance and palaemonid grass shrimp were nearly absent. Densities of economically important taxa in urban creeks were only half that observed in five of the six undeveloped or industrial creeks, but were similar to those observed in mosquito ditches suggesting that habitat quality in urban and mosquito-ditch tributaries is suboptimal compared to undeveloped tidal creeks. Furthermore, five of nine common taxa were rarely collected in urban creeks. Our results suggest that urban development in coastal areas has the potential to alter the quality of habitat for nekton in small tidal tributaries as reflected by variation in the nekton community.

  16. GEE CREEK WILDERNESS, TENNESSEE.

    USGS Publications Warehouse

    Epstein, Jack B.; Gazdik, Gertrude C.

    1984-01-01

    On the basis of geologic, geochemical, and mine and prospect surveys, it was determined that the Gee Creek Wilderness, Tennessee has little promise for the occurrence of mineral resources. Iron ore was formerly mined, but the deposits are small, have a high phosphorous content, and are inaccessible. Shale, suitable for brick or lightweight aggregate, and sandstone, which could be utilized for crushed stone or sand, are found in the area, but are also found in areas closer to potential markets. The geologic setting precludes the presence of oil and gas resources in the surface rocks, but the possibility of finding natural gas at depth below the rocks exposed in the area cannot be discounted. Geophysical exploration would be necessary to define the local structure in rocks at depth to properly evaluate the potential of the area for gas.

  17. PINEY CREEK WILDERNESS, MISSOURI.

    USGS Publications Warehouse

    Pratt, Walden P.; Ellis, Clarence

    1984-01-01

    The Piney Creek Wilderness in southwest Missouri was investigated by geologic, geochemical, and mineral-occurrence surveys. These is no evidence of metallic mineral deposits in the rock units exposed at the surface in the wilderness, but the entire area has a probable potential for significant zinc-lead deposits at depths of several hundred feet. A probable potential also exists for a small to moderate-sized iron ore deposit at a depth of at least 2100 ft along the northwest side of the wilderness. Evaluation of these potentials would require deep drilling, and in the case of the possible iron ore deposit, a detailed magnetic survey. No energy resource potential was identified within this area.

  18. Coyote Creek Trash Reduction Project: Clean Creeks, Healthy Communities

    EPA Pesticide Factsheets

    Information about the SFBWQP Coyote Creek Trash Reduction Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  19. Tidal Power Exploitation in Korea

    NASA Astrophysics Data System (ADS)

    Choi, Byung Ho; Kim, Kyeong Ok; Choi, Jae Cheon

    The highest tides in South Korea are found along the northwest coast between latitudes 36-38 degrees and the number of possible sites for tidal range power barrages to create tidal basins is great due to irregular coastlines with numerous bays. At present Lake Sihwa tidal power plant is completed. The plant is consisted of 10 bulb type turbines with 8 sluice gates. The installed capacity of turbines and generators is 254MW and annual energy output expected is about 552.7 GWh taking flood flow generation scheme. Three other TPP projects are being progressed at Garolim Bay (20 turbines with 25.4MW capacity), Kangwha (28 turbines with 25.4MW capacity), Incheon (44 or 48 turbines with 30 MW capacity) and project features will be outlined here. The introduction of tidal barrages into four major TPP projects along the Kyeonggi bay will render wide range of potential impacts. Preliminary attempts were performed to quantify these impacts using 2 D hydrodynamic model demonstrating the changes in tidal amplitude and phase under mean tidal condition, associated changes in residual circulation (indicator for SPM and pollutant dispersion), bottom stress (indicator for bedload movement), and tidal front (positional indicator for bio-productivity) in both shelf scale and local context. Tidal regime modeling system for ocean tides in the seas bordering the Korean Peninsula is designed to cover an area that is broad in scope and size, yet provide a high degree of resolution in strong tidal current region including off southwestern tip of the Peninsula (Uldolmok , Jangjuk, Wando-Hoenggan), Daebang Sudo (Channel) and Kyeonggi Bay. With this simulation system, real tidal time simulation of extended springneap cycles was performed to estimate spatial distribution of tidal current power potentials in terms of power density, energy density and then extrapolated annual energy density.

  20. TIDAL AND TIDALLY AVERAGED CIRCULATION CHARACTERISTICS OF SUISUN BAY, CALIFORNIA.

    USGS Publications Warehouse

    Smith, Lawrence H.; Cheng, Ralph T.

    1987-01-01

    Availability of extensive field data permitted realistic calibration and validation of a hydrodynamic model of tidal circulation and salt transport for Suisun Bay, California. Suisun Bay is a partially mixed embayment of northern San Francisco Bay located just seaward of the Sacramento-San Joaquin Delta. The model employs a variant of an alternating direction implicit finite-difference method to solve the hydrodynamic equations and an Eulerian-Lagrangian method to solve the salt transport equation. An upwind formulation of the advective acceleration terms of the momentum equations was employed to avoid oscillations in the tidally averaged velocity field produced by central spatial differencing of these terms. Simulation results of tidal circulation and salt transport demonstrate that tides and the complex bathymetry determine the patterns of tidal velocities and that net changes in the salinity distribution over a few tidal cycles are small despite large changes during each cycle.

  1. Tidal Pools--Miniature Oceans

    ERIC Educational Resources Information Center

    Plake, Linda Perry

    1977-01-01

    A comprehensive discussion of the biological activity in tidal pools is provided. The importance of environmental factors such as oxygen supply, temperature, salinity, and light is detailed. Plants and animals that might be found in a tidal pool are identified and described. (BT)

  2. Water quality monitoring report for the White Oak Creek Embayment

    SciTech Connect

    Ford, C.J. ); Wefer, M.T. )

    1993-01-01

    Water quality monitoring activities that focused on the detection of resuspended sediments in the Clinch River were conducted in conjunction with the White Oak Creek Embayment (WOCE) time-critical Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to construct a sediment-retention structure at the mouth of White Oak Creek (WOC). Samples were collected by use of a 24-h composite sampler and through real-time water grab sampling of sediment plumes generated by the construction activities. Sampling stations were established both at the WOC mouth, immediately adjacent to the construction site, and at K-1513, the Oak Ridge K-25 Site drinking water intake approximately 9.6 km downstream in the Clinch River. Results are described.

  3. DTP: a Tidal Power Revolution

    NASA Astrophysics Data System (ADS)

    Steijn, Robbert; Hulsbergen, Kees; van Banning, Gijs

    2013-04-01

    Tidal power can significantly contribute to the global mix of sustainable energy resources. It is climate-independent, fully predictable, and if designed properly it is environmentally friendly and socio-economically feasible. The two traditional methods of exploiting tidal power are Tidal Barrage and Tidal Stream. This study deals with an alternative Third Method, named Dynamic Tidal Power (DTP), which contrary to the other methods, utilises the oscillating character of tides, or more precisely: the acceleration inherent to unsteady flow. DTP uses a long dam (order of tens of km's), attached and perpendicular to a coast with shore-parallel tidal currents, to generate a local hydraulic head. This time-varying head is used to generate electricity in a more or less standard way with turbines and generators placed in (many) dam openings. For a first impression only: typical installed power for one DTP is more than 10 GW with electricity output > 2.1010 kWh/y and construction costs of ca. 1 EUR/W. The physical mechanism behind the creation of the head has been described by Hulsbergen e.a., (2012). Following a heuristic approach based on analytical work done by Kolkman (unpubl.), and output from numerical tidal models, Hulsbergen (2012) concluded that the maximum head (near the coast), is: hmax = 6,8*?*D*Vmax/(g*T), with Vmax the maximum alongshore flow velocity during the tidal cycle, T the tidal period and D the length of dam. Such simple relationship was also found by Mei (2012) who made a rigorous analysis of a process-based model. After a thorough reflection on DTP, this study will first check the above formula for hmax , by comparing its predictions with the output from various numerical tidal models. Any differences will be analysed in the study through an evaluation of the dominant physical processes and the schematisations inherent to both the analytical and the numerical models. The study will also address the effect of the openings in the dam, as well as the

  4. 1. DEADWOOD CREEK BRIDGE FACING SOUTHWEST. MOUNT RAINIER AND EMMONS ...

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

    1. DEADWOOD CREEK BRIDGE FACING SOUTHWEST. MOUNT RAINIER AND EMMONS GLACIER VISIBLE IN BACKGROUND. - Deadwood Creek Bridge, Spanning Deadwood Creek on Mather Memorial Parkway, Longmire, Pierce County, WA

  5. Alameda Creeks Healthy Watersheds Project

    EPA Pesticide Factsheets

    Information about the SFBWQP Alameda Creeks Healthy Watersheds Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resour

  6. 77 FR 13592 - AER NY-Gen, LLC; Eagle Creek Hydro Power, LLC, Eagle Creek Water Resources, LLC, Eagle Creek Land...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-07

    ... Energy Regulatory Commission AER NY-Gen, LLC; Eagle Creek Hydro Power, LLC, Eagle Creek Water Resources... Power, LLC, Eagle Creek Water Resources, LLC, and Eagle Creek Land Resources, LLC (transferees) filed an...) 805-1469. Transferees: Mr. Bernard H. Cherry, Eagle Creek Hydro Power, LLC, Eagle Creek...

  7. A coupled geomorphic and ecological model of tidal marsh evolution.

    PubMed

    Kirwan, Matthew L; Murray, A Brad

    2007-04-10

    The evolution of tidal marsh platforms and interwoven channel networks cannot be addressed without treating the two-way interactions that link biological and physical processes. We have developed a 3D model of tidal marsh accretion and channel network development that couples physical sediment transport processes with vegetation biomass productivity. Tidal flow tends to cause erosion, whereas vegetation biomass, a function of bed surface depth below high tide, influences the rate of sediment deposition and slope-driven transport processes such as creek bank slumping. With a steady, moderate rise in sea level, the model builds a marsh platform and channel network with accretion rates everywhere equal to the rate of sea-level rise, meaning water depths and biological productivity remain temporally constant. An increase in the rate of sea-level rise, or a reduction in sediment supply, causes marsh-surface depths, biomass productivity, and deposition rates to increase while simultaneously causing the channel network to expand. Vegetation on the marsh platform can promote a metastable equilibrium where the platform maintains elevation relative to a rapidly rising sea level, although disturbance to vegetation could cause irreversible loss of marsh habitat.

  8. A coupled geomorphic and ecological model of tidal marsh evolution

    PubMed Central

    Kirwan, Matthew L.; Murray, A. Brad

    2007-01-01

    The evolution of tidal marsh platforms and interwoven channel networks cannot be addressed without treating the two-way interactions that link biological and physical processes. We have developed a 3D model of tidal marsh accretion and channel network development that couples physical sediment transport processes with vegetation biomass productivity. Tidal flow tends to cause erosion, whereas vegetation biomass, a function of bed surface depth below high tide, influences the rate of sediment deposition and slope-driven transport processes such as creek bank slumping. With a steady, moderate rise in sea level, the model builds a marsh platform and channel network with accretion rates everywhere equal to the rate of sea-level rise, meaning water depths and biological productivity remain temporally constant. An increase in the rate of sea-level rise, or a reduction in sediment supply, causes marsh-surface depths, biomass productivity, and deposition rates to increase while simultaneously causing the channel network to expand. Vegetation on the marsh platform can promote a metastable equilibrium where the platform maintains elevation relative to a rapidly rising sea level, although disturbance to vegetation could cause irreversible loss of marsh habitat. PMID:17389384

  9. Tidal Venuses: Triggering a Climate Catastrophe via Tidal Heating

    PubMed Central

    Mullins, Kristina; Goldblatt, Colin; Meadows, Victoria S.; Kasting, James F.; Heller, René

    2013-01-01

    Abstract Traditionally, stellar radiation has been the only heat source considered capable of determining global climate on long timescales. Here, we show that terrestrial exoplanets orbiting low-mass stars may be tidally heated at high-enough levels to induce a runaway greenhouse for a long-enough duration for all the hydrogen to escape. Without hydrogen, the planet no longer has water and cannot support life. We call these planets “Tidal Venuses” and the phenomenon a “tidal greenhouse.” Tidal effects also circularize the orbit, which decreases tidal heating. Hence, some planets may form with large eccentricity, with its accompanying large tidal heating, and lose their water, but eventually settle into nearly circular orbits (i.e., with negligible tidal heating) in the habitable zone (HZ). However, these planets are not habitable, as past tidal heating desiccated them, and hence should not be ranked highly for detailed follow-up observations aimed at detecting biosignatures. We simulated the evolution of hypothetical planetary systems in a quasi-continuous parameter distribution and found that we could constrain the history of the system by statistical arguments. Planets orbiting stars with masses<0.3 MSun may be in danger of desiccation via tidal heating. We have applied these concepts to Gl 667C c, a ∼4.5 MEarth planet orbiting a 0.3 MSun star at 0.12 AU. We found that it probably did not lose its water via tidal heating, as orbital stability is unlikely for the high eccentricities required for the tidal greenhouse. As the inner edge of the HZ is defined by the onset of a runaway or moist greenhouse powered by radiation, our results represent a fundamental revision to the HZ for noncircular orbits. In the appendices we review (a) the moist and runaway greenhouses, (b) hydrogen escape, (c) stellar mass-radius and mass-luminosity relations, (d) terrestrial planet mass-radius relations, and (e) linear tidal theories. Key Words: Extrasolar terrestrial

  10. Galileo's tidal theory.

    PubMed

    Naylor, Ron

    2007-03-01

    The aim of Galileo's tidal theory was to show that the tides were produced entirely by the earth's motion and thereby to demonstrate the physical truth of Copernicanism. However, in the Dialogue Concerning the Two Chief World Systems Galileo did not explain some of the most significant aspects of the theory completely. As a consequence, the way the theory works has long been disputed. Though there exist a number of interpretations in the literature, the most widely accepted are based on ideas that are not explicitly articulated by Galileo in the Dialogue. This essay attempts to understand the way the theory functions in terms of Galilean physics. It is an interpretation of the theory based solely on Galileo's arguments--and one that reveals it to have had some unrecognized consequences. This interpretation indicates that Galileo's theory would not have worked in the manner he described in the Dialogue.

  11. Tidal Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Houck, James R.; Higdon, Sarah

    2004-09-01

    Tidal Dwarf Galaxies (TDG's) are formed from material stripped from the disks of spiral galaxies, which are undergoing tidal interactions with a nearby companion. These galaxies provide important clues to our understanding of galaxy formation, evolution and cosmic recycling. Using the IRS we will measure the star formation activity in 6 TDG candidates. We will measure the ionization state ( [NeII] 12.8 um, [NeIII] 15.6 um and [NeV] 14.3um and [OIV] 25.9 um), the density in the ionized gas ([SIII] 18.7um/33.5um), the PAH fractions at 5.5-9um and 11-12.2um and possibly (optimistic here!) molecular hydrogen emission form PDRs at H2 (S0) 28um and H2 (S1) at 17um. In addition to the IRS observations we will map both the Guitar and Stephan's Quintet with IRAC. This will enable us to compare the PAH fraction in the dwarf galaxy to that of its parent. Similarly we will compare our observation of the proposed TDG at the southern tip of NGC 4038 with the GT observations of the central region of the Antennae. This program compliments two existing GT programmes: 1) the high-Z program - these observations enable us to observe in fine detail the nearby/present day analogs of galaxy formation in the early universe. 2) Blue Compact Dwarf programme - On first inpsection BCD's and TDG's appear the same: BCDs are similar in size to TDG's, but TDG's may not have a large dark matter halo component (affecting the long term stability of an object) and BCD's typically have a much lower metallicity. We will be able to compare the star formation activity in terms of the ionization state and PAH fraction in the two galaxy types.

  12. Five years (2000-2004) of post-reconstruction monitoring of freshwater tidal wetlands in the urban Anacostia River, Washington, D.C. USA

    USGS Publications Warehouse

    Hammerschlag, D.; Krafft, C.

    2006-01-01

    The Anacostia River in Washington, D.C. USA consisted of over 809 hectares (2000 acres) of freshwater tidal wetlands before mandatory dredging removed most of them in the first half of the 20th century. Much of this13 kilometer (8 mile) reach was transferred to the National Park Service (NPS). Planning processes in the 1980's envisioned a restoration (rejuvenation) of some wetlands for habitat, aesthetics, water quality and interpretative purposes. Subsequently, the U.S. Army Corps of Engineers in a cost share agreement with the District of Columbia reconstructed wetlands on NPS lands at Kenilworth - 12.5 hectares (1993), Kingman 27 hectares (2000), a Fringe Marsh - 6.5 hectares (2003) and is currently constructing Heritage Marsh - 2.5 hectares (2005/2006). The USGS Patuxent Wildlife Research Center in conjunction with the University of Maryland Biological Engineering Department was contracted to conduct post-reconstruction monitoring (2000-2004) to document the relative success and progress of the Kingman Marsh reconstruction primarily based on vegetative response but also in conjunction with seed bank and soil characteristics. Results from Kingman were compared to Kenilworth Marsh (reconstructed 7 years prior), Dueling Creek Marsh (last best remaining freshwater tidal wetland bench in the urbanized Anacostia watershed) and Patuxent River Marsh (in a more natural adjacent watershed). Vegetation establishment was initially strong at Kingman, but declined rapidly as measured by cover, richness, diversity, etc. under grazing pressure from resident Canada geese and associated reduction in sediment levels. This decline did not occur at the other wetlands. The decline occurred despite a substantial seed bank that was sustained primarily be water born propagules. Soil development, as true for most juvenile wetlands, was slow with almost no organic matter accumulation. By 2004 only two of 7 planted species remained (mostly Peltandra virginica) at Kingman which did provide

  13. Water Conservation Study for Manastash Creek Water Users, Kittias County, Washington, Final Report 2002.

    SciTech Connect

    Montgomery Watson Harza

    2002-12-31

    Manastash Creek is tributary of the Yakima River and is located southwest and across the Yakima River from the City of Ellensburg. The creek drains mountainous terrain that ranges in elevation from 2,000 feet to over 5,500 feet and is primarily snowmelt fed, with largest flows occurring in spring and early summer. The creek flows through a narrow canyon until reaching a large, open plain that slopes gently toward the Yakima River and enters the main stem of the Yakima River at river mile 154.5. This area, formed by the alluvial fan of the Creek as it leaves the canyon, is the subject of this study. The area is presently dominated by irrigated agriculture, but development pressures are evident as Ellensburg grows and develops as an urban center. Since the mid to late nineteenth century when irrigated agriculture was established in a significant manner in the Yakima River Basin, Manastash Creek has been used to supply irrigation water for farming in the area. Adjudicated water rights dating back to 1871 for 4,465 acres adjacent to Manastash Creek allow appropriation of up to 26,273 acre-feet of creek water for agricultural irrigation and stock water. The diversion of water from Manastash Creek for irrigation has created two main problems for fisheries. They are low flows or dewatered reaches of Manastash Creek and fish passage barriers at the irrigation diversion dams. The primary goal of this study, as expressed by Yakama Nation and BPA, is to reestablish safe access in tributaries of the Yakima River by removing physical barriers and unscreened diversions and by adding instream flow where needed for fisheries. The goal expressed by irrigators who would be affected by these projects is to support sustainable and profitable agricultural use of land that currently uses Manastash Creek water for irrigation. This study provides preliminary costs and recommendations for a range of alternative projects that will partially or fully meet the goal of establishing safe access

  14. Geo-morphological changes of the Wanpingkou tidal system arising from the building of a sailing boat station in Rizhao of China.

    PubMed

    Bian, Shuhua; Zhang, Yuanzhi; Feng, Aiping; Chiu, Long; Wu, Sangyun; Hu, Zejian

    2008-03-01

    This paper examines a small tidal system in Wanpingkou, Rizhao of China. The tidal system was originally maintained by a balance of the natural interaction between tidal currents and waves. But this tidal system was diminishing by reclamation processes since the 1980s, especially in 2003 when a sailing boat station was built in the study area. To investigate the stability and development mechanism of the tidal system, its feasibility was evaluated before the sailing boat station was built. The erosion and deposition in and out of the tidal system was analyzed, forecasted and compared with the data from field monitoring. The results show that the tidal system would remain relatively stable, although its adjacent shoreline might change somewhat after the newly built sailing boat station. This change would also affect the coastal water and wetland environment in the study area. Further field monitoring in the area is still necessary.

  15. Tidal dunes versus tidal bars: The sedimentological and architectural characteristics of compound dunes in a tidal seaway, the lower Baronia Sandstone (Lower Eocene), Ager Basin, Spain

    NASA Astrophysics Data System (ADS)

    Olariu, Cornel; Steel, Ronald J.; Dalrymple, Robert W.; Gingras, Murray K.

    2012-11-01

    The Lower Eocene Baronia Formation in the Ager Basin is interpreted as a series of stacked compound dunes confined within a tectonically generated embayment or tidal seaway. This differs from the previous interpretation of lower Baronia sand bodies as tidal bars in the front of a delta. The key architectural building block of the succession, the deposit of a single compound dune, forms a 1-3 m-thick, upward coarsening succession that begins with highly bioturbated, muddy, very fine to fine grained sandstone that contains an open-marine Cruziana ichnofacies. This is overlain gradationally by ripple-laminated sandstone that is commonly bioturbated and contains mud drapes. The succession is capped by fine- to coarse-grained sandstones that contain both planar and trough cross-strata with unidirectional or bi-directional paleocurrent directions and occasional thin mud drapes on the foresets. The base of a compound dune is gradational where it migrated over muddy sandstone deposited between adjacent dunes, but is sharp and erosional where it migrated over the stoss side of a previous compound dune. The cross strata that formed by simple superimposed dunes dip in the same direction as the inclined master bedding planes within the compound dune, forming a forward-accretion architecture. This configuration is the fundamental reason why these sandbodies are interpreted as compound tidal dunes rather than as tidal bars, which, in contrast, generate lateral-accretion architecture. In the Baronia, fields of compound dunes generated tabular sandbodies 100s to 1000s of meters in extent parallel to the paleocurrent direction and up to 6 m thick that alternate vertically with highly bioturbated muddy sandstones (up to 10 m thick) that represent the low-energy fringes of the dune fields or periods of high sea level when current speeds decreased. Each cross-stratified sandstone sheet (compound-dune complexes) contains overlapping lenticular "shingles" formed by individual compound

  16. Tidal circulation alteration for salt marsh mosquito control

    NASA Astrophysics Data System (ADS)

    Resh, Vincent H.; Balling, Steven S.

    1983-01-01

    Mosquito control ditches designed to increase tidal circulation are widely used as a physical control alternative to insecticidal applications The impact of such ditching on Pacific Coast marshlands was largely unknown before this five-year study of impact in two types of San Francisco Bay salt marshes, a Salicornia virginica (pickleweed) monoculure and a mixed vegetation marsh Results of our studies suggest that ditches cause less environmental disturbance than insecticidal applications The article describes the following environmental consequences of ditching for mosquito control: increased tidal flushing of soils occurs adjacent to ditches compared with that in the open marsh, thereby reducing ground water and soil surface salinities and water table height; primary productivity of S. virginica, as determined by both the harvest method and infrared photographic analysis, is higher directly adjacent to ditches than in the open marsh, distribution of selected arthropod populations is similar at ditches and natural channels, although arthropod community response differs seasonally; aquatic invertebrate biomass is similar within ditched and natural ponds, but diversity is lower in ditched habitats, ditching increases fish diversity and density by improving fish access from tidal channels; ditches provide additional salt marsh song sparrow habitat, although ditches are less preferred than natural channels or sloughs. Management criteria can be used to design ditches that provide effective mosquito control and reduced environmental impact

  17. Big Bayou Creek and Little Bayou Creek Watershed Monitoring Program

    SciTech Connect

    Kszos, L.A.; Peterson, M.J.; Ryon; Smith, J.G.

    1999-03-01

    Biological monitoring of Little Bayou and Big Bayou creeks, which border the Paducah Site, has been conducted since 1987. Biological monitoring was conducted by University of Kentucky from 1987 to 1991 and by staff of the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) from 1991 through March 1999. In March 1998, renewed Kentucky Pollutant Discharge Elimination System (KPDES) permits were issued to the US Department of Energy (DOE) and US Enrichment Corporation. The renewed DOE permit requires that a watershed monitoring program be developed for the Paducah Site within 90 days of the effective date of the renewed permit. This plan outlines the sampling and analysis that will be conducted for the watershed monitoring program. The objectives of the watershed monitoring are to (1) determine whether discharges from the Paducah Site and the Solid Waste Management Units (SWMUs) associated with the Paducah Site are adversely affecting instream fauna, (2) assess the ecological health of Little Bayou and Big Bayou creeks, (3) assess the degree to which abatement actions ecologically benefit Big Bayou Creek and Little Bayou Creek, (4) provide guidance for remediation, (5) provide an evaluation of changes in potential human health concerns, and (6) provide data which could be used to assess the impact of inadvertent spills or fish kill. According to the cleanup will result in these watersheds [Big Bayou and Little Bayou creeks] achieving compliance with the applicable water quality criteria.

  18. EPA Proposes to Add Dutchess County Creek, N.Y. to the Federal Superfund List, Sediment Contaminated with Mercury, Polycyclic Aromatic Hydrocarbons

    EPA Pesticide Factsheets

    (New York, N.Y.) The U.S. Environmental Protection Agency today proposed adding the Wappinger Creek in Dutchess County, N.Y. to its Superfund National Priorities List of the country's most hazardous waste sites. Sediment within the two mile long tidal port

  19. Recent progress in tidal modeling

    NASA Technical Reports Server (NTRS)

    Vial, F.; Forbes, J. M.

    1989-01-01

    Recent contributions to tidal theory during the last five years are reviewed. Specific areas where recent progress has occurred include: the action of mean wind and dissipation on tides, interactions of other waves with tides, the use of TGCM in tidal studies. Furthermore, attention is put on the nonlinear interaction between semidiurnal and diurnal tides. Finally, more realistic thermal excitation and background wind and temperature models have been developed in the past few years. This has led to new month-to-month numerical simulations of the semidiurnal tide. Some results using these models are presented and compared with ATMAP tidal climatologies.

  20. Development and morphology of point bars in tidal rivers, observations from Sapelo and the Altamaha River, GA

    NASA Astrophysics Data System (ADS)

    Hughes, Z. J.; Georgiou, I. Y.; Howes, N. C.; Weathers, D.; Kulp, M.; FitzGerald, D. M.

    2012-12-01

    Many tidal creeks and rivers exhibit bars associated with meander bends. However, hydrodynamic and morphodynamic studies of these point-bars are scarce, compared with the extensive studies of fluvial-point bars. The few studies that have been undertaken suggest significant differences between tidal bars and their fluvial counterparts, including low rates of channel migration, a unique planform morphology resulting from the bi-directional tidal flows and tidal asymmetry, and variation in stage-discharge behavior. We examine point-bars in two closely situated estuaries on the Georgia coast: the Altamaha and Sapelo. Both sites are meso-tidal; however, the Altamaha has significant fluvial input, whereas the Sapelo creeks have minimal fluvial input. Both sites exhibit mixed sand-mud point bars of various sizes. However, sites dominated by fluvial processes are coarser-grained and contain a higher percentage of sand. Velocity measurements from vessel-mounted and moored acoustic Doppler current profilers record the separation of flood and ebb flows to either side of the tidal bars, which results in a residual circulation over their surface. Large bedforms with opposing migration directions are observed on either side of the bar, suggesting that each side of the channel experiences a separate sediment transport regime. Shallow seismic data at two resolutions (Boomer and Chirp) indicate that the internal architecture of the tidal bars consists of lateral accretion surfaces with multi-directional strike orientations and dips, suggesting a more complex pattern of growth and development. We compare and contrast the hydrodynamics and the resulting morphologies of the bars and identify differences between fluvially-influenced and purely tidal environments. This data set also allows us to examine the hypothesis that these forms are scale invariant by examining a wide range of bars in both large and small channels.

  1. Spatial variability in denitrification rates in an Oregon tidal salt marsh

    EPA Science Inventory

    Modeling denitrification (DeN) is particularly challenging in tidal systems, which play a vital role in buffering adjacent coastal waters from nitrogen inputs. These systems are hydrologically and biogeochemically complex, varying on fine temporal and spatial scales. As part of a...

  2. Limited Influence of Urban Stormwater Runoff on Salt Marsh Platform and Marsh Creek Oxygen Dynamics in Coastal Georgia

    NASA Astrophysics Data System (ADS)

    Savidge, William B.; Brink, Jonathan; Blanton, Jackson O.

    2016-12-01

    Oxygen concentrations and oxygen utilization rates were monitored continuously for 23 months on marsh platforms and in small tidal creeks at two sites in coastal Georgia, USA, that receive urban stormwater runoff via an extensive network of drainage canals. These data were compared to nearby control sites that receive no significant surface runoff. Overall, rainfall and runoff per se were not associated with differences in the oxygen dynamics among the different locations. Because of the large tidal range and long tidal excursions in coastal Georgia, localized inputs of stormwater runoff are rapidly mixed with large volumes of ambient water. Oxygen concentrations in tidal creeks and on flooded marsh platforms were driven primarily by balances of respiration and photosynthesis in the surrounding regional network of marshes and open estuarine waters. Local respiration, while measurable, was of relatively minor importance in determining oxygen concentrations in tidal floodwaters. Water residence time on the marshes could explain differences in oxygen concentration between the runoff-influenced and control sites.

  3. Enceladus' tidal dissipation revisited

    NASA Astrophysics Data System (ADS)

    Tobie, Gabriel; Behounkova, Marie; Choblet, Gael; Cadek, Ondrej; Soucek, Ondrej

    2016-10-01

    A series of chemical and physical evidence indicates that the intense activity at Enceladus' South Pole is related to a subsurface salty water reservoir underneath the tectonically active ice shell. The detection of a significant libration implies that this water reservoir is global and that the average ice shell thickness is about 20-25km (Thomas et al. 2016). The interpretation of gravity and topography data further predicts large variations in ice shell thickness, resulting in a shell potentially thinner than 5 km in the South Polar Terrain (SPT) (Cadek et al. 2016). Such an ice shell structure requires a very strong heat source in the interior, with a focusing mechanism at the SPT. Thermal diffusion through the ice shell implies that at least 25-30 GW is lost into space by passive diffusion, implying a very efficient dissipation mechanism in Enceladus' interior to maintain such an ocean/ice configuration thermally stable.In order to determine in which conditions such a large dissipation power may be generated, we model the tidal response of Enceladus including variable ice shell thickness. For the rock core, we consider a wide range of rheological parameters representative of water-saturated porous rock materials. We demonstrate that the thinning toward the South Pole leads to a strong increase in heat production in the ice shell, with a optimal thickness obtained between 1.5 and 3 km, depending on the assumed ice viscosity. Our results imply that the heat production in the ice shell within the SPT may be sufficient to counterbalance the heat loss by diffusion and to power eruption activity. However, outside the SPT, a strong dissipation in the porous core is required to counterbalance the diffusive heat loss. We show that about 20 GW can be generated in the core, for an effective viscosity of 1012 Pa.s, which is comparable to the effective viscosity estimated in water-saturated glacial tills on Earth. We will discuss the implications of this revisited tidal

  4. Tidal disruption of inviscid planetesimals

    NASA Technical Reports Server (NTRS)

    Boss, A. P.; Cameron, A. G. W.; Benz, W.

    1991-01-01

    In view of previous efforts' demonstration that strongly dissipative planetesimals are immune to tidal disruption, an examination is presently conducted of the complementary case of inviscid planetesimals arising from collisions that are sufficiently energetic to entirely melt the resulting planetesimal and debris. The tidal disruption is numerically simulated by means of the smoothed particle hydrodynamics (SPH) code of Cameron and Benz (1991), concentrating on the tidal disruption of 0.01 earth-mass planetesimals passing by the earth with variations in the impact parameter at perigee and velocity at infinity. The SPH models show that tidal forces during a close encounter can efficiently convert orbital angular momentum into spin angular momentum, thereby initiating equatorial mass-shedding to inviscid planetesimals that have been spun up beyond the limit of rotational stability.

  5. Tidal day organic and inorganic material flux of ponds in the Liberty Island freshwater tidal wetland.

    PubMed

    Lehman, Peggy W; Mayr, Shawn; Liu, Leji; Tang, Alison

    2015-01-01

    The loss of inorganic and organic material export and habitat produced by freshwater tidal wetlands is hypothesized to be an important contributing factor to the long-term decline in fishery production in San Francisco Estuary. However, due to the absence of freshwater tidal wetlands in the estuary, there is little information on the export of inorganic and organic carbon, nutrient or phytoplankton community biomass and the associated mechanisms. A single-day study was conducted to assess the potential contribution of two small vegetated ponds and one large open-water pond to the inorganic and organic material flux within the freshwater tidal wetland Liberty Island in San Francisco Estuary. The study consisted of an intensive tidal day (25.5 h) sampling program that measured the flux of inorganic and organic material at three ponds using continuous monitoring of flow, chlorophyll a, turbidity and salt combined with discrete measurements of phytoplankton community carbon, total and dissolved organic carbon and nutrient concentration at 1.5 h intervals. Vegetated ponds had greater material concentrations than the open water pond and, despite their small area, contributed up to 81% of the organic and 61% of the inorganic material flux of the wetland. Exchange between ponds was important to wetland flux. The small vegetated pond in the interior of the wetland contributed as much as 72-87% of the total organic carbon and chlorophyll a and 10% of the diatom flux of the wetland. Export of inorganic and organic material from the small vegetated ponds was facilitated by small-scale topography and tidal asymmetry that produced a 40% greater material export on ebb tide. The small vegetated ponds contrasted with the large open water pond, which imported 29-96% of the inorganic and 4-81% of the organic material into the wetland from the adjacent river. This study identified small vegetated ponds as an important source of inorganic and organic material to the wetland and the

  6. Resurgence of submersed aquatic macrophytes in the tidal Potomac River, Maryland, Virginia, and the District of Columbia

    USGS Publications Warehouse

    Carter, V.; Rybicki, N.

    1986-01-01

    A 1978-81 survey of submersed aquatic macrophytes in the tidal Potomac River showed that there were virtually no plants in the freshwater tidal river between Chain Bridge and Quantico, Virginia, decades after the disappearance of plants in the late 1930's. Plant populations were monitored in subsequent years (1983-85) using qualitative shoreline surveys and quantitative resampling of the original 1978-81 transects. In 1983, 12 species of submersed aquatic macrophytes were found in the tidal river. Population increases were dramatic; by fall 1985, plants had colonized all shallow areas between Alexandria and Gunston Cove, Virginia. Hydrilla verticillata dominated in Dyke Marsh-Hunting Creek and Swan Creek. Most other areas contained a variable mixture of Heteranthera dubia, Myriophyllum spicatum, Ceratophyllum demersum, Vallisneria americana, Najas guadalupensis and Hydrilla verticillata. No plants were found along the main river or in tidal embayments in the reach between Gunston Cove and Quantico, Virginia. Total dry weight collected in the upper tidal river in fall 1985 was 14.5 times that of spring 1985, and four times that of fall 1984. ?? 1986 Estuarine Research Federation.

  7. Water quality study at the Congaree Swamp National monument of Myers Creek, Reeves Creek and Toms Creek. Technical report

    SciTech Connect

    Rikard, M.

    1991-11-01

    The Congaree Swamp National Monument is one of the last significant near virgin tracts of bottom land hardwood forests in the Southeast United States. The study documents a water quality monitoring program on Myers Creek, Reeves Creek and Toms Creek. Basic water quality parameters were analyzed. High levels of aluminum and iron were found, and recommendations were made for further monitoring.

  8. Tidal Power for San Francisco

    DTIC Science & Technology

    2003-09-01

    venturi created by design of the subsea tidal station. All mechanical moving parts for the system are on land including conventional air-driven...energy has a global resource base of approximately 30 Tera Watt (TW) (see Table 1). TABLE 1. GLOBAL RENEWABLE RESOURCES Resource Potential...www.sfports.wr.usgs.gov) couples over 20 years of USGS tidal data with a 3-D computational model [4] to provide real-time information from deployed instruments in SF

  9. Tidal and residual flows in the western Dutch Wadden Sea III: Vorticity balances

    NASA Astrophysics Data System (ADS)

    Ridderinkhof, H.

    A vorticity-dynamics approach is used to examine the origin of the small-scale residual current field in the western Dutch Wadden Sea. For a representative part of the Wadden Sea, the magnitude of vorticity and of terms in the balance equation for vorticity is determined on the basis of results from a two-dimensional numerical model. The torque from bottom friction along the side walls of the tidal channels appears to be the dominating mechanism in generating tidal relative vorticity, the magnitude of which is much larger than planetary vorticity. Especially near a tidal inlet, stretching and squeezing of fluid columns is of importance in increasing/decreasing relative vorticity. Averaging over a tidal period shows, compared to the tidal equations, an increased influence of the non-linear advective and streching/squeezing terms in the tidally-averaged balance. However, although the relative influence of these strong non-linear terms increases, the influence of the weak non-linear terms originating in bottom friction cannot be ignored. The mechanism responsible for the headland eddies near a tidal inlet and the topographical eddies in the channels of the Wadden Sea is essentially the same, viz. the transfer of vorticity from a source region where this vorticity is produced by differential bottom friction, to adjacent regions. This transfer of tidal vorticity, or advection, is most effective near a transition from straight to curved isobaths where a gradient in the production of tidal vorticity occurs. This is illustrated by showing the vorticity possessed by a particular fluid column during a tidal excursion. The dominant influence of the bathymetry on the small scale residual current pattern is used for a qualitative discussion of the residual flow field in other parts of our numerical model.

  10. Effect of subseabed salt domes on Tidal Residual currents in the Persian Gulf

    NASA Astrophysics Data System (ADS)

    Mashayekh Poul, Hossein; Backhaus, Jan; Dehghani, Ali; Huebner, Udo

    2016-05-01

    Geological studies in the Persian Gulf (PG) have revealed the existence of subseabed salt-domes. With suitable filtering of a high-resolution PG seabed topography, it is seen that the domes leave their signature in the seabed, i.e., numerous hills and valleys with amplitudes of several tens of meters and radii from a few up to tens of kilometers. It was suspected that the "shark skin" of the PG seabed may affect the tidal residual flow. The interaction of tidal dynamics and these obstacles was investigated in a nonlinear hydrodynamic numerical tidal model of the PG. The model was first used to characterize flow patterns of residual currents generated by a tidal wave passing over symmetric, elongated and tilted obstacles. Thereafter it was applied to the entire PG. The model was forced at its open boundary by the four dominant tidal constituents residing in the PG. Each tidal constituent was simulated separately. Results, i.e., tidal residual currents in the PG, as depicted by Lagrangian trajectories reveal a stationary flow that is very rich in eddies. Each eddy can be identified with a topographic obstacle. This confirms that the tidal residual flow field is strongly influenced by the nonlinear interaction of the tidal wave with the bottom relief which, in turn, is deformed by salt-domes beneath the seabed. Different areas of maximum residual current velocities are identified for major tidal constituents. The pattern of trajectories indicates the presence of two main cyclonic gyres and several adjacent gyres rotating in opposite directions and a strong coastal current in the northern PG.

  11. Asotin Creek Model Watershed Plan

    SciTech Connect

    Browne, D.; Holzmiller, J.; Koch, F.; Polumsky, S.; Schlee, D.; Thiessen, G.; Johnson, C.

    1995-04-01

    The Asotin Creek Model Watershed Plan is the first to be developed in Washington State which is specifically concerned with habitat protection and restoration for salmon and trout. The plan is consistent with the habitat element of the ``Strategy for Salmon``. Asotin Creek is similar in many ways to other salmon-bearing streams in the Snake River system. Its watershed has been significantly impacted by human activities and catastrophic natural events, such as floods and droughts. It supports only remnant salmon and trout populations compared to earlier years. It will require protection and restoration of its fish habitat and riparian corridor in order to increase its salmonid productivity. The watershed coordinator for the Asotin County Conservation District led a locally based process that combined local concerns and knowledge with technology from several agencies to produce the Asotin Creek Model Watershed Plan.

  12. Land claim and loss of tidal flats in the Yangtze Estuary

    NASA Astrophysics Data System (ADS)

    Chen, Ying; Dong, Jinwei; Xiao, Xiangming; Zhang, Min; Tian, Bo; Zhou, Yunxuan; Li, Bo; Ma, Zhijun

    2016-04-01

    Tidal flats play a critical role in supporting biodiversity and in providing ecosystem services but are rapidly disappearing because of human activities. The Yangtze Estuary is one of the world’s largest alluvial estuaries and is adjacent to the most developed economic zone in China. Using the Yangtze Estuary as a study region, we developed an automatic algorithm to estimate tidal flat areas based on the Land Surface Water Index and the Normalized Difference Vegetation Index. The total area of tidal flats in the Yangtze Estuary has decreased by 36% over the past three decades, including a 38% reduction in saltmarshes and a 31% reduction in barren mudflats. Meanwhile, land claim has accumulated to 1077 km2, a value that exceeds the area of the remaining tidal flats. We divided the Yangtze Estuary into Shanghai and Jiangsu areas, which differ in riverine sediment supply and tidal flat management patterns. Although land claim has accelerated in both areas, the decline in tidal flat area has been much greater in Jiangsu than in Shanghai because of abundant supplies of sediment and artificial siltation in the latter area. The results highlight the need for better coastal planning and management based on tidal flat dynamics.

  13. Land claim and loss of tidal flats in the Yangtze Estuary

    PubMed Central

    Chen, Ying; Dong, Jinwei; Xiao, Xiangming; Zhang, Min; Tian, Bo; Zhou, Yunxuan; Li, Bo; Ma, Zhijun

    2016-01-01

    Tidal flats play a critical role in supporting biodiversity and in providing ecosystem services but are rapidly disappearing because of human activities. The Yangtze Estuary is one of the world’s largest alluvial estuaries and is adjacent to the most developed economic zone in China. Using the Yangtze Estuary as a study region, we developed an automatic algorithm to estimate tidal flat areas based on the Land Surface Water Index and the Normalized Difference Vegetation Index. The total area of tidal flats in the Yangtze Estuary has decreased by 36% over the past three decades, including a 38% reduction in saltmarshes and a 31% reduction in barren mudflats. Meanwhile, land claim has accumulated to 1077 km2, a value that exceeds the area of the remaining tidal flats. We divided the Yangtze Estuary into Shanghai and Jiangsu areas, which differ in riverine sediment supply and tidal flat management patterns. Although land claim has accelerated in both areas, the decline in tidal flat area has been much greater in Jiangsu than in Shanghai because of abundant supplies of sediment and artificial siltation in the latter area. The results highlight the need for better coastal planning and management based on tidal flat dynamics. PMID:27035525

  14. 76 FR 35379 - Archers Creek, Ribbon Creek, and Broad River; U.S. Marine Corps Recruit Depot, Parris Island, SC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ... Department of the Army, Corps of Engineers 33 CFR Part 334 Archers Creek, Ribbon Creek, and Broad River; U.S... fishing shops. The public will continue to be able to use these portions of Archers Creek, Ribbon Creek.... 3). 2. Revise Sec. 334.480 to read as follows: Sec. 334.480 Archers Creek, Ribbon Creek, and...

  15. Hulburt Creek Hydrology, Southwestern Wisconsin

    USGS Publications Warehouse

    Gebert, Warren A.

    1971-01-01

    The purpose of this study was to determine the hydrologic characteristics of Hulburt Creek, Sauk County, Wis., in order to evaluate a proposed reservoir. The streamflow characteristics estimated are the low flow, monthly flow, and inflow flood. The study was done by the U.S. Geological Survey in cooperation with the Wisconsin Department of Natural Resources. The following estimates are for the point on Hulburt Creek at the proposed Dell Lake damsite near Wisconsin Dells. The drainage area is 11.2 square miles.

  16. 27 CFR 9.85 - Willow Creek.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Willow Creek. 9.85 Section... THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.85 Willow Creek. (a) Name. The name of the viticultural area described in this section is “Willow Creek.”...

  17. 27 CFR 9.85 - Willow Creek.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Willow Creek. 9.85 Section... THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.85 Willow Creek. (a) Name. The name of the viticultural area described in this section is “Willow Creek.”...

  18. 27 CFR 9.85 - Willow Creek.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Willow Creek. 9.85 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.85 Willow Creek. (a) Name. The name of the viticultural area described in this section is “Willow Creek.”...

  19. 27 CFR 9.85 - Willow Creek.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Willow Creek. 9.85 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.85 Willow Creek. (a) Name. The name of the viticultural area described in this section is “Willow Creek.”...

  20. 27 CFR 9.85 - Willow Creek.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Willow Creek. 9.85 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.85 Willow Creek. (a) Name. The name of the viticultural area described in this section is “Willow Creek.”...

  1. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake Creek bridge, at Islamorada, Florida, shall open...

  2. Flux of crab larvae in a mangrove creek in the Gulf of Nicoya, Costa Rica

    NASA Astrophysics Data System (ADS)

    Dittel, A. I.; Epifanio, C. E.; Lizano, O.

    1991-02-01

    Transport of crab zoeae, megalopae, and early juveniles was measured in a mangrove estero (creek) in the Gulf of Nicoya on the Pacific coast of Costa Rica. In 1987, larvae were collected by quantitative pumping from a platform moored in the mouth of the estero. During each sampling period, larvae were collected every 2 h over five consecutive tidal cycles. The investigation consisted of one spring-tide sampling period and one neap-tide sampling period during each season of the year (dry season, dry-rainy transition, rainy season, and rainy-dry transition). Hourly tidal heights were available for each sampling period. A model for hindcasting tidal volume flux from the change in sea level over each half tidal cycle was developed from measurements made in the estero in 1989. This model was used to calculate tidal volume flux and consequent larval flux during each of the 1987 sampling periods. There was a net export of zoea stage I of four taxonomic groups ( Uca spp., Pinnotheres spp., Petrolistes spp., and Grapsidae) during most sampling periods, while there was a net import of zoea stage I of only two groups ( Pinnixa spp. and Xanthidae). Intermediate and late zoeal stages of all taxonomic groups were generally imported into the estero, as were megalopal and juvenile stages. Quantitative estimates of net larval transport corroborated earlier qualitative models of larval transport that had been based on observations of the vertical distribution of larvae in the water column.

  3. Contrasting rainfall generated debris flows from adjacent watersheds at Forest Falls, southern California, USA

    NASA Astrophysics Data System (ADS)

    Morton, Douglas M.; Alvarez, Rachel M.; Ruppert, Kelly R.; Goforth, Brett

    2008-04-01

    Debris flows are widespread and common in many steeply sloping areas of southern California. The San Bernardino Mountains community of Forest Falls is probably subject to the most frequently documented debris flows in southern California. Debris flows at Forest Falls are generated during short-duration high-intensity rains that mobilize surface material. Except for debris flows on two consecutive days in November 1965, all the documented historic debris flows have occurred during high-intensity summer rainfall, locally referred to as 'monsoon' or 'cloudburst' rains. Velocities of the moving debris range from about 5 km/h to about 90 km/h. Velocity of a moving flow appears to be essentially a function of the water content of the flow. Low velocity debris flows are characterized by steep snouts that, when stopped, have only small amounts of water draining from the flow. In marked contrast are high-velocity debris flows whose deposits more resemble fluvial deposits. In the Forest Falls area two adjacent drainage basins, Snow Creek and Rattlesnake Creek, have considerably different histories of debris flows. Snow Creek basin, with an area about three times as large as Rattlesnake Creek basin, has a well developed debris flow channel with broad levees. Most of the debris flows in Snow Creek have greater water content and attain higher velocities than those of Rattlesnake Creek. Most debris flows are in relative equilibrium with the geometry of the channel morphology. Exceptionally high-velocity flows, however, overshoot the channel walls at particularly tight channel curves. After overshooting the channel, the flows degrade the adjacent levee surface and remove trees and structures in the immediate path, before spreading out with decreasing velocity. As the velocity decreases the clasts in the debris flows pulverize the up-slope side of the trees and often imbed clasts in them. Debris flows in Rattlesnake Creek are relatively slow moving and commonly stop in the channel

  4. Contrasting rainfall generated debris flows from adjacent watersheds at Forest Falls, southern California, USA

    USGS Publications Warehouse

    Morton, D.M.; Alvarez, R.M.; Ruppert, K.R.; Goforth, B.

    2008-01-01

    Debris flows are widespread and common in many steeply sloping areas of southern California. The San Bernardino Mountains community of Forest Falls is probably subject to the most frequently documented debris flows in southern California. Debris flows at Forest Falls are generated during short-duration high-intensity rains that mobilize surface material. Except for debris flows on two consecutive days in November 1965, all the documented historic debris flows have occurred during high-intensity summer rainfall, locally referred to as 'monsoon' or 'cloudburst' rains. Velocities of the moving debris range from about 5??km/h to about 90??km/h. Velocity of a moving flow appears to be essentially a function of the water content of the flow. Low velocity debris flows are characterized by steep snouts that, when stopped, have only small amounts of water draining from the flow. In marked contrast are high-velocity debris flows whose deposits more resemble fluvial deposits. In the Forest Falls area two adjacent drainage basins, Snow Creek and Rattlesnake Creek, have considerably different histories of debris flows. Snow Creek basin, with an area about three times as large as Rattlesnake Creek basin, has a well developed debris flow channel with broad levees. Most of the debris flows in Snow Creek have greater water content and attain higher velocities than those of Rattlesnake Creek. Most debris flows are in relative equilibrium with the geometry of the channel morphology. Exceptionally high-velocity flows, however, overshoot the channel walls at particularly tight channel curves. After overshooting the channel, the flows degrade the adjacent levee surface and remove trees and structures in the immediate path, before spreading out with decreasing velocity. As the velocity decreases the clasts in the debris flows pulverize the up-slope side of the trees and often imbed clasts in them. Debris flows in Rattlesnake Creek are relatively slow moving and commonly stop in the

  5. Geomorphic Function and Restoration Potential of Spring Creeks in Southeastern Idaho: Analysis and Communication

    NASA Astrophysics Data System (ADS)

    Hanrahan, T. P.; Hill, Z.; Levell, A.; Maguire, T.; Risso, D.

    2014-12-01

    A large wetland and floodplain complex adjacent to the Snake River in southeastern Idaho, USA, encompasses numerous spring-fed creeks that originate on the floodplain and discharge at their confluence with the Snake River and American Falls Reservoir. Resource managers are implementing a program to restore these spring creeks for the recovery of Yellowstone cutthroat trout and ecosystem health. Our objectives were to evaluate the physical characteristics of these spring creeks, develop a conceptual model of their geomorphic function, compare the restoration potential of individual reaches, and communicate our findings to a broad audience of resource managers and regional stakeholders in order to foster restoration planning. A geomorphic assessment along 38 km of three spring creeks was completed by collecting data at several transects within distinct geomorphic reaches, and by collecting data continuously throughout all reaches. These data were summarized in a GIS database and used to quantify the overall geomorphic functioning of each reach. The geomorphic functional scores were scaled from 0% (non-functional) to 100% (fully functional). Among all three spring creeks, geomorphic function ranged from 29% to 63%, with bank conditions and riparian vegetation being the primary causes of overall channel degradation. Results from the geomorphic assessment fostered the development of a conceptual model for spring creek function, whereby degraded bank conditions represent the primary controlling factor of decreased geomorphic function and fish habitat quality. The reach-based geomorphic functional scoring provides an indicator of relative restoration potential for each reach, and is one of the factors used in determining site-specific priorities for protecting, enhancing, and restoring spring creeks on the Fort Hall Bottoms. The study results, conceptual model and restoration strategy were communicated to resource managers and regional stakeholders through a graphically

  6. Dynamics of arsenic in the mining sites of Pine Creek Geosyncline, Northern Australia.

    PubMed

    Eapaea, Miro Peter; Parry, David; Noller, Barry

    2007-07-01

    The transportation and fixation of arsenic (As) in soil and sediments from five mine sites within the Pine Creek Geosyncline, Northern Territory, were examined based on measurements of operationally-defined fractions of As in soils, sediment and evaporates. Arsenic was mainly retained in sediments in the form iron arsenate (Fe-As). In wetland systems, As was retained as Fe-As together with calcium arsenate (Ca-As) from alkaline groundwater and organic-bound As from detrital material. In retention ponds As was retained as Fe-As, Ca-As and residual As (Res-As) up to 1700 mg/kg. Sediment traps can retain As from alkaline and acidic source seepages. The retention of Res-As and other mineral particulates during erosional or controlled process water discharges was associated with high Fe-As and organic-bound As in sediment. Arsenic was retained as Fe-As, Ca-As and residual As in 100 year old tailings at Millar's Battery, Union Reefs mine nearby McKinlay River and the small copper mine lease MLN 95 adjacent Copperfield Creek nearby Pine Creek. Natural geo-mobilisation of As was observed in upstream sediments at Copperfield Creek (5-8 mg/kg), Mt. Bundey Creek (10-12 mg/kg), upstream Ryan's Creek (10-12 mg/kg) and downstream East branch Ryan's Creek (7 mg/kg). Erosion of As-containing mineralisation was observed in the McKinlay River upstream and downstream (23-26 mg/kg) and upstream Ryan's Creek boundary of the Goodall mine lease MLN 1049 (24-40 mg/kg). Overall, As was mainly retained in sediments in the form Fe-As. The concentration data for As were used to propose mechanisms of As dispersion and retention occurring at the various mine sites that can be utilised for future mine water management design to minimise As dispersion.

  7. Tidal flat stability analysis based on GIS & RS technology: a case study in Dongsha sandbank, offshore the coast of Jiangsu province

    NASA Astrophysics Data System (ADS)

    Liu, Yongxue; Li, Manchun; Yang, Jing; Shu, Yuanming

    2007-06-01

    Stability of the tidal flat in silt-muddy coast is the ability to keep its terrain from erosion under the ocean dynamic processes. Evaluating the stability of the tidal flat is one of the most important issues insediment dynamics research field , and has been attached more and more importance. Dongsha Sandbank is one of the largest sandbanks of the radial sand ridges, and serves as an important barrier to the inner sandbank and has a direct impact on the process of Tiaozini Sandbank merging into mainland. To evaluate the stability of Dongsha Sandbank will provide guidance for coastal zone environmental protection (such as environmental protection and coast protection, etc.) to make a rational use of tidal flat resources for sustainable development. In the study, 63 scenes of remotely sensed imageries from 1973 to 2007 were collected, taken by different sensors such as MSS, TM, ETM+, SPOT, ASTER and CBERS. GIS & RS technology was used in the stability analysis of Dongsha Sandbank tidal flat based on field investigation, RS classification and overlay analysis. Major relate factors such as sediment dynamic environment, tidal channel and tidal creek system were discussed in the paper. Some conclusion can be summarized as follows :( 1) Integral stability of Dongsha Sandbank tidal flat has been gradually declined from 1973 to 2007. This trend was embedded in two aspects: both area of stable tidal flat and maximum value of stability coefficient degraded. (2) Tidal flat with high stability is mainly distributed on the sand ridges of Dongsha Sandbank, and has an integrally contractive trend: in the mid-continental region, one region with high stability coefficient has been broken into two small parts-- the northern part has a southwards movement while the southern has a northern wards movement; within the north part, stability of the tidal flat reduced with the northwards movement of the shoreline; in the west part, the tidal flat is in an unstable state due to the lateral

  8. Tidal disruption event demographics

    NASA Astrophysics Data System (ADS)

    Kochanek, C. S.

    2016-09-01

    We survey the properties of stars destroyed in tidal disruption events (TDEs) as a function of black hole (BH) mass, stellar mass and evolutionary state, star formation history and redshift. For M_{BH} ≲ 10^7 M_{⊙}, the typical TDE is due to a M* ˜ 0.3 M⊙ M-dwarf, although the mass function is relatively flat for M_{ast } ≲ M_{⊙}. The contribution from older main-sequence stars and sub-giants is small but not negligible. From MBH ≃ 107.5-108.5 M⊙, the balance rapidly shifts to higher mass stars and a larger contribution from evolved stars, and is ultimately dominated by evolved stars at higher BH masses. The star formation history has little effect until the rates are dominated by evolved stars. TDE rates should decline very rapidly towards higher redshifts. The volumetric rate of TDEs is very high because the BH mass function diverges for low masses. However, any emission mechanism which is largely Eddington-limited for low BH masses suppresses this divergence in any observed sample and leads to TDE samples dominated by MBH ≃ 106.0-107.5 M⊙ BHs with roughly Eddington peak accretion rates. The typical fall-back time is relatively long, with 16 per cent having tfb < 10-1 yr (37 d), and 84 per cent having longer time-scales. Many residual rate discrepancies can be explained if surveys are biased against TDEs with these longer tfb, which seems very plausible if tfb has any relation to the transient rise time. For almost any BH mass function, systematic searches for fainter, faster time-scale TDEs in smaller galaxies, and longer time-scale TDEs in more massive galaxies are likely to be rewarded.

  9. Tidal Boundary Conditions in SEAWAT

    USGS Publications Warehouse

    Mulligan, Ann E.; Langevin, Christian; Post, Vincent E.A.

    2011-01-01

    SEAWAT, a U.S. Geological Survey groundwater flow and transport code, is increasingly used to model the effects of tidal motion on coastal aquifers. Different options are available to simulate tidal boundaries but no guidelines exist nor have comparisons been made to identify the most effective approach. We test seven methods to simulate a sloping beach and a tidal flat. The ocean is represented in one of the three ways: directly using a high hydraulic conductivity (high-K) zone and indirect simulation via specified head boundaries using either the General Head Boundary (GHB) or the new Periodic Boundary Condition (PBC) package. All beach models simulate similar water fluxes across the upland boundary and across the sediment-water interface although the ratio of intertidal to subtidal flow is different at low tide. Simulating a seepage face results in larger intertidal fluxes and influences near-shore heads and salinity. Major differences in flow occur in the tidal flat simulations. Because SEAWAT does not simulate unsaturated flow the water table only rises via flow through the saturated zone. This results in delayed propagation of the rising tidal signal inland. Inundation of the tidal flat is delayed as is flow into the aquifer across the flat. This is severe in the high-K and PBC models but mild in the GHB models. Results indicate that any of the tidal boundary options are fine if the ocean-aquifer interface is steep. However, as the slope of that interface decreases, the high-K and PBC approaches perform poorly and the GHB boundary is preferable.

  10. A siltation simulation and desiltation measurement study downstream of the Suzhou Creek Sluice, China

    NASA Astrophysics Data System (ADS)

    Ji, Yong-xing; Yang, Fei; Zhang, Han-yun; Lu, Yong-jin

    2013-12-01

    The Suzhou Creek Sluice is currently the largest underwater plain gate in the world, with a single span of 100 m. It is located in a tidal estuary at the junction of the Huangpu River and Suzhou Creek in Shanghai, China. In this study, physical and 2D vertical mathematical models were used to investigate and distinguish the mechanism of siltation downstream of an underwater plain gate from that of other gates types. According to quantitative data obtained by site investigation and the application of the physical hydrodynamic models, it was found that the characteristics of the tidal estuary as well as the fact that the sluice span is equal to the creek width are the major reasons contributing to siltation. A possible desiltation treatment system is proposed for the underwater plain gate. The system includes selection of a suitable location that allows the determination of a reasonable top elevation of the sluice floor, reserving sufficient space under the gate to accommodate siltation, setting up a mechanical desiltation system, and flushing silt along with overflow over the top of the gate. Furthermore, on-site hydraulic silt flushing experiments and a topography survey were conducted. These results showed that the measurement system is effective, and by maintaining this scheduled operation once a month, the downstream riverbed has been maintained in a good condition.

  11. Clear Creek Watershed Flood Risk Management Habitat Assessments Using Habitat Evaluation Procedures (HEP): Analyses, Results and Documentation

    DTIC Science & Technology

    2013-07-01

    the reach also cut off many of the natural channel meanders when excavated material was mounded along the north bank. A series of forested oxbow lakes ...19  Eco Eco-Reach 1: Clear Lake from its mouth at Galveston Bay upstream to I-45 ..... 24  Eco-Reach 2: Clear Creek Tidal from I...larger tributaries (i.e., identified as separate subwatersheds) flowing into Clear Lake from the north. The watershed is approximately 45 miles long

  12. Water quality, bed-sediment quality, and simulation of potential contaminant transport in Foster Creek, Berkeley County, South Carolina, 1991-93

    USGS Publications Warehouse

    Campbell, T.R.; Bower, D.E.

    1996-01-01

    Foster Creek, a freshwater tidal creek in Berkeley County, South Carolina, is located in an area of potential contaminant sources from residential, commercial, light industrial, and military activities. The creek is used as a secondary source of drinking water for the surrounding Charleston area. Foster Creek meets most of the freshwater- quality requirements of State and Federal regulatory agencies, but often contains low concentrations of dissolved oxygen and has been characterized as eutrophic. Investigations of water- and bed-sediment quality were made between 1991 and 1993 to assess the effects of anthropogenic sources of contamination on Foster Creek. Low-flow surface-water samples were generally free of toxic compounds with the exception of laboratory artifacts and naturally occurring trace metals. Storm-runoff samples generally contained very low concentrations (near detection limits) of a small number of volatile and semivolatile organics and naturally occurring trace metals. Concentrations of toxic compounds in excess of current (1995) South Carolina Department of Health and Environmental Control and U.S. Environmental Protection Agency regulations were not detected in surface-water samples collected from Foster Creek. Chemical analyses of streambed sediments indicated minimal anthropogenic effects on sediment quality. The particle-tracking option of the U.S. Geological Survey one-dimensional unsteady-flow model (BRANCH) indicated that as the simulated volume of rainfall runoff increased in the Foster Creek Basin, simulated particles in Foster Creek were transported greater distances. Simulating flow through the Bushy Park Dam (also known as Back River Dam) had little effect on particle movement in Foster Creek. Simulating typical withdrawal rates at a water-supply intake resulted in a slight attraction of particles toward the intake during conditions of relatively low runoff. These withdrawals had a greater influence on particles downstream of the intake

  13. TIDAL LIMITS TO PLANETARY HABITABILITY

    SciTech Connect

    Barnes, Rory; Jackson, Brian; Greenberg, Richard; Raymond, Sean N.

    2009-07-20

    The habitable zones (HZs) of main-sequence stars have traditionally been defined as the range of orbits that intercept the appropriate amount of stellar flux to permit surface water on a planet. Terrestrial exoplanets discovered to orbit M stars in these zones, which are close-in due to decreased stellar luminosity, may also undergo significant tidal heating. Tidal heating may span a wide range for terrestrial exoplanets and may significantly affect conditions near the surface. For example, if heating rates on an exoplanet are near or greater than that on Io (where tides drive volcanism that resurfaces the planet at least every 1 Myr) and produce similar surface conditions, then the development of life seems unlikely. On the other hand, if the tidal heating rate is less than the minimum to initiate plate tectonics, then CO{sub 2} may not be recycled through subduction, leading to a runaway greenhouse that sterilizes the planet. These two cases represent potential boundaries to habitability and are presented along with the range of the traditional HZ for main-sequence, low-mass stars. We propose a revised HZ that incorporates both stellar insolation and tidal heating. We apply these criteria to GJ 581 d and find that it is in the traditional HZ, but its tidal heating alone may be insufficient for plate tectonics.

  14. The bly creek ecosystem study: Phosphorus transport within a euhaline salt marsh basin, North Inlet, South Carolina

    NASA Astrophysics Data System (ADS)

    Dame, Richard F.; Wolaver, Thomas G.; Williams, Thomas M.; Spurrier, John D.; Miller, Anne B.

    Phosphorus transport through the tidal creek linking the Bly Creek basin (North Inlet, South Carolina) and the surrounding water body was studied on 34 tidal cycles between 20 June 1983 and 19 June 1984. Annual estimates of phosphorus input to the basin via streamwater, groundwater, and via streamwater, groundwater, and rain totalled 19.6 kg P·y -1; PO 4 export from the basin was not significant. Within the basin, the salt marsh was shown to be an important sink for PO 4 (207 kg P·y -1) while the oyster reef community exported a statistically insignificant 7.7 kg P·y -1. The data suggest that the source of the PO 4 to the salt marsh is the water column or benthic sediments of the tidal creek. The salt marsh was a significant sink for particulate phosphorus, but those uptakes were less than the error on the insignificant fluxes into the basin via the water column. The oyster reef community was a statistically significant sink for total phosphorus (98 kg P·y -1).

  15. Seasonal variations in suspended-sediment dynamics in the tidal reach of an estuarine tributary

    USGS Publications Warehouse

    Downing-Kunz, Maureen A.; Schoellhamer, David H.

    2013-01-01

    Quantifying sediment supply from estuarine tributaries is an important component of developing a sediment budget, and common techniques for estimating supply are based on gages located above tidal influence. However, tidal interactions near tributary mouths can affect the magnitude and direction of sediment supply to the open waters of the estuary. We investigated suspended-sediment dynamics in the tidal reach of Corte Madera Creek, an estuarine tributary of San Francisco Bay, using moored acoustic and optical instruments. Flux of both water and suspended-sediment were calculated from observed water velocity and turbidity for two periods in each of wet and dry seasons during 2010. During wet periods, net suspended-sediment flux was seaward; tidally filtered flux was dominated by the advective component. In contrast, during dry periods, net flux was landward; tidally filtered flux was dominated by the dispersive component. The mechanisms generating this landward flux varied; during summer we attributed wind–wave resuspension in the estuary and subsequent transport on flood tides, whereas during autumn we attributed increased spring tide flood velocity magnitude leading to local resuspension. A quadrant analysis similar to that employed in turbulence studies was developed to summarize flux time series by quantifying the relative importance of sediment transport events. These events are categorized by the direction of velocity (flood vs. ebb) and the magnitude of concentration relative to tidally averaged conditions (relatively turbid vs. relatively clear). During wet periods, suspended-sediment flux was greatest in magnitude during relatively turbid ebbs, whereas during dry periods it was greatest in magnitude during relatively turbid floods. A conceptual model was developed to generalize seasonal differences in suspended-sediment dynamics; model application to this study demonstrated the importance of few, relatively large events on net suspended-sediment flux

  16. Tidal variations of earth rotation

    NASA Technical Reports Server (NTRS)

    Yoder, C. F.; Williams, J. G.; Parke, M. E.

    1981-01-01

    The periodic variations of the earths' rotation resulting from the tidal deformation of the earth by the sun and moon were rederived including terms with amplitudes of 0.002 millisec and greater. The series applies to the mantle, crust, and oceans which rotate together for characteristic tidal periods; the scaling parameter is the ratio of the fraction of the Love number producing tidal variations in the moment of inertia of the coupled mantle and oceans (k) to the dimensionless polar moment of inertia of the coupled moments (C). The lunar laser ranging data shows that k/C at monthly and fortnightly frequencies equals 0.99 + or - 0.15 and 0.99 + or - 0.20 as compared to the theoretical value of 0.94 + or - 0.04.

  17. Tidal disruption of inviscid protoplanets

    NASA Technical Reports Server (NTRS)

    Boss, Alan P.; Cameron, A. G. W.; Benz, W.

    1991-01-01

    Roche showed that equilibrium is impossible for a small fluid body synchronously orbiting a primary within a critical radius now termed the Roche limit. Tidal disruption of orbitally unbound bodies is a potentially important process for planetary formation through collisional accumulation, because the area of the Roche limit is considerably larger then the physical cross section of a protoplanet. Several previous studies were made of dynamical tidal disruption and different models of disruption were proposed. Because of the limitation of these analytical models, we have used a smoothed particle hydrodynamics (SPH) code to model the tidal disruption process. The code is basically the same as the one used to model giant impacts; we simply choose impact parameters large enough to avoid collisions. The primary and secondary both have iron cores and silicate mantles, and are initially isothermal at a molten temperature. The conclusions based on the analytical and numerical models are summarized.

  18. Tidal disruption of dissipative planetesimals

    NASA Technical Reports Server (NTRS)

    Mizuno, H.; Boss, A. P.

    1985-01-01

    A self-consistent numerical model is developed for the tidal disruption of a solid planetesimal. The planetesimal is treated as a highly viscous, slightly compressible fluid whose disturbed parts are an inviscid, pressureless fluid undergoing distortion and disruption. The distortions were constrained to being symmetrical above and below the equatorial plane. The tidal potential is expanded in terms of Legendre polynomials, which eliminates the center of mass acceleration effects, permitting definition of equations of motion in a noninertial frame. Consideration is given to viscous dissipation and to characteristics of the solid-atmosphere boundary. The model is applied to sample cases in one, two and three dimensions.

  19. Tidal disruption of viscous bodies

    NASA Technical Reports Server (NTRS)

    Sridhar, S.; Tremaine, S.

    1992-01-01

    Tidal disruptions are investigated in viscous-fluid planetesimals whose radius is small relative to the distance of closest (parabolic-orbit) approach to a planet. The planetesimal surface is in these conditions always ellipsoidal, facilitating treatment by coupled ODEs which are solvable with high accuracy. While the disrupted planetesimals evolve into needlelike ellipsoids, their density does not decrease. The validity of viscous fluid treatment holds for solid (ice or rock) planetesimals in cases where tidal stresses are greater than material strength, but integrity is maintained by self-gravity.

  20. Preservation of daily tidal cycles and stacked alluvial swamp deposits: Depositional response to early compaction of buried peat bodies

    SciTech Connect

    Demko, T.M.; Gastaldo, R.A. )

    1990-05-01

    The character of the clastic depositional environments represented in the lower Mary Lee coal zone of the Pennsylvanian Pottsville Formation in the Warrior basin Alabama (tidally influenced mud flats and alluvial swamps) was controlled by the compaction of buried peat bodies. The lowest mineable coal in the Mary Lee coal zone, the Jagger, is overlain by laminated shale and sandstone exhibiting pronounced cycle bedding. This bedding records daily tidal cyclicity in the form of sand-mud couplets. These correspond to flood-current deposition of the coarser fraction followed by fallout of the finer grained fraction during ensuing slack-water periods. These couplets are cyclically bundled-sandier bundles corresponding to spring tides and muddier bundles to neap tides (lamination counts suggest a 24-30-day cycle). The clastic sequence above the overlying Blue Creek coal is characterized by a series of stacked alluvial swamp horizons. These can be identified by autochthonous fossil plants and pedological features indicative of gleyed paleosols. Catastrophic flooding buried and preserved these horizons. The rapid, early compaction of the buried Jagger and Blue Creek peat bodies created accommodation space that allowed both the preservation of tidalites in the Jagger coal to Blue Creek coal interval and the stacking of alluvial swamp paleosols above the Blue Creek seam. Carboniferous peats were comprised of highly compressible plant parts and hence, were sensitive to sediment loading. Once the peat bodies had compressed to a certain extent, stability of the overlying sediment surface created conditions amenable to resumption of peat accumulation.

  1. Food limitation in cockles ( Cerastoderma edule (L.)): Influences of location on tidal flat and of nearby presence of mussel beds

    NASA Astrophysics Data System (ADS)

    Kamermans, Pauline

    Dilution of phytoplankton concentrations by suspension-feeding organisms, and local reduction in current velocity, may lower food supply for other suspension feeders, and consequently affect their growth. Influences of food supply on stomach contents and growth of the suspension-feeding bivalve Cerastoderma edule were studied in two situations: (a) inside and outside an experimental mussel bed in a basin with a natural seawater supply, and (b) along tidal creeks in the field. Cockles showed a lower increase in shell length, body weight and condition inside the experimental mussel bed than outside. In the field, phytoplankton concentrations in the water were lower at upper than at lower tidal-creek sites. At these upper creek sites, cockles were smaller, as were their growth rates and stomach contents, compared to the lower creek sites. Largest reductions of phytoplankton concentration in the water were observed at sites near a mussel bed. It is concluded that phytoplankton uptake by suspension feeders (particularly in mussel beds), as well as relatively low current velocities, negatively affects food supply, stomach contents and growth of C. edule.

  2. Tidal frequency estimation for closed basins

    NASA Technical Reports Server (NTRS)

    Eades, J. B., Jr.

    1978-01-01

    A method was developed for determining the fundamental tidal frequencies for closed basins of water, by means of an eigenvalue analysis. The mathematical model employed, was the Laplace tidal equations.

  3. Summary geochemical maps, Hoover Wilderness and adjacent study area, Mono and Tuolumne counties, California

    USGS Publications Warehouse

    Chaffee, M.A.; Hill, R.H.; Sutley, S.J.

    1984-01-01

    The Hoover Wilderness and the adjacent Hoover Extension (East), Hoover Extension (West), and Cherry Creek A Roadless Areas (the adjacent study area) encompass approximately 153,900 acres (241 mi2; 623 km2) in the Inyo, Stanislaus, and Toiyabe Naitonal Forests, Mono and Tuolumne Counties, Calif. These two areas lie along and mostly east of the crest of the Sierra Nevada, along the north and east sides of Yosemite National Park. Elevations vary from a high of 12,446 ft (3,793 m) on the crest of the Sierra Nevada to a low of about 6,500 ft (1,981 m) near the Bridgeport Ranger Station. Access to the Hoover Wilderness and adjacent study area is by U.S. Highway 395, California State Highways 108 (Sonora Pass) and 120 (Tioga Pass), and by other paved and graded roads that lead off of these U.S. and State highways.

  4. Geomorphic modeling of macro-tidal embayment with extensive tidal flats: Skagit Bay, Washington

    DTIC Science & Technology

    2012-09-30

    DISTRIBUTION A: Distribution approved for public release; distribution is unlimited. Geomorphic modeling of macro- tidal embayment with extensive... tidal flats: Skagit Bay, Washington Lyle Hibler Battelle-Pacific Northwest Division Marine Sciences Laboratory Sequim, WA 98382 phone: (360) 681...of muddy tidal flats and to quantify the effects of tidal action, river discharge, and shoreline development (e.g. dikes and jetties) on these

  5. A tale of two interfaces: Dynamic nitrate removal in the hyporheic zone of a tidal fresh river

    NASA Astrophysics Data System (ADS)

    Sawyer, A. H.; Knights, D. H.; Barnes, R. T.; Wallace, C.; Bray, S. N.; Musial, C.

    2015-12-01

    At the interface of rivers and oceans, tidal freshwater zones (TFZs) stretch for tens to hundreds of kilometers but are rarely monitored for nitrogen export due to their complex hydrodynamics. Field observations from the TFZ of White Clay Creek (Delaware, USA) show that river discharge and nitrate export rates decrease during rising tide, while hyporheic storage increases. During falling tide, river discharge and nitrate export rates increase, while stored hyporheic water is released to the river. We estimate that 11% of river water exchanges through the hyporheic zone of this TFZ due to tidal pumping alone. We developed a one-dimensional, coupled fluid flow and solute transport model to quantify the influence of tidal pumping on nitrate removal in the riverbed. Tidal pumping promotes a deep, oscillating zone of aerobic respiration that limits denitrification near the sediment-water interface. As tide rises, groundwater residence times in shallow riverbed sediments increase, which causes a doubling of denitrification rates relative to falling tide. Given a uniform substrate along TFZs, removal rates of groundwater-borne nitrate should decrease as tidal amplitude increases downstream. Denitrification hot spots should occur in less permeable, organic-rich sediment under low tidal ranges. Because TFZs connect lowland nitrogen sources to the ocean, it is imperative that we expand monitoring efforts and elucidate their role in nitrogen export to the coast.

  6. RICHLAND CREEK ROADLESS AREA, ARKANSAS.

    USGS Publications Warehouse

    Miller, Mary H.; Wood, Robert H.

    1984-01-01

    On the basis of geologic and mineral surveys, Richland Creek Roadless Area, Arkanses, has little promise for the occurrence of metallic mineral resources, gas and oil, or oil shale. The Boone Formation of Mississippian age and the Everton Formation of Ordovician age, both known to contain zinc and lead deposits in northern Arkansas, underlie the roadless area. The presence or absence of zinc and lead deposits in these formations in the subsurface can be neither confirmed nor ruled out without exploratory drilling. Most of the Richland Creek Roadless Area is under lease for oil and gas; however two wells drilled near the eastern boundary of the area did not show contained gas or oil.

  7. Evaluation of protected, threatened, and endangered fish species in Upper Bear Creek watershed

    SciTech Connect

    Ryon, M.G.

    1998-07-01

    The East Bear Creek Site for the proposed centralized waste facility on the US Department of Energy`s Oak Ridge Reservation was evaluated for potential rare, threatened or endangered (T and E) fish species in the six primary tributaries and the main stem of Bear Creek that are within or adjacent to the facility footprint. These tributaries and portion of Bear Creek comprise the upper Bear Creek watershed. One T and E fish species, the Tennessee dace (Phoxinus tennesseensis), was located in these streams. The Tennessee dace is listed by the State of Tennessee as being in need of management, and as such its habitat is afforded some protection. Surveys indicated that Tennessee dace occupy the northern tributaries NT-1, NT-4, and NT-5, as well as Bear Creek. Several specimens of the dace were gravid females, indicating that the streams may function as reproductive habitat for the species. The implications of impacts on the species are discussed and mitigation objectives are included.

  8. Methane cycling in a tidal freshwater swamp

    SciTech Connect

    Megonigal, J.P.; Schlesinger, W.H. )

    1993-06-01

    Previous studies of methanogenesis in a tidal freshwater swamp on the North Carolina coast have found that potential rates of methane production overestimate observed rates of methane flux, especially during summer months. This research investigates three possibilities for the unexplained losses: methane oxidation, lateral export of dissolved methane to the adjacent river, and ebullition. It is possible that each of these sinks increase during the summer. The potential for methane oxidation was demonstrated in intact soil cores incubated for 21 hours under a 0.5% CH[sub 3]F atmosphere. Methane flux increased from 10+/-27 (mean+/-sd) to 60+/-3 mg m[sup [minus]2] d[sup [minus]1] in treated cores; control core fluxes were 15+/-3 and 19+/-3 mg m[sup [minus]2] d[sup [minus]1] over the same periods. Incubations of slightly unsaturated soils with [sup 14]CH[sub 4] confirmed rapid potential rates of methane oxidation.

  9. Otter Creek Wilderness, West Virginia

    SciTech Connect

    Warlow, R.C.; Behum, P.T.

    1984-01-01

    A mineral-resource survey of the Otter Creek Wilderness conducted in 1978 resulted in the determination of demonstrated coal resources estimated to total about 24 million short tons in beds more than 28 in. thick and an additional 62 million short tons of coal in beds between 14 and 28 in. thick. There is little promise for the occurrence of mineral or other energy resources in the area.

  10. 76 FR 62631 - Archers Creek, Ribbon Creek, and Broad River; U.S. Marine Corps Recruit Depot, Parris Island, SC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-11

    ... Department of the Army, Corps of Engineers 33 CFR Part 334 Archers Creek, Ribbon Creek, and Broad River; U.S... Depot Parris Island. The public will continue to be able to use these portions of Archers Creek, Ribbon... Archers Creek, Ribbon Creek, and Broad River; U.S. Marine Corps Recruit Depot, Parris Island,...

  11. Preliminary estimates of the quantity and quality of groundwater discharge to a section of Bear Creek in central Iowa

    SciTech Connect

    Caron, G.A.; Simpkins, W.W.; Schultz, R.C. )

    1994-04-01

    Studies in Iowa and elsewhere in the Midwest have suggested that most agrichemicals enter surface water through runoff events of tile drainage. Although it also contains agrichemicals, groundwater's contribution to surface water contamination is largely unknown, particularly in till-dominated watersheds. The purpose of this study was to estimate the quantity and quality of groundwater discharge to a 1,000-m-long section of Bear Creek in central Iowa. The study is part of a larger project that is evaluating constructed, multi-species riparian buffer strips as a Best Management Practice for agriculture. Groundwater discharge to the creek was estimated using: (1) differences in discharge between an upstream and downstream weir (minus tile drain outflow), (2) seepage meter data from the creek bed, and (3) Darcy's Law, using hydraulic gradient and K data from piezometers adjacent to the creek and minipiezometers in the creek. The authors preliminary estimates show groundwater discharge rates of 2 to 15 L/s (weirs), 10 L/s (seepage meters), and 3 L/s (Darcy's Law). Discharge in Bear Creek ranged from 100 to 400 L/s during the period; thus, groundwater contributed only a small part of the total creek discharge. Water samples from minipiezometers beneath the creek bed are characterized by NO[sub 3]-N concentrations < 3 mg/L and atrazine concentrations < 0.1 [mu]g/L. In contrast, water samples from Bear Creek typically show NO[sub 3]-N concentrations > 20 mg/L and atrazine concentrations up to 1.0 [mu]g/L. These water quality data suggest that groundwater may not be a significant contributor to agrichemical contamination of surface water in this till-dominated watershed.

  12. Rejuvenating Poldered Landscapes in a Tidally-Dominated, Sediment-Rich Delta: A Numerical Model and Analysis of the Effectiveness of Tidal River Management in Coastal Bangladesh

    NASA Astrophysics Data System (ADS)

    Tasich, C. M.; Goodbred, S. L., Jr.; Gilligan, J. M.; Wilson, C.

    2014-12-01

    The low-lying, coastal region of Bangladesh has relied on poldering (the creation of embanked islands) since the 1960s to mitigate the effects of tidal inundation and storm surge from tropical cyclones. The result has been an increase in total arable land and the ability to sustain food production for one of the most densely populated countries in the world. However, poldering has had the unintended consequences of starving embanked landscapes of sediment and increasing high water levels through tidal amplification. Thus, polder elevations have been declining while tidal channels have been aggrading. Recent small-scale engineering projects, locally referred to as tidal river management (TRM), have attempted to combat these effects by allowing water and sediment exchange between the polders and the tidal network. Anecdotal reports claim great success for TRM in some locations, but not in others. However, to date there has been almost no quantitative analysis. Here, we used measured sedimentation rates and water level data from Polder 32 (P32) and the adjacent pristine mangrove forest in southwest Bangladesh to parameterize a simple model of tidal inundation and resultant sediment accretion. P32 elevations are currently ~1 m lower than natural elevations resulting in ~105 cm of tidal inundation when embankments were breached versus only ~20 cm for the mangrove forest. We measured sedimentation rates of 20 cm/yr and 1 cm/yr, respectively. When normalized to the cumulative annual flooding depth, the resulting sediment extraction rates yield similar values of 300 mg/L and 230 mg/L. We employ these flooding depth and sediment extraction parameters in our model to quantify the amount of time and sediment needed to re-equilibrate the lowered polder elevation to that of the natural environment. Although relatively simple, results from this preliminary model corroborate anecdotes of TRM's effectiveness at restoring land-surface elevations in the polders of Bangladesh. Future

  13. Chemical data for bottom sediment, lake water, bottom-sediment pore water, and fish in Mountain Creek Lake, Dallas, Texas, 1994-96

    USGS Publications Warehouse

    Jones, S.A.; Van Metre, P.C.; Moring, J.B.; Braun, C.L.; Wilson, J.T.; Mahler, B.J.

    1997-01-01

    Mountain Creek Lake is a reservoir adjacent to two U.S. Department of the Navy facilities, the Naval Weapons Industrial Reserve Plant and the Naval Air Station in Dallas, Texas. A Resource Conservation and Recovery Act Facility Investigation found ground-water plumes containing chlorinated solvents on both facilities. These findings led to a U.S. Geological Survey study of Mountain Creek Lake adjacent to both facilities between June 1994 and August 1996. Bottom sediments, lake water, bottom-sediment pore water, and fish were collected for chemical analysis.

  14. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  15. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  16. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  17. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  18. Traveltime characteristics of Gore Creek and Black Gore Creek, upper Colorado River basin, Colorado

    USGS Publications Warehouse

    Gurdak, Jason J.; Spahr, Norman E.; Szmajter, Richard J.

    2002-01-01

    In the Rocky Mountains of Colorado, major highways are often constructed in stream valleys. In the event of a vehicular accident involving hazardous materials, the close proximity of highways to the streams increases the risk of contamination entering the streams. Recent population growth has contributed to increased traffic volume along Colorado highways and has resulted in increased movement of hazardous materials, particularly along Interstate 70. Gore Creek and its major tributary, Black Gore Creek, are vulnerable to such contamination from vehicular accidents along Interstate 70. Gore Creek, major tributary of the Eagle River, drains approximately 102 square miles, some of which has recently undergone significant urban development. The headwaters of Gore Creek originate in the Gore Range in the eastern part of the Gore Creek watershed. Gore Creek flows west to the Eagle River. Beginning at the watershed boundary on Vail Pass, southeast of Vail Ski Resort, Interstate 70 parallels Black Gore Creek and then closely follows Gore Creek the entire length of the watershed. Interstate 70 crosses Gore Creek and tributaries 20 times in the watershed. In the event of a vehicular accident involving a contaminant spill into Gore Creek or Black Gore Creek, a stepwise procedure has been developed for water-resource managers to estimate traveltimes of the leading edge and peak concentration of a conservative contaminant. An example calculating estimated traveltimes for a hypothetical contaminant release in Black Gore Creek is provided. Traveltime measurements were made during May and September along Black Gore Creek and Gore Creek from just downstream from the Black Lakes to the confluence with the Eagle River to account for seasonal variability in stream discharge. Fluorometric dye injection of rhodamine WT and downstream dye detection by fluorometry were used to measure traveltime characteristics of Gore Creek and Black Gore Creek. During the May traveltime measurements

  19. Modeling the tidal and sub-tidal hydrodynamics in a shallow, micro-tidal estuary

    NASA Astrophysics Data System (ADS)

    Rayson, Matthew D.; Gross, Edward S.; Fringer, Oliver B.

    2015-05-01

    The three-dimensional hydrodynamics of Galveston Bay were simulated in two periods of several month duration. The physical setting of Galveston Bay is described by synthesis of long-term observations. Several processes in addition to tidal hydrodynamics and baroclinic circulation processes contribute substantially to the observed variability of currents, water level and salinity. The model was therefore forced with realistic water levels, river discharges, winds, coastal buoyancy currents (due to the Mississippi River plume) and surface heat fluxes. Quantitative metrics were used to evaluate model performance against observations and both spatial and temporal variability in tidal and sub-tidal hydrodynamics were generally well represented by the model. Three different unstructured meshes were tested, a triangular mesh that under-resolved the shipping channel, a triangular mesh that resolved it, and a mixed quadrilateral-triangular grid with approximately equivalent resolution. It is shown that salinity and sub-tidal velocity are better predicted when the important topographic features, such as the shipping channel, are resolved. It was necessary to increase the seabed drag roughness in the mixed quadrilateral-triangular grid simulation to attain similar performance to the equivalent triangular mesh.

  20. Relative value of managed wetlands and tidal marshlands for wintering northern pintails

    USGS Publications Warehouse

    Coates, Peter S.; Casazza, Michael L.; Halstead, Brian J.; Fleskes, Joseph P.

    2012-01-01

    Northern pintail Anas acuta (hereafter, pintail) populations have declined substantially throughout the western US since the 1970s, largely as a result of converting wetlands to cropland. Managed wetlands have been developed throughout the San Francisco Bay estuaries to provide wildlife habitat, particularly for waterfowl. Many of these areas were historically tidal baylands and plans are underway to remove dikes and restore tidal action. The relationship between tidal baylands and waterfowl populations is poorly understood. Our objective was to provide information on selection and avoidance of managed and tidal marshland by pintails. During 1991–1993 and 1998–2000, we radio-marked and relocated 330 female pintails (relocations, n =11,574) at Suisun Marsh, the largest brackish water estuary within San Francisco Bay, to estimate resource selection functions during the nonbreeding months (winter). Using a distance-based modeling approach, we calculated selection functions for different ecological communities (e.g., tidal baylands) and investigated variation explained by time of day (day or night hours) to account for differences in pintail behavior (i.e., foraging vs. roosting). We found strong evidence for selection of managed wetlands. Pintails also avoided tidal marshes and bays and channels. We did not detect differences in selection function between day and night hours for managed wetlands but the degree of avoidance of other habitats varied by time of day. We also found that areas subjected to tidal action did not influence the selection of immediately adjacent managed wetlands. If current management goals include providing habitat for wintering waterfowl populations, particularly pintail, then we recommend wildlife managers focus tidal restoration on areas that are not currently managed wetland and/or improve conditions in areas of managed wetlands to increase local carrying capacities

  1. 78 FR 62616 - Salmon Creek Hydroelectric Company, Salmon Creek Hydroelectric Company, LLC; Notice of Transfer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ... Salmon Creek Hydroelectric Project, FERC No. 3730, originally issued August 10, 1981.\\1\\ The project is... Hydroelectric Project of 5 Megawatts or Less and Dismissing Application for Preliminary Permit. 2. Salmon Creek Hydroelectric Company, LLC is now the exemptee of the Salmon Creek Hydroelectric Project, FERC No. 3730....

  2. Tidal flow separation at protruding beach nourishments

    NASA Astrophysics Data System (ADS)

    Radermacher, Max; de Schipper, Matthieu A.; Swinkels, Cilia; MacMahan, Jamie H.; Reniers, Ad J. H. M.

    2017-01-01

    In recent years, the application of large-scale beach nourishments has been discussed, with the Sand Motor in the Netherlands as the first real-world example. Such protruding beach nourishments have an impact on tidal currents, potentially leading to tidal flow separation and the generation of tidal eddies of length scales larger than the nourishment itself. The present study examines the characteristics of the tidal flow field around protruding beach nourishments under varying nourishment geometry and tidal conditions, based on extensive field observations and numerical flow simulations. Observations of the flow field around the Sand Motor, obtained with a ship-mounted current profiler and a set of fixed current profilers, show that a tidal eddy develops along the northern edge of the mega-nourishment every flood period. The eddy is generated around peak tidal flow and gradually gains size and strength, growing much larger than the cross-shore dimension of the coastline perturbation. Based on a 3 week measurement period, it is shown that the intensity of the eddy modulates with the spring-neap tidal cycle. Depth-averaged tidal currents around coastline perturbations are simulated and compared to the field observations. The occurrence and behavior of tidal eddies is derived for a large set of simulations with varying nourishment size and shape. Results show that several different types of behavior exist, characterized by different combinations of the nourishment aspect ratio, the size of the nourishment relative to the tidal excursion length, and the influence of bed friction.

  3. Extraction of tidal channel networks from airborne scanning laser altimetry

    NASA Astrophysics Data System (ADS)

    Mason, David C.; Scott, Tania R.; Wang, Hai-Jing

    Tidal channel networks are important features of the inter-tidal zone, and play a key role in tidal propagation and in the evolution of salt marshes and tidal flats. The study of their morphology is currently an active area of research, and a number of theories related to networks have been developed which require validation using dense and extensive observations of network forms and cross-sections. The conventional method of measuring networks is cumbersome and subjective, involving manual digitisation of aerial photographs in conjunction with field measurement of channel depths and widths for selected parts of the network. This paper describes a semi-automatic technique developed to extract networks from high-resolution LiDAR data of the inter-tidal zone. A multi-level knowledge-based approach has been implemented, whereby low-level algorithms first extract channel fragments based mainly on image properties then a high-level processing stage improves the network using domain knowledge. The approach adopted at low level uses multi-scale edge detection to detect channel edges, then associates adjacent anti-parallel edges together to form channels. The higher level processing includes a channel repair mechanism. The algorithm may be extended to extract networks from aerial photographs as well as LiDAR data. Its performance is illustrated using LiDAR data of two study sites, the River Ems, Germany and the Venice Lagoon. For the River Ems data, the error of omission for the automatic channel extractor is 26%, partly because numerous small channels are lost because they fall below the edge threshold, though these are less than 10 cm deep and unlikely to be hydraulically significant. The error of commission is lower, at 11%. For the Venice Lagoon data, the error of omission is 14%, but the error of commission is 42%, due partly to the difficulty of interpreting channels in these natural scenes. As a benchmark, previous work has shown that this type of algorithm

  4. Maine Tidal Power Initiative: Environmental Impact Protocols For Tidal Power

    SciTech Connect

    Peterson, Michael Leroy; Zydlewski, Gayle Barbin; Xue, Huijie; Johnson, Teresa R.

    2014-02-02

    The Maine Tidal Power Initiative (MTPI), an interdisciplinary group of engineers, biologists, oceanographers, and social scientists, has been conducting research to evaluate tidal energy resources and better understand the potential effects and impacts of marine hydro-kinetic (MHK) development on the environment and local community. Project efforts include: 1) resource assessment, 2) development of initial device design parameters using scale model tests, 3) baseline environmental studies and monitoring, and 4) human and community responses. This work included in-situ measurement of the environmental and social response to the pre-commercial Turbine Generator Unit (TGU®) developed by Ocean Renewable Power Company (ORPC) as well as considering the path forward for smaller community scale projects.

  5. Coop Creek Bridge with Checkerboard Mesa in background, historic photograph, ...

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

    Co-op Creek Bridge with Checkerboard Mesa in background, historic photograph, no date, Zion National Park collection - Zion-Mount Carmel Highway, Co-op Creek Bridge, Spanning Co-op Creek, Springdale, Washington County, UT

  6. 2. Big Creek Road, worm fence and road at trailhead. ...

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

    2. Big Creek Road, worm fence and road at trailhead. - Great Smoky Mountains National Park Roads & Bridges, Big Creek Road, Between State Route 284 & Big Creek Campground, Gatlinburg, Sevier County, TN

  7. 8. DETAIL VIEW OF DATEPLATE WHICH READS 'HARP CREEK, LUTEN ...

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

    8. DETAIL VIEW OF DATEPLATE WHICH READS 'HARP CREEK, LUTEN BRIDGE CO., CONTRACTOR, ARKANSAS STATE HIGHWAY DEPARTMENT, 1928' - Harp Creek Bridge, Spans Harp Creek at State Highway 7, Harrison, Boone County, AR

  8. 59. Credit FM. Flood waters on South Battle Creek next ...

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

    59. Credit FM. Flood waters on South Battle Creek next to powerhouse. Note height of water in relation to tailraces. - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  9. 2. Deep Creek Road, old bridge at campground entrance. ...

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

    2. Deep Creek Road, old bridge at campground entrance. - Great Smoky Mountains National Park Roads & Bridges, Deep Creek Road, Between Park Boundary near Bryson City & Deep Creek Campground, Gatlinburg, Sevier County, TN

  10. 5. Big Creek Road, old bridge on Walnut Bottom Road, ...

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

    5. Big Creek Road, old bridge on Walnut Bottom Road, deck view. - Great Smoky Mountains National Park Roads & Bridges, Big Creek Road, Between State Route 284 & Big Creek Campground, Gatlinburg, Sevier County, TN

  11. 4. Big Creek Road, old bridge on Walnut Bottom Road, ...

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

    4. Big Creek Road, old bridge on Walnut Bottom Road, elevation view. - Great Smoky Mountains National Park Roads & Bridges, Big Creek Road, Between State Route 284 & Big Creek Campground, Gatlinburg, Sevier County, TN

  12. 1. Deep Creek Road, picnic pavilion Great Smoky Mountains ...

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

    1. Deep Creek Road, picnic pavilion - Great Smoky Mountains National Park Roads & Bridges, Deep Creek Road, Between Park Boundary near Bryson City & Deep Creek Campground, Gatlinburg, Sevier County, TN

  13. 2. Salmon Creek Diversion Dam, overview, diversion weir center foreground, ...

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

    2. Salmon Creek Diversion Dam, overview, diversion weir center foreground, headworks overflow weir to center left, view to east - Salmon Creek Diversion Dam, Salmon Creek, Okanogan, Okanogan County, WA

  14. 1. Salmon Creek Diversion Dam, weir (to left), sand and ...

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

    1. Salmon Creek Diversion Dam, weir (to left), sand and silt sluice gate (center), main canal headworks (to right), view to northwest - Salmon Creek Diversion Dam, Salmon Creek, Okanogan, Okanogan County, WA

  15. General perspective view of the Spring Creek Bridge, view looking ...

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

    General perspective view of the Spring Creek Bridge, view looking northwest. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  16. Approach view of the Spring Creek Bridge, view looking south. ...

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

    Approach view of the Spring Creek Bridge, view looking south. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  17. Topographic view of the Spring Creek Bridge and Collier State ...

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

    Topographic view of the Spring Creek Bridge and Collier State Park, view looking east. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  18. Approach view of the Spring Creek Bridge, view looking north. ...

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

    Approach view of the Spring Creek Bridge, view looking north. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  19. General perspective view of the Spring Creek Bridge, view looking ...

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

    General perspective view of the Spring Creek Bridge, view looking southeast. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  20. Elevation view of the Spring Creek Bridge, view looking east. ...

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

    Elevation view of the Spring Creek Bridge, view looking east. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  1. General perspective view of the Spring Creek Bridge, view looking ...

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

    General perspective view of the Spring Creek Bridge, view looking east. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  2. 2. View of Clear Creek Bridge railing and understructure, looking ...

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

    2. View of Clear Creek Bridge railing and under-structure, looking northwest. - Zion-Mount Carmel Highway, 62-foot Concrete Arch Pine Creek Bridge, Spanning Clear Creek, Springdale, Washington County, UT

  3. 7. Cable Creek Bridge after completion. Zion National Park negative ...

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

    7. Cable Creek Bridge after completion. Zion National Park negative number 1485, classification series 002, 12. - Floor of the Valley Road, Cable Creek Bridge, Spanning Cable Creek on Floor of Valley, Springdale, Washington County, UT

  4. 121. Credit JE. Galpin Creek ditch, a feeder leading water ...

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

    121. Credit JE. Galpin Creek ditch, a feeder leading water to the Keswick ditch, supplying Volta powerhouse. (JE, v. 12 1902 p. 235). - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  5. 3. Threequarter view of Oak Creek Bridge behind visitor center ...

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

    3. Three-quarter view of Oak Creek Bridge behind visitor center facing southwest - Oak Creek Administrative Center, One half mile east of Zion-Mount Carmel Highway at Oak Creek, Springdale, Washington County, UT

  6. Detail view of 850 plate girder span directly over creek, ...

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

    Detail view of 85-0 plate girder span directly over creek, looking west. - New York, Chicago & St. Louis Railroad, Elk Creek Trestle, Spanning Elk Creek, south of Elk Park Road, Lake City, Erie County, PA

  7. Perspective view showing 850 plate girder span directly over creek, ...

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

    Perspective view showing 85-0 plate girder span directly over creek, looking west. - New York, Chicago & St. Louis Railroad, Elk Creek Trestle, Spanning Elk Creek, south of Elk Park Road, Lake City, Erie County, PA

  8. Seasonal occurrence and distribution of submerged aquatic macrophytes in the tidal Potomac River

    USGS Publications Warehouse

    Haramis, G.M.; Carter, V.; Gammon, P.; Hupp, C.

    1979-01-01

    A systematic survey was conducted in the Tidal Potomac River in 1978 to determine the presence, abundance, and phenology of submersed aquatic macrophytes. The survey covered 81.5 km of main river and 59.3 km of tributary on the Maryland shore. Four regions were selected for the study: (1) Piscataway - Mattawoman Creek region (fresh-tidal river), (2) Nanjemoy Creek-Port Tobacco River region (transition zone), (3) Wicomico River region (estuary), and (4) St. Marys River region (estuary). The Wicomico River region was subdivided into fresh tidal river, transition zone and estuary for purposes of date analysis. Data were gathered by sampling each 15 m along transects running perpendicular to shore for a maximum distance of 300 m. Modified oyster tongs were used to sample both plants and benthic soils from an outboard boat. A total of 131 transects were established with a total of approximately 3500 grabs being taken per sampling period. Sampling was initiated in the spring and repeated in the summer and fall. Highest plant diversity and productivity were measured in the transition zone extending from Lower Cedar Point to beyond Maryland Point, a distance of approximately 30 km, and in the transition zone of the Wicomico River above Chaptico Bay. Fresh tidal areas were devoid of plants. The estuary had a sparse growth of horned pondweed (Zannichellia palustris) and widgeon grass (Ruppia maritima) in the spring: horned pondweed was not found in summer or fall. Redhead grass (Potomageton perfoliatus) was the most abundant pondweed; it matured in early summer and died back in mid-to-late summer. Wild celery (Vallisneria americana) and widgeon grass matured in early-to-late fall and were the most abundant plants during that period. Data analysis is being finalized and a publication is in preparation. This research will be continued over the next several seasons as part of the long term USGS effort on the Potomac

  9. Active layer hydrology for Imnavait Creek, Toolik, Alaska

    SciTech Connect

    Hinzman, L.D.; Kane, D.L.

    1987-04-01

    The hydrology of the active layer of a watershed is described. In the annual hydrologic cycle, snowmelt is the most significant event at Imnavait Creek located near Toolik Lake, Alaska. Precipitation that has accumulated for more than 6 months on the surface melts in a relatively short period of 7 to 10 days once sustained melting occurs. Significant runoff events are few. Convective storms covering relatively small areas on the North Slope of Alaska can produce significant small-scale events in a small watershed scale,but these events are rapidly attenuated outside the basin. Data collection began in August 1984. We have continuously monitored the hydrologic, the meteorologic, and the soil`s physical conditions. Information was collected through implementation of four snowmelt runoff plots and measurements of essential microclimate parameters. Soil moisture and temperature profiles were measured adjacent to each snowmelt runoff plot, and heat flux is collected adjacent to one of these plots. Meteorological parameters were measured locally. The water content of the snowpack prior to snowmelt was measured throughout the watershed and measured daily adjacent to each plot during snowmelt. The stream draining the basin was measured regularly during the spring melt event to provide information on watershed runoff rates and the volume of snowmelt.

  10. Active layer hydrology for Imnavait Creek, Toolik, Alaska

    SciTech Connect

    Hinzman, L.D.; Kane, D.L.

    1987-04-01

    The hydrology of the active layer of a watershed is described. In the annual hydrologic cycle, snowmelt is the most significant event at Imnavait Creek located near Toolik Lake, Alaska. Precipitation that has accumulated for more than 6 months on the surface melts in a relatively short period of 7 to 10 days once sustained melting occurs. Significant runoff events are few. Convective storms covering relatively small areas on the North Slope of Alaska can produce significant small-scale events in a small watershed scale,but these events are rapidly attenuated outside the basin. Data collection began in August 1984. We have continuously monitored the hydrologic, the meteorologic, and the soil's physical conditions. Information was collected through implementation of four snowmelt runoff plots and measurements of essential microclimate parameters. Soil moisture and temperature profiles were measured adjacent to each snowmelt runoff plot, and heat flux is collected adjacent to one of these plots. Meteorological parameters were measured locally. The water content of the snowpack prior to snowmelt was measured throughout the watershed and measured daily adjacent to each plot during snowmelt. The stream draining the basin was measured regularly during the spring melt event to provide information on watershed runoff rates and the volume of snowmelt.

  11. Simulating hydrodynamics on tidal mudflats

    NASA Astrophysics Data System (ADS)

    Cook, S.; Lippmann, T. C.

    2014-12-01

    Biogeochemical cycling in estuaries is governed by fluxes from both riverine sources and through estuarine sediment deposits. Although estimates from river sources are relatively common and easily sampled, estimates of nutrient fluxes through the fluid-sediment interface are less common and limited to deeper portions of the bays away from intertidal areas. Lack of quantifiable shear stress estimates over intertidal areas limits our overall understanding of nutrient budgets in estuaries. Unfortunately, observation of intertidal hydrodynamics and nutrient fluxes over tidal flats and near the water's edge is difficult owing to the temporally varying and spatially extensive region where the tides inundate, and thus numerical modeling is often employed. In this work, the Regional Ocean Modeling System (ROMS), a three dimensional numerical hydrodynamic model was used to investigate the shear stresses over intertidal mudflats in the Great Bay, a tidally-dominated New England estuary cut by several tidal channels and with over 50% of the estuary exposed at low tide. The ROMS wetting and drying scheme was used to simulate the rising and falling tide on the flats, a successful approach adapted in other regions of the world but not always inclusive of tidal channels. Bathymetric data obtained in 2009 and 2013 was used to define the model grid. Predicted tides are forced at Adam's Pt., a natural constriction in the estuary about 20 km upstream of the mouth and at the entrance to the Great Bay. Of particular interest are fluxes of material on-to and off-of the tidal flats which contribute to water quality conditions in the estuary, and are largely governed by shear stresses that drive nutrient fluxes at the fluid-sediment interface. Basin wide estimates of near-bottom shear stresses can be used to estimate first order nutrient fluxes over a tidal cycle and hence describe general biogeochemical dynamics of the estuary. Future work will include enhanced forcing of currents by

  12. Dispersal potential of a tidal river and colonization of a created tidal freshwater marsh

    PubMed Central

    Leck, Mary Allessio

    2012-01-01

    Background and aims A created tidal freshwater wetland, with no extant seed bank, was monitored to evaluate the colonization potential of a tidal river, vegetation and seed bank changes, and also species persistence. Methodology The 32.3-ha mitigation, adjacent to the Delaware River, was completed in 1994. Three sites, with differing completion dates, and three locations (channel edge, midpoint, upland edge) were sampled. From 1995 to 1999, surveys permitted a view of initial dynamics involving soil seed bank density or field vegetation cover, as well as species composition. Vegetation was monitored through 2011, and in 2011 a seed bank survey was also undertaken. Principal results Between 1995 and 1999, 177 species emerged from soil samples, with a maximum of 32.3 ± 1.8 (SE)/sample. Eight species were added in 2011, indicating continuing dispersal and input. Comparing species richness across three sites for midpoint locations, 2011 totals and species/sample were lower (61–90 % and 53–72 %, respectively) than 1998 values. In vegetation plots during the first 5 years, 72 cover species were present. In 2011, there were 44; 14 were new and the majority (13) were woody and part of an overhanging edge canopy. Dispersal was primarily via water. Overall, the trend was towards lower seed bank densities, except for Mikania scandens and Phragmites australis which had higher densities, as well as cover values. Species richness also decreased. Species varied in persistence in the seed bank and vegetation, and among sites and with location. Initial site colonization differences were still apparent in 2011 seed bank samples. While present, Lythrum salicaria did not reduce species richness; Phragmites, in contrast, had substantial impact. Conclusions The single most important change was an increase in Phragmites in the vegetation. Vegetation dynamics are now determined by this species, and the persistent seed bank and continuing dispersal input have little obvious future in

  13. Prediction of CBS tidal evolution

    NASA Astrophysics Data System (ADS)

    Dryomova, G. N.

    The time series of basic processes, accompanying the tidal evolution of star components of Close Binary Systems (CBS) are predicted in the framework of evolutionary stellar models by Claret (2004). The series includes the apsidal motion period, timescale of synchronization of axial rotation of a star with the orbital revolution, the orbit circularization timescale, and the age. Data from the catalogues by Svechnikov & Perevozkina (1999) and by Torres, Andersen, Gimenez (2010) are used for testing the sensitivity of the numerical prediction algorithm.

  14. Trans World Tidal Gravity Profile.

    DTIC Science & Technology

    1984-12-31

    America Curitiba (BraziZ) This station, situated at the Universidade Federal do Parana, in the Instituto de Ciencias Geod6sicas under Professor C...SUL COMPOSANTE VEPTICALE ERESIL 29 40 17S 53 49 22W H 700M P 2M 0 330KM DEPOTS SEDIMENTAIRES SUk BASALTE DEPT* DE INGENIERIA RURAL-UNIV. FED. DE SANTA...PRECAMBRIENIGNEISS * UNIVERSIDADE FEDERAL DO RIO GRANDE DO NORTE - DEPARTAMENTO DE FISICA TRANS WORLD TIDAL GRAVITY PROFILES P. MELCHIOR CENTRO POLITECNICO

  15. Tidally-Induced Thermonuclear Supernovae

    SciTech Connect

    Rosswog, S.; Ramirez-Ruiz, E.; Hix, William Raphael

    2009-01-01

    We discuss the results of 3D simulations of tidal disruptions of white dwarfs by moderate-mass black holes as they may exist in the cores of globular clusters or dwarf galaxies. Our simulations follow self-consistently the hydrodynamic and nuclear evolution from the initial parabolic orbit over the disruption to the build-up of an accretion disk around the black hole. For strong enough encounters (pericentre distances smaller than about 1/3 of the tidal radius) the tidal compression is reversed by a shock and finally results in a thermonuclear explosion. These explosions are not restricted to progenitor masses close to the Chandrasekhar limit, we find exploding examples throughout the whole white dwarf mass range. There is, however, a restriction on the masses of the involved black holes: black holes more massive than 2x105M{circle_dot} swallow a typical 0.6M{circle_dot} white dwarf before their tidal forces can overwhelm the star's selfgravity. Therefore, this mechanism is characteristic for black holes of moderate masses. The material that remains bound to the black hole settles into an accretion disk and produces an Xray flare close to the Eddington limit of L{sub Edd} {approx} 10{sup 41}erg/s (Mbh/1000M{circle_dot}), typically lasting for a few months. The combination of a peculiar thermonuclear supernova together with an X-ray flare thus whistle-blows the existence of such moderate-mass black holes. The next generation of wide field space-based instruments should be able to detect such events.

  16. ARRAY OPTIMIZATION FOR TIDAL ENERGY EXTRACTION IN A TIDAL CHANNEL – A NUMERICAL MODELING ANALYSIS

    SciTech Connect

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea

    2014-04-18

    This paper presents an application of a hydrodynamic model to simulate tidal energy extraction in a tidal dominated estuary in the Pacific Northwest coast. A series of numerical experiments were carried out to simulate tidal energy extraction with different turbine array configurations, including location, spacing and array size. Preliminary model results suggest that array optimization for tidal energy extraction in a real-world site is a very complex process that requires consideration of multiple factors. Numerical models can be used effectively to assist turbine siting and array arrangement in a tidal turbine farm for tidal energy extraction.

  17. North American tidal power prospects

    NASA Astrophysics Data System (ADS)

    Wayne, W. W., Jr.

    1981-07-01

    Prospects for North American tidal power electrical generation are reviewed. Studies by the US Army Corps of Engineers of 90 possible generation schemes in Cobscook Bay, ME, indicated that maximum power generation rather than dependable capacity was the most economic method. Construction cost estimates for 15 MW bulb units in a single effect mode from basin to the sea are provided; five projects were considered ranging from 110-160 MW. Additional tidal power installations are examined for: Half-Moon Cove, ME (12 MW, 18 ft tide); Cook Inlet, AK, which is shown to pose severe environmental and engineering problems due to fish migration, earthquake hazards, and 300 ft deep silt deposits; and the Bay of Fundy, Canada. This last has a 17.8 MW plant under construction in a 29 ft maximum tide area. Other tidal projects of the Maritime Provinces are reviewed, and it is noted that previous economic evaluations based on an oil price of $16/barrel are in need of revision.

  18. Cache Creek terrane entrapment: Oroclinal paradox within the Canadian Cordillera

    NASA Astrophysics Data System (ADS)

    Mihalynuk, Mitch G.; Nelson, Joanne; Diakow, Larry J.

    1994-06-01

    Exotic and far-traveled oceanic crustal rocks of the Cache Creek terrane (CC) are bordered by less exotic Quesnel (QN) and Stikine (ST) arc terranes to the east, north, and west. All of these terranes are enveloped by an arcuate belt of displaced continental margin rocks; the Kootenay (KO), Nisling (NS), and parts of the Yukon-Tanana (YTT) terranes, that have indirect ties to ancestral North America (NA). Initial 87Sr/86Sr isopleths conform to this arcuate pattern. Such a pattern of concentric belts presents a geological conundrum: How did the QN, ST, and CC come to be virtually enveloped by terranes with ties to NA? Past and current models that explain assembly of the Canadian Cordillera are deficient in their treatment of this problem. We propose that Early Mesozoic QN and ST were joined through their northern ends as two adjacent arc festoons that faced south toward the Cache Creek ocean (Panthalassa?). Oceanic plateau remnants within the CC today were transported from the Tethyan realm and collided with these arcs during subduction of the Cache Creek ocean. Counterclockwise oroclinal rotation of ST and NS terranes in the Late Triassic to Early Jurassic caused enclosure of the CC. Rotation continued until these terranes collided with QN in the Middle Jurassic. Paleomagnetic declination data provide support for this model in the form of large average anticlockwise rotations for Permian to Early Jurassic sites in ST but moderate clockwise rotations for sites in QN. Specific modern analogues for the Cordilleran orocline include the Yap trench, where the Caroline rise is colliding end-on with the Mariana Arc and the Banda Arc, located on the southeastern "tail" of the Asian plate, which is being deformed into a tight loop by interactions with the Australian and Pacific plates.

  19. SANDY CREEK ROADLESS AREA, MISSISSIPPI.

    USGS Publications Warehouse

    Haley, Boyd R.; Bitar, Richard F.

    1984-01-01

    The Sandy Creek Roadless Area includes about 3. 7 sq mi in the southeastern part of Adams County, Mississippi. On the basis of a mineral survey, the area offers little promise for the occurrence of metallic mineral resources but has a probable resource potential for oil and natural gas. It is possible that wells drilled deep enough to penetrate the older reservoirs will encounter significant quantities of oil and natural gas in the roadless area. The deposits of gravel, sand, and clay present in the area could be utilized in the construction industry, but similar deposits elsewhere are much closer to available markets.

  20. The Effect of Landuse and Other External Factors on Water Quality Within two Creeks in Northern Kentucky

    NASA Astrophysics Data System (ADS)

    Boateng, S.

    2006-05-01

    The purpose of this study was to monitor the water quality in two creeks in Northern Kentucky. These are the Banklick Creek in Kenton County and the Woolper Creek in Boone County, Kentucky. The objective was to evaluate the effect of landuse and other external factors on surface water quality. Landuse within the Banklick watershed is industrial, forest and residential (urban) whereas that of Woolper Creek is agricultural and residential (rural). Two testing sites were selected along the Banklick Creek; one site was upstream the confluence with an overflow stream from an adjacent lake; the second site was downstream the confluence. Most of the drainage into the lake is over a near-by industrial park and the urban residential areas of the cities of Elsmere and Erlanger, Kentucky. Four sampling locations were selected within the Woolper Creek watershed to evaluate the effect of channelization and subsequent sedimentation on the health of the creek. Water quality parameters tested for include dissolved oxygen, phosphates, chlorophyll, total suspended sediments (TSS), pH, oxidation reduction potential (ORP), nitrates, and electrical conductivity. Sampling and testing were conducted weekly and also immediately after storm events that occurred before the regular sampling dates. Sampling and testing proceeded over a period of 29 weeks. Biological impact was determined, only in Woolper Creek watershed, by sampling benthic macroinvertebrates once every four weeks. The results showed significant differences in the water quality between the two sites within the Banklick Creek. The water quality may be affected by the stream overflow from the dammed lake. Also, channelization in the Woolper Creek seemed to have adverse effects on the water quality. A retention pond, constructed to prevent sediments from flowing into the Woolper Creek, did not seem to be effective. This is because the water quality downstream of the retention pond was significantly worse than that of the

  1. 33 CFR 117.725 - Manantico Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Manantico Creek. 117.725 Section 117.725 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.725 Manantico Creek. The draw of...

  2. 33 CFR 117.745 - Rancocas Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Rancocas Creek. 117.745 Section 117.745 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.745 Rancocas Creek. (a) The...

  3. 33 CFR 117.732 - Nacote Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Nacote Creek. 117.732 Section 117.732 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.732 Nacote Creek. (a) The Route 9 bridge,...

  4. 33 CFR 117.750 - Schellenger Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Schellenger Creek. 117.750 Section 117.750 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.750 Schellenger Creek. The draw...

  5. 33 CFR 117.732 - Nacote Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Nacote Creek. 117.732 Section 117.732 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.732 Nacote Creek. (a) The Route 9 bridge,...

  6. 33 CFR 117.737 - Oldmans Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Oldmans Creek. 117.737 Section 117.737 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.737 Oldmans Creek. The draws of...

  7. 33 CFR 117.745 - Rancocas Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Rancocas Creek. 117.745 Section 117.745 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.745 Rancocas Creek. (a) The...

  8. 33 CFR 117.725 - Manantico Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Manantico Creek. 117.725 Section 117.725 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.725 Manantico Creek. The draw of...

  9. 33 CFR 117.732 - Nacote Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Nacote Creek. 117.732 Section 117.732 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.732 Nacote Creek. (a) The Route 9 bridge,...

  10. 33 CFR 117.737 - Oldmans Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Oldmans Creek. 117.737 Section 117.737 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.737 Oldmans Creek. The draws of...

  11. 33 CFR 117.725 - Manantico Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Manantico Creek. 117.725 Section 117.725 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.725 Manantico Creek. The draw of...

  12. 33 CFR 117.715 - Debbies Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Debbies Creek. 117.715 Section 117.715 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.715 Debbies Creek. (a) The draw...

  13. 33 CFR 117.750 - Schellenger Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Schellenger Creek. 117.750 Section 117.750 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.750 Schellenger Creek. The draw...

  14. 33 CFR 117.750 - Schellenger Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Schellenger Creek. 117.750 Section 117.750 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.750 Schellenger Creek. The draw...

  15. 33 CFR 117.725 - Manantico Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Manantico Creek. 117.725 Section 117.725 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.725 Manantico Creek. The draw of...

  16. 33 CFR 117.750 - Schellenger Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Schellenger Creek. 117.750 Section 117.750 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.750 Schellenger Creek. The draw...

  17. 33 CFR 117.732 - Nacote Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Nacote Creek. 117.732 Section 117.732 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.732 Nacote Creek. (a) The Route 9 bridge,...

  18. 33 CFR 117.737 - Oldmans Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Oldmans Creek. 117.737 Section 117.737 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.737 Oldmans Creek. The draws of...

  19. 33 CFR 117.737 - Oldmans Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Oldmans Creek. 117.737 Section 117.737 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.737 Oldmans Creek. The draws of...

  20. 33 CFR 117.737 - Oldmans Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Oldmans Creek. 117.737 Section 117.737 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.737 Oldmans Creek. The draws of...

  1. 33 CFR 117.750 - Schellenger Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Schellenger Creek. 117.750 Section 117.750 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.750 Schellenger Creek. The draw...

  2. 33 CFR 117.745 - Rancocas Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Rancocas Creek. 117.745 Section 117.745 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.745 Rancocas Creek. (a) The...

  3. 33 CFR 117.725 - Manantico Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Manantico Creek. 117.725 Section 117.725 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.725 Manantico Creek. The draw of...

  4. 33 CFR 117.732 - Nacote Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Nacote Creek. 117.732 Section 117.732 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.732 Nacote Creek. (a) The Route 9 bridge,...

  5. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  6. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  7. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  8. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  9. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  10. 33 CFR 117.841 - Smith Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Smith Creek. 117.841 Section 117.841 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.841 Smith Creek. The draw of the...

  11. 33 CFR 117.185 - Pacheco Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Pacheco Creek. 117.185 Section 117.185 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.185 Pacheco Creek. The draw of the Contra Costa County highway bridge, mile 1.0,...

  12. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draw of the...

  13. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draws of the...

  14. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draw of the...

  15. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draw of the...

  16. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draws of the...

  17. Pine Creek Ranch; Annual Report 2002.

    SciTech Connect

    Berry, Mark E.

    2003-02-01

    This report gives information about the following four objectives: OBJECTIVE 1--Gather scientific baseline information for monitoring purposes and to assist in the development of management plans for Pine Creek Ranch; OBJECTIVE 2--Complete and implement management plans; OBJECTIVE 3--Protect, manage and enhance the assets and resources of Pine Creek Ranch; and OBJECTIVE 4--Deliverables.

  18. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  19. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  20. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  1. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  2. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  3. 33 CFR 117.557 - Curtis Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Curtis Creek. 117.557 Section 117.557 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.557 Curtis Creek. The draw of the I695...

  4. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  5. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  6. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  7. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  8. 33 CFR 117.335 - Taylor Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Taylor Creek. 117.335 Section 117.335 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.335 Taylor Creek. The draw of US441 bridge, mile...

  9. Seasonal dynamics of circulation in Hooghly Estuary and its adjacent coastal oceans

    NASA Astrophysics Data System (ADS)

    Mishra, Shashank Kr.; Nayak, Gourav; Nayak, R. K.; Dadhwal, V. K.

    2016-05-01

    Hooghly is one of the major estuaries in Ganges, the largest and longest river in the Indian subcontinent. The Hooghly estuary is a coastal plain estuary lying approximately between 21°-23° N and 87°-89° E. We used a terrain following ocean model to study tide driven residual circulations, seasonal mean flow patterns and its energetics in the Hooghly estuary and adjacent coastal oceans on the north eastern continental shelf of India. The model is driven by tidal levels at open ocean end and winds at the air-sea interface. The sources of forcing fields for tides were from FES2012, winds from ECMWF. Harmonic analysis is carried out to compute the tidal and non-tidal components of currents and sea level from the model solutions. The de-tidal components were averaged for the entire period of simulation to describe residual and mean-seasonal circulations in the regions. We used tide-gauge, SARAL-ALTIKA along track sea level measurements to evaluate model solutions. Satellite measure Chla were used along with simulated currents to describe important features of the circulations in the region.

  10. Palynology of the Vermillion Creek coal bed and associated strata

    SciTech Connect

    Nichols, D.J.

    1987-01-01

    Fifty-four species of spores, pollen, fungi, and algal palynomorphs were identified from the Vermillion Creek coal bed and associated strata, including underlying and overlying deposits and partings within the coal. The stratigraphic distribution and relative abundances of these plant microfossils were determined in samples from three cores. The palynomorph assemblage, which is late early Eocene in age, includes 8 species of pterophyte spores, 4 species of gymnosperm pollen, 39 species of angiosperm pollen, 2 species of algal coenobia or cysts, and 1 species of fungal spore. The assemblage is dominated by the pollen species Platycarya paltycaryoides and Arecipites tenuiexinous. Ten species appear to have biostratigraphic importance, based on their stratigraphic ranges in the Rocky Mountain region. The record of their occurrence in a well-dated stratigraphic section is a contribution to Tertiary biostratigraphy in the central Rockies. Palynologic evidence supplements stratigraphic, sedimentologic, geochemical, coal petrographic and other paleontologic evidence on the nature of the depositional environment. The Vermillion Creek coal was deposited in a paludal environment adjacent to a nonsaline lacustrine system. Evidence from botanical affinities of palynomorph species and habitats of living relatives indicates that the region had a moist subtropical climate in late early Eocene time.

  11. Water resources of the Sycamore Creek watershed, Maricopa County, Arizona

    USGS Publications Warehouse

    Thomsen, B.W.; Schumann, Herbert H.

    1969-01-01

    The Sycamore Creek watershed is representative of many small watersheds in the Southwest where much of the streamflow originates in the mountainous areas and disappears rather quickly into the alluvial deposits adjacent to the mountains. Five years of .streamflow records from the Sycamore Creek watershed show that an average annual water yield of 6,110 acre-feet was obtained from the 165 square miles (105,000 acres) of the upper hard-rock mountain area, which receives an average annual precipitation of about 20 inches. Only a small percentage of the ,annual water yield, however, reaches the Verde River as surface flow over the 9-mile reach of the alluvial channel below the mountain front. Flows must be more ,than 200 cubic feet per second to reach the river; flows less than this rate disappear into the 1,ower alluvial area and are stored temporarily in the ground-Water reservoir : most of this water is released as ground-water discharge to the Verde River at a relatively constant rate of about 4,000 acre-feet per year. Evapotranspiration losses in the lower alluvial area are controlled by the depth of the water table and averaged about 1,500 acre-feet per year.

  12. Analysis of Ground-Water Flow in the Madison Aquifer using Fluorescent Dyes Injected in Spring Creek and Rapid Creek near Rapid City, South Dakota, 2003-04

    USGS Publications Warehouse

    Putnam, Larry D.; Long, Andrew J.

    2007-01-01

    , which is located adjacent to the loss zone, was similar to the concentration in the stream. Fluorescein arrived at well NON (injection at site S1), which is located about 2 miles northeast of the loss zone, within about 1.6 days, and the maximum concentration was 44 ug/L. For injection at site S4, when streamflow was about 12 ft3/s, fluorescein was detected in samples from six wells and time to first arrival ranged from 0.2 to 16 days. Following injection at site S4 in 2004, the length of time that dye remained in the capture zone of well NON, which is located approximately 2 miles from the loss zone, was almost an order of magnitude greater than in 2003. For injection at site R1, Rhodamine WT was detected at well DRU and spring TI-SP with time to first arrival of about 0.5 and 1.1 days and maximum concentrations of 6.2 and 0.91 ug/L, respectively. Well DRU and spring TI-SP are located near the center of the Rapid Creek loss zone where the creek has a large meander. Measurable concentrations were observed for spring TI-SP as many as 109 days after the dye injection. The direction of a conduit flow path in the Spring Creek area was to the northeast with ground-water velocities that ranged from 770 to 6,500 feet per day. In the Rapid Creek loss zone, a conduit flow path east of the loss zone was not evident from the dye injection.

  13. TIDAL FRICTION AND TIDAL LAGGING. APPLICABILITY LIMITATIONS OF A POPULAR FORMULA FOR THE TIDAL TORQUE

    SciTech Connect

    Efroimsky, Michael; Makarov, Valeri V. E-mail: vvm@usno.navy.mil

    2013-02-10

    Tidal torques play a key role in rotational dynamics of celestial bodies. They govern these bodies' tidal despinning and also participate in the subtle process of entrapment of these bodies into spin-orbit resonances. This makes tidal torques directly relevant to the studies of habitability of planets and their moons. Our work begins with an explanation of how friction and lagging should be built into the theory of bodily tides. Although much of this material can be found in various publications, a short but self-consistent summary on the topic has been lacking in the hitherto literature, and we are filling the gap. After these preparations, we address a popular concise formula for the tidal torque, which is often used in the literature, for planets or stars. We explain why the derivation of this expression, offered in the paper by Goldreich and in the books by Kaula (Equation (4.5.29)) and Murray and Dermott (Equation (4.159)), implicitly sets the time lag to be frequency independent. Accordingly, the ensuing expression for the torque can be applied only to bodies having a very special (and very hypothetical) rheology which makes the time lag frequency independent, i.e., the same for all Fourier modes in the spectrum of tide. This expression for the torque should not be used for bodies of other rheologies. Specifically, the expression cannot be combined with an extra assertion of the geometric lag being constant, because at finite eccentricities the said assumption is incompatible with the constant-time-lag condition.

  14. TIDAL NOVAE IN COMPACT BINARY WHITE DWARFS

    SciTech Connect

    Fuller, Jim; Lai Dong

    2012-09-01

    Compact binary white dwarfs (WDs) undergoing orbital decay due to gravitational radiation can experience significant tidal heating prior to merger. In these WDs, the dominant tidal effect involves the excitation of outgoing gravity waves in the inner stellar envelope and the dissipation of these waves in the outer envelope. As the binary orbit decays, the WDs are synchronized from outside in (with the envelope synchronized first, followed by the core). We examine the deposition of tidal heat in the envelope of a carbon-oxygen WD and study how such tidal heating affects the structure and evolution of the WD. We show that significant tidal heating can occur in the star's degenerate hydrogen layer. This layer heats up faster than it cools, triggering runaway nuclear fusion. Such 'tidal novae' may occur in all WD binaries containing a CO WD, at orbital periods between 5 minutes and 20 minutes, and precede the final merger by 10{sup 5}-10{sup 6} years.

  15. Gravitoelectromagnetic analogy based on tidal tensors

    SciTech Connect

    Costa, L. Filipe O.; Herdeiro, Carlos A. R.

    2008-07-15

    We propose a new approach to a physical analogy between general relativity and electromagnetism, based on tidal tensors of both theories. Using this approach we write a covariant form for the gravitational analogues of the Maxwell equations, which makes transparent both the similarities and key differences between the two interactions. The following realizations of the analogy are given. The first one matches linearized gravitational tidal tensors to exact electromagnetic tidal tensors in Minkowski spacetime. The second one matches exact magnetic gravitational tidal tensors for ultrastationary metrics to exact magnetic tidal tensors of electromagnetism in curved spaces. In the third we show that our approach leads to a two-step exact derivation of Papapetrou's equation describing the force exerted on a spinning test particle. Analogous scalar invariants built from tidal tensors of both theories are also discussed.

  16. Sedimentation and response to sea-level rise of a restored marsh with reduced tidal exchange: Comparison with a natural tidal marsh

    USGS Publications Warehouse

    Vandenbruwaene, W.; Maris, T.; Cahoon, D.R.; Meire, P.; Temmerman, S.

    2011-01-01

    Along coasts and estuaries, formerly embanked land is increasingly restored into tidal marshes in order to re-establish valuable ecosystem services, such as buffering against flooding. Along the Scheldt estuary (Belgium), tidal marshes are restored on embanked land by allowing a controlled reduced tide (CRT) into a constructed basin, through a culvert in the embankment. In this way tidal water levels are significantly lowered (ca. 3 m) so that a CRT marsh can develop on formerly embanked land with a ca. 3 m lower elevation than the natural tidal marshes. In this study we compared the long-term change in elevation (ΔE) within a CRT marsh and adjacent natural tidal marsh. Over a period of 4 years, the observed spatio-temporal variations in ΔE rate were related to variations in inundation depth, and this relationship was not significantly different for the CRT marsh and natural tidal marsh. A model was developed to simulate the ΔE over the next century. (1) Under a scenario without mean high water level (MHWL) rise in the estuary, the model shows that the marsh elevation-ΔE feedback that is typical for a natural tidal marsh (i.e. rising marsh elevation results in decreasing inundation depth and therefore a decreasing increase in elevation) is absent in the basin of the CRT marsh. This is because tidal exchange of water volumes between the estuary and CRT marsh are independent from the CRT marsh elevation but dependent on the culvert dimensions. Thus the volume of water entering the CRT remains constant regardless of the marsh elevation. Consequently the CRT MHWL follows the increase in CRT surface elevation, resulting after 75 years in a 2–2.5 times larger elevation gain in the CRT marsh, and a faster reduction of spatial elevation differences. (2) Under a scenario of constant MHWL rise (historical rate of 1.5 cm a-1), the equilibrium elevation (relative to MHWL) is 0.13 m lower in the CRT marsh and is reached almost 2 times faster. (3) Under a scenario of

  17. Tidal deformability of compact boson stars

    NASA Astrophysics Data System (ADS)

    Sennett, Noah; Steinhoff, Jan; Hinderer, Tanja; Buonanno, Alessandra

    2017-01-01

    Gravitational waves can be used to probe the structure of compact objects in coalescing binary systems. This structure enters the pre-merger waveform through tidal interactions between the two bodies, characterized by each object's tidal deformability. We investigate whether these effects can differentiate binary black holes from systems containing compact boson stars. We compute the tidal deformability for various boson star models, including ultracompact non-topological solitonic solutions.

  18. Stratification and loading of fecal indicator bacteria (FIB) in a tidally muted urban salt marsh.

    PubMed

    Johnston, Karina K; Dorsey, John H; Saez, Jose A

    2015-03-01

    Stratification and loading of fecal indicator bacteria (FIB) were assessed in the main tidal channel of the Ballona Wetlands, an urban salt marsh receiving muted tidal flows, to (1) determine FIB concentration versus loading within the water column at differing tidal flows, (2) identify associations of FIB with other water quality parameters, and (3) compare wetland FIB concentrations to the adjacent estuary. Sampling was conducted four times during spring-tide events; samples were analyzed for FIB and turbidity (NTU) four times over a tidal cycle at pre-allocated depths, depending on the water level. Additional water quality parameters measured included temperature, salinity, oxygen, and pH. Loadings were calculated by integrating the stratified FIB concentrations with water column cross-sectional volumes corresponding to each depth. Enterococci and Escherichia coli were stratified both by concentration and loading, although these variables portrayed different patterns over a tidal cycle. Greatest concentrations occurred in surface to mid-strata levels, during flood tides when contaminated water flowed in from the estuary, and during ebb flows when sediments were suspended. Loading was greatest during flood flows and diminished during low tide periods. FIB concentrations within the estuary often were significantly greater than those within the wetland tide channel, supporting previous studies that the wetlands act as a sink for FIB. For public health water quality monitoring, these results indicate that more accurate estimates of FIB concentrations would be obtained by sampling a number of points within a water column rather than relying only on single surface samples.

  19. Hydrology of the Johnson Creek Basin, Oregon

    USGS Publications Warehouse

    Lee, Karl K.; Snyder, Daniel T.

    2009-01-01

    The Johnson Creek basin is an important resource in the Portland, Oregon, metropolitan area. Johnson Creek forms a wildlife and recreational corridor through densely populated areas of the cities of Milwaukie, Portland, and Gresham, and rural and agricultural areas of Multnomah and Clackamas Counties. The basin has changed as a result of agricultural and urban development, stream channelization, and construction of roads, drains, and other features characteristic of human occupation. Flooding of Johnson Creek is a concern for the public and for water management officials. The interaction of the groundwater and surface-water systems in the Johnson Creek basin also is important. The occurrence of flooding from high groundwater discharge and from a rising water table prompted this study. As the Portland metropolitan area continues to grow, human-induced effects on streams in the Johnson Creek basin will continue. This report provides information on the groundwater and surface-water systems over a range of hydrologic conditions, as well as the interaction these of systems, and will aid in management of water resources in the area. High and low flows of Crystal Springs Creek, a tributary to Johnson Creek, were explained by streamflow and groundwater levels collected for this study, and results from previous studies. High flows of Crystal Springs Creek began in summer 1996, and did not diminish until 2000. Low streamflow of Crystal Springs Creek occurred in 2005. Flow of Crystal Springs Creek related to water-level fluctuations in a nearby well, enabling prediction of streamflow based on groundwater level. Holgate Lake is an ephemeral lake in Southeast Portland that has inundated residential areas several times since the 1940s. The water-surface elevation of the lake closely tracked the elevation of the water table in a nearby well, indicating that the occurrence of the lake is an expression of the water table. Antecedent conditions of the groundwater level and autumn

  20. Tidally dominated sediment dispersal offshore of a small mountainous river: Elwha River, Washington State

    NASA Astrophysics Data System (ADS)

    Eidam, E. F.; Ogston, A. S.; Nittrouer, C. A.; Warrick, J. A.

    2016-03-01

    Sediment supplied by small mountainous rivers (SMRs) represents a major fraction of the global ocean sediment budget. Studies from the past two decades have shown that much of this sediment is dispersed by episodic wind and wave energy along storm-dominated coasts. In tidally dominated environments, however, different transport styles and deposits may result from persistent tidal dispersal. This study investigates episodic sediment releases generated by dam removal from a SMR in Washington State, in order to evaluate the mechanics of tidally dominated sediment dispersal in an energetic marine environment. The results indicate that asymmetric tidal currents with peak magnitudes of ∼50 to >80 cm/s produce daily sediment export in the direction of the dominant tidal phase (i.e., the semi-diurnal phase with faster currents and longer duration), resulting in dispersal of fluvially derived fine sediment to distal sinks. These effects are observed throughout all seasons in the presence or absence of wave events. During the first two years of dam removal, more than 8 million tonnes of sediment were discharged to the coast. The net result was little to no change in grain size at 10-60 m water depth across >70% of the seabed offshore of the river mouth. Over the remaining ∼2 to 3 km2 of the subaqueous delta, several cm of mud and sand accumulated in a sheltered coastal embayment adjacent to the river mouth. These results demonstrate that SMR discharge events may form patchy, isolated deposits-or even no deposits-along coastlines with strong tidal currents, in contrast to the mid-shelf mud belts formed on storm-dominated shelves. Over longer timescales, knowledge of the erosional capacity of local and regional tidal currents may be key to interpreting the terrestrial event record preserved in (or possibly excluded from) marine SMR deposits.

  1. Nursery function of an estuarine tidal marsh for the brown shrimp Crangon crangon

    NASA Astrophysics Data System (ADS)

    Cattrijsse, André; Dankwa, Hederick R.; Mees, Jan

    1997-12-01

    The brown shrimp Crangon crangon migrates into the brackish part of the Westerschelde estuary (southwest Netherlands) shortly after metamorphosis and uses the tidal marsh habitat as a nursery until reaching a total length of about 15 mm. The importance of the marsh as a nursery was evaluated by estimating foraging activity, predation mortality and residence time. In early postlarval stages, C. crangon utilised the intertidal creeks of an estuarine tidal marsh from early spring (March-April) until late autumn (October-November). Postlarval shrimp leaving the marsh with the ebb tide always had significantly more food in their stomachs than shrimp entering the marsh with the incoming flood water. Predation upon the shrimp population was relatively low during most months, but in increased between August and October when common gobies, Pomatoschistus microps, were present in high densities. There was also predation by the small seabass Dicentrarchus labrax. The marsh creeks function both as foraging areas and as predation refuge. Depending on temperature, postlarval shrimp stayed in the marsh for a period of two to three weeks. Quantitatively, the value of the marsh as a nursery area had changed drastically during a second year of sampling, illustrating high natural year-to-year variability. However, the seasonal pattern remained. Recruitment to the subtidal adult population represents an export of animals from the marsh to the estuary. This export is negligible in terms of biomass (as compared to the total biomass of the estuarine population) but it may be important in terms of numbers of individuals.

  2. Effects of crab halophytic plant interactions on creek growth in a S.W. Atlantic salt marsh: A Cellular Automata model

    NASA Astrophysics Data System (ADS)

    Minkoff, Darío R.; Escapa, Mauricio; Ferramola, Félix E.; Maraschín, Silvio D.; Pierini, Jorge O.; Perillo, Gerardo M. E.; Delrieux, Claudio

    2006-09-01

    The Bahía Blanca Estuary (38° 50' S, and 62° 30' W) presents salt marshes where interactions between the local flora ( Sarcocornia perennis) and fauna ( Chasmagnathus granulatus) generate some kind of salt pans that alter the normal water circulation and condition its flow and course towards tidal creeks. The crab-vegetation dynamics in the salt marsh presents variations that cannot be quantified in a reasonable period of time. The interaction between S. perennis plant and C. granulatus crab is based on simple laws, but its result is a complex biological mechanism that causes an erosive process on the salt marsh and favors the formation of tidal creeks. To study it, a Cellular Automata model is proposed, based on the laws deduced from the observation of these phenomena in the field, and then verified with measurable data within macroscale time units. Therefore, the objective of this article is to model how the interaction between C. granulatus and S. perennis modifies the landscape of the salt marsh and influences the path of tidal creeks. The model copies the basic laws that rule the problem based on purely biological factors. The Cellular Automata model proved capable of reproducing the effects of the interaction between plants and crabs in the salt marsh. A study of the water drainage of the basins showed that this interaction does indeed modify the development of tidal creeks. Model dynamics would likewise follow different laws, which would provide a different formula for the probability of patch dilation. The patch shape can be obtained changing the pattern that dilates.

  3. Calculating lunar retreat rates using tidal rhythmites

    USGS Publications Warehouse

    Kvale, E.P.; Johnson, H.W.; Sonett, C.P.; Archer, A.W.; Zawistoski, A.N.N.

    1999-01-01

    Tidal rhythmites are small-scale sedimenta??r}- structures that can preserve a hierarchy of astronomically induced tidal periods. They can also preserve a record of periodic nontidal sedimentation. If properly interpreted and understood, tidal rhjthmites can be an important component of paleoastronomy and can be used to extract information on ancient lunar orbital dynamics including changes in Earth-Moon distance through geologic time. Herein we present techniques that can be used to calculate ancient Earth-Moon distances. Each of these techniques, when used on a modern high-tide data set, results in calculated estimates of lunar orbital periods and an EarthMoon distance that fall well within 1 percent of the actual values. Comparisons to results from modern tidal data indicate that ancient tidal rhythmite data as short as 4 months can provide suitable estimates of lunar orbital periods if these tidal records are complete. An understanding of basic tidal theory allows for the evaluation of completeness of the ancient tidal record as derived from an analysis of tidal rhythmites. Utilizing the techniques presented herein, it appears from the rock record that lunar orbital retreat slowed sometime during the midPaleozoic. Copyright ??1999, SEPM (Society for Sedimentary Geology).

  4. 81. PHOTOCOPY OF PHOTOGRAPH SHOWING NEW CREEK CHANNEL UNDER CONSTRUCTION ...

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

    81. PHOTOCOPY OF PHOTOGRAPH SHOWING NEW CREEK CHANNEL UNDER CONSTRUCTION AT P STREET BEND, FROM 1940 REPORT ON PROPOSED DEVELOPMENT OF ROCK CREEK AND POTOMAC PARKWAY, SECTION II (ROCK CREEK AND POTOMAC PARKWAY FILE, HISTORY DEPARTMENT ARCHIVES, NATIONAL PARK SERVICE, WASHINGTON, DC). - Rock Creek & Potomac Parkway, Washington, District of Columbia, DC

  5. 1. EXTERIOR OVERVIEW OF SOUTH END OF RUSH CREEK POWERHOUSE ...

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

    1. EXTERIOR OVERVIEW OF SOUTH END OF RUSH CREEK POWERHOUSE RESIDENTIAL COMPLEX SHOWING THE RUSH CREEK POWERHOUSE AT PHOTO RIGHT (TAILRACE IN FOREGROUND), BUILDING 106 NEXT TO THE POWERHOUSE AT PHOTO LEFT CENTER, AND BUILDING 103 AT UPPER PHOTO LEFT ABOVE AND BEHIND BUILDING 106. VIEW TO SOUTH. - Rush Creek Hydroelectric System, Worker Cottage, Rush Creek, June Lake, Mono County, CA

  6. 1. EXTERIOR OVERVIEW OF NORTH END OF RUSH CREEK POWERHOUSE ...

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

    1. EXTERIOR OVERVIEW OF NORTH END OF RUSH CREEK POWERHOUSE RESIDENTIAL COMPLEX SHOWING BUILDING 108 AT PHOTO RIGHT AND BUILDING 105 AT PHOTO CENTER BEHIND TREE. RUSH CREEK POWERHOUSE IS PARTIALLY VISIBLE AT EXTREME PHOTO LEFT). VIEW TO WEST. - Rush Creek Hydroelectric System, Clubhouse Cottage, Rush Creek, June Lake, Mono County, CA

  7. Flood discharges and hydraulics near the mouths of Wolf Creek, Craig Branch, Manns Creek, Dunloup Creek, and Mill Creek in the New River Gorge National River, West Virginia

    USGS Publications Warehouse

    Wiley, J.B.

    1994-01-01

    The U.S. Geological Survey, in cooperation with the National Park Service, studied the frequency and magnitude of flooding near the mouths of five tributaries to the New River in the New River Gorge National River. The 100-year peak discharge at each tributary was determined from regional frequency equations. The 100-year discharge at Wolf Creek, Craig Branch, Manns Creek, Dunloup Creek, and Mill Creek was 3,400 cubic feet per second, 640 cubic feet per second, 8,200 cubic feet per second, 7,100 cubic feet per second, and 9,400 cubic feet per second, respectively. Flood elevations for each tributary were determined by application of a steady-state, one-dimensional flow model. Manning's roughness coefficients for the stream channels ranged from 0.040 to 0.100. Bridges that would be unable to contain the 100-year flood within the bridge opening included: the State Highway 82 bridge on Wolf Creek, the second Fayette County Highway 25 bridge upstream from the confluence with New River on Dunloup Creek, and an abandoned log bridge on Mill Creek.

  8. Tidal disruption of solid bodies

    NASA Technical Reports Server (NTRS)

    Dobrovolskis, Anthony R.

    1990-01-01

    The problem of stress, strain, and breakup in solid satellites and stray bodies subject to tidal perturbations is presently addressed in view of three novel considerations. After presenting a new analytic solution for the stress tensor in a homogeneous and compressible elastic sphere, where the inclusion of compressibility alters stresses by several percent, realistic failure criteria are noted to demonstrate the general failure of such ductile bodies as iron meteoroids by plastic shear, while brittle ice bodies fail by either tensile or shear fracture. A reexamination of crack propagation after initial failure allows the diverse breakup criteria to be reconciled.

  9. Patterns and Controls of Nutrient Concentrations in a Southeastern United States Tidal Creek

    DTIC Science & Technology

    2013-09-01

    in sui face water chemistry, Ihis knowledge improves our ability to predict how coastal systems will respond to a nt h 11 >pi gen ic per tui bat 11...DOM, represented hereby DON ’ in Figure IB) concentra- ti’ins increased from the mouth of the Duplin to the upper Duplm and from winter in summer...groundwater became POf ( M) DON ( M) TSS(mg L") Chl-a^gL3-) 33 SU W Su 3p 9ii f \\N 3p Su F WSp Figure 2. Source-sink

  10. River discharge controlling a tidal delta: the interplay between monsoon input and tidal reworking in SW Bangladesh

    NASA Astrophysics Data System (ADS)

    Hale, R. P.; Goodbred, S. L., Jr.; Bain, R. L.; Wilson, C.; Best, J.; Reed, M. J.

    2015-12-01

    The Ganges-Brahmaputra-Meghna River system (GBM) is among the world's largest in terms of both annual water and sediment discharge. The subaerial delta (110,000 km2) is home to ~160 million people, in addition to the ecologically and economically critical Sundarbans National Forest (SNF). Recent sediment budgets suggest that ~15% of the 1 x 109 t yr-1 sediment load carried by the GBM is subsequently advected along shore and inland via tidal activity, to the otherwise-abandoned SW portion of the delta. A unit-scale estimate based on observed offshore suspended sediment concentrations (SSC) >1.0 g L-1 suggests that sufficient sediment is available in the system to maintain the elevation of the subaerial delta plain, even under current relative sea-level-rise rates. Recent work measuring sedimentation within SNF corroborates this finding, and understanding these sediment delivery dynamics will be critical for protecting the future of nearby regions that are heavily populated, but drastically altered by human activities. Cross-channel hydrodynamic surveys were conducted to estimate what fraction of the water (and sediment) is diverted from the major tidal channels toward the SNF interior. Measurements including profiles of velocity and SSC were collected on spring and neap tides during the dry and monsoon seasons, along transects bracketing major conduit channels into the SNF. During the dry season, we observe water flux at the southern end of the study area to be in approximate equilibrium regardless of tidal range, with SSC <0.3 g L-1 during neap tides, and <1.0 g L-1 during spring tides. North of the SNF conduit channels, we observe equilibrium water discharge and similarly low SSC during neap tides, but a modest ebb dominance and surface SSC >1.0 g L-1 during spring tides. This suggests the possibility of additional inputs of water and sediment from an adjacent tidal channel, as well as a potential source for the deposition observed on the Sundarbans platform

  11. Social Contexts of Development in Natural Outdoor Environments: Children's Motor Activities, Personal Challenges and Peer Interactions at the River and the Creek

    ERIC Educational Resources Information Center

    McClain, Cara; Vandermaas-Peeler, Maureen

    2016-01-01

    This study examined the influence of spending time outdoors on young children's physical and socioemotional development. We observed preschoolers' activities in two naturally provisioned outdoor environments over the course of one year. Eleven preschoolers were videotaped continuously for 16 days at a local river and 9 days at a creek adjacent to…

  12. Finding of No Significant Impact & Tiered Environmental Assessment: Public Law 84-99 Rehabilitation Program Levee Unit 624-627 - Mosquito Creek Pottawattamie County, Iowa

    DTIC Science & Technology

    2014-10-01

    7 3.3 Migratory Birds ...Water Quality, wetlands, migratory birds , threatened and endangered species, and cultural resources are included in this site specific analysis. Other...9 3.3 Migratory Birds The habitat in the proposed project area consists of trees and grasses adjacent to Mosquito Creek (Figure 6). It is

  13. River environmental decision support system development for Suzhou Creek in Shanghai.

    PubMed

    Liao, Zhenliang; Xu, Zuxin; Wang, Dingbao; Lu, Shiqiang; Hannam, Phillip M

    2011-09-01

    The Suzhou Creek Rehabilitation Project (SCRP) is one of the largest water-related environmental rehabilitation schemes ever undertaken in the vicinity of Shanghai, China. This paper details the development and application of a River Environmental Decision Support System (REDSS) for scientific planning and decision-making on the Suzhou Creek project, and illustrates the flexibility of the REDSS framework. We developed the following components: (1) a GIS-based analysis employing Component technology; (2) a "data mart" for multi-dimensional, multi-level, integrated, dynamic, and flexible data querying; and (3) a set of hydrodynamic and water quality models which can simulate complex tidal river networks. In addition, we detail how a water quality assessment model is embedded into the REDSS by employing an Identification Index Method. With the REDSS, all GIS and non-GIS components are integrated seamlessly and data from different sources can be queried simultaneously. This allows for various scenarios to be simulated and analyzed in advance to predict and assess the effects of proposed engineering and management measures. Generated information can thus support effective decisions. All operations of the REDSS can be implemented conveniently through user-friendly interfaces. The function of the REDSS framework is demonstrated through an application to Suzhou Creek. Because the REDSS characteristics are quite general, it may be applied in different geographic regions.

  14. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  15. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  16. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  17. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  18. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  19. Steel Creek wildlife: L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1987

    SciTech Connect

    Giffin, M.A.; Patterson, K.K.

    1988-03-01

    Reptile and amphibian populations in Steel Creek below L-Lake were assessed in monthly or quarterly sampling programs. Thirty-eight species of reptiles or amphibians were collected during 1987 in the Steel Creek corridor below the L-Lake impoundment, and in the delta and channel. Juvenile turtles and alligators, and larval amphibians were observed or collected during the study, indicating continued reproduction in Steel Creek. The reptile and amphibian populations in Steel Creek show no indication of any effect due to the impoundment of the lake or the operation of L-Reactor. Waterfowl and associated birds in Steel Creek below L-Lake were observed, in conjunction with other sampling programs, during winter--spring and fall--winter migrations. Nine species of waterfowl and five species of associated birds were observed in 1987 in the Steel Creek corridor below the L-Lake impoundment and in the delta and channel.

  20. Flood of August 27-28, 1977, West Cache Creek and Blue Beaver Creek, southwestern Oklahoma

    USGS Publications Warehouse

    Corley, Robert K.; Huntzinger, Thomas L.

    1979-01-01

    This report documents a major storm which occurred August 27-28, 1977, in southwest Oklahoma near the communities of Cache and Faxon, OK. Blue Beaver Creek and West Cache Creek and their tributaries experienced extensive flooding that caused an estimated $1 million in damages. Reported rainfall amounts of 8 to 12 inches in 6 hours indicate the storm had a frequency in excess of the 100-year rainfall. Peak discharges on Blue Beaver Creek near Cache and West Cache Creek near Faxon were 13,500 cubic feet per second and 45,700 cubic feet per second respectively. The estimated flood frequency was in excess of 100 years on Blue Beaver Creek and in excess of 50 years on West Cache Creek. Unit runoff on small basins were in excess of 2000 cubic feet per second per square mile. Surveyed highwater marks were used to map the flooded area. (USGS)

  1. Panther Creek, Idaho, Habitat Rehabilitation, Final Report.

    SciTech Connect

    Reiser, Dudley W.

    1986-01-01

    The purpose of the project was to achieve full chinook salmon and steelhead trout production in the Panther Creek, Idaho, basin. Plans were developed to eliminate the sources of toxic effluent entering Panther Creek. Operation of a cobalt-copper mine since the 1930's has resulted in acid, metal-bearing drainage entering the watershed from underground workings and tailings piles. The report discusses plans for eliminating and/or treating the effluent to rehabilitate the water quality of Panther Creek and allow the reestablishment of salmon and trout spawning runs. (ACR)

  2. LOST CREEK ROADLESS AREA, CALIFORNIA.

    USGS Publications Warehouse

    Muffler, L.J. Patrick; Campbell, Harry W.

    1984-01-01

    Geologic and mineral-resource investigations identified no mineral-resource potential in the Lost Creek Roadless Area, California. Sand and gravel have been mined from alluvial flood-plain deposits less than 1 mi outside the roadless area; these deposits are likely to extend into the roadless area beneath a Holocene basalt flow that may be as much as 40 ft thick. An oil and gas lease application which includes the eastern portion of the roadless area is pending. Abundant basalt in the area can be crushed and used as aggregate, but similar deposits of volcanic cinders or sand and gravel in more favorable locations are available outside the roadless area closer to major markets. No indication of coal or geothermal energy resources was identified.

  3. Snow Distribution Patterns in Clearings and Adjacent Forest

    NASA Astrophysics Data System (ADS)

    Golding, Douglas L.; Swanson, Robert H.

    1986-12-01

    Snow accumulation patterns were determined for clearings and adjacent forest at Marmot Creek experimental watershed and James River, Alberta. At maximum accumulation snow water equivalent (SWE) was greater in clearings than in forest whether clearings were large, as in 8- to 13-ha blocks where SWE averaged 20% more than in the forest, or small as in the ¼ to 6-H (height) diameter circular clearings where SWE was 13-45% greater than in the forest. SWE was 42 to 52% less in north than in south sectors of 2-6 H clearings. These differences increased with clearing size and time since beginning of accumulation period and are caused by snow ablation (melt and evaporation), a function of direct solar radiation reaching the snowpack. In such situations the snow that has accumulated on the ground cannot be considered a measure of the snow that has actually fallen there. For water balances and hydrologic modeling, snow measurements in partially cleared watersheds must be adjusted for temporal and spatial factors specific to the watershed.

  4. 78 FR 5798 - Grouse Creek Wind Park, LLC, Grouse Creek Wind Park II, LLC; Notice of Petition for Enforcement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Grouse Creek Wind Park, LLC, Grouse Creek Wind Park II, LLC; Notice of... Utility Regulatory Policies Act of 1978 (PURPA), Grouse Creek Wind Park, LLC and Grouse Creek Wind Park...

  5. Geologic strip map along the Hines Creek Fault showing evidence for Cenozoic displacement in the western Mount Hayes and northeastern Healy quadrangles, eastern Alaska Range, Alaska

    USGS Publications Warehouse

    Nokleberg, Warren J.; Aleinikoff, John N.; Bundtzen, Thomas K.; Hanshaw, Maiana N.

    2013-01-01

    Geologic mapping of the Hines Creek Fault and the adjacent Trident Glacier and McGinnis Glacier Faults to the north in the eastern Alaska Range, Alaska, reveals that these faults were active during the Cenozoic. Previously, the Hines Creek Fault, which is considered to be part of the strike-slip Denali Fault system (Ridgway and others, 2002; Nokleberg and Richter, 2007), was interpreted to have been welded shut during the intrusion of the Upper Cretaceous Buchanan Creek pluton (Wahrhaftig and others, 1975; Gilbert, 1977; Sherwood and Craddock, 1979; Csejtey and others, 1992). Our geologic mapping along the west- to west-northwest-striking Hines Creek Fault in the northeastern Healy quadrangle and central to northwestern Mount Hayes quadrangle reveals that (1) the Buchanan Creek pluton is truncated by the Hines Creek Fault and (2) a tectonic collage of fault-bounded slices of various granitic plutons, metagabbro, metabasalt, and sedimentary rock of the Pingston terrane occurs south of the Hines Creek Fault.

  6. Trace Elemental Analyses of Suspended Sediments in the San Francisco Estuary and its Tidal Marshes

    NASA Astrophysics Data System (ADS)

    Malamud-Roam, F. P.; Ingram, B. L.; Yang, W.; Collins, J.

    2004-12-01

    This research evaluates the trace elemental compositions of inorganic sediments in the San Francisco Bay estuary marshes over space and time. These sediments create and maintain the tidal marshes that surround the Sand Francisco Bay, yet a thorough analysis of the sources of these sediments remains understudied. Determining the sources of sediments is of interest because current mitigation and restoration projects around the Bay must consider whether the sediment supply will be sufficient for projects, or if opening diked wetlands to tidal flow will result in salt water intrusion further up-estuary (into the Delta). Results of trace element analyses of suspended sediments that pass through the Sacramento-San Joaquin Delta (the Delta) are compared with those of local watershed tributaries. Differences in bedrock lithology can be seen in the varying trace elemental concentrations; for example, K, Nd, Sm, Rb and Sr concentrations are significantly lower in the Sacramento river sediments than those of the San Joaquin river and can be used to differentiate further the Delta input. Results from marsh surface samples throughout the North Bay and preliminary results from 4 1-m long sediment cores collected along a transect of the Novato creek marsh (NCM) reflect local versus Delta sediment source patterns. The suspended sediment samples from the Sacramento and San Joaquin rivers and from local creeks reflect the end members of the sediment supply for local marshes. The marsh surface samples represent the most recent period (last few years or so) and reflect the extent of Delta influence into the estuary. Finally, the cores collected from the Novato creek marsh provide details on the gradient of dominant source supply (i.e., are the sediments well inland predominantly from the local watershed and how far does that influence extend downstream), as well as a history of how the sediment supply conditions have changed, comparing pre-Gold Rush and agriculture era (before about

  7. Seasonal variability of the M2 tide in the seas adjacent to Korea

    NASA Astrophysics Data System (ADS)

    Kang, Sok Kuh; Chung, Jong-yul; Lee, Sang-Ryong; Yum, Ki-Dat

    1995-08-01

    Seasonal variability of the M2 tidal harmonic constants is revealed through analyses of monthly tidal data at 12 representative tidal stations in the seas adjacent to the Korean peninsula. The variability remain systematic over the 9 years (1965-1973) of data analysis with a range comparable to that of the 18.6 year nodal modulation. Spatial inhomogeneity of the seasonal variability in the observed harmonic constants is found to exist. The largest seasonal variability in M2 appears in the stations located along the Korea Strait. This variability is not explained by the equilibrium theory of tides, and such a variability or irregularities in the harmonic constants are considered as either a noise as done by Cartwright and Amin (1986), Deutsch Hydrography Zeitschrift, 39, 235-253, or a manifestation of frictional interaction as done by Godin and Gutierrez (1986) Continental Shelf Research, 5, 379-402 for the Bay of Fundy. Considering the opposite relation between monthly mean sea level differences in Izuhara-Pusan section and tidal characteristics in the Korea Strait, it is hypothesized that the interaction between the predominant tidal currents and oceanic currents varying with the seasons might be the main cause of the observed temporal variability in the M2 tide. The nonlinear effect of the Kuroshio is investigated along the shelf break region through scale analyses, which show that the presence of a mean current increases the non-linear terms in the momentum balance by about one order of magnitude. The seasonally different damping effect of the Tsushima Current to the M2 tide is also discussed to explain the process of dominant seasonal variability along the Korea Strait based on the actual current data, but further thorough investigation, considering the advection effect of the mean current, is required to investigate the associated dynamics more completely.

  8. Kozai Cycles and Tidal Friction

    SciTech Connect

    L, K; P.P., E

    2009-07-17

    Several studies in the last three years indicate that close binaries, i.e. those with periods of {approx}< 3 d, are very commonly found to have a third body in attendance. We argue that this proves that the third body is necessary in order to make the inner period so short, and further argue that the only reasonable explanation is that the third body causes shrinkage of the inner period, from perhaps a week or more to the current short period, by means of the combination of Kozai cycles and tidal friction (KCTF). In addition, once KCTF has produced a rather close binary, magnetic braking also combined with tidal friction (MBTF) can decrease the inner orbit further, to the formation of a contact binary or even a merged single star. Some of the products of KCTF that have been suggested, either by others or by us, are W UMa binaries, Blue Stragglers, X-ray active BY Dra stars, and short-period Algols. We also argue that some components of wide binaries are actually merged remnants of former close inner pairs. This may include such objects as rapidly rotating dwarfs (AB Dor, BO Mic) and some (but not all) Be stars.

  9. Tidal streams in triaxial systems

    NASA Astrophysics Data System (ADS)

    Price-Whelan, Adrian M.; Johnston, Kathryn V.; Pearson, Sarah; Kupper, Andreas Hans Wilhelm

    2015-01-01

    Tidal streams form from the steady disruption of stellar systems orbiting within the gravitational field of some parent galaxy. Many streams and debris structures have been discovered in the halo of the Milky Way and have been used to model the potential of the Galaxy. However, few of these models have yet explored the properties of tidal debris in triaxial potentials. The existence of a variety of orbits, resonances, and chaotic regions in such potentials suggest that the morphologies and dispersal timescales of debris could differ significantly from the simpler spherical and oblate cases. In this work we use a series of N-body simulations of stellar systems over a range of masses of disruption in triaxial potentials to understand the influence of the nature and types of orbits on debris morphologies. Our results suggest that the mere existence of the multitude of thin streams already known to orbit the Milky Way provides significant constraints on the classes of triaxial potentials that provide a good representation for its dark matter halo.

  10. Generation of mock tidal streams

    NASA Astrophysics Data System (ADS)

    Fardal, Mark A.; Huang, Shuiyao; Weinberg, Martin D.

    2015-09-01

    In this paper, we discuss a method for the generation of mock tidal streams. Using an ensemble of simulations in an isochrone potential where the actions and frequencies are known, we derive an empirical recipe for the evolving satellite mass and the corresponding mass-loss rate, and the ejection conditions of the stream material. The resulting stream can then be quickly generated either with direct orbital integration, or by using the action-angle formalism. The model naturally produces streaky features within the stream. These are formed due to the radial oscillation of the progenitor and the bursts of stars emitted near pericentre, rather than clumping at particular oscillation phases as sometimes suggested. When detectable, these streaky features are a reliable diagnostic for the stream's direction of motion and encode other information on the progenitor and its orbit. We show several tests of the recipe in alternate potentials, including a case with a chaotic progenitor orbit which displays a marked effect on the width of the stream. Although the specific ejection recipe may need adjusting when elements such as the orbit or satellite density profile are changed significantly, our examples suggest that model tidal streams can be quickly and accurately generated by models of this general type for use in Bayesian sampling.

  11. Preliminary Geologic Map of the Southern Funeral Mountains and Adjacent Ground-Water Discharge Sites, Inyo County, California, and Nye County, Nevada

    USGS Publications Warehouse

    Fridrich, Christopher J.; Thompson, Ren A.; Slate, Janet L.; Berry, M.E.; Machette, Michael N.

    2008-01-01

    This map covers the southern part of the Funeral Mountains, and adjacent parts of four structural basins - Furnace Creek, Amargosa Valley, Opera House, and central Death Valley. It extends over three full 7.5-minute quadrangles, and parts of eleven others - a total area of about 950 square kilometers. The boundaries of this map were drawn to include all of the known proximal hydrogeologic features that may affect the flow of ground water that discharges from the springs of the Furnace Creek wash area, in the west-central part of the map. These springs provide the major potable water supply for Death Valley National Park.

  12. Tidal deformations of a spinning compact object

    NASA Astrophysics Data System (ADS)

    Pani, Paolo; Gualtieri, Leonardo; Maselli, Andrea; Ferrari, Valeria

    2015-07-01

    The deformability of a compact object induced by a perturbing tidal field is encoded in the tidal Love numbers, which depend sensibly on the object's internal structure. These numbers are known only for static, spherically-symmetric objects. As a first step to compute the tidal Love numbers of a spinning compact star, here we extend powerful perturbative techniques to compute the exterior geometry of a spinning object distorted by an axisymmetric tidal field to second order in the angular momentum. The spin of the object introduces couplings between electric and magnetic deformations and new classes of induced Love numbers emerge. For example, a spinning object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second order in the spin. The deformations are encoded in a set of inhomogeneous differential equations which, remarkably, can be solved analytically in vacuum. We discuss certain subtleties in defining the tidal Love numbers in general relativity, which are due to the difficulty in separating the tidal field from the linear response of the object in the solution, even in the static case. By extending the standard procedure to identify the linear response in the static case, we prove analytically that the Love numbers of a Kerr black hole remain zero to second order in the spin. As a by-product, we provide the explicit form for a slowly-rotating, tidally-deformed Kerr black hole to quadratic order in the spin, and discuss its geodesic and geometrical properties.

  13. Changes in the composition of ichthyoplankton assemblage and plastic debris in mangrove creeks relative to moon phases.

    PubMed

    Lima, A R A; Barletta, M; Costa, M F; Ramos, J A A; Dantas, D V; Melo, P A M C; Justino, A K S; Ferreira, G V B

    2016-07-01

    Lunar influence on the distribution of fish larvae, zooplankton and plastic debris in mangrove creeks of the Goiana Estuary, Brazil, was studied over a lunar cycle. Cetengraulis edentulus, Anchovia clupeoides and Rhinosardinia bahiensis were the most abundant fish larvae (56·6%), independent of the moon phase. The full moon had a positive influence on the abundance of Gobionellus oceanicus, Cynoscion acoupa and Atherinella brasiliensis, and the new moon on Ulaema lefroyi. The full and new moons also influenced the number of zoeae and megalopae of Ucides cordatus, protozoeae and larvae of caridean shrimps, and the number of hard and soft plastic debris, both <5 and >5 mm. Micro and macroplastics were present in samples from all 12 creeks studied, at densities similar to the third most abundant taxon, R. bahiensis. Cetengraulis edentulus and R. bahiensis showed a strong positive correlation with the last quarter moon, when there was less zooplankton available in the creeks and higher abundance of microplastic threads. Anchovia clupeoides, Diapterus rhombeus, U. lefroyi and hard microplastics were positively associated with different moon phases, when calanoid copepods, Caridean larvae and zoeae of U. cordatus were highly available in the creeks. Cynoscion acoupa, G. oceanicus and A. brasiliensis were strongly associated with the full moon, when protozoeae of caridean shrimps and megalopae of U. cordatus were also highly available, as were hard and soft macroplastics, paint chips (<5 mm) and soft microplastics. The results reinforce the role of mangrove creeks as nursery habitats. The moon phases influenced the distribution of fish larvae species, zooplankton and plastic debris by changing their compositions and abundances in the mangrove creeks of the Goiana Estuary when under the influence of different tidal current regimes.

  14. Assessment of volatile organic compounds in surface water at West Branch Canal Creek, Aberdeen Proving Ground, Maryland, 1999

    USGS Publications Warehouse

    Olsen, Lisa D.; Spencer, Tracey A.

    2000-01-01

    The U.S. Geological Survey (USGS) collected 13 surface-water samples and 3 replicates from 5 sites in the West Branch Canal Creek area at Aberdeen Proving Ground from February through August 1999, as a part of an investigation of ground-water contamination and natural attenuation processes. The samples were analyzed for volatile organic compounds, including trichloroethylene, 1,1,2,2-tetrachloroethane, carbon tetrachloride, and chloroform, which are the four major contaminants that were detected in ground water in the Canal Creek area in earlier USGS studies. Field blanks were collected during the sampling period to assess sample bias. Field replicates were used to assess sample variability, which was expressed as relative percent difference. The mean variability of the surface-water replicate analyses was larger (35.4 percent) than the mean variability of ground-water replicate analyses (14.6 percent) determined for West Branch Canal Creek from 1995 through 1996. The higher variability in surface-water analyses is probably due to heterogeneities in the composition of the surface water rather than differences in sampling or analytical procedures. The most frequently detected volatile organic compound was 1,1,2,2- tetrachloroethane, which was detected in every sample and in two of the replicates. The surface-water contamination is likely the result of cross-media transfer of contaminants from the ground water and sediments along the West Branch Canal Creek. The full extent of surface-water contamination in West Branch Canal Creek and the locations of probable contaminant sources cannot be determined from this limited set of data. Tidal mixing, creek flow patterns, and potential effects of a drought that occurred during the sampling period also complicate the evaluation of surface-water contamination.

  15. Steel Creek fish, L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1991

    SciTech Connect

    Sayers, R.E. Jr.; Mealing, H.G. III

    1992-04-01

    The Savannah River Site (SRS) encompasses 300 sq mi of the Atlantic Coastal plain in west-central South Carolina. The Savannah River forms the western boundary of the site. Five major tributaries of the Savannah River -- Upper Three Runs Creek, Four Mile Creek, Pen Branch, Steel Creek, and Lower Three Runs Creek -- drain the site. All but Upper Three Runs Creek receive, or in the past received, thermal effluents from nuclear production reactors. In 1985, L Lake, a 400-hectare cooling reservoir, was built on the upper reaches of Steel Creek to receive effluent from the restart of L-Reactor, and protect the lower reaches from thermal impacts. The lake has an average width of approximately 600 m and extends along the Steel Creek valley approximately 7000 m from the dam to the headwaters. Water level is maintained at a normal pool elevation of 58 m above mean sea level by overflow into a vertical intake tower that has multilevel discharge gates. The intake tower is connected to a horizontal conduit that passes through the dam and releases water into Steel Creek. The Steel Creek Biological Monitoring Program was designed to meet environmental regulatory requirements associated with the restart of L-Reactor and complements the Biological Monitoring Program for L Lake. This extensive program was implemented to address portions of Section 316(a) of the Clean Water Act. The Department of Energy (DOE) must demonstrate that the operation of L-Reactor will not significantly alter the established aquatic ecosystems.

  16. The hydrodynamics of surface tidal flow exchange in saltmarshes

    NASA Astrophysics Data System (ADS)

    Young, David L.; Bruder, Brittany L.; Haas, Kevin A.; Webster, Donald R.

    2016-04-01

    Modeling studies of estuary circulation show great sensitivity to the water exchange into and out of adjacent marshes, yet there is significant uncertainty in resolving the processes governing marsh surface flow. The objective of this study is to measure the estuary channel-to-saltmarsh pressure gradient and to guide parameterization for how it affects the surface flow in the high marsh. Current meters and high-resolution pressure transducers were deployed along a transect perpendicular to the nearby Little Ogeechee River in a saltmarsh adjacent to Rose Dhu Island near Savannah, Georgia, USA. The vertical elevations of the transducers were surveyed with static GPS to yield high accuracy water surface elevation data. It is found that water level differences between the Little Ogeechee River and neighboring saltmarsh are up to 15 cm and pressure gradients are up to 0.0017 m of water surface elevation change per m of linear distance during rising and falling tides. The resulting Little-Ogeechee-River-to-saltmarsh pressure gradient substantially affects tidal velocities at all current meter locations. At the velocity measurement station located closest to the Little Ogeechee River bank, the tidal velocity is nearly perpendicular to the bank. At this location, surface flow is effectively modeled as a balance between the pressure gradient force and the drag force due to marsh vegetation and bottom stress using the Darcy-Weisbach/Lindner's equations developed for flow-through-vegetation analysis in open channel flow. The study thus provides a direct connection between the pressure gradient and surface flow velocity in the high marsh, thereby overcoming a long-standing barrier in directly relating flow-through-saltmarsh studies to flow-through-vegetation studies in the open channel flow literature.

  17. Upslope development of a tidal marsh as a function of upland land use.

    PubMed

    Anisfeld, Shimon C; Cooper, Katharine R; Kemp, Andrew C

    2017-02-01

    To thrive in a time of rapid sea-level rise, tidal marshes will need to migrate upslope into adjacent uplands. Yet little is known about the mechanics of this process, especially in urbanized estuaries, where the adjacent upland is likely to be a mowed lawn rather than a wooded natural area. We studied marsh migration in a Long Island Sound salt marsh using detailed hydrologic, edaphic, and biotic sampling along marsh-to-upland transects in both wooded and lawn environments. We found that the overall pace of marsh development was largely unaffected by whether the upland being invaded was lawn or wooded, but the marsh-edge plant communities that developed in these two environments were quite different, and some indicators (soil salinity, foraminifera) appeared to migrate more easily into lawns. In addition, we found that different aspects of marsh structure and function migrated at different rates: Wetland vegetation appeared to be a leading indicator of marsh migration, while soil characteristics such as redox potential and surface salinity developed later in the process. We defined a 'hydrologic migration zone', consisting of elevations that experience tidal inundation with frequencies ranging from 20% to 0.5% of high tides. This hydrologically defined zone - which extended to an elevation higher than the highest astronomical tide datum - captured the biotic and edaphic marsh-upland ecotone. Tidal inundation at the upper border of this migration zone is highly variable over time and may be rising more rapidly than mean sea level. Our results indicate that land management practices at the upland periphery of tidal marshes can facilitate or impede ecosystem migration in response to rising sea level. These findings are applicable to large areas of tidal marsh along the U.S. Atlantic coast and in other urbanized coastal settings.

  18. Relativistic theory of tidal Love numbers

    SciTech Connect

    Binnington, Taylor; Poisson, Eric

    2009-10-15

    In Newtonian gravitational theory, a tidal Love number relates the mass multipole moment created by tidal forces on a spherical body to the applied tidal field. The Love number is dimensionless, and it encodes information about the body's internal structure. We present a relativistic theory of Love numbers, which applies to compact bodies with strong internal gravities; the theory extends and completes a recent work by Flanagan and Hinderer, which revealed that the tidal Love number of a neutron star can be measured by Earth-based gravitational-wave detectors. We consider a spherical body deformed by an external tidal field, and provide precise and meaningful definitions for electric-type and magnetic-type Love numbers; and these are computed for polytropic equations of state. The theory applies to black holes as well, and we find that the relativistic Love numbers of a nonrotating black hole are all zero.

  19. Tidal triggering effect on earthquakes occurrence

    NASA Astrophysics Data System (ADS)

    Contadakis, M. E.; Arabelos, D.; Spatalas, S. D.

    2016-01-01

    In this review we present the investigation for the tidal triggering evidence on the earthquakes at various seismic areas of Greece. The result of our analysis using the HiCum method, indicate that the monthly variation of the frequencies of earthquake occurrence is in accordance with the period of the tidal lunar monthly (Mm) variations. The same happens with the corresponding diurnal and semi-diurnal variations of the frequencies of earthquake occurrence with the diurnal (K1), (O1) and semi-diurnal solar (S2) and semidiurnal lunar (M2) tidal variations. The confidence level of the Tidal-Earthquake frequency period compliance is very sensitive to the seismicity of the area and we call it Tidal - Earthquake frequency compliance parameter. We suggest that this parameter may be used in earthquake risk evaluation.

  20. Water quality monitoring report for the White Oak Creek Embayment. Environmental Restoration Program

    SciTech Connect

    Ford, C.J.; Wefer, M.T.

    1993-01-01

    Water quality monitoring activities that focused on the detection of resuspended sediments in the Clinch River were conducted in conjunction with the White Oak Creek Embayment (WOCE) time-critical Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to construct a sediment-retention structure at the mouth of White Oak Creek (WOC). Samples were collected by use of a 24-h composite sampler and through real-time water grab sampling of sediment plumes generated by the construction activities. Sampling stations were established both at the WOC mouth, immediately adjacent to the construction site, and at K-1513, the Oak Ridge K-25 Site drinking water intake approximately 9.6 km downstream in the Clinch River. Results are described.

  1. 33 CFR 117.738 - Overpeck Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.738 Overpeck Creek. (a) The draws of the Conrail and the New York, Susquehanna and Western railroad bridges, mile 0.0 both at...

  2. 33 CFR 117.701 - Alloway Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.701 Alloway Creek. (a) The draws of the Salem County bridges, miles 5.1 at Hancocks Bridge, and 6.5 at New Bridge, shall open on signal...

  3. 33 CFR 117.701 - Alloway Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.701 Alloway Creek. (a) The draws of the Salem County bridges, miles 5.1 at Hancocks Bridge, and 6.5 at New Bridge, shall open on signal...

  4. 33 CFR 117.738 - Overpeck Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.738 Overpeck Creek. (a) The draws of the Conrail and the New York, Susquehanna and Western railroad bridges, mile 0.0 both at...

  5. 33 CFR 117.738 - Overpeck Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.738 Overpeck Creek. (a) The draws of the Conrail and the New York, Susquehanna and Western railroad bridges, mile 0.0 both at...

  6. 33 CFR 117.701 - Alloway Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.701 Alloway Creek. (a) The draws of the Salem County bridges, miles 5.1 at Hancocks Bridge, and 6.5 at New Bridge, shall open on signal...

  7. 33 CFR 117.701 - Alloway Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.701 Alloway Creek. (a) The draws of the Salem County bridges, miles 5.1 at Hancocks Bridge, and 6.5 at New Bridge, shall open on signal...

  8. 33 CFR 117.701 - Alloway Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.701 Alloway Creek. (a) The draws of the Salem County bridges, miles 5.1 at Hancocks Bridge, and 6.5 at New Bridge, shall open on signal...

  9. 33 CFR 117.738 - Overpeck Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.738 Overpeck Creek. (a) The draws of the Conrail and the New York, Susquehanna and Western railroad bridges, mile 0.0 both at...

  10. 33 CFR 117.736 - Oceanport Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.736 Oceanport Creek. The drawspan for the New Jersey Transit Rail Operations Drawbridge, mile 8.4 near Oceanport, must open on signal...

  11. 33 CFR 117.736 - Oceanport Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.736 Oceanport Creek. The drawspan for the New Jersey Transit Rail Operations Drawbridge, mile 8.4 near Oceanport, must open on signal...

  12. 33 CFR 117.929 - Durham Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OPERATION REGULATIONS Specific Requirements South Carolina § 117.929 Durham Creek. The removable span of the... Charleston of an emergency in the Bushy Park Reservoir, the span shall be removed as soon as possible...

  13. 33 CFR 117.929 - Durham Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OPERATION REGULATIONS Specific Requirements South Carolina § 117.929 Durham Creek. The removable span of the... Charleston of an emergency in the Bushy Park Reservoir, the span shall be removed as soon as possible...

  14. 33 CFR 117.929 - Durham Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OPERATION REGULATIONS Specific Requirements South Carolina § 117.929 Durham Creek. The removable span of the... Charleston of an emergency in the Bushy Park Reservoir, the span shall be removed as soon as possible...

  15. 33 CFR 117.929 - Durham Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OPERATION REGULATIONS Specific Requirements South Carolina § 117.929 Durham Creek. The removable span of the... Charleston of an emergency in the Bushy Park Reservoir, the span shall be removed as soon as possible...

  16. Proctor Creek Watershed/Atlanta (Georgia)

    EPA Pesticide Factsheets

    Proctor Creek Watershed/Atlanta (Georgia) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating with community-led efforts.

  17. Featured Partner: Saddle Creek Logistics Services

    EPA Pesticide Factsheets

    This EPA fact sheet spotlights Saddle Creek Logistics as a SmartWay partner committed to sustainability in reducing greenhouse gas emissions and air pollution caused by freight transportation, partly by growing its compressed natural gas (CNG) vehicles for

  18. News and Updates from Proctor Creek

    EPA Pesticide Factsheets

    This page contains news and updates from the Proctor Creek Urban Waters Partnership location. They span ongoing projects, programs, and initiatives that this Atlanta-based partnership is taking on in its work plan.

  19. Proctor Creek Boone Boulevard Fact Sheet

    EPA Pesticide Factsheets

    This fact sheet provides an overview of the Proctor Creek watershed and community, green infrastructure, the Boone Boulevard Green Street Project Conceptual Design, and the added value and application of Health Impact Assessment (HIA) to the project.

  20. Lunar influence on prey availability, diet shifts and niche overlap between Engraulidae larvae in tropical mangrove creeks.

    PubMed

    Lima, A R A; Barletta, M

    2016-10-01

    The influence of the lunar cycle on prey availability, diet shifts and overlap between larval Anchovia clupeoides and Cetengraulis edentulus was evaluated in mangrove creeks of the Goiana Estuary. Copepod eggs were highly abundant in the first and last quarter, at the full moon and zoea of Ucides cordatus (Ocypodidae) in the new moon. The Engraulidae larvae fed on microcrustaceans, algae and early planktonic stages of benthic organisms. The relative importance of prey varied according to prey availability in all moon phases. Larval diets were more even in the full and new moons, when the relative importance of calanoid copepods and zoeae of U. cordatus as food items increased (index of relative importance, >80% IRI ). Mangrove creeks were very important feeding grounds for engraulid larvae during spring tides. Larval diets were more diverse in the first and last-quarter moon and included protozoeae of Caridean shrimp, larvae of Anomalocardia brasiliana (Veneridae), Isopoda, Gastropoda, ephippium of Daphnia sp. and nauplii of Cirripedia, Harpacticoidia and cyclopoid Copepoda. The last five items were not found in the creeks, suggesting feeding in the main channel. During neap tides, mangrove creeks were probably also used as refugia. These larvae are opportunistic and feed on highly available prey and both species feed on the same items, leading to high dietary overlap in all moon phases. The lunar cycle, which is related to the spring-neap tidal cycle, was the major driver of quantitative and qualitative changes in feeding of engraulid larvae on a short time scale.

  1. Final Environmental Assessment, Horse Creek Bridge Replacement

    DTIC Science & Technology

    2010-10-01

    floodplain, deep swamp, meander scars, loops, and oxbow lakes . Sandy Run Creek, along the southern boundary of Robins AFB, has a floodplain up to 2,000...River floodplain (Figure 3). The erosion action of the Ocmulgee has created bluffs, high floodplain, deep swamp, meander scars, loops, and oxbow ... lakes . Robins Air Force Base Horse Creek Bridge Replacement J. Gross L. Neal 15268146 April 2010 CLIENT: TITLE: PROJECT: DATE: SCALE: FILE: DESIGNED

  2. Salinity influences on aboveground and belowground net primary productivity in tidal wetlands

    USGS Publications Warehouse

    Pierfelice, Kathryn N.; Graeme Lockaby, B.; Krauss, Ken W.; Conner, William H.; Noe, Gregory; Ricker, Matthew C.

    2017-01-01

    Tidal freshwater wetlands are one of the most vulnerable ecosystems to climate change and rising sea levels. However salinification within these systems is poorly understood, therefore, productivity (litterfall, woody biomass, and fine roots) were investigated on three forested tidal wetlands [(1) freshwater, (2) moderately saline, and (3) heavily salt-impacted] and a marsh along the Waccamaw and Turkey Creek in South Carolina. Mean aboveground (litterfall and woody biomass) production on the freshwater, moderately saline, heavily salt-impacted, and marsh, respectively, was 1,061, 492, 79, and 0  g m−2 year−1 versus belowground (fine roots) 860, 490, 620, and 2,128  g m−2 year−1. Litterfall and woody biomass displayed an inverse relationship with salinity. Shifts in productivity across saline sites is of concern because sea level is predicted to continue rising. Results from the research reported in this paper provide baseline data upon which coupled hydrologic/wetland models can be created to quantify future changes in tidal forest functions.

  3. Hydrological exchanges and Organic Matter dynamics in highly vulnerable tidal wetland ecosystems at the land-ocean interface

    NASA Astrophysics Data System (ADS)

    Tzortziou, M.; Neale, P.; Megonigal, P.; Loughner, C.

    2014-12-01

    Occupying a critical interface between the land and the sea, tidal wetlands are amongst the most ecologically valuable and economically important ecosystems on Earth, but also especially vulnerable to human pressures and climate change. These rich in biodiversity and highly productive ecosystems are hot spots of biogeochemical transformations, consistently exchanging Organic Matter with adjacent estuarine waters through tidal flushing. Here we discuss new results on the amount and directions of biogeochemical exchanges at the tidal wetland-estuary interface. Detailed microbial and photochemical degradation experiments and high resolution bio-optical observations in tidal freshwater and salt marsh systems of the Eastern US coast provide insights on the quality and fate of the organic compounds exported from tidal marshes and their influence on near-shore biological processes, biogeochemical cycles and optical variability. Impacts of anthropogenic activities and resulting air-pollution are also discussed. High resolution model runs were performed using the Community Multi-scale Air Quality (CMAQ) model, to examine atmospheric composition along the shoreline where processes such as sea and bay breeze circulations often favor the accumulation and air-deposition of atmospheric pollutants, impacting biogeochemical processes in sensitive tidal wetland ecosystems.

  4. Use of PIT tag and underwater video recording in assessing estuarine fish movement in a high intertidal mangrove and salt marsh creek

    NASA Astrophysics Data System (ADS)

    Meynecke, Jan-Olaf; Poole, Geoffrey C.; Werry, Jonathan; Lee, Shing Yip

    2008-08-01

    We assessed movement patterns in relation to habitat availability (reflected by the extent of tidal flooding) for several commercially and recreationally important species in and out of a small mangrove creek within the subtropical Burrum River estuary (25°10'S 152°37'E) in Queensland, Australia. Movement patterns of Acanthopagrus australis, Pomadasys kaakan, Lutjanus russelli and Mugil cephalus were examined between December 2006 and April 2007 using a stationary passive integrated transponder (PIT) system adapted for saline environments (30-38 ppt) and underwater digital video cameras (DVCs). This is the second known application of a stationary PIT tag system to studying fish movement in estuarine environments. The transponder system was set in place for 104 days and recorded >5000 detections. Overall 'recapture' rate of tagged fish by the transponder system was >40%. We used PIT tags implanted in a total of 75 fish from a tidal creek connected to the main channel of the estuary. We also developed a high-resolution digital elevation (2.5 m cell size) model of the estuary derived from airborne light detection and ranging (LIDAR) and aerial imagery to estimate inundation dynamics within the tidal creek, and related the timing of inundation in various habitats to the timing of fish immigration to and emigration from the creek. Over 50% of all tagged fish were moving in and out of the creek at a threshold level when 50% of the mangrove forest became flooded. Individuals of all four species moved into and out of the tidal creek repeatedly at different times depending on species and size, indicating strong residential behaviour within the estuary. The main activity of fishes was at night time. Manual interpretation of video from >700 fish sightings at three different mangrove sites confirmed the findings of the stationary PIT system, that the function of shelter vs food in mangrove habitat may be size dependent. Our established techniques assess the spatial ecology

  5. Assessment of water resources in lead-zinc mined areas in Cherokee County, Kansas, and adjacent areas

    USGS Publications Warehouse

    Spruill, T.B.

    1984-01-01

    A study was conducted to evaluate water-resource problems related to abandoned lead and zinc mines in Cherokee County, and adjacent areas in Oklahoma and Missouri. Discontinuities and perforations, which were produced by mining in the confining shale west of the Pennsylvanian-Mississippian geologic contact, have created artificial groundwater recharge and discharge areas. Abandoned wells and drill holes present the greatest contamination hazard to water supplies in the deep aquifer. There is a potential for downward movement from the shallow to the deep aquifer throughout the study area, with greatest potential in Ottawa County, Oklahoma. Principal effects of abandoned mines on groundwater quality are lowered pH and increased concentrations of sulfate and trace metals of water in the mines. No conclusive evidence of lateral migration of contaminated mine water from the mines into the water-supply wells adjacent to the mines was found. Analyses of water from the deep aquifer did not indicate trace-metal contamination. The effects of abandoned mines on streamwater quality are most severe in Short Creek and Tar Creek. Increased concentrations of zinc and manganese were observed in the Spring River below Short Creek Kansas. (USGS)

  6. Morphological equilibrium of short channels dissecting the tidal flats of coastal lagoons

    NASA Astrophysics Data System (ADS)

    Toffolon, Marco; Lanzoni, Stefano

    2010-12-01

    The equilibrium bed profile of tidal channels dissecting the tidal flats of coastal lagoons is studied within a rational one-dimensional framework. A general analytical solution is obtained which expresses the bed profile in terms of a modified longitudinal coordinate, accounting implicitly for channel convergence and adjacent shoals. For values of the relevant parameters typical of costal lagoons, inertia and friction effects as well as overtides are shown to provide minor corrections to the equilibrium bed profile. The overall shape of the profile is also shown to be slightly affected by the equilibrium condition used in its derivation, consisting in a requirement on either residual erosion/deposition fluxes or maximum velocity. In particular, the asymptotic form of the analytical solution is common to both the equilibrium requirements, thus suggesting the existence of general morphological relationships relating the depth at the channel mouth or, alternatively, the length of the channel to the tidal amplitude, to the degree of channel convergence, to the critical velocity for erosion/deposition and to the extent of intertidal storage areas. The profile shape is affected as well; for instance, nearly constant-depth channels tend to form when convergence is strong. The equilibrium configuration also implies that a power law relationship of the type proposed by O'Brien-Jarret-Marchi for tidal inlets, relating the channel cross section to the tidal prism, holds throughout the entire channel. Finally, the theoretical profile is shown to reasonably reproduce the bed configurations observed in a number of tidal channels surveyed within the Lagoon of Venice (Italy).

  7. Debris flows on Belding Creek, Salmonberry River basin, northern Oregon Coast Range

    SciTech Connect

    Burris, L.M. . Dept. of Geology)

    1993-04-01

    Belding Creek, a tributary of the Salmonberry River, has experienced repeated debris flow episodes. The Salmonberry River flows through Paleocene Tillamook Basalt and is located at longitude 45[degree]43 minutes in the Northern Oregon Coast Range. On January 9, 1990, a debris flow initiated on a first order tributary of Belding Creek during a heavy precipitation event. A month later another debris flow initiated on a different first order stream under similar conditions. Both debris flows traveled for a distance of approximately 2.1 km and poured into the main Belding Creek channel washing out Belding Road which crosses the stream. Numerical data was obtained from the youngest flow deposit. The debris flow material density is 2.5 g/cm[sup 3]. It traveled at an average velocity of 2.9 m/s with a shear strength of 2.5 [times] 10[sup 4] dn/cm[sup 2], a friction angle of 4[degree], and a cohesion value of 1.4 [times] 10[sup 4] dn/cm[sup 3]. Less than 3% of the fine sediments deposited are clay and silt. Deposits from previous, older debris flow events are in and adjacent to the Belding Creek stream channel. Similar processes are evident in other major tributaries of the Salmonberry River, although these other stream channels have not shown recent activity. Each stream in the area that has experienced past debris flows similar to Belding Creek has a landslide feature at the top and follows regional lineation patterns.

  8. Tidal interactions of inspiraling compact binaries

    NASA Technical Reports Server (NTRS)

    Bildsten, Lars; Cutler, Curt

    1992-01-01

    We discuss the tidal interaction in neutron star-neutron star and neutron star-black hole binaries and argue that they will not be tidally locked during the gravitational inspiral. More specifically, we show that, for inspiraling neutron stars of mass greater than about 1.2 solar mass, the shortest possible tidal synchronization time exceeds the gravitational decay time, so that the neutron star cannot be tidally locked prior to tidal disruption, regardless of its internal viscosity. For smaller mass neutron stars, an implausibly large kinematic viscosity - nearly the speed of light times the stellar radius - is required for tidal locking. We also argue that the mass transfer which occurs when the neutron star reaches the tidal radius will be unstable in neutron star-black hole binaries, and the instability will destroy the neutron star in a few orbital periods. The implications of our work for the detection of these sources by LIGO and other gravitational wave observatories and for the gamma-ray burst scenarios of Paczynski (1986, 1991) are discussed.

  9. Gravitomagnetic tidal currents in rotating neutron stars

    NASA Astrophysics Data System (ADS)

    Poisson, Eric; Douçot, Jean

    2017-02-01

    It was recently revealed that a rotating compact body responds dynamically when it is subjected to a gravitomagnetic tidal field, even when this field is idealized as time independent. The dynamical response is characterized by time-changing internal currents, and it was suspected to originate from zero-frequency g -modes and r -modes driven by the tidal forces. In this paper, we provide additional insights into the phenomenon by examining the tidal response of a rotating body within the framework of post-Newtonian gravity. This approach allows us to develop an intuitive picture for the phenomenon, which relies on the close analogy between post-Newtonian gravity and Maxwell's theory of electromagnetism. In this picture, the coupling between the gravitomagnetic tidal field and the body's rotational velocity is naturally expected to produce an unbalanced Lorentz-like force within the body, and it is this force that is responsible for the tidal currents. The simplicity of the fluid equations in the post-Newtonian setting allows us to provide a complete description of the zero-frequency modes and demonstrate their precise role in the establishment of the tidal currents. We estimate the amplitude of these currents, and find that for neutron-star binaries of relevance to LIGO, the scale of the velocity perturbation is measured in kilometers per second when the rotation period is comparable to 100 milliseconds. This estimate indicates that the tidal currents may have a significant impact on the physics of neutron stars near merger.

  10. Modeling sand bank formation around tidal headlands

    USGS Publications Warehouse

    Signell, Richard P.; Harris, Courtney K.

    2000-01-01

    Sandbanks are often found in the vicinity of coastal headlands around which tidal flows are strong enough to generate significant tidally-forced residual eddies, typically with scales of 2-10 km. One popular hypothesis is that these sandbanks are generated by a 'tidal stirring' mechanism in which the inward-directed pressure gradient associated with these residual eddies produces an inward-directed movement of sand near the seabed. This hypothesis predicts asymmetric sandbank formation when planetary vorticity is significant compared to the relative vorticity of the residual eddies. This mechanism is tested with a numerical sediment transport model, using idealized symmetrical coastline geometry and tidal forcing that represents conditions similar to regions where these tidal headland sandbanks are known to occur. For both suspended and bedload simulations, we find that nearly symmetric sandbanks form, and that the sediment transport patterns that are responsible for building and maintaining the banks are due more the patterns of shear stress and sediment flux that occur over the course of the tidal cycle rather than to the characteristics of the tidally-averaged residual fields. We also find that sediment supply can be an important factor in controlling the nature of the resulting sandbanks.

  11. Carbon dioxide dynamics driven by groundwater discharge in a coastal floodplain creek

    NASA Astrophysics Data System (ADS)

    Atkins, Marnie L.; Santos, Isaac R.; Ruiz-Halpern, Sergio; Maher, Damien T.

    2013-06-01

    Dissolved carbon dioxide (CO2) may be highly enriched in groundwater. However, the contribution of groundwater discharge as a source of CO2 to rivers, estuaries and coastal waters is poorly understood. We performed high resolution measurements of radon (222Rn, a natural groundwater tracer) and the partial pressure of CO2 (pCO2) in a highly modified tidal creek and estuary (North Creek, Richmond River, New South Wales, Australia) to assess whether CO2 in surface waters was driven by groundwater discharge. A spatial survey revealed increasing 222Rn activities (up to 17.3 dpm L-1) and pCO2 (up to 11,151 μatm) in the upstream direction. The enrichment occurred in a drained coastal acid sulphate soil wetland upstream of a mangrove forest. Time series experiments (24-h) were performed at two stations upstream and downstream of the pCO2 enrichment area. Upstream measurements demonstrated a significant correlation between pCO2 and 222Rn while downstream values resulted in a significant inverse relationship between pCO2 and dissolved oxygen apparently as a result of respiration in nearby mangroves. Measurements taken 2 days after a 245 mm precipitation event revealed the highest recorded 222Rn activities (up to 86.1 dpm L-1) and high pCO2 (up to 11,217 μatm), showing a strong groundwater influence after flooding. These observations imply that groundwater discharge drove CO2 dynamics at the upstream station while multiple complex processes drove CO2 at the downstream station. A 222Rn mass balance model demonstrated that groundwater discharge accounted for about 76% of surface water in this floodplain creek. The CO2 evasion rates (799 ± 225 mmol m-2 d-1) were driven primarily by currents rather than wind. Groundwater-derived CO2 fluxes into the creek averaged 1622 mmol m-2 d-1, a value twice as high as atmospheric CO2 evasion and consistent with carbon uptake within the creek and downstream exports. These results demonstrate that groundwater seepage was a major factor

  12. 4. O'BRIAN CANAL/SECOND CREEK INTERSECTION Second Creek is in the ...

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

    4. O'BRIAN CANAL/SECOND CREEK INTERSECTION Second Creek is in the foreground; the O'Brian Canal is in the background; vicinity of East 112th Avenue and Potomac Road in Adams County - O'Brian Canal, South Platte River Drainage Area Northest of Denver, Brighton, Adams County, CO

  13. Creek Women and the "Civilizing" of Creek Society, 1790-1820.

    ERIC Educational Resources Information Center

    Dysart, Jane E.

    Women in traditional Creek society, while making few decisions in the public domain, held almost absolute power in the domestic realm. When a Creek couple married, the husband moved into his wife's house and lived among her clan, her matrilineal kin. The house, household goods, fields, and children belonged to her. Boys were educated by their…

  14. Tidal river dynamics: Implications for deltas

    NASA Astrophysics Data System (ADS)

    Hoitink, A. J. F.; Jay, D. A.

    2016-03-01

    Tidal rivers are a vital and little studied nexus between physical oceanography and hydrology. It is only in the last few decades that substantial research efforts have been focused on the interactions of river discharge with tidal waves and storm surges into regions beyond the limit of salinity intrusion, a realm that can extend inland hundreds of kilometers. One key phenomenon resulting from this interaction is the emergence of large fortnightly tides, which are forced long waves with amplitudes that may increase beyond the point where astronomical tides have become extinct. These can be larger than the linear tide itself at more landward locations, and they greatly influence tidal river water levels and wetland inundation. Exploration of the spectral redistribution and attenuation of tidal energy in rivers has led to new appreciation of a wide range of consequences for fluvial and coastal sedimentology, delta evolution, wetland conservation, and salinity intrusion under the influence of sea level rise and delta subsidence. Modern research aims at unifying traditional harmonic tidal analysis, nonparametric regression techniques, and the existing understanding of tidal hydrodynamics to better predict and model tidal river dynamics both in single-thread channels and in branching channel networks. In this context, this review summarizes results from field observations and modeling studies set in tidal river environments as diverse as the Amazon in Brazil, the Columbia, Fraser and Saint Lawrence in North America, the Yangtze and Pearl in China, and the Berau and Mahakam in Indonesia. A description of state-of-the-art methods for a comprehensive analysis of water levels, wave propagation, discharges, and inundation extent in tidal rivers is provided. Implications for lowland river deltas are also discussed in terms of sedimentary deposits, channel bifurcation, avulsion, and salinity intrusion, addressing contemporary research challenges.

  15. Particle release transport in Danshuei River estuarine system and adjacent coastal ocean: a modeling assessment.

    PubMed

    Chen, Wei-Bo; Liu, Wen-Cheng; Kimura, Nobuaki; Hsu, Ming-Hsi

    2010-09-01

    A three-dimensional hydrodynamic model was created to study the Danshuei River estuarine system and adjacent coastal ocean in Taiwan. The model was verified using measurements of the time-series water surface elevation, tidal current, and salinity from 1999. We conclude that our model is consistent with these observations. Our particle-tracking model was also used to explore the transport of particles released from the Hsin-Hai Bridge, an area that is heavily polluted. The results suggest that it takes a much longer time for the estuary to be flushed out under low freshwater discharge conditions than with high freshwater discharge. We conclude that the northeast and southwest winds minimally impact particle dispersion in the estuary. The particles fail to settle to the bottom in the absence of density-induced circulation. Our model was also used to simulate the ocean outfall at the Bali. Our experimental results suggest that the tidal current dominates the particle trajectories and influences the transport properties in the absence of a wind stress condition. The particles tend to move northeast or southwest along the coast when northeast or southwest winds prevail. Our data suggest that wind-driven currents and tidal currents play important roles in water movement as linked with ocean outfall in the context of the Danshuei River.

  16. Baseline Characteristics of Jordan Creek, Juneau, Alaska

    USGS Publications Warehouse

    Host, Randy H.; Neal, Edward G.

    2004-01-01

    Anadromous fish populations historically have found healthy habitat in Jordan Creek, Juneau, Alaska. Concern regarding potential degradation to the habitat by urban development within the Mendenhall Valley led to a cooperative study among the City and Borough of Juneau, Alaska Department of Environmental Conservation, and the U.S. Geological Survey, that assessed current hydrologic, water-quality, and physical-habitat conditions of the stream corridor. Periods of no streamflow were not uncommon at the Jordan Creek below Egan Drive near Auke Bay stream gaging station. Additional flow measurements indicate that periods of no flow are more frequent downstream of the gaging station. Although periods of no flow typically were in March and April, streamflow measurements collected prior to 1999 indicate similar periods in January, suggesting that no flow conditions may occur at any time during the winter months. This dewatering in the lower reaches likely limits fish rearing and spawning habitat as well as limiting the migration of juvenile salmon out to the ocean during some years. Dissolved-oxygen concentrations may not be suitable for fish survival during some winter periods in the Jordan Creek watershed. Dissolved-oxygen concentrations were measured as low as 2.8 mg/L at the gaging station and were measured as low as 0.85 mg/L in a tributary to Jordan Creek. Intermittent measurements of pH and dissolved-oxygen concentrations in the mid-reaches of Jordan Creek were all within acceptable limits for fish survival, however, few measurements of these parameters were made during winter-low-flow conditions. One set of water quality samples was collected at six different sites in the Jordan Creek watershed and analyzed for major ions and dissolved nutrients. Major-ion chemistry showed Jordan Creek is calcium bicarbonate type water with little variation between sampling sites.

  17. Assessment of water quality, benthic invertebrates, and periphyton in the Threemile Creek basin, Mobile, Alabama, 1999-2003

    USGS Publications Warehouse

    McPherson, Ann K.; Gill, Amy C.; Moreland, Richard S.

    2005-01-01

    The U.S. Geological Survey conducted a 4-year investigation of water quality and aquatic-community structure in Threemile Creek, an urban stream that drains residential areas in Mobile, Alabama. Water-quality samples were collected between March 2000 and September 2003 at four sites on Threemile Creek, and between March 2000 and October 2001 at two tributary sites that drain heavily urbanized areas in the watershed. Stream samples were analyzed for major ions, nutrients, fecal-indicator bacteria, and selected organic wastewater compounds. Continuous measurements of dissolved-oxygen concentrations, water temperature, specific conductance, and turbidity were recorded at three sites on Threemile Creek during 1999?2003. Aquatic-community structure was evaluated by conducting one survey of the benthic invertebrate community and multiple surveys of the algal community (periphyton). Benthic invertebrate samples were collected in July 2000 at four sites on Threemile Creek; periphyton samples were collected at four sites on Threemile Creek and the two tributary sites during 2000 ?2003. The occurrence and distribution of chemical constituents in the water column provided an initial assessment of water quality in the streams; the structure of the benthic invertebrate and algal communities provided an indication of the cumulative effects of water quality on the aquatic biota. Information contained in this report can be used by planners and resource managers in the evaluation of proposed total maximum daily loads and other restoration efforts that may be implemented on Threemile Creek. The three most upstream sites on Threemile Creek had similar water chemistry, characterized by a strong calcium-bicarbonate component; the most downstream site on Threemile Creek was affected by tidal fluctuations and mixing from Mobile Bay and had a strong sodium-chloride component. The water chemistry at the tributary site on Center Street was characterized by a strong sodium-chloride component

  18. Tidal-induced Groundwater Responses in L-shaped Coastal Aquifers considering Storm Surge and Rainfall Effect

    NASA Astrophysics Data System (ADS)

    Li, Wei-Ci; Chuang, Mo-Hsiung; Ni, Chuen-Fa

    2016-04-01

    Sea level fluctuations influenced by tidal variations are natural phenomenon in coastal areas aquifers and had been recognized the key mechanisms controlling groundwater flow fields in coastal aquifers. This study considered an L-shaped coastal aquifer system that includes Fengshan Creek in Hsinchu County, Taiwan, to quantify groundwater responses induced by sea level fluctuations. This study employed MODFLOW model to simulate tidal-induced head fluctuation dynamics, storm surge and rainfall effect in the coastal aquifer. The numerical results will compared with those obtained from analytical solutions and in situ data. The simulation domain and input parameters were obtained based on the field data from three boreholes, one tide stations, two river level gauges, three groundwater wells, and the DTM for the local area. This study focuses on the development of theoretical models of groundwater hydrology system located downstream rivers, estuaries, coastal regions, such as tidal environment to investigate the groundwater level fluctuation and flow in tidal area considering environmental planning issues. On the basis of the numerical model, the groundwater head fluctuations induced by the joint effect of storm surge, rainfall and oceanic tides is investigated and discussed in the coastal aquifer.

  19. Reactive trace element enrichment in a highly modified, tidally inundated acid sulfate soil wetland: East Trinity, Australia.

    PubMed

    Keene, Annabelle F; Johnston, Scott G; Bush, Richard T; Burton, Edward D; Sullivan, Leigh A

    2010-04-01

    This study examines the abundance of trace elements in surface sediments of a former acid sulfate soil (ASS) wetland subjected to marine tidal inundation. Sediment properties of this highly modified study site are compared with those of an adjacent unmodified, intertidal mangrove forest. Whilst some trace elements (Al, Cd, Mn, Ni and Zn) were clearly depleted due to mobilisation and leaching in the previous oxic-acidic phase, other trace elements (As and Cr) displayed significant enrichment in the tidally inundated ASS. Many trace elements were strongly associated with the reactive Fe and acid volatile sulfide (AVS) fractions, suggesting that trace elements may be adsorbed to abundant reactive Fe phases or sequestered as sulfide minerals. These findings provide an important understanding of the fate and mobility of reactive iron, AVS and trace elements during tidal remediation of a formerly acidified Great Barrier Reef (GBR) catchment.

  20. Characterization of Biogeochemical Variability in a Tidal Estuary Using High Resolution Optical Measurements

    NASA Astrophysics Data System (ADS)

    Chang, G.; Jones, C.; Martin, T.

    2015-12-01

    The Berry's Creek Study Area (BCSA) is a tidal estuary located in New Jersey. Several chemicals of potential concern (COPCs) are present in the BCSA waterway and marshes, including mercury, methyl mercury, and polychlorinated biphenyls. Concentrations of COPCs and suspended solids in the BCSA vary temporally and spatially due to tidal variability, freshwater flow events, and interaction of marsh, waterway, and sediment bed materials. This system-wide variability confounds evaluation of COPC sources and transport mechanisms when using conventional laboratory-based analysis of discrete water column samples. Therefore, an optically-based biogeochemical monitoring program was conducted using near-continuous measurements of optical properties and an optical-biogeochemical partial least-squares regression model pioneered by B. Bergamaschi (USGS) and colleagues. The objective of the study was to characterize COPC concentration dynamics in the BCSA water column and relate the analysis to sediment bed processes. Optical-biogeochemical model results indicated that, in general, measured optical properties were sufficient for predicting COPC concentrations to within 10% of the accuracy of laboratory-based analytical measurements. The continuous, high temporal resolution time series of COPC concentrations determined by the optical-biogeochemical model enabled evaluation of the sediment bed dynamics and variability of COPCs in the surface water of the BCSA. Results indicate that tidally-induced resuspension of waterway sediment bed particulates is the primary mechanism for transport of COPCs to surface water. Waterway-marsh tidal exchange shows a net mass flux of particulate COPCs from waterway to marsh, indicating that particulate COPCs are retained and accumulate in the marshes with relatively little net export of dissolved COPCs from the marshes to the waterway.

  1. Sediment accretion in tidal freshwater forests and oligohaline marshes of the Waccamaw and Savannah Rivers, USA

    USGS Publications Warehouse

    Ensign, Scott H.; Hupp, Cliff R.; Noe, Gregory B.; Krauss, Ken W.; Stagg, Camille L.

    2014-01-01

    Sediment accretion was measured at four sites in varying stages of forest-to-marsh succession along a fresh-to-oligohaline gradient on the Waccamaw River and its tributary Turkey Creek (Coastal Plain watersheds, South Carolina) and the Savannah River (Piedmont watershed, South Carolina and Georgia). Sites included tidal freshwater forests, moderately salt-impacted forests at the freshwater–oligohaline transition, highly salt-impacted forests, and oligohaline marshes. Sediment accretion was measured by use of feldspar marker pads for 2.5 year; accessory information on wetland inundation, canopy litterfall, herbaceous production, and soil characteristics were also collected. Sediment accretion ranged from 4.5 mm year−1 at moderately salt-impacted forest on the Savannah River to 19.1 mm year−1 at its relict, highly salt-impacted forest downstream. Oligohaline marsh sediment accretion was 1.5–2.5 times greater than in tidal freshwater forests. Overall, there was no significant difference in accretion rate between rivers with contrasting sediment loads. Accretion was significantly higher in hollows than on hummocks in tidal freshwater forests. Organic sediment accretion was similar to autochthonous litter production at all sites, but inorganic sediment constituted the majority of accretion at both marshes and the Savannah River highly salt-impacted forest. A strong correlation between inorganic sediment accumulation and autochthonous litter production indicated a positive feedback between herbaceous plant production and allochthonous sediment deposition. The similarity in rates of sediment accretion and sea level rise in tidal freshwater forests indicates that these habitats may become permanently inundated if the rate of sea level rise increases.

  2. Lithologic Coring in the Lower Anacostia Tidal Watershed, Washington, D.C., July 2002

    USGS Publications Warehouse

    Tenbus, Frederick J.

    2003-01-01

    Little is known about the volumetric flux of ground water to the lower tidal Anacostia River, or whether ground-water flow is an important component of the contaminant load in this part of the Anacostia River. The watershed is in the eastern part of Washington, D.C., and has been subjected to over 200 years of urbanization and modifications of the river channel and nearby land areas. These anthropogenic factors, along with tidal fluctuations in the river, make ground-water data collection and interpretations difficult. The U.S. Geological Survey is cooperating with the District of Columbia Department of Health, Environmental Health Administration, Bureau of Environmental Quality, Water Quality Division, in a study to assess nonpoint-source pollution from ground water into the lower tidal Anacostia River. Lithologic cores from drilling activities conducted during July 2002 in the study area have been interpreted in the context of geologic and hydrogeologic information from previous studies in the lower Anacostia tidal watershed. These interpretations can help achieve the overall project goals of characterizing ground-water flow and contaminant load in the study area. Hydrostratigraphic units encountered during drilling generally consisted of late Pleistocene to Holocene fluvial deposits overlying Cretaceous fluvial/deltaic deposits. Cores collected in Beaverdam Creek and the Anacostia River indicated high- and low-energy environments of deposition, respectively. Two cores collected near the river showed different types of anthropogenic fill underlain by low-energy deposits, which were in turn underlain by sand and gravel. A third core collected near the river consisted primarily of sand and gravel with no artificial fill.

  3. Suspended sediment dynamics during the inter-monsoon season in the subaqueous Mekong Delta and adjacent shelf, southern Vietnam

    NASA Astrophysics Data System (ADS)

    Unverricht, Daniel; Nguyen, Thanh Cong; Heinrich, Christoph; Szczuciński, Witold; Lahajnar, Niko; Stattegger, Karl

    2014-01-01

    tidal current velocities. High tidal current velocities of up to 0.6 m/s near the sea bottom generate increasing SSCs of more than 25 μl/l in the water column. Additionally a significant trend of decreasing SSC from the near-seabed to the upper part of the water column can be observed. In terms of sediment transport the ebb phase dominates the tidal cycle by its higher tidal current velocities but the flood phase has the longer duration. The switch of the tidal current direction from ebb to flood phase occurs rapidly against which the change from flood to ebb phase requires up to 3 h. This leads to an asymmetry of the tidal ellipses and may cause a net-sediment transport from the shelf into the subaqueous Mekong Delta.In the subaqueous Mekong Delta and adjacent shelf, seven transects show similar patterns of SSCs dependent to the tidal phase. A hypopycnal sediment plume from the subaqueous Mekong Delta into the shelf region was not observed. Our results imply that resuspension by tidal currents dominates the sediment transport in the subaqueous Mekong Delta and adjacent shelf regions during the inter-monsoon season.

  4. Environmental setting of Maple Creek watershed, Nebraska

    USGS Publications Warehouse

    Fredrick, Brian S.; Linard, Joshua I.; Carpenter, Jennifer L.

    2006-01-01

    The Maple Creek watershed covers a 955-square-kilometer area in eastern Nebraska, which is a region dominated by agricultural land use. The Maple Creek watershed is one of seven areas currently included in a nationwide study of the sources, transport, and fate of water and chemicals in agricultural watersheds. This study, known as the topical study of 'Agricultural Chemicals: Sources, Transport, and Fate' is part of the National Water-Quality Assessment Program being conducted by the U.S. Geological Survey. The Program is designed to describe water-quality conditions and trends based on representative surface- and ground-water resources across the Nation. The objective of the Agricultural Chemicals topical study is to investigate the sources, transport, and fate of selected agricultural chemicals in a variety of agriculturally diverse environmental settings. The Maple Creek watershed was selected for the Agricultural Chemicals topical study because its watershed represents the agricultural setting that characterizes eastern Nebraska. This report describes the environmental setting of the Maple Creek watershed in the context of how agricultural practices, including agricultural chemical applications and irrigation methods, interface with natural settings and hydrologic processes. A description of the environmental setting of a subwatershed within the drainage area of Maple Creek is included to improve the understanding of the variability of hydrologic and chemical cycles at two different scales.

  5. Lunar Tidal Deformation and the Deep Interior

    NASA Astrophysics Data System (ADS)

    Williams, James G.; Konopliv, Alex S.; Park, Ryan; Boggs, Dale H.; Asmar, Sami W.; Yuan, Dah-Ning; Ratcliff, James; Watkins, Michael M.; Smith, David E.; Zuber, Maria

    2016-10-01

    The gravitational attractions of the Earth and Sun raise tides on the Moon. The amplitudes of vertical tidal variations are typically 0.1 to 0.15 m in size. The GRAIL mission determines the potential Love number k2 = 0.02422 with <1% uncertainty. Models with a crust, mantle, deep dissipating region, and fluid core can match the k2. Lunar Laser Ranging determines tidal dissipation Q=38 at 1 month period and Q=41 at 1 yr. Dissipation in the deep mantle appears to cause the low tidal Q and Q versus tidal period is a clue about the dissipation mechanism. The dissipating region has an upper radius of at least 535 km. The vertical displacement Love number h2 is detected.

  6. Cullinan Ranch Tidal Marsh Restoration Project

    EPA Pesticide Factsheets

    Information about the SFBWQP Cullinan Ranch Tidal Marsh Restoration Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  7. On the time-course of adjacent and non-adjacent transposed-letter priming

    PubMed Central

    Ktori, Maria; Kingma, Brechtsje; Hannagan, Thomas; Holcomb, Phillip J.; Grainger, Jonathan

    2014-01-01

    We compared effects of adjacent (e.g., atricle-ARTICLE) and non-adjacent (e.g., actirle-ARTICLE) transposed-letter (TL) primes in an ERP study using the sandwich priming technique. TL priming was measured relative to the standard double-substitution condition. We found significantly stronger priming effects for adjacent transpositions than non-adjacent transpositions (with 2 intervening letters) in behavioral responses (lexical decision latencies), and the adjacent priming effects emerged earlier in the ERP signal, at around 200 ms post-target onset. Non-adjacent priming effects emerged about 50 ms later and were short-lived, being significant only in the 250-300 ms time-window. Adjacent transpositions on the other hand continued to produce priming in the N400 time-window (300-500 ms post-target onset). This qualitatively different pattern of priming effects for adjacent and non-adjacent transpositions is discussed in the light of different accounts of letter transposition effects, and the utility of drawing a distinction between positional flexibility and positional noise. PMID:25364497

  8. Floodtide pulses after low tides in shallow subembayments adjacent to deep channels

    USGS Publications Warehouse

    Warner, J.C.; Schoellhamer, D.H.; Ruhl, C.A.; Burau, J.R.

    2004-01-01

    In shallow waters surface gravity waves (tides) propagate with a speed proportional to the square root of water depth (c = ???g(h+??)). As the ratio of free surface displacement to mean depth (??/h) approaches unity the wave will travel noticeably faster at high tide than at low tide, creating asymmetries in the tidal form. This physical process is explained analytically by the increased significance of friction and the nonlinear terms in the continuity and momentum equations. In a tidal system comprising a shallow bay adjacent to a deeper channel, tidal asymmetries will be more prevalent in the shallow bay. Thus strong barotropic gradients can be generated between the two, producing rapid accelerations of currents into the bay (relative to other bay tidal processes) and create a maximum peak in the flood tide that we describe as a floodtide pulse. These floodtide pulses can promote a landward flux of suspended-sediment into the bay. In Grizzly Bay (part of northern San Francisco Bay, USA), field observations verify the occurrence of floodtide pulses during the lowest low tides of the year. No pulses were observed in neighboring Honker Bay, which has an average depth ???30 cm greater than Grizzly Bay. Numerical simulations of northern San Francisco Bay using realistic bathymetry demonstrated that floodtide pulses occurred in Grizzly Bay but not in Honker Bay, consistent with the observations. Both observations and numerical simulations show that floodtide pulses promote a landward flux of sediment into Grizzly Bay. Numerical simulations of an idealized bay-channel system quantify the importance of mean depth and friction in creating these floodtide pulses. ?? 2004 Elsevier Ltd. All rights reserved.

  9. Half Moon Cove Tidal Project. Feasibility report

    SciTech Connect

    Not Available

    1980-11-01

    The proposed Half Moon Cove Tidal Power Project would be located in a small cove in the northern part of Cobscook Bay in the vicinity of Eastport, Maine. The project would be the first tidal electric power generating plant in the United States of America. The basin impounded by the barrier when full will approximate 1.2 square miles. The average tidal range at Eastport is 18.2 feet. The maximum spring tidal range will be 26.2 feet and the neap tidal range 12.8 feet. The project will be of the single pool-type single effect in which generation takes place on the ebb tide only. Utilizing an average mean tidal range of 18.2 feet the mode of operation enables generation for approximately ten and one-half (10-1/2) hours per day or slightly in excess of five (5) hours per tide. The installed capacity will be 12 MW utilizing 2 to 6 MW units. An axial flow, or Bulb type of turbine was selected for this study.

  10. TIDAL INTERACTIONS IN MERGING WHITE DWARF BINARIES

    SciTech Connect

    Piro, Anthony L.

    2011-10-20

    The recently discovered system J0651 is the tightest known detached white dwarf (WD) binary. Since it has not yet initiated Roche-lobe overflow, it provides a relatively clean environment for testing our understanding of tidal interactions. I investigate the tidal heating of each WD, parameterized in terms of its tidal Q parameter. Assuming that the heating can be radiated efficiently, the current luminosities are consistent with Q {sub 1} {approx} 7 x 10{sup 10} and Q {sub 2} {approx} 2 x 10{sup 7}, for the He and C/O WDs, respectively. Conversely, if the observed luminosities are merely from the cooling of the WDs, these estimated values of Q represent the upper limits. A large Q {sub 1} for the He WD means its spin velocity will be slower than that expected if it was tidally locked, which, since the binary is eclipsing, may be measurable via the Rossiter-McLaughlin effect. After one year, gravitational wave emission shifts the time of eclipses by 5.5 s, but tidal interactions cause the orbit to shrink more rapidly, changing the time by up to an additional 0.3 s after a year. Future eclipse timing measurements may therefore infer the degree of tidal locking.

  11. Tidal wave transformations in the German Bight

    NASA Astrophysics Data System (ADS)

    Stanev, Emil V.; Al-Nadhairi, Rahma; Staneva, Joanna; Schulz-Stellenfleth, Johannes; Valle-Levinson, Arnoldo

    2014-07-01

    Mesoscale and submesoscale dynamics associated with tidal wave transformations were addressed in the German Bight using numerical simulations. Tidal gauge and velocity observations in several locations were used to validate the numerical model. A downscaling approach included analysis of simulations with horizontal resolutions of 1, 0.4, and 0.2 km. It was shown that the modified tidal wave lost most of its energy after reflection or refraction over the eastern part of the German Bight. Energy loss resulted in a pronounced change of the wave's spectral composition and generation of overtides. Tidal oscillations were modified by mesoscale processes associated with bathymetric channels. Semidiurnal and quarterdiurnal tides revealed very different spatial patterns. The former were aligned with the bathymetric channels, while the latter were rather "patchy" and had about half the spatial scales. In numerous areas around the bathymetric channels, the major axis of the M4 ellipses was normal or at some angle with the major axis of the M2 ellipses. Thus, higher harmonics developed "orthogonal" patterns that drove secondary circulations. Moreover, the ratio between spring and neap tidal amplitudes was relatively low in the Wadden Sea, showing reduced sensitivity of this very shallow area to fortnightly tidal variations. It was demonstrated that simulated hydrodynamics patterns help explain the physical mechanism shaping the median grain size distribution in the German Bight.

  12. VISCOELASTIC MODELS OF TIDALLY HEATED EXOMOONS

    SciTech Connect

    Dobos, Vera; Turner, Edwin L.

    2015-05-01

    Tidal heating of exomoons may play a key role in their habitability, since the elevated temperature can melt the ice on the body even without significant solar radiation. The possibility of life has been intensely studied on solar system moons such as Europa or Enceladus where the surface ice layer covers a tidally heated water ocean. Tidal forces may be even stronger in extrasolar systems, depending on the properties of the moon and its orbit. To study the tidally heated surface temperature of exomoons, we used a viscoelastic model for the first time. This model is more realistic than the widely used, so-called fixed Q models because it takes into account the temperature dependence of the tidal heat flux and the melting of the inner material. Using this model, we introduced the circumplanetary Tidal Temperate Zone (TTZ), which strongly depends on the orbital period of the moon and less on its radius. We compared the results with the fixed Q model and investigated the statistical volume of the TTZ using both models. We have found that the viscoelastic model predicts 2.8 times more exomoons in the TTZ with orbital periods between 0.1 and 3.5 days than the fixed Q model for plausible distributions of physical and orbital parameters. The viscoelastic model provides more promising results in terms of habitability because the inner melting of the body moderates the surface temperature, acting like a thermostat.

  13. 8. VIEW LOOKING SOUTH OF KILLBUCK CREEK TAKEN FROM THE ...

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

    8. VIEW LOOKING SOUTH OF KILLBUCK CREEK TAKEN FROM THE BRIDGE DECK SHOWING THE SECOND OR THIRD GROWTH SPROUT. - Madison County Bridge 90, Spanning Killbuck Creek on County Road No. 600, Moonville, Madison County, IN

  14. Detail view of Fanno Creek trestle, showing trestle substructure, view ...

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

    Detail view of Fanno Creek trestle, showing trestle substructure, view looking north - Oregon Electric Railroad, Fanno Creek Trestle, Garden Home to Wilsonville Segment, Milepost 34.7, Garden Home, Washington County, OR

  15. 1. WATER ENTERING CONFLUENCE POOL FROM BEAR CREEK AT LEFT, ...

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

    1. WATER ENTERING CONFLUENCE POOL FROM BEAR CREEK AT LEFT, AND FROM SANTA ANA RIVER THROUGH TUNNEL #0 AT RIGHT. VIEW TO NORTHEAST. - Santa Ana River Hydroelectric System, Bear Creek Diversion Dam & Confluence Pool, Redlands, San Bernardino County, CA

  16. Rock Creek and Potomac Parkway / Waterside Drive Sycamore and ...

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

    Rock Creek and Potomac Parkway / Waterside Drive Sycamore and White Ash Trees, Rock Creek and Potomac Parkway, median between northbound and southbound lanes near the Waterside Drive exit and entrance ramps., Washington, District of Columbia, DC

  17. 17. View from Sterling Creek Marsh looking west, with berm ...

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

    17. View from Sterling Creek Marsh looking west, with berm to the left and Henry Ford Mansion in the far background - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  18. 8. View of Sterling Creek Marsh looking northeast across the ...

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

    8. View of Sterling Creek Marsh looking northeast across the berm with the marsh to the left - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  19. 10. View of Sterling Creek Marsh looking south with house ...

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

    10. View of Sterling Creek Marsh looking south with house in the background and marsh in foreground - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  20. 9. View of Sterling Creek Marsh looking southwest, with the ...

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

    9. View of Sterling Creek Marsh looking southwest, with the marsh in the background and the berm in the foreground - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  1. 20. View of Sterling Creek Marsh looking southwest with oyster ...

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

    20. View of Sterling Creek Marsh looking southwest with oyster house in the tree line - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  2. 14. View of Sterling Creek Marsh east across the marsh, ...

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

    14. View of Sterling Creek Marsh east across the marsh, with canal in foreground - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  3. 12. View of Sterling Creek Marsh looking southeast across marsh, ...

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

    12. View of Sterling Creek Marsh looking southeast across marsh, with canal in foreground - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  4. 3. View of Sterling Creek Marsh at low tide showing ...

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

    3. View of Sterling Creek Marsh at low tide showing rubble at the entrance of dam/bridge looking southwest - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  5. 4. View of Sterling Creek Marsh at low tide showing ...

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

    4. View of Sterling Creek Marsh at low tide showing rubble at the entrance of the dam/bridge looking east - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  6. Big Creek Hydroelectric System, East & West Transmission Line, 241mile ...

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

    Big Creek Hydroelectric System, East & West Transmission Line, 241-mile transmission corridor extending between the Big Creek Hydroelectric System in the Sierra National Forest in Fresno County and the Eagle Rock Substation in Los Angeles, California, Visalia, Tulare County, CA

  7. 13. View of Sterling Creek Marsh looking southeast; looking at ...

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

    13. View of Sterling Creek Marsh looking southeast; looking at canal going to the tree line - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  8. 5. View of Sterling Creek lettuce shed looking northwest showing ...

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

    5. View of Sterling Creek lettuce shed looking northwest showing office - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  9. 15. Detail view of Sterling Creek lettuce shed showing second ...

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

    15. Detail view of Sterling Creek lettuce shed showing second floor support beams. - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  10. 13. Detail view of Sterling Creek lettuce shed showing second ...

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

    13. Detail view of Sterling Creek lettuce shed showing second floor window sill - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  11. 1. View of Sterling Creek lettuce shed looking south, with ...

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

    1. View of Sterling Creek lettuce shed looking south, with road in foreground - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  12. 12. Detail view of Sterling Creek lettuce shed showing floor ...

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

    12. Detail view of Sterling Creek lettuce shed showing floor joist and support beams - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  13. Water-quality appraisal, Mammoth Creek and Hot Creek, Mono County, California

    USGS Publications Warehouse

    Setmire, J.G.

    1984-01-01

    A late summer reconnaissance in 1981 and a spring high-flow sampling in 1982 of Mammoth Creek and Hot Creek, located in the Mammoth crest area of the Sierra Nevada, indicated that mineralization, eutrophication, sedimentation, and limited areas of fecal contamination were occurring. Mineralization, indicated by a downstream increase in dissolved-solids concentration, was due primarily to geothermal springs that gradually decreased in the percentage of calcium, increased in the percentage of magnesium and sodium, and caused fluctuating, but overall increasing percentage of fluoride, sulfate, and chloride. Resulting water quality in Mammoth Creek was similar to that of the springs forming Hot Creek. Eutrophication was observed in Twin Lakes and the reach of Hot Creek below the fish hatchery. Twin Lakes had floating mats of algae and a high dissolved-oxygen saturation of 147 percent at a pH of 9.2. Hot Creek had excessive aquatic vascular plant and algae growth, dissolved-oxygen saturations ranging from 65 to 200 percent, algal growth potential of 30 milligrams per liter, and nitrates and phosphates of 0.44 and 0.157 milligrams per liter. Sedimentation was noted in observations of bed-material composition showing the presence of fine material beginning at Sherwin Creek Road. Fecal contamination was indicated by fecal coliform counts of 250 colonies per 100 milliliters and fecal streptococcal counts greater than 1,000 colonies per 100 milliliters. (USGS)

  14. Steel Creek fish: L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1987

    SciTech Connect

    Paller, M.H.; Heuer, J.H.; Kissick, L.A.

    1988-03-01

    Fish samples were collected from Steel Creek during 1986 and 1987 following the impoundment of the headwaters of the stream to form L-Lake, a cooling reservoir for L-Reactor which began operating late in 1985. Electrofishing and ichthyoplankton sample stations were located throughout the creek. Fykenetting sample stations were located in the creek mouth and just above the Steel Creek swamp. Larval fish and fish eggs were collected with 0.5 m plankton nets. Multivariate analysis of the electrofishing data suggested that the fish assemblages in Steel Creek exhibited structural differences associated with proximity to L-Lake, and habitat gradients of current velocity, depth, and canopy cover. The Steel Creek corridor, a lotic reach beginning at the base of the L-Lake embankment was dominated by stream species and bluegill. The delta/swamp, formed where Steel Creek enters the Savannah River floodplain, was dominated by fishes characteristic of slow flowing waters and heavily vegetated habitats. The large channel draining the swamp supported many of the species found in the swamp plus riverine and anadromous forms.

  15. Steel Creek water quality: L-Lake/Steel Creek Biological Monitoring Program, November 1985--December 1991

    SciTech Connect

    Bowers, J.A.; Kretchmer, D.W.; Chimney, M.J.

    1992-04-01

    The Savannah River Site (SRS) encompasses 300 sq mi of the Atlantic Coastal Plain in west-central South Carolina. The Savannah River forms the western boundary of the site. Five major tributaries of the Savannah River -- upper Three Runs Creek, Four Mile Creek, Pen Branch, Steel Creek, and Lower Three Runs Creek -- drain the site. All but Upper Three Runs Creek receive, or in the past received, thermal effluents from nuclear production reactors. In 1985, L Lake, a 400-hectare cooling reservoir, was built on the upper reaches of Steel Creek to receive effluent from the restart of L-Reactor, and protect the lower reaches from thermal impacts. The Steel Creek Biological Monitoring Program was designed to meet envirorunental regulatory requirements associated with the restart of L-Reactor and complements the Biological Monitoring Program for L Lake. This extensive program was implemented to address portions of Section 316(a) of the Clean Water Act. The Department of Energy (DOE) must demonstrate that the operation of L-Reactor will not significantly alter the established aquatic ecosystems.

  16. Effects of Relative Mean Sea Level Variations on Tidal Networks Generated on Experimental Setting

    NASA Astrophysics Data System (ADS)

    Stefanon, L.; Carniello, L.; D'Alpaos, A.; Rinaldo, A.

    2012-12-01

    We present the results of laboratory experiments carried out in a large experimental apparatus aimed at reproducing a typical lagoonal environment subject to tidal forcings. The experimental apparatus consists of two adjoining basins reproducing the sea and the lagoon. The tide is generated at the sea by a vertical steel sharp-edge weir, oscillating vertically. The weir is driven by an ad hoc developed software which continuously corrects the weir motion on the basis of water levels measured at the sea, allowing us to generate a sinusoidal tide of fixed amplitude and period, oscillating around mean water level. The bottom of the lagoon is covered by a layer of cohesionless plastic grains, with a density of 1041 kg/m3. The cohesionless plastic grains are characterized by a nearly uniform grain size distribution, with a median grain size of 0.8 mm. The lack of external sediment supply, the absence of vegetation, and the prevalence of bedload transport prevent any deposition processes and lateral surface accretion, attributing a purely erosive character to the experimental lagoon. As a consequence, in this experimental lagoon the main morphodynamic process responsible for tidal network initiation and development is the differential erosion between the channels and the adjacent surface. The experiments were designed in order to analyze the effects of mean sea level variations on channel network dynamics, focusing on the changes of the relevant geomorphic characteristics of the experimental networks, such as e.g. drainage density, based on the probability distribution of unchanneled lengths, and flowing tidal prism. Our results suggest that a decrease in the tidal prism leads to network retreat and contraction of channel cross sections. Conversely, an increase in the tidal prism promotes network re-incision and re-expansion of channel cross sections. In general, contractions and expansions tend to occur within the same planar blueprint and the network re-expands cutting

  17. Changes in surfzone morphodynamics driven by multi-decadel contraction of a large ebb-tidal delta

    USGS Publications Warehouse

    Hansen, Jeff E.; Elias, Edwin; Barnard, Patrick L.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    The impact of multi-decadal, large-scale deflation (76 million m3 of sediment loss) and contraction (~ 1 km) of a 150 km2 ebb-tidal delta on hydrodynamics and sediment transport at adjacent Ocean Beach in San Francisco, CA (USA), is examined using a coupled wave and circulation model. The model is forced with representative wave and tidal conditions using recent (2005) and historic (1956) ebb-tidal delta bathymetry data sets. Comparison of the simulations indicates that along north/south trending Ocean Beach the contraction and deflation of the ebb-tidal delta have resulted in significant differences in the flow and sediment dynamics. Between 1956 and 2005 the transverse bar (the shallow attachment point of the ebb-tidal delta to the shoreline) migrated northward ~ 1 km toward the inlet while a persistent alongshore flow and transport divergence point migrated south by ~ 500 m such that these features now overlap. A reduction in tidal prism and sediment supply over the last century has resulted in a net decrease in offshore tidal current-generated sediment transport at the mouth of San Francisco Bay, and a relative increase in onshore-directed wave-driven transport toward the inlet, accounting for the observed contraction of the ebb-tidal delta. Alongshore migration of the transverse bar and alongshore flow divergence have resulted in an increasing proportion of onshore migrating sediment from the ebb-tidal delta to be transported north along the beach in 2005 versus south in 1956. The northerly migrating sediment is then trapped by Pt. Lobos, a rocky headland at the northern extreme of the beach, consistent with the observed shoreline accretion in this area. Conversely, alongshore migration of the transverse bar and divergence point has decreased the sediment supply to southern Ocean Beach, consistent with the observed erosion of the shoreline in this area. This study illustrates the utility of applying a high-resolution coupled circulation-wave model for

  18. Meager Creek Geothermal Project: preliminary resource evaluation

    SciTech Connect

    Stauder, J.J.; Menzies, A.J.; Harvey, C.C.; Leach, T.M.

    1983-09-01

    A 190-200/sup 0/C geothermal resource has been identified in the Meager Creek Geothermal Area (South Meager, previously called the South Reservoir), British Columbia, Canada, on the basis of surface and near surface exploration and the results of a three well deep drilling exploration program. The geothermal resource appears to be fracture dominated with limited flow capacity. It is associated with the Meager Creek Fault Zone which was encountered by the deep wells at a depth of 1200-1600 meters (400-800 meters below MSL). Temperatures of up to 270/sup 0/C were encountered below the Meager Creek Fault Zone but both petrologic and well testing data indicate that the rock is generally impermeable. The high temperatures at depth appear to be a manifestation of the abnormally high (approximately equal to 90/sup 0/C/km) regional geothermal gradient.

  19. The Boulder Creek Batholith, Front Range, Colorado

    USGS Publications Warehouse

    Gable, Dolores J.

    1980-01-01

    The Boulder Creek batholith is the best known of several large Precambrian batholiths of similar rock composition that crop out across central Colorado. The rocks in the batholith belong to the calc-alkaline series and range in composition from granodiorite through quartz diorite (tonalite) to gneissic aplite. Two rock types dominate': the Boulder Creek Granodiorite, the major rock unit, and a more leucocratic and slightly younger unit herein named Twin Spruce Quartz Monzonite. Besides mafic inclusions, which occur mainly in hornblende-bearing phases of the Boulder Creek Granodiorite, there are cogenetic older and younger lenses, dikes, and small plutons of hornblende diorite, hornblendite, gabbro, and pyroxenite. Pyroxenite is not found in the batholith. The Boulder Creek Granodiorite in the batholith represents essentially two contemporaneous magmas, a northern body occurring in the Gold Hill and Boulder quadrangles and a larger southern body exposed in the Blackhawk and the greater parts of the Tungsten and Eldorado Springs quadrangles. The two bodies are chemically and mineralogically distinct. The northern body is richer in CaO and poorer in K2O, is more mafic, and has a larger percentage of plagioclase than the southern body. A crude sequence of rock types occurs from west to east in the batholith accompanied by a change in plagioclase composition from calcic plagioclase on the west to sodic on the east. Ore minerals tend to decrease, and the ratio potassium feldspar:plagioclase increases inward from the western contact of the batholith, indicating that the Boulder Creek batholith is similar to granodiorite batholiths the world over. Emplacement of the Boulder Creek batholith was contemporaneous with plastic deformation and high-grade regional metamorphism that folded the country rock and the batholith contact along west-northwest and north-northwest axes. Also, smaller satellitic granodiorite bodies tend to conform to the trends of foliation and fold axes in

  20. Water-quality appraisal. Mammoth Creek and Hot Creek, Mono County, California

    SciTech Connect

    Setmire, J.G.

    1984-06-01

    A late summer reconnaissance in 1981 and a spring high-flow sampling in 1982 of Mammoth Creek and Hot Creek, located in the Mammoth crest area of the Sierra Nevada, indicated that three water-quality processes were occurring: (1) mineralization; (2) eutrophication; and (3) sedimentation. Limited areas of fecal contamination were also observed. Mineralization due primarily to geothermal springs increased dissolved-solids concentration downstream, which changed the chemical composition of the water. The percentage of calcium decreased gradually, the percentage of magnesium and sodium increased, and the percentage of fluoride, sulfate, and chloride fluctuated, but increased overall. These changes produced water quality in Mammoth Creek similar to that of the springs forming Hot Creek. Twin Lakes and the reach of Hot Creek below the fish hatchery showed evidence of eutrophication. Twin Lakes had floating mats of algae and a high dissolved-oxygen saturation of 147% at a pH of 9.2. Hot Creek had abundant growth of aquatic vascular plants and algae, dissolved-oxygen saturations ranging from 65% to 200%, algal growth potential of 30 milligrams per liter, nitrate concentration of 0.44 milligram per liter, and phosphate concentration of 0.157 milligram per liter. Sediment deposition was determined from detailed observations of bed-material composition, which showed that fine material was deposited at Sherwin Creek Road and downstream. Fecal contamination was indicated by fecal-coliform bacteria counts of 250 colonies per 100 milliliters and fecal-streptococcal bacteria counts greater than 1000 colonies per 100 milliliters. Although bacterial sampling was sporadic and incomplete, it did indicate adverse effects on water quality for the following beneficial uses that have been identified for Mammoth Creek and Hot Creek: (1) municipal supply; (2) cold-water habitat; and (3) contact and noncontact water recreation. 6 refs., 15 figs., 15 tabs.

  1. Hydrology and Flood Profiles of Duck Creek and Jordan Creek Downstream from Egan Drive, Juneau, Alaska

    USGS Publications Warehouse

    Curran, Janet H.

    2007-01-01

    Hydrologic and hydraulic updates for Duck Creek and the lower part of Jordan Creek in Juneau, Alaska, included computation of new estimates of peak streamflow magnitudes and new water-surface profiles for the 10-, 50-, 100-, and 500-year floods. Computations for the 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence interval flood magnitudes for both streams used data from U.S. Geological Survey stream-gaging stations weighted with regional regression equations for southeast Alaska. The study area for the hydraulic model consisted of three channels: Duck Creek from Taku Boulevard near the stream's headwaters to Radcliffe Road near the end of the Juneau International Airport runway, an unnamed tributary to Duck Creek from Valley Boulevard to its confluence with Duck Creek, and Jordan Creek from a pedestrian bridge upstream from Egan Drive to Crest Street at Juneau International Airport. Field surveys throughout the study area provided channel geometry for 206 cross sections, and geometric and hydraulic characteristics for 29 culverts and 15 roadway, driveway, or pedestrian bridges. Hydraulic modeling consisted of application of the U.S. Army Corps of Engineers' Hydrologic Engineering Center River Analysis System (HEC-RAS) for steady-state flow at the selected recurrence intervals using an assumed high tide of 20 feet and roughness coefficients refined by calibration to measured water-surface elevations from a 2- to 5-year flood that occurred on November 21, 2005. Model simulation results identify inter-basin flow from Jordan Creek to the southeast at Egan Drive and from Duck Creek to Jordan Creek downstream from Egan Drive at selected recurrence intervals.

  2. 1. EXTERIOR OVERVIEW OF SOUTH END OF RUSH CREEK POWERHOUSE ...

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

    1. EXTERIOR OVERVIEW OF SOUTH END OF RUSH CREEK POWERHOUSE RESIDENTIAL COMPLEX SHOWING THE RUSH CREEK POWERHOUSE AT PHOTO RIGHT, BUILDING 106 NEXT TO THE POWERHOUSE AT PHOTO CENTER, BUILDING 103 AT UPPER PHOTO LEFT, AND BUILDING 104 ABOVE BUILDING 106 PARTIALLY OBSCURED BEHIND TREE AT UPPER PHOTO CENTER. VIEW TO SOUTH. - Rush Creek Hydroelectric System, Worker Cottage, Rush Creek, June Lake, Mono County, CA

  3. Flood-inundation maps for Indian Creek and Tomahawk Creek, Johnson County, Kansas, 2014

    USGS Publications Warehouse

    Peters, Arin J.; Studley, Seth E.

    2016-01-25

    Digital flood-inundation maps for a 6.4-mile upper reach of Indian Creek from College Boulevard to the confluence with Tomahawk Creek, a 3.9-mile reach of Tomahawk Creek from 127th Street to the confluence with Indian Creek, and a 1.9-mile lower reach of Indian Creek from the confluence with Tomahawk Creek to just beyond the Kansas/Missouri border at State Line Road in Johnson County, Kansas, were created by the U.S. Geological Survey in cooperation with the city of Overland Park, Kansas. The flood-inundation maps, which can be accessed through the U.S. Geological Survey Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the U.S. Geological Survey streamgages on Indian Creek at Overland Park, Kansas; Indian Creek at State Line Road, Leawood, Kansas; and Tomahawk Creek near Overland Park, Kansas. Near real time stages at these streamgages may be obtained on the Web from the U.S. Geological Survey National Water Information System at http://waterdata.usgs.gov/nwis or the National Weather Service Advanced Hydrologic Prediction Service at http://water.weather.gov/ahps/, which also forecasts flood hydrographs at these sites.Flood profiles were computed for the stream reaches by means of a one-dimensional step-backwater model. The model was calibrated for each reach by using the most current stage-discharge relations at the streamgages. The hydraulic models were then used to determine 15 water-surface profiles for Indian Creek at Overland Park, Kansas; 17 water-surface profiles for Indian Creek at State Line Road, Leawood, Kansas; and 14 water-surface profiles for Tomahawk Creek near Overland Park, Kansas, for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from bankfull to the next interval above the 0.2-percent annual exceedance probability flood level (500-year recurrence interval). The

  4. Selected hydrologic data for Fountain Creek and Monument Creek basins, east-central Colorado

    USGS Publications Warehouse

    Kuhn, Gerhard; Ortiz, Roderick F.

    1989-01-01

    Selected hydrologic data were collected during 1986, 1987, and 1988 by the U.S. Geological Survey for the Fountain Creek and Monument Creek basins, east-central Colorado. The data were obtained as part of a study to determine the present and projected effects of wastewater discharges on the two creeks. The data, which are available for 129 surface-water sites, include: (1) About 1,100 water quality analyses; (2) about 420 measurements of discharge, (3) characteristics of about 50 dye clouds associated with measurements of traveltime and reaeration , and (4) about 360 measurements of channel geometry. (USGS)

  5. 78 FR 28897 - Lost Creek ISR, LLC, Lost Creek Uranium In-Situ Recovery Project; Sweetwater County, Wyoming

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-16

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Lost Creek ISR, LLC, Lost Creek Uranium In-Situ Recovery Project; Sweetwater County, Wyoming AGENCY: Nuclear Regulatory Commission. ACTION: Environmental assessment and finding of no...

  6. 20. DISTANT HELICOPTER VIEW TO SOUTHEAST UP LITTLE ROCK CREEK ...

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

    20. DISTANT HELICOPTER VIEW TO SOUTHEAST UP LITTLE ROCK CREEK CANYON, WITH DAM AND RESERVOIR AT RIGHT CENTER. PALMDALE-LITTLEROCK DITCH, MARKED BY DENSE VEGETATION, CROSSES ROAD AT LOWER CENTER - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  7. 1. EXTERIOR OVERVIEW OF NORTH END OF RUSH CREEK POWERHOUSE ...

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

    1. EXTERIOR OVERVIEW OF NORTH END OF RUSH CREEK POWERHOUSE RESIDENTIAL COMPLEX SHOWING BUILDING 108 AT PHOTO RIGHT AND BUILDING 105 AT PHOTO CENTER BEHIND SWITCHRACKS AND TREE. POWERHOUSE IS AT EXTREME PHOTO LEFT. VIEW TO WEST. - Rush Creek Hydroelectric System, Worker Cottage, Rush Creek, June Lake, Mono County, CA

  8. 77 FR 5201 - Drawbridge Operation Regulation; Bear Creek, Dundalk, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-02

    ... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulation; Bear Creek, Dundalk, MD... across Bear Creek, mile 3.4, between Dundalk and Sparrows Point, MD. The proposed change will alter the... Avenue across Bear Creek, mile 3.4 between Dundalk and Sparrows Point, MD. This change would require...

  9. 77 FR 73967 - Drawbridge Operation Regulation; Bear Creek, Dundalk, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-12

    ... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulation; Bear Creek, Dundalk, MD... highway bridge at Wise Avenue across Bear Creek, mile 3.4, between Dundalk and Sparrows Point, MD. The... Regulation; Bear Creek, Dundalk, MD'' in the Federal Register (77 FR 5201). The rulemaking concerned...

  10. 1. EXTERIOR OVERVIEW SHOWING BISHOP CREEK PLANT 4 RESIDENTIAL COMPLEX. ...

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

    1. EXTERIOR OVERVIEW SHOWING BISHOP CREEK PLANT 4 RESIDENTIAL COMPLEX. BUILDING 122 IS VISIBLE AT PHOTO CENTER. PLANT 5 INTAKE DAM AT PHOTO LEFT. VIEW TO WEST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

  11. 1. EXTERIOR OVERVIEW SHOWING BISHOP CREEK PLANT 4 RESIDENTIAL COMPLEX. ...

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

    1. EXTERIOR OVERVIEW SHOWING BISHOP CREEK PLANT 4 RESIDENTIAL COMPLEX. BUILDING 113 IS VISIBLE AT RIGHT PHOTO CENTER. PLANT 5 INTAKE DAM AT PHOTO LEFT. VIEW TO WEST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

  12. 1. EXTERIOR OVERVIEW SHOWING BISHOP CREEK PLANT 4 RESIDENTIAL COMPLEX. ...

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

    1. EXTERIOR OVERVIEW SHOWING BISHOP CREEK PLANT 4 RESIDENTIAL COMPLEX. ROOF OF BUILDING 105 IS VISIBLE IN UPPER PHOTO CENTER. PLANT 5 INTAKE DAM AT PHOTO LEFT. VIEW TO WEST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

  13. 75 FR 8036 - Monitor-Hot Creek Rangeland Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... Forest Service Monitor-Hot Creek Rangeland Project AGENCY: Forest Service, USDA. ACTION: Notice of intent... continued livestock grazing ] within the Monitor-Hot Creek Rangeland Project area. The analysis will... conditions within the Monitor-Hot Creek Rangeland Project area towards desired conditions. The project...

  14. 76 FR 13524 - Radio Broadcasting Services; Willow Creek, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-14

    ... COMMISSION 47 CFR Part 73 Radio Broadcasting Services; Willow Creek, CA AGENCY: Federal Communications... FM Channel 258A at Willow Creek, California. Channel 258A can be allotted at Willow Creek, consistent... Congressional Review Act, see U.S.C. 801(a)(1)(A). List of Subjects in 47 CFR Part 73 Radio, Radio...

  15. 75 FR 52463 - Safety Zone; Raccoon Creek, Bridgeport, NJ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-26

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Raccoon Creek, Bridgeport, NJ AGENCY: Coast... specified waters of Raccoon Creek, Bridgeport, NJ. This action is necessary to provide for the safety of... intended to restrict vessel access in order to protect mariners in a portion of Raccoon Creek. DATES:...

  16. 75 FR 54069 - Drawbridge Operation Regulations; Curtis Creek, Baltimore, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-03

    ...-2010-0265] RIN 1625--AA09 Drawbridge Operation Regulations; Curtis Creek, Baltimore, MD AGENCY: Coast....9, across Curtis Creek at Baltimore, MD. The requested change would have allowed the bridge to... Regulation Curtis Creek, Baltimore, MD'' in the Federal Register (75 FR 30747-30750). The...

  17. 75 FR 1705 - Drawbridge Operation Regulations; Curtis Creek, Baltimore, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-13

    ... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulations; Curtis Creek... operation of the I695 Bridge across Curtis Creek, mile 0.9, at Baltimore, MD. The deviation is necessary to... section of Curtis Creek and the bridge will not be able to open in the event of an emergency. Coast...

  18. 33 CFR 334.480 - Archers Creek, Ribbon Creek and Broad River, S.C.; U.S. Marine Corps Recruit Depot rifle and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Archers Creek, Ribbon Creek and... DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.480 Archers Creek, Ribbon Creek and Broad River... navigation: (1) At the rifle range. Archers Creek between Broad River and Beaufort River and Ribbon...

  19. Reservoir heterogeneity in Carter Sandstone, North Blowhorn Creek oil unit and vicinity, Black Warrior Basin, Alabama

    SciTech Connect

    Kugler, R.L.; Pashin, J.C.

    1992-05-01

    This report presents accomplishments made in completing Task 3 of this project which involves development of criteria for recognizing reservoir heterogeneity in the Black Warrior basin. The report focuses on characterization of the Upper Mississippian Carter sandstone reservoir in North Blowhorn Creek and adjacent oil units in Lamar County, Alabama. This oil unit has produced more than 60 percent of total oil extracted from the Black Warrior basin of Alabama. The Carter sandstone in North Blowhorn Creek oil unit is typical of the most productive Carter oil reservoirs in the Black Warrior basin of Alabama. The first part of the report synthesizes data derived from geophysical well logs and cores from North Blowhorn Creek oil unit to develop a depositional model for the Carter sandstone reservoir. The second part of the report describes the detrital and diagenetic character of Carter sandstone utilizing data from petrographic and scanning electron microscopes and the electron microprobe. The third part synthesizes porosity and pore-throat-size-distribution data determined by high-pressure mercury porosimetry and commercial core analyses with results of the sedimentologic and petrographic studies. The final section of the report discusses reservoir heterogeneity within the context of the five-fold classification of Moore and Kugler (1990).

  20. Outline of the water resources of the Status Creek basin, Yakima Indian Reservation, Washington

    USGS Publications Warehouse

    Molenaar, Dee

    1976-01-01

    On the Yakima Indian Reservation, Washington, only about 5 percent of the Satus Creek basin--in the relatively flat eastern lowland adjacent to and including part of the Yakima River lowland--is agriculturally developed, mostly through irrigation. Because the basin 's streams do not contain adequate water for irrigation, most irrigation is by canal diversion from the adjoining Toppenish Creek basin. Irrigation application of as much as 9.25 acre-feet per acre per year, combined with the presence of poorly drained silt and clay layers in this area, and the natural upward discharge of ground water from deeper aquifers (water-bearing layers), has contributed to a waterlogging problem, which has affected about 10,500 acres, or about 25 percent of the irrigated area. In the upland of the basin, a large average annual base flow of about 30 cubic feet per second in Logy Creek indicates the presence of a potentially highly productive aquifer in young (shallow) basalt lavas underlying the higher western parts of the upland. This aquifer may provide a reservoir from which streamflow may be augmented by ground-water pumping or, alternatively, it may be used as a source of ground water for irrigation of upland areas directly. (Woodard-USGS)

  1. Plant distributions along salinity and tidal gradients in Oregon tidal marshes

    EPA Science Inventory

    Accurately modeling climate change effects on tidal marshes in the Pacific Northwest requires understanding how plant assemblages and species are presently distributed along gradients of salinity and tidal inundation. We outline on-going field efforts by the EPA and USGS to dete...

  2. Description and User Manual for a Web-Based Interface to a Transit-Loss Accounting Program for Monument and Fountain Creeks, El Paso and Pueblo Counties, Colorado

    USGS Publications Warehouse

    Kuhn, Gerhard; Krammes, Gary S.; Beal, Vivian J.

    2007-01-01

    -loss computations for a variable number of reusable return flows discharged into Monument Creek at selected locations; (3) enable diversion of all or a part of a reusable return flow at any selected node for purposes of storage in off-stream reservoirs or other similar types of reusable water management; (4) and provide flexibility in the accounting program to change the number of return-flow entities, the locations at which the return flows discharge into Monument or Fountain Creeks, or the locations to which the return flows are delivered. The primary component of the Web-based interface is a data-entry form that displays data stored in the accounting program input file; the data-entry form allows for entry and modification of new data, which then is rewritten to the input file. When the data-entry form is displayed, up-to-date discharge data for each station are automatically computed and entered on the data-entry form. Data for native return flows, reusable return flows, reusable return flow diversions, and native diversions also are entered automatically or manually, if needed. In computing the estimated quantities of reusable return flow and the associated transit losses, the accounting program uses two sets of computations. The first set of computations is made between any two adjacent streamflow-gaging stations (termed 'stream-segment loop'); the primary purpose of the stream-segment loop is to estimate the loss or gain in native discharge between the two adjacent streamflow-gaging stations. The second set of computations is made between any two adjacent nodes (termed 'subreach loop'); the actual transit-loss computations are made in the subreach loop, using the result from the stream-segment loop. The stream-segment loop is completed for a stream segment, and then the subreach loop is completed for each subreach within the segment. When the subreach loop is completed for all subreaches within a stream segment, the stream-segment loop is initiated for the ne

  3. Pressure-gradient-driven nearshore circulation on a beach influenced by a large inlet-tidal shoal system

    USGS Publications Warehouse

    Shi, F.; Hanes, D.M.; Kirby, J.T.; Erikson, L.; Barnard, P.; Eshleman, J.

    2011-01-01

    The nearshore circulation induced by a focused pattern of surface gravity waves is studied at a beach adjacent to a major inlet with a large ebb tidal shoal. Using a coupled wave and wave-averaged nearshore circulation model, it is found that the nearshore circulation is significantly affected by the heterogeneous wave patterns caused by wave refraction over the ebb tidal shoal. The model is used to predict waves and currents during field experiments conducted near the mouth of San Francisco Bay and nearby Ocean Beach. The field measurements indicate strong spatial variations in current magnitude and direction and in wave height and direction along Ocean Beach and across the ebb tidal shoal. Numerical simulations suggest that wave refraction over the ebb tidal shoal causes wave focusing toward a narrow region at Ocean Beach. Due to the resulting spatial variation in nearshore wave height, wave-induced setup exhibits a strong alongshore nonuniformity, resulting in a dramatic change in the pressure field compared to a simulation with only tidal forcing. The analysis of momentum balances inside the surf zone shows that, under wave conditions with intensive wave focusing, the alongshore pressure gradient associated with alongshore nonuniform wave setup can be a dominant force driving circulation, inducing heterogeneous alongshore currents. Pressure-gradient- forced alongshore currents can exhibit flow reversals and flow convergence or divergence, in contrast to the uniform alongshore currents typically caused by tides or homogeneous waves.

  4. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  5. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  6. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  7. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  8. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  9. Carbonate tidal flat in mixed carbonate-siliciclastic clore formation (upper chesterian) in Southern Illinois

    SciTech Connect

    Abegg, F.E.

    1988-01-01

    The upper Chesterian Clore Formation consists primarily of delta-front sandstones of the Tygett Sandstone Member and interbedded offshore mud-rich carbonates and prodelta shales of the Cora and Ford Station Limestone Members. The basal Ford Station limestone in south-central Illinois contains a carbonate sequence 1.0 m thick marked by (1) laminated pelletal lime mudstones, (2) bird's-eye structures containing internal sediment, (3) vertical burrows, (4) horizontal shrinkage cracks, (5) autoclastic brecciation, (6) root. tubes, and (7) calciphers. These features indicate tidal-flat deposition. Other examples of peritidal carbonate deposition are unknown in the Chesterian of the Illinois basin. Tidal-flat strata overlie 1.9 m of interbedded shale and lime mudstones containing linguloid brachiopods, pectin bivalves, and ostracods. The lime mudstones and shales are interpreted as shallow-subtidal, restricted-shelf deposits overlying crevasse-splay deposits of the upper Tygett sandstone. Carbonate tidal-flat deposition in the upper Chesterian of the Illinois basin is an exception to the generally accepted model of nearshore terrigenous and offshore carbonate sedimentation. Delta switching is the most plausible explanation for development of the Clore tidal flat. Following deposition of the deltaic Tygett sandstone, peritidal carbonate deposition occurred in the basal Ford Station limestone when terrigenous sedimentation was deflected westward, as indicated by thin delta-front sandstones in the basal Ford Station limestone in southwestern Illinois. The tidal flat developed locally because south-central Illinois was the region of maximum progradation of the Tygett delta and because upper Tygett crevasse-splay deposits compacted less than adjacent shales.

  10. Geohydrology of the stratified-drift aquifer system in the lower Sixmile Creek and Willseyville Creek trough, Tompkins County, New York

    USGS Publications Warehouse

    Miller, Todd S.; Karig, Daniel E.

    2010-01-01

    retreats of the ice in the study area resulted in several sequences of various types of glacial deposits. A large moraine (Valley Heads Moraine) dominates the southern part of the study area, a large delta dominates the central part, and ground moraine (mostly till) dominates the northern part. Glacial sediments in the center of the lower Sixmile Creek and Willseyville Creek trough typically range from 150 to 200 ft but can be greater than 300 ft in some places. Where the sediments are composed of sand and gravel they form aquifers. In most parts of the lower Sixmile Creek and Willseyville Creek trough, there is an upper and a basal confined aquifer. However, underlying the central parts of the Brooktondale delta, there are as many as four confined aquifers, whereas in the northern part of the study area, only one extensive confined aquifer is present. The major sources of recharge to these confined aquifers are (1) direct infiltration of precipitation where confined aquifers crop out at land surface (mostly along the western trough wall in the southern and central parts of the study area and, to a lesser degree, along the eastern trough wall); (2) unchanneled surface and subsurface runoff from adjacent upland areas that seeps into the aquifer along the western trough walls; (3) subsurface flow from underlying till or bedrock at the lateral contacts at trough walls; (4) adjacent fine-grained stratified drift, especially when the aquifer is pumped; and (5) discharge from bedrock at the bottom and sides of the trough. In the central part of the study area, the surficial coarse-grained sediments (sand and gravel) comprise a delta near Brooktondale and form a small unconfined aquifer (0.3 square mile). Although much of the upper part of the delta has been removed by several aggregate mining operations, sufficient amounts of sand and gravel remain in most places to form a thin unconfined aquifer. The major sources of recharge to the unconfined aquifer are (1)

  11. Sea-level rise and refuge habitats for tidal marsh species: can artificial islands save the California Ridgway's rail?

    USGS Publications Warehouse

    Overton, Cory T.; Takekawa, John Y.; Casazza, Michael L.; Bui, Thuy-Vy D.; Holyoak, Marcel; Strong, Donald R.

    2014-01-01

    Terrestrial species living in intertidal habitats experience refuge limitation during periods of tidal inundation, which may be exacerbated by seasonal variation in vegetation structure, tidal cycles, and land-use change. Sea-level rise projections indicate the severity of refuge limitation may increase. Artificial habitats that provide escape cover during tidal inundation have been proposed as a temporary solution to alleviate these limitations. We tested for evidence of refuge habitat limitation in a population of endangered California Ridgway's rail (Rallus obsoletus obsoletus; hereafter California rail) through use of artificial floating island habitats provided during two winters. Previous studies demonstrated that California rail mortality was especially high during the winter and periods of increased tidal inundation, suggesting that tidal refuge habitat is critical to survival. In our study, California rail regularly used artificial islands during higher tides and daylight hours. When tide levels inundated the marsh plain, use of artificial islands was at least 300 times more frequent than would be expected if California rails used artificial habitats proportional to their availability (0.016%). Probability of use varied among islands, and low levels of use were observed at night. These patterns may result from anti-predator behaviors and heterogeneity in either rail density or availability of natural refuges. Endemic saltmarsh species are increasingly at risk from habitat change resulting from sea-level rise and development of adjacent uplands. Escape cover during tidal inundation may need to be supplemented if species are to survive. Artificial habitats may provide effective short-term mitigation for habitat change and sea-level rise in tidal marsh environments, particularly for conservation-reliant species such as California rails.

  12. Hydrologic Data for Deep Creek Lake and Selected Tributaries, Garrett County, Maryland, 2007-08

    USGS Publications Warehouse

    Banks, William S.L.; Davies, William J.; Gellis, Allen C.; LaMotte, Andrew E.; McPherson, Wendy S.; Soeder, Daniel J.

    2010-01-01

    Introduction Recent and ongoing efforts to develop the land in the area around Deep Creek Lake, Garrett County, Maryland, are expected to change the volume of sediment moving toward and into the lake, as well as impact the water quality of the lake and its many tributaries. With increased development, there is an associated increased demand for groundwater and surface-water withdrawals, as well as boat access. Proposed dredging of the lake bottom to improve boat access has raised concerns about the adverse environmental effects such activities would have on the lake. The Maryland Department of Natural Resources (MDDNR) and the U.S. Geological Survey (USGS) entered into a cooperative study during 2007 and 2008 to address these issues. This study was designed to address several objectives to support MDDNR?s management strategy for Deep Creek Lake. The objectives of this study were to: Determine the current physical shape of the lake through bathymetric surveys; Initiate flow and sediment monitoring of selected tributaries to characterize the stream discharge and sediment load of lake inflows; Determine sedimentation rates using isotope analysis of sediment cores; Characterize the degree of hydraulic connection between the lake and adjacent aquifer systems; and Develop an estimate of water use around Deep Creek Lake. Summary of Activities Data were collected in Deep Creek Lake and in selected tributaries from September 2007 through September 2008. The methods of investigation are presented here and all data have been archived according to USGS policy for future use. The material presented in this report is intended to provide resource managers and policy makers with a broad understanding of the bathymetry, surface water, sedimentation rates, groundwater, and water use in the study area. The report is structured so that the reader can access each topic separately using any hypertext markup (HTML) language reader. In order to establish a base-line water-depth map of

  13. Intensive survey of the bay creek watershed, July 1992

    SciTech Connect

    Short, M.B.; Kelly, T.G.; Hefley, J.E.

    1995-05-01

    During July 1992, the Illinois Environmental Protection Agency conducted an intensive survey of the Bay Creek basin, a fifth order tributary in the Mississippi River North Central Basin. Bay Creek drains approximately 176.4 square miles primarily in Pike and a small portion of Calhoun counties. Four stations were sampled on the Bay Creek main stem and one on Honey Creek. The survey focused on macroinvertebrate communities, fish populations, instream habitat, fish tissue, sediment and water chemistry, and land use as well as a review of ambient water quality data from IEPA station KCA-01 near Nebo, Illinois, as tools to document the biological and chemical status of Bay Creek.

  14. Drywell corrosion stopped at Oyster Creek

    SciTech Connect

    Lipford, B.L. ); Flynn, J.C.

    1993-11-01

    This article describes the detection of corrosion on the drywell containment vessel of Oyster Creek Nuclear Plant and the application of a protective coating to repair the drywell. The topics of the article include drywell design features, identification of the problem, initial action, drywell corrosion, failure of cathodic protection, long-term repair, and repair results.

  15. How Fern Creek Is Beating Goliath

    ERIC Educational Resources Information Center

    Donovan, Margaret; Galatowitsch, Patrick; Hefferin, Keri; Highland, Shanita

    2013-01-01

    The "David" is Fern Creek Elementary, a small urban school in Orlando, Florida, that serves an overwhelmingly disadvantaged student population. The "Goliaths" are the mountains of problems that many inner-city students face--poverty, homelessness, mobility, instability, limited parent involvement, and violent neighborhood…

  16. Gold Creek: Preserving an Environmental Studies Center.

    ERIC Educational Resources Information Center

    Brooks, Suzanne

    In response to a Board of Trustees request for information and recommendations concerning the future use of the Gold Creek property owned by the Los Angeles Community College District, this report emphasizes that the use of this site for instructional field experiences enhances the quality of environmental education for the district's diverse…

  17. 33 CFR 117.709 - Cheesequake Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.709 Cheesequake Creek. (a) The draw of the S35 Bridge, at mile 0.0, at Morgan, South Amboy, New Jersey, shall operate as follows: (1... calling the number posted at the bridge. (b) The draw of the New Jersey Transit Rail Operations...

  18. 33 CFR 117.709 - Cheesequake Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.709 Cheesequake Creek. (a) The draw of the S35 Bridge, at mile 0.0, at Morgan, South Amboy, New Jersey, shall operate as follows: (1... calling the number posted at the bridge. (b) The draw of the New Jersey Transit Rail Operations...

  19. 27 CFR 9.211 - Swan Creek.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...-Salem, North Carolina, 1984, photoinspected 1982; (2) Boone, North Carolina-Tennessee, 1985; and (3... viticultural area is as described below: (1) The beginning point is on the Winston-Salem, North Carolina map at..., returning to the Winston-Salem map, to the intersection of Rocky Creek with State Highway 115 at New Hope...

  20. 27 CFR 9.211 - Swan Creek.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...-Salem, North Carolina, 1984, photoinspected 1982; (2) Boone, North Carolina-Tennessee, 1985; and (3... viticultural area is as described below: (1) The beginning point is on the Winston-Salem, North Carolina map at..., returning to the Winston-Salem map, to the intersection of Rocky Creek with State Highway 115 at New Hope...