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Sample records for concreto estrutural leve

  1. Geophysical applications for levee assessment

    NASA Astrophysics Data System (ADS)

    Chlaib, Hussein Khalefa

    Levees are important engineering structures that build along the rivers to protect the human lives and shield the communities as well as agriculture lands from the high water level events. Animal burrows, subsurface cavities, and low density (high permeability) zones are weakness features within the levee body that increase its risk of failure. To prevent such failure, continuous monitoring of the structure integrity and early detection of the weakness features must be conducted. Application of Ground Penetrating Radar (GPR) and Capacitively Coupled Resistivity (CCR) methods were found to be very effective in assessing the levees and detect zones of weakness within the levee body. GPR was implemented using multi-frequency antennas (200, 400, and 900 MHz) with survey cart/wheel and survey vehicle. The (CCR) method was applied by using a single transmitter and three receivers. Studying the capability and the effectiveness of these methods in levee monitoring, subsurface weakness feature detection, and studying the structure integrity of levees were the main tasks of this dissertation. A set of laboratory experiments was conducted at the Geophysics Laboratory of the University of Arkansas at Little Rock (UALR) to analyze the polarity change in GPR signals in the presence of subsurface voids and water-filled cavities. Also three full scale field expeditions at the Big Dam Bridge (BDB) Levee, Lollie Levee, and Helena Levee in Arkansas were conducted using the GPR technique. This technique was effective in detecting empty, water, and clay filled cavities as well as small scale animal burrows (small rodents). The geophysical work at BDB and Lollie Levees expressed intensive subsurface anomalies which might decrease their integrity while the Helena Levee shows less subsurface anomalies. The compaction of levee material is a key factor affecting piping phenomenon. The structural integrity of the levee partially depends on the density/compaction of the soil layers. A

  2. Levee Health Monitoring With Radar Remote Sensing

    NASA Astrophysics Data System (ADS)

    Jones, C. E.; Bawden, G. W.; Deverel, S. J.; Dudas, J.; Hensley, S.; Yun, S.

    2012-12-01

    Remote sensing offers the potential to augment current levee monitoring programs by providing rapid and consistent data collection over large areas irrespective of the ground accessibility of the sites of interest, at repeat intervals that are difficult or costly to maintain with ground-based surveys, and in rapid response to emergency situations. While synthetic aperture radar (SAR) has long been used for subsidence measurements over large areas, applying this technique directly to regional levee monitoring is a new endeavor, mainly because it requires both a wide imaging swath and fine spatial resolution to resolve individual levees within the scene, a combination that has not historically been available. Application of SAR remote sensing directly to levee monitoring has only been attempted in a few pilot studies. Here we describe how SAR remote sensing can be used to assess levee conditions, such as seepage, drawing from the results of two levee studies: one of the Sacramento-San Joaquin Delta levees in California that has been ongoing since July 2009 and a second that covered the levees near Vicksburg, Mississippi, during the spring 2011 floods. These studies have both used data acquired with NASA's UAVSAR L-band synthetic aperture radar, which has the spatial resolution needed for this application (1.7 m single-look), sufficiently wide imaging swath (22 km), and the longer wavelength (L-band, 0.238 m) required to maintain phase coherence between repeat collections over levees, an essential requirement for applying differential interferometry (DInSAR) to a time series of repeated collections for levee deformation measurement. We report the development and demonstration of new techniques that employ SAR polarimetry and differential interferometry to successfully assess levee health through the quantitative measurement of deformation on and near levees and through detection of areas experiencing seepage. The Sacramento-San Joaquin Delta levee study, which covers

  3. Using geophysics to characterize levee stability

    NASA Astrophysics Data System (ADS)

    Dalton, Laura M.

    Shallow slough slides have occurred along the river side slope of Mississippi River Levees for over sixty years. Shallow slough slides also occur along smaller levees that protect tributaries of the Mississippi River. This investigation takes place along a section of the Coldwater River Levee, a tributary levee of the Mississippi River. Field observation, soil samples, and geophysical data were collected at two field sites located on the border of Tate and Tunica County, MS. The first site consists of a developed shallow slough slide that had occurred that has not yet been repaired and the second site is a potential slide area. Electromagnetic induction and electrical resistivity tomography were the geophysical methods used to define subsurface conditions that make a levee vulnerable to failure. These electrical methods are sensitive to the electrical conductivity of the soil and therefore depend upon: soil moisture, clay content, pore size distribution as well as larger scale structures at depth such as cracks and fissures. These same physical properties of the soil are also important to assessing the vulnerability of a levee to slough slides. Soil tests and field observations were also implemented in this investigation to describe and classify the soil composition of the levee material. The problem of slough slide occurrence can potentially be reduced if vulnerabilities are located with the help of geophysical techniques.

  4. Risk-based planning analysis for a single levee

    NASA Astrophysics Data System (ADS)

    Hui, Rui; Jachens, Elizabeth; Lund, Jay

    2016-04-01

    Traditional risk-based analysis for levee planning focuses primarily on overtopping failure. Although many levees fail before overtopping, few planning studies explicitly include intermediate geotechnical failures in flood risk analysis. This study develops a risk-based model for two simplified levee failure modes: overtopping failure and overall intermediate geotechnical failure from through-seepage, determined by the levee cross section represented by levee height and crown width. Overtopping failure is based only on water level and levee height, while through-seepage failure depends on many geotechnical factors as well, mathematically represented here as a function of levee crown width using levee fragility curves developed from professional judgment or analysis. These levee planning decisions are optimized to minimize the annual expected total cost, which sums expected (residual) annual flood damage and annualized construction costs. Applicability of this optimization approach to planning new levees or upgrading existing levees is demonstrated preliminarily for a levee on a small river protecting agricultural land, and a major levee on a large river protecting a more valuable urban area. Optimized results show higher likelihood of intermediate geotechnical failure than overtopping failure. The effects of uncertainty in levee fragility curves, economic damage potential, construction costs, and hydrology (changing climate) are explored. Optimal levee crown width is more sensitive to these uncertainties than height, while the derived general principles and guidelines for risk-based optimal levee planning remain the same.

  5. National Levee Database: monitoring, vulnerability assessment and management in Italy

    NASA Astrophysics Data System (ADS)

    Barbetta, Silvia; Camici, Stefania; Maccioni, Pamela; Moramarco, Tommaso

    2015-04-01

    A properly designed and constructed levees system can often be an effective device for repelling floodwaters and provide barriers against inundation to protect urbanized and industrial areas. However, the delineation of flooding-prone areas and the related hydraulic hazard mapping taking account of uncertainty (Apel et al., 2008) are usually developed with a scarce consideration of the possible occurrence of levee failures along river channels (Mazzoleni et al., 2014). Indeed, it is well known that flooding is frequently the result of levee failures that can be triggered by several factors, as: (1) overtopping, (2) scouring of the foundation, (3) seepage/piping of levee body/foundation, and (4) sliding of the foundation. Among these failure mechanisms that are influenced by the levee's geometrical configuration, hydraulic conditions (e.g. river level and seepage), and material properties (e.g. permeability, cohesion, porosity, compaction), the piping caused by seepage (ICOLD, http://www.icold-cigb.org) is considered one of the most dominant levee failure mechanisms (Colleselli F., 1994; Wallingford H. R., 2003). The difficulty of estimating the hydraulic parameters to properly describe the seepage line within the body and foundation of the levee implies that the study of the critical flood wave routing is typically carried out by assuming that the levee system is undamaged during the flood event. In this context, implementing and making operational a National Levee Database (NLD), effectively structured and continuously updated, becomes fundamental to have a searchable inventory of information about levees available as a key resource supporting decisions and actions affecting levee safety. The ItaliaN LEvee Database (INLED) has been recently developed by the Research Institute for Geo-Hydrological Protection (IRPI) for the Civil Protection Department of the Presidency of Council of Ministers. INLED has the main focus of collecting comprehensive information about

  6. Optimized Radar Remote Sensing for Levee Health Monitoring

    NASA Technical Reports Server (NTRS)

    Jones, Cathleen E.

    2013-01-01

    Radar remote sensing offers great potential for high resolution monitoring of ground surface changes over large areas at one time to detect movement on and near levees and for location of seepage through levees. Our NASA-funded projects to monitor levees in the Sacramento Delta and the Mississippi River have developed and demonstrated methods to use radar remote sensing to measure quantities relevant to levee health and of great value to emergency response. The DHS-funded project will enable us is to define how to optimally monitor levees in this new way and set the stage for transition to using satellite SAR (synthetic aperture radar) imaging for better temporal and spatial coverage at lower cost to the end users.

  7. Screening of Earthen Levees Using Synthetic Aperture Radar

    NASA Astrophysics Data System (ADS)

    Aanstoos, J. V.; O'Hara, C.; Prasad, S.; Dabbiru, L.; Nobrega, R.; Lee, M.

    2009-12-01

    Earthen levees protect large areas of populated and cultivated land in the US from flooding. As shown recently with hurricanes Katrina and Ike and the recent floods in the Midwest, the potential loss of life and property associated with the catastrophic failure of levees can be extremely large. Over the entire US, there are over 100,000 miles of levee structures of varying designs and conditions. Currently, there are limited processes in place to prioritize the monitoring of large numbers of dam and levee structures. Levee managers and federal agencies need to assess levee health rapidly with robust techniques that identify, classify and prioritize levee vulnerabilities with lower costs than traditional soil-boring programs, which can cost many of millions of dollars and provide information about the subsurface only in the immediate vicinity of a small-diameter borehole. This paper reports preliminary results of a project studying the use of airborne synthetic aperture radar (SAR) as an aid to the levee screening process. The SAR sensor being studied is the NASA UAVSAR (Unmanned Aerial Vehicle SAR), a fully polarimetric L-band SAR which is specifically designed to acquire airborne repeat track SAR data for differential interferometric measurements. The instrument is capable of sub-meter ground sample distance. NASA has imaged with this instrument 230 km of levees along the lower Mississippi River for use in this study. SAR interferometric mode is capable of identifying vertical displacements on the order of a few millimeters. Its multipolarization measurements can penetrate soil to as much as one meter depth. Thus it is valuable in detecting changes in levees that will be key inputs to a levee vulnerability classification system. Once vulnerable levee reaches have been identified, further actions such as more detailed examination or repairs can be focused on these higher-priority sections. We report on the use of various feature detection algorithms being applied

  8. Overtopping breaching of river levees constructed with cohesive sediments

    NASA Astrophysics Data System (ADS)

    Wei, Hongyan; Yu, Minghui; Wang, Dangwei; Li, Yitian

    2016-07-01

    Experiments were conducted in a bend flume to study the overtopping breaching process and the corresponding overflow rates of river levees constructed with cohesive sediments. The river and land regions were separated by the constructed levee in the bend flume. Results showed that the levee breaching process can be subdivided into a slope erosion stage, a headcut retreat stage and a breach widening stage. Mechanisms such as flow shear erosion, impinging jet erosion, side slope erosion and cantilever collapse were discovered in the breaching process. The erosion characteristics were determined by both flow and soil properties. Finally, a depth-averaged 2-D flow model was used to simulate the levee breaching flow rates, which is well expressed by the broad-crested weir flow formula. The deduced discharge coefficient was smaller than that of common broad-crested rectangular weirs because of the shape and roughness of the breach.

  9. Cibola High Levee Pond Annual Report 2003. Interim Report

    USGS Publications Warehouse

    Mueller, G.A.; Carpenter, J.; Marsh, P.C.; Minckley, C.O.

    2003-01-01

    Bonytail and razorback sucker have once again spawned and produced swim-up larvae in Cibola High Levee Pond (CHLP). CHLP continues to support annual recruitment of bonytail while recent razorback sucker recruitment remains elusive. Thus far, razorbacks have experienced intermittent years of spawning success. Both native species were observed spawning on, or near, the riprap on the river levee. Razorbacks spawned from late January until mid-March over gravel and large cobble along the levee toe (2-3 m depth) and bonytail spawned along the levee shoreline during mid-April. Razorback suckers rapidly fin during the reproductive act, which flushes fines from the substrate and leaves gravel relatively clean. Bonytail on the other hand, appear to spawn over or on substrate that has been disturbed by beaver activity. Substrate scour or disturbance appears to be an important factor in spawning site selectiona?|

  10. 33 CFR 203.51 - Levee owner's manual.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Maintenance Manual specified by 33 CFR 208.10(a)(10) will fulfill the requirement of providing a levee owner's... Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and...

  11. 33 CFR 203.51 - Levee owner's manual.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Maintenance Manual specified by 33 CFR 208.10(a)(10) will fulfill the requirement of providing a levee owner's... Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and...

  12. 33 CFR 203.51 - Levee owner's manual.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Maintenance Manual specified by 33 CFR 208.10(a)(10) will fulfill the requirement of providing a levee owner's... Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and...

  13. 33 CFR 203.51 - Levee owner's manual.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Maintenance Manual specified by 33 CFR 208.10(a)(10) will fulfill the requirement of providing a levee owner's... Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and...

  14. 33 CFR 203.51 - Levee owner's manual.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Maintenance Manual specified by 33 CFR 208.10(a)(10) will fulfill the requirement of providing a levee owner's... Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and...

  15. Game Theory and Risk-Based Levee System Design

    NASA Astrophysics Data System (ADS)

    Hui, R.; Lund, J. R.; Madani, K.

    2014-12-01

    Risk-based analysis has been developed for optimal levee design for economic efficiency. Along many rivers, two levees on opposite riverbanks act as a simple levee system. Being rational and self-interested, land owners on each river bank would tend to independently optimize their levees with risk-based analysis, resulting in a Pareto-inefficient levee system design from the social planner's perspective. Game theory is applied in this study to analyze decision making process in a simple levee system in which the land owners on each river bank develop their design strategies using risk-based economic optimization. For each land owner, the annual expected total cost includes expected annual damage cost and annualized construction cost. The non-cooperative Nash equilibrium is identified and compared to the social planner's optimal distribution of flood risk and damage cost throughout the system which results in the minimum total flood cost for the system. The social planner's optimal solution is not feasible without appropriate level of compensation for the transferred flood risk to guarantee and improve conditions for all parties. Therefore, cooperative game theory is then employed to develop an economically optimal design that can be implemented in practice. By examining the game in the reversible and irreversible decision making modes, the cost of decision making myopia is calculated to underline the significance of considering the externalities and evolution path of dynamic water resource problems for optimal decision making.

  16. Levee Breach Experiment by Overflow at the Full Scale Experimental Channel

    NASA Astrophysics Data System (ADS)

    Shimada, T.; Yokoyama, H.

    2010-12-01

    The increased occurrence of storm disasters caused by typhoons and local downpours in recent years has given rise to concerns over the possibility of large-scale floods resulting from river overflow. Levee breaches cause particularly severe damage, and in Japan, more than 80% of such accidents in the past have been attributed to overflow. Studies on levee breach by overflow have been conducted from various viewpoints using diverse methods. However, the mechanism of three-dimensional levee breach by overflow has not been clarified in past studies. Elucidation of this mechanism is very important for disaster prevention as well as for the future progress of studies on levee breach by overflow. Levees (levee crown width; 3m, levee height; 3m, levee length; 80m) were built in the Chiyoda Experimental Channel (full-scale experimental channel; width is 30m, length is 1,300m, maximum discharge is 170t/s) in Hokkaido Japan in 2010, and a three-dimensional experiment on levee breach by overflow. The findings of the experiment are as follows: After the beginning of overflow, levee breach widening did not begin until after most of the levee section had collapsed. It was also considered that, even if overflow occurred, extremely serious damage (e.g., sudden increase in levee breach width and overflow discharge) was unlikely unless the majority of the levee section collapsed.

  17. Earthflow yield strength constrained by lateral levee morphology

    NASA Astrophysics Data System (ADS)

    Nereson, A. L.; Finnegan, N. J.

    2015-12-01

    Slow-moving landslides, or earthflows, are characterized by persistent, flow-like motion that is commonly modeled using various viscous and viscoplastic rheologies. One of the manifestations of viscoplastic flow down a slope is the emergence of stationary bodies of fluid at the margins of the flow (i.e. lateral levees). These levees are common signatures of earthflow morphology and, while they are frequently used to outline boundaries for mapping purposes, they have received little attention for what they may indicate about the history and properties of the flow itself. In contrast, lateral levees along lava flows have long been used by physical volcanologists as tools to learn about their non-Newtonian rheologies and chemical compositions. Hulme (1974) was the first to note that, for a given slope, levee width may be characteristic of a fluids's yield strength and his methodology has been subsequently used to infer properties of lavas on the Earth, the Moon, and Mars. Using these lavas as analogies, we apply Hulme's approach to earthflows in a variety of settings globally. We find that calculated yield strengths for individual earthflows fall within a relatively narrow range between 101-102 kPa. In addition, individual earthflow complexes often preserve multiple generations of levees, which in some cases may record apparent reductions in yield strength over time for a given flow, possibly from weakening of previously failed material. Knowledge of earthflow yield strength permits the calculation of a critical earthflow thickness below which there will be no downslope motion for a given slope angle. Thicknesses calculated in this manner could thus be used to estimate the flux of landslide material for earthflows without direct depth constraints, provided that surface velocity measurements are obtained by other methods (e.g. InSAR, GPS, manual feature tracking).

  18. Game theory and risk-based leveed river system planning with noncooperation

    NASA Astrophysics Data System (ADS)

    Hui, Rui; Lund, Jay R.; Madani, Kaveh

    2016-01-01

    Optimal risk-based levee designs are usually developed for economic efficiency. However, in river systems with multiple levees, the planning and maintenance of different levees are controlled by different agencies or groups. For example, along many rivers, levees on opposite riverbanks constitute a simple leveed river system with each levee designed and controlled separately. Collaborative planning of the two levees can be economically optimal for the whole system. Independent and self-interested landholders on opposite riversides often are willing to separately determine their individual optimal levee plans, resulting in a less efficient leveed river system from an overall society-wide perspective (the tragedy of commons). We apply game theory to simple leveed river system planning where landholders on each riverside independently determine their optimal risk-based levee plans. Outcomes from noncooperative games are analyzed and compared with the overall economically optimal outcome, which minimizes net flood cost system-wide. The system-wide economically optimal solution generally transfers residual flood risk to the lower-valued side of the river, but is often impractical without compensating for flood risk transfer to improve outcomes for all individuals involved. Such compensation can be determined and implemented with landholders' agreements on collaboration to develop an economically optimal plan. By examining iterative multiple-shot noncooperative games with reversible and irreversible decisions, the costs of myopia for the future in making levee planning decisions show the significance of considering the externalities and evolution path of dynamic water resource problems to improve decision-making.

  19. Process of Levee Breach by Overflow at the Full Scale Chiyoda Experimental Channel

    NASA Astrophysics Data System (ADS)

    Shimada, T.; Yokoyama, H.

    2011-12-01

    The increased occurrence of storm disasters caused by typhoons and local downpours in recent years has given rise to concerns over the possibility of large-scale floods resulting from river overflow. Levee breaches cause particularly severe damage, and in Japan, more than 80% of such accidents in the past have been attributed to overflow. Previous studies on overflow-induced levee breaches have not revealed the mechanisms of these issues on a full-scale 3D basis (i.e., side-overflow taking river flow on the riverside land into consideration). It is important to clarify these mechanisms in terms of disaster prevention and for the purpose of bringing progress in future studies on overflow-induced failure. Levees (levee crown width is 3m in 2010 and 6m in 2011, levee height is 3m, levee length is 80m) were built in the Chiyoda Experimental Channel (full-scale experimental channel; width is 30m, length is 1,300m, maximum discharge is 170t/s) in Hokkaido Japan, and a three-dimensional experiment on levee breach by overflow. The findings of the experiment are as follows: After the beginning of overflow, levee breach widening did not begin until after most of the levee section had collapsed. And in case of 6m of the levee crown width, that time in becomes long. It was also considered that, even if overflow occurred, extremely serious damage (e.g., sudden increase in levee breach width and overflow discharge) was unlikely unless the majority of the levee section collapsed.

  20. 77 FR 9637 - Process for Requesting a Variance From Vegetation Standards for Levees and Floodwalls; Additional...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-17

    ... requesting a variance from vegetation standards for levees and floodwalls to reflect organizational changes... as armoring or overbuilt sections) intended to preserve system reliability and resiliency...

  1. 75 FR 6364 - Process for Requesting a Variance From Vegetation Standards for Levees and Floodwalls

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-09

    ... requesting a variance from vegetation standards for levees and floodwalls to reflect organizational changes...) intended to preserve system reliability and resiliency by preventing or mitigating vegetation impacts....

  2. Experimental analysis of the levees safety based on geophysical monitoring

    NASA Astrophysics Data System (ADS)

    Rizzo, Enzo; Valeria, Giampaolo; Mario, Votta; Lapenna, Vincenzo; Moramarco, Tommaso; Aricò, Costanza; Camici, S.; Morbidelli, Renato; Sinagra, M.; Tucciarelli, T.

    2010-05-01

    Several flood events brought river levees into the focus of attention for some disasters due to their collapse. This phenomena is quite complex to investigate, because of different factors that can affect the stability of levees, among them the non uniformity of material properties, which influencing the permeability of the embankment, might induce high percolation velocity of flux thus triggering the unstability. Thus, to apply a fast and integrate investigation methods with a non-destructive characteristics should have a large interest, if they are able to furnish ready and usable information necessary to hydrogeological models. In order to achieve this goal, the University of Perugia (Department of Civil and Environmental Engineering) and the National Research Council (IRPI and IMAA research institutes) developed a collaborating project on the study of the internal structure of the river embankment by carrying out experiments in laboratory. The purpose of this study is to show the preliminary results of the experimental investigation. The laboratory embankment was built using material coming from a real levee and gathered inside a 1.5m x 1.2m plexiglas box. The box has two compartments: a water reservoir at one hand where a constant water head was reached after some time and a soil simulating the presence of levee. We perform a geoelectrical multichannel acquisition system with three parallel profiles characterized by 16 mini-electrodes connected to georesistivimeter Syscal Pro. An automatic acquisition protocol has been performed to obtain time slice electrical tomographies during the experiments. The geophysical results show the effect of the water table inside the embankment during the wetting and emptying. In order to assess the capability of the geophysical monitoring for addressing the soil parameters estimate, the resistivity results are investigated by using two analytical and one hydraulic numerical models. The analytical models represent a linear

  3. Tree growth and recruitment in a leveed floodplain forest in the Mississippi River Alluvial Valley, USA

    USGS Publications Warehouse

    Gee, Hugo K.W.; King, Sammy L.; Keim, Richard F.

    2014-01-01

    Flooding is a defining disturbance in floodplain forests affecting seed germination, seedling establishment, and tree growth. Globally, flood control, including artificial levees, dams, and channelization has altered flood regimes in floodplains. However, a paucity of data are available in regards to the long-term effects of levees on stand establishment and tree growth in floodplain forests. In this study, we used dendrochronological techniques to reconstruct tree recruitment and tree growth over a 90-year period at three stands within a ring levee in the Mississippi River Alluvial Valley (MAV) and to evaluate whether recruitment patterns and tree growth changed following levee construction. We hypothesized that: (1) sugarberry is increasing in dominance and overcup oak (Quercus lyrata) is becoming less dominant since the levee, and that changes in hydrology are playing a greater role than canopy disturbance in these changes in species dominance; and (2) that overcup oak growth has declined following construction of the levee and cessation of overbank flooding whereas that of sugarberry has increased. Recruitment patterns shifted from flood-tolerant overcup oak to flood-intolerant sugarberry (Celtis laevigata) after levee construction. None of the 122 sugarberry trees cored in this study established prior to the levee, but it was the most common species established after the levee. The mechanisms behind the compositional change are unknown, however, the cosmopolitan distribution of overcup oak during the pre-levee period and sugarberry during the post-levee period, the lack of sugarberry establishment in the pre-levee period, and the confinement of overcup oak regeneration to the lowest areas in each stand after harvest in the post-levee period indicate that species-specific responses to flooding and light availability are forcing recruitment patterns. Overcup oak growth was also affected by levee construction, but in contrast to our hypothesis, growth actually

  4. Evidence of an emerging levee failure mechanism causing disastrous floods in Italy

    NASA Astrophysics Data System (ADS)

    Orlandini, Stefano; Moretti, Giovanni; Albertson, John D.

    2015-10-01

    A levee failure occurred along the Secchia River, Northern Italy, on 19 January 2014, resulting in flood damage in excess of $500 million. In response to this failure, immediate surveillance of other levees in the region led to the identification of a second breach developing on the neighboring Panaro River, where rapid mitigation efforts were successful in averting a full levee failure. The paired breach events that occurred along the Secchia and Panaro Rivers provided an excellent window on an emerging levee failure mechanism. In the Secchia River, by combining the information content of photographs taken from helicopters in the early stage of breach development and 10 cm resolution aerial photographs taken in 2010 and 2012, animal burrows were found to exist in the precise levee location where the breach originated. In the Panaro River, internal erosion was observed to occur at a location where a crested porcupine den was known to exist and this erosion led to the collapse of the levee top. This paper uses detailed numerical modeling of rainfall, river flow, and variably saturated flow in the levee to explore the hydraulic and geotechnical mechanisms that were triggered along the Secchia and Panaro Rivers by activities of burrowing animals leading to levee failures. As habitats become more fragmented and constrained along river corridors, it is possible that this failure mechanism could become more prevalent and, therefore, will demand greater attention in both the design and maintenance of earthen hydraulic structures as well as in wildlife management.

  5. An assessment of two methods for identifying undocumented levees using remotely sensed data

    USGS Publications Warehouse

    Czuba, Christiana R.; Williams, Byron K.; Westman, Jack; LeClaire, Keith

    2015-01-01

    Many undocumented and commonly unmaintained levees exist in the landscape complicating flood forecasting, risk management, and emergency response. This report describes a pilot study completed by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers to assess two methods to identify undocumented levees by using remotely sensed, high-resolution topographic data. For the first method, the U.S. Army Corps of Engineers examined hillshades computed from a digital elevation model that was derived from light detection and ranging (lidar) to visually identify potential levees and then used detailed site visits to assess the validity of the identifications. For the second method, the U.S. Geological Survey applied a wavelet transform to a lidar-derived digital elevation model to identify potential levees. The hillshade method was applied to Delano, Minnesota, and the wavelet-transform method was applied to Delano and Springfield, Minnesota. Both methods were successful in identifying levees but also identified other features that required interpretation to differentiate from levees such as constructed barriers, high banks, and bluffs. Both methods are complementary to each other, and a potential conjunctive method for testing in the future includes (1) use of the wavelet-transform method to rapidly identify slope-break features in high-resolution topographic data, (2) further examination of topographic data using hillshades and aerial photographs to classify features and map potential levees, and (3) a verification check of each identified potential levee with local officials and field visits.

  6. Balancing Play, Meaning and Reality: The Design Philosophy of LEVEE PATROLLER

    ERIC Educational Resources Information Center

    Harteveld, Casper; Guimaraes, Rui; Mayer, Igor S.; Bidarra, Rafael

    2010-01-01

    Most serious games have been developed without a proper and comprehensive design theory. To contribute to the development of such a theory, this article presents the underlying design philosophy of LEVEE PATROLLER, a game to train levee patrollers in the Netherlands. This philosophy stipulates that the design of a digital serious game is a…

  7. A Model for Variable Levee Formation Rates in an Active Lava Flow

    NASA Technical Reports Server (NTRS)

    Glaze, L. S.; Baloga, S. M.; Mouginis-Mark, P.; Crisp, J.

    2004-01-01

    Channelized lava flows on Mars and the Earth often feature levees and collateral margins that change in volume along the path of the flow. Consistent with field observations of terrestrial flows, this suggests that the rate of levee formation varies with distance and other factors. Previous models have assumed a constant rate of levee growth, specified by a single parameter, lambda. The rate of levee formation for lava flows is a good indicator of the mass eruption rate and rheology of the flow. Insight into levee formation will help us better understand whether or not the effusion rate was constant during an eruption, and once local topography is considered, allows us to look at cooling and/or rheology changes downslope. Here we present a more realistic extension of the levee formation model that treats the rate of levee growth as a function of distance along the flow path. We show how this model can be used with a terrestrial flow and a long lava flow on Mars. The key statement of the new formulation is the rate of transfer from the active component to the levees (or other passive components) through an element dx along the path of the flow. This volumetric transfer equation is presented.

  8. Documenting Tragedy and Resilience: The Importance of Spike Lee's "When the Levees Broke"

    ERIC Educational Resources Information Center

    Foster, Kevin Michael; Blakes, Tifani; McKay, Jenny

    2008-01-01

    Spike Lee's documentary, "When the Levees Broke," provides an informative, enduring, and alternative presentation surrounding the human and man-made debacle associated with Hurricane Katrina. Levees centers the voices of survivors and others involved in the weeks during and after the hurricane, historicizes residents' understandings and reactions,…

  9. Study of Movement and Seepage Along Levees Using DINSAR and the Airborne UAVSAR Instrument

    NASA Technical Reports Server (NTRS)

    Jones, Cathleen E.; Bawden, Gerald; Deverel, Steven; Dudas, Joel; Hensley, Scott

    2012-01-01

    We have studied the utility of high resolution SAR (synthetic aperture radar) for levee monitoring using UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar) data collected along the dikes and levees in California's Sacramento-San Joaquin Delta and along the lower Mississippi River. Our study has focused on detecting and tracking changes that are indicative of potential problem spots, namely deformation of the levees, subsidence along the levee toe, and seepage through the levees, making use of polarimetric and interferometric SAR techniques. Here was present some results of those studies, which show that high resolution, low noise SAR imaging could supplement more traditional ground-based monitoring methods by providing early indicators of seepage and deformation.

  10. Refuge management analyses: levee alternatives at Clarence Cannon National Wildlife Refuge

    USGS Publications Warehouse

    Auble, Gregor T.; Hamilton, David B.; Roelle, James E.

    1984-01-01

    Do not maintain a levee so that the Refuge will flood directly with river stage. Repair of the major breaks in the levee, but not the more general wave damage, was considered as a short term alternative. Participants first specified the habitats and management controls desired at Clarence Cannon National Wildlife Refuge. These were centered around attaining the maximum feasible development and management of moist soil units. Levee alternatives were evaluated in terms of their ability to provide the desired habitats and management controls. Preliminary cost estimates were prepared for each alternative, and the qualitative consequences of each alternative identified for the full set of outputs from the Refuge Master Plan. The alternative of improving the existing levee by raising the height was unanimously preferred on purely “biological” grounds (with cost not considered). Repairing the levee with no change in elevation was unanimously selected as the most cost effective alternative.

  11. Evidence of an Emerging Disturbance of Earthen Levees Causing Disastrous Floods in Italy

    NASA Astrophysics Data System (ADS)

    Orlandini, S.; Moretti, G.; Albertson, J. D.

    2015-12-01

    A levee failure occurred along the Secchia River, Northern Italy, on January 19, 2014, resulting in flood damage in excess of $500 Million (Figure). In response to this failure, immediate surveillance of other levees in the region led to the identification of a second breach developing on the neighboring Panaro River, where rapid mitigation efforts were successful in averting a full levee failure. The paired breach events that occurred along the Secchia and Panaro Rivers provided an excellent window on an emerging disturbance of levees and related failure mechanism. In the Secchia River, by combining the information content of photographs taken from helicopters in the early stage of breach development and 10-cm resolution aerial photographs taken in 2010 and 2012, animal burrows were found to exist in the precise levee location where the breach originated. In the Panaro River, internal erosion was observed to occur at a location where a crested porcupine den was known to exist and this erosion led to the collapse of the levee top. Evidence collected suggested that it is quite likely that the levee failure of the Secchia River was of a similar mechanism as the observed failure of the Panaro River. Detailed numerical modeling of rainfall, river flow, and variably saturated flow occurring in disturbed levees in response to complex hydroclimatic forcing indicated that the levee failure of the Secchia River may have been triggered by direct river inflow into the den system or collapse of a hypothetical den separated by a 1-m earthen wall from the levee riverside, which saturated during the hydroclimatic event. It is important to bring these processes to the attention of hydrologists and geotechnical engineers as well as to trigger an interdisciplinary discussion on habitat fragmentation and wildlife shifts due to development and climate pressures. These disturbances come together with changes in extreme events to inform the broader concern of risk analysis due to floods.

  12. Levee crest elevation profiles derived from airborne lidar-based high resolution digital elevation models in south Louisiana

    USGS Publications Warehouse

    Palaseanu-Lovejoy, Monica; Thatcher, Cindy A.; Barras, John A.

    2014-01-01

    This study explores the feasibility of using airborne lidar surveys to derive high-resolution digital elevation models (DEMs) and develop an automated procedure to extract levee longitudinal elevation profiles for both federal levees in Atchafalaya Basin and local levees in Lafourche Parish. Generally, the use of traditional manual surveying methods to map levees is a costly and time consuming process that typically produces cross-levee profiles every few hundred meters, at best. The purpose of our paper is to describe and test methods for extracting levee crest elevations in an efficient, comprehensive manner using high resolution lidar generated DEMs. In addition, the vertical uncertainty in the elevation data and its effect on the resultant estimate of levee crest heights is addressed in an assessment of whether the federal levees in our study meet the USACE minimum height design criteria.

  13. Terrestrial Lidar Datasets of New Orleans, Louisiana, Levee Failures from Hurricane Katrina, August 29, 2005

    USGS Publications Warehouse

    Collins, Brian D.; Kayen, Robert; Minasian, Diane L.; Reiss, Thomas

    2009-01-01

    Hurricane Katrina made landfall with the northern Gulf Coast on August 29, 2005, as one of the strongest hurricanes on record. The storm damage incurred in Louisiana included a number of levee failures that led to the inundation of approximately 85 percent of the metropolitan New Orleans area. Whereas extreme levels of storm damage were expected from such an event, the catastrophic failure of the New Orleans levees prompted a quick mobilization of engineering experts to assess why and how particular levees failed. As part of this mobilization, civil engineering members of the United States Geological Survey (USGS) performed terrestrial lidar topographic surveys at major levee failures in the New Orleans area. The focus of the terrestrial lidar effort was to obtain precise measurements of the ground surface to map soil displacements at each levee site, the nonuniformity of levee height freeboard, depth of erosion where scour occurred, and distress in structures at incipient failure. In total, we investigated eight sites in the New Orleans region, including both earth and concrete floodwall levee breaks. The datasets extend from the 17th Street Canal in the Orleans East Bank area to the intersection of the Gulf Intracoastal Waterway (GIWW) with the Mississippi River Gulf Outlet (MRGO) in the New Orleans East area. The lidar scan data consists of electronic files containing millions of surveyed points. These points characterize the topography of each levee's postfailure or incipient condition and are available for download through online hyperlinks. The data serve as a permanent archive of the catastrophic damage of Hurricane Katrina on the levee systems of New Orleans. Complete details of the data collection, processing, and georeferencing methodologies are provided in this report to assist in the visualization and analysis of the data by future users.

  14. Late Pleistocene channel-levee development on Monterey submarine fan, central California

    USGS Publications Warehouse

    Normark, W.R.

    1999-01-01

    Much of the modern upper (proximal) Monterey fan is a channel-levee complex, the Upper Turbidite Sequence (UTS), that was deeply eroded after the channel breached a volcanic ridge to reach a deeper base level. Ages of sediment samples collected with the ALVIN submersible from the deepest outcrop within the channel-levee system, 390 m below the adjacent western levee crest, indicate that the UTS deposits accumulated at ???1 m ka-1 during the last 500 ka. Neogene and Early Pleistocene sediment accumulation on the fan prior to the UTS was much slower (<0.03 m ka-1), and underlying turbidite systems(?) had substantially different morphologic expression(s).

  15. Aggradation of Leveed Channels and Their Flood Plains in Arroyo Bottoms

    NASA Astrophysics Data System (ADS)

    Vincent, K. R.

    2005-12-01

    Many arroyos that formed by incision more than a century ago in the southwestern United States are currently filling with sediment. This reversal of processes is important because it causes changes in riparian ecology, erosion hazards, ground water recharge, and sediment supply to downstream. Along the Rio Puerco and Chaco Wash in New Mexico, we examined the geometry and facies of channel and floodplain stratigraphy exposed in trenches, used high-resolution dating of the sedimentary beds, and used photographs and other historical evidence to investigate the processes of aggradation in naturally leveed channels within arroyos. Prior to the onset of aggradation, the streambeds were composed of sand and had low relief, and arroyo walls retreated rapidly due to stream undermining. Aggradation began with the formation of sand levees at the margins of the streambeds, followed by formation of newer levees increasingly closer to the thalweg. These levees coincide with rows of woody shrubs (tamarisk and willow), plants that germinated in moist sand along the high-water marks of moderate flows, and survived because subsequent periods lacked flows large enough to remove them. Flow entering a row of woody shrubs decelerates, promoting deposition of suspended sand. Stream flows in this setting are always turbid but do not have the rheology of debris flows. The rows of shrubs probably are a requirement for initial formation of sand levees on low relief streambeds in this setting. As new levees formed closer to the thalweg the channel effectively narrowed, and smaller discharges overtopped the levees adjacent to the channel. Those closer levees accumulated sand most rapidly, leaving the suspended sand concentration depleted by the time water reached more distant ones. All levees aggraded vertically. As the main channel narrowed it acquired a roughly trapezoidal-shape (Top Width/Depth ~ 9 to 5) with banks inclined close to the angle of repose. In addition, sediment deposited on

  16. Application of High Resolution Multispectral Imagery for Levee Slide Detection and Monitoring

    NASA Technical Reports Server (NTRS)

    Hossain, A. K. M. Azad; Easson, Greg

    2007-01-01

    The objective is to develop methods to detect and monitor levee slides using commercially available high resolution multispectral imagery. High resolution multispectral imagery like IKONOS and QuickBird are suitable for detecting and monitoring levee slides. IKONOS is suitable for visual inspection, image classification and Tasseled Cap transform based slide detection. Tasseled Cap based model was found to be the best method for slide detection. QuickBird was suitable for visual inspection and image classification.

  17. Possible Weakening Processes Imposed on California's Earthen Levees under Protracted Drought

    NASA Astrophysics Data System (ADS)

    Robinson, J. D.; Vahedifard, F.; AghaKouchak, A.

    2015-12-01

    California is currently suffering from a multiyear extreme drought and the impacts of the drought are anticipated to worsen in a warming climate. The resilience of critical infrastructure under extreme drought conditions is a major concern which has not been well understood. Thus, there is a crucial need to improve our understanding about the potential threats of drought on infrastructure and take subsequent actions in a timely manner to mitigate these threats and adopt our infrastructure for forthcoming extreme events. The need is more pronounced for earthen levees, since their functionality to protect limited water resources and dryland is more critical during drought. A significant amount of California's levee systems are currently operating under a high risk condition. Protracted drought can further threaten the structural competency of these already at-risk levee systems through several thermo-hydro mechanical weakening processes that undermine their stability. Viable information on the implications of these weakening processes, particularly on California's earthen levees, is relatively incomplete. This article discusses, from a geotechnical engineering perspective, how California's protracted drought might threaten the integrity of levee systems through the imposition of several thermo-hydro mechanical weakening processes. Pertinent facts and statistics regarding the drought in California are presented and discussed. Catastrophic levee failures and major damages resulting from drought-induce weakening processes such as shear strength reduction, desiccation cracking, land subsidence and surface erosion, fissuring and soil softening, and soil carbon oxidation are discussed to illustrate the devastating impacts that the California drought might impose on existing earthen levees. This article calls for further research in light of these potential drought-inducing weakening mechanisms to support mitigation strategies for reducing future catastrophic levee failures.

  18. Time-lapse seismic study of levees in southern New Mexico

    USGS Publications Warehouse

    Ivanov, J.; Miller, R.D.; Stimac, N.; Ballard, R.F.; Dunbar, J. Joseph; Smullen, S. Steve

    2006-01-01

    The primary objective of this work was to measure changes in compressional- (Vp) and shear-wave (Vs) velocities in an earthen levee during a ponding experiment designed to simulate flood conditions on the Rio Grande in south New Mexico. Although similar to such experiment, performed an year earlier on the Rio Grande in south Texas, the levee seismic response results are different. This work was similar to previous Preliminary testing at three levee sites, all within a 1 km radius and each with unique physical, EM, and core characteristics, was completed and a single low-conductivity, highly fractured site was selected for investigation. Several different types of seismic data were recorded. Seismic data analysis techniques appraised included P-refraction tomography and Rayleigh surface-wave analysis using multichannel analysis of surface waves (MASW). P-wave velocity change (decrease) was rapid and isolated to one section within the pool confines, which already had anomalously high velocity most likely related to burrowing animals modification of the levee structure. S-wave velocity change was gradual and could be observed along the whole width of the pond within and below the levee. The results within the levee sand core were consistent with the observations of sand S-wave velocity changed due to saturation. ?? 2005 Society of Exploration Geophysicists.

  19. Numerical Modeling of the Effect of Woody Vegetation on Seepage in Levees

    NASA Astrophysics Data System (ADS)

    Tracy, F. T.; Corcoran, M. K.

    2011-12-01

    A remarkable number and diversity of levees exist in the United States. One controversial and complicated concern is the effect of woody vegetation on the performance of levees. Some really appreciate the trees on levees because they are beautiful and great for the environment and habitat. However, others do not like trees on levees because they can cause defects and get in the way of doing maintenance, especially during the time of floods. This poster will focus on two-dimensional (2-D) and three-dimensional (3-D) numerical modeling of seepage in levees to determine the effect of woody vegetation on piping and internal erosion of the foundation of the levee. The finite element method is the modeling tool that is used. The approach in the overall modeling study was to select several levees around the country for further analysis. Then for each levee, trees were placed at different locations on the levee. A given root zone from a tree was modeled in three ways: (1) a 6 ft X 5 ft constant hydraulic conductivity zone where the original hydraulic conductivity of the zone was varied from 0.01 to 100.0 times its original value, (2) a randomly generated macropore heterogeneous zone where the hydraulic conductivity was varied from 0.01 to 100.0 times its original value for each finite element in the zone, and (3) a defect in actual root shapes embedded into the root zone where the hydraulic conductivity of the defect was chosen to be 100.0 times that of its original value without the defect. Both steady-state and transient flow simulations were done. Output from the models consisted of equipotentials, velocities, pore pressures, and isosurfaces of potential. From these data, the likelihood of the initiation of sand boils and internal erosion of the levee foundation was determined. Data generated with and without the presence of trees were compared to see possible helpful or detrimental effects of the woody vegetation. A 3-D finite element model was generated by taking a 2

  20. Methods to quantify seepage beneath Levee 30, Miami-Dade County, Florida

    USGS Publications Warehouse

    Sonenshein, R.S.

    2001-01-01

    A two-dimensional, cross-sectional, finite-difference, ground-water flow model and a simple application of Darcy?s law were used to quantify ground-water flow (from a wetlands) beneath Levee 30 in Miami-Dade County, Florida. Geologic and geophysical data, vertical seepage data from the wetlands, canal discharge data, ground-water-level data, and surface-water-stage data collected during 1995 and 1996 were used as boundary conditions and calibration data for the ground-water flow model and as input for the analytical model. Vertical seepage data indicated that water from the wetlands infiltrated the subsurface, near Levee 30, at rates ranging from 0.033 to 0.266 foot per day when the gates at the control structures along Levee 30 canal were closed. During the same period, stage differences between the wetlands (Water Conservation Area 3B) and Levee 30 canal ranged from 0.11 to 1.27 feet. A layer of low-permeability limestone, located 7 to 10 feet below land surface, restricts vertical flow between the surface water in the wetlands and the ground water. Based on measured water-level data, ground-water flow appears to be generally horizontal, except in the direct vicinity of the canal. The increase in discharge rate along a 2-mile reach of the Levee 30 canal ranged from 9 to 30 cubic feet per second per mile and can be attributed primarily to ground-water inflow. Flow rates in Levee 30 canal were greatest when the gates at the control structures were open. The ground-water flow model data were compared with the measured ground-water heads and vertical seepage from the wetlands. Estimating the horizontal ground-water flow rate beneath Levee 30 was difficult owing to the uncertainty in the horizontal hydraulic conductivity of the main flow zone of the Biscayne aquifer. Measurements of ground-water flows into Levee 30 canal, a substantial component of the water budget, were also uncertain, which lessened the ability to validate the model results. Because of vertical

  1. Root Development of Salix purpurea L. on Heavily Compacted Levee Soils

    NASA Astrophysics Data System (ADS)

    Lammeranner, W.

    2012-04-01

    The effect of woody vegetation on levee stability is discussed controversially. On the one hand woody plants improve slope stability, prevent erosion failures and may aid in levee stability. On the other hand it is believed that woody vegetation has negative impacts which are largely related to the rooting system. Hence, root penetration can facilitate water movement - seepage or piping - as well as living and decaying roots can lead to voids and threaten the structural integrity of levees. In general root architecture is known for many plant species, but specific root characteristics and their interaction with soils are influenced by many factors, and therefore poorly understood. Consequently the current research investigates the rooting performance of woody vegetation by singling out a special type of vegetation which is often used within soil bioengineering techniques at river embankments. This vegetation type is a dense stand of shrubby willows (Salix purpurea L.), implemented with brush mattresses. The data is collected from a test site constructed in 2007, 5 km northeast of Vienna, Austria. Part of the test site is a research levee built true to natural scale. The fill material of the levee is a mineral silt-sand-gravel compound classified as silty sand, which was compacted to a dry density of 1.86 g/cm3. The planting of vegetation was applied directly to the compacted levee body using only a thin layer (2-4 cm) of humus topsoil. In 2009 the studies were supplemented with a lysimeter-like setup consisting of a total of 20 containers. The lysimeters were filled homogenously with the same soil as the levees and were consolidated to the same degree of compaction. They were planted similar to the research levees. Within the investigations a comprehensive annual vegetation monitoring program was carried out. Measured aboveground parameters were shoot diameter, shoot length, biomass and leaf area index (LAI). Monitored rooting parameters - examined by excavation

  2. Advanced Unsupervised Classification Methods to Detect Anomalies on Earthen Levees Using Polarimetric SAR Imagery

    PubMed Central

    Marapareddy, Ramakalavathi; Aanstoos, James V.; Younan, Nicolas H.

    2016-01-01

    Fully polarimetric Synthetic Aperture Radar (polSAR) data analysis has wide applications for terrain and ground cover classification. The dynamics of surface and subsurface water events can lead to slope instability resulting in slough slides on earthen levees. Early detection of these anomalies by a remote sensing approach could save time versus direct assessment. We used L-band Synthetic Aperture Radar (SAR) to screen levees for anomalies. SAR technology, due to its high spatial resolution and soil penetration capability, is a good choice for identifying problematic areas on earthen levees. Using the parameters entropy (H), anisotropy (A), alpha (α), and eigenvalues (λ, λ1, λ2, and λ3), we implemented several unsupervised classification algorithms for the identification of anomalies on the levee. The classification techniques applied are H/α, H/A, A/α, Wishart H/α, Wishart H/A/α, and H/α/λ classification algorithms. In this work, the effectiveness of the algorithms was demonstrated using quad-polarimetric L-band SAR imagery from the NASA Jet Propulsion Laboratory’s (JPL’s) Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR). The study area is a section of the lower Mississippi River valley in the Southern USA, where earthen flood control levees are maintained by the US Army Corps of Engineers. PMID:27322270

  3. A Hybrid Model for Leveed Lava Flows: Implications for Eruption Styles on Mars

    NASA Technical Reports Server (NTRS)

    Glaze, Lori S.; Baloga, Stephen M.; Garry, W. Brent; Fagents, Sarah A.; Parcheta, Carolyn

    2009-01-01

    Many cehannelized lava flows on the plains of Mars have substantial embanking margins and levees inferred to have been stationary while the central channel was active. Levee formation can be attributed to two end-member processes during emplacement; construction during passage of the flow front and growth along the entire length of the flow while it is active. It is shown here that the amount of lava that can be deposited by the flow front alone is limited. Estimates of the levee volume for many Mars plains flows exceed this limit and must have formed by processes that continued after the passage of the front. Experimental studies of analogous laboratory flows also indicate a combination of both modes of emplacement. A model that combines both modes of levee formation. is presented, including a method for estimating volumetric flow rate, eruption duration, and viscosity. Six lava flows on the plains of the Tharsis volcanic province are used as illustrative examples. Crustal thicknesses for the six flows examined range from 9 to 23 m. Estimated emplacement times required to cool crusts of these thicknesses range from I year to 10 years. Correspondini viscosities are on the order of 10 5-106 Pa s. Effusion rates range from 25 to 840 m 3 s - and are all within the range of terrestrial observations. Therefore, the large leveed plains flows on Mars are not dramatically different in eruption rate or lava viscosity from large terrestrial analogs.

  4. Using ground penetrating radar in levee assessment to detect small scale animal burrows

    NASA Astrophysics Data System (ADS)

    Chlaib, Hussein K.; Mahdi, Hanan; Al-Shukri, Haydar; Su, Mehmet M.; Catakli, Aycan; Abd, Najah

    2014-04-01

    Levees are civil engineering structures built to protect human lives, property, and agricultural lands during flood events. To keep these important structures in a safe condition, continuous monitoring must be performed regularly and thoroughly. Small rodent burrows are one of the major defects within levees; however, their early detection and repair helps in protecting levees during flooding events. A set of laboratory experiments was conducted to analyze the polarity change in GPR signals in the presence of subsurface voids and water-filled cavities. Ground Penetrating Radar (GPR) surveys using multi frequency antennas (400 MHz and 900 MHz) were conducted along an 875 meter section of the Lollie Levee near Conway, Arkansas, USA, to assess the levee's structural integrity. Many subsurface animal burrows, water-filled cavities, clay clasts, and metallic objects were investigated and identified. These anomalies were located at different depths and have different sizes. To ground truth the observations, hand dug trenches were excavated to confirm several anomalies. Results show an excellent match between GPR interpreted anomalies and the observed features. In-situ dielectric constant measurements were used to calculate the feature depths. The results of this research show that the 900 MHz antenna has more advantages over the 400 MHz antenna.

  5. Advanced Unsupervised Classification Methods to Detect Anomalies on Earthen Levees Using Polarimetric SAR Imagery.

    PubMed

    Marapareddy, Ramakalavathi; Aanstoos, James V; Younan, Nicolas H

    2016-01-01

    Fully polarimetric Synthetic Aperture Radar (polSAR) data analysis has wide applications for terrain and ground cover classification. The dynamics of surface and subsurface water events can lead to slope instability resulting in slough slides on earthen levees. Early detection of these anomalies by a remote sensing approach could save time versus direct assessment. We used L-band Synthetic Aperture Radar (SAR) to screen levees for anomalies. SAR technology, due to its high spatial resolution and soil penetration capability, is a good choice for identifying problematic areas on earthen levees. Using the parameters entropy (H), anisotropy (A), alpha (α), and eigenvalues (λ, λ₁, λ₂, and λ₃), we implemented several unsupervised classification algorithms for the identification of anomalies on the levee. The classification techniques applied are H/α, H/A, A/α, Wishart H/α, Wishart H/A/α, and H/α/λ classification algorithms. In this work, the effectiveness of the algorithms was demonstrated using quad-polarimetric L-band SAR imagery from the NASA Jet Propulsion Laboratory's (JPL's) Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR). The study area is a section of the lower Mississippi River valley in the Southern USA, where earthen flood control levees are maintained by the US Army Corps of Engineers.

  6. Advanced Unsupervised Classification Methods to Detect Anomalies on Earthen Levees Using Polarimetric SAR Imagery.

    PubMed

    Marapareddy, Ramakalavathi; Aanstoos, James V; Younan, Nicolas H

    2016-01-01

    Fully polarimetric Synthetic Aperture Radar (polSAR) data analysis has wide applications for terrain and ground cover classification. The dynamics of surface and subsurface water events can lead to slope instability resulting in slough slides on earthen levees. Early detection of these anomalies by a remote sensing approach could save time versus direct assessment. We used L-band Synthetic Aperture Radar (SAR) to screen levees for anomalies. SAR technology, due to its high spatial resolution and soil penetration capability, is a good choice for identifying problematic areas on earthen levees. Using the parameters entropy (H), anisotropy (A), alpha (α), and eigenvalues (λ, λ₁, λ₂, and λ₃), we implemented several unsupervised classification algorithms for the identification of anomalies on the levee. The classification techniques applied are H/α, H/A, A/α, Wishart H/α, Wishart H/A/α, and H/α/λ classification algorithms. In this work, the effectiveness of the algorithms was demonstrated using quad-polarimetric L-band SAR imagery from the NASA Jet Propulsion Laboratory's (JPL's) Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR). The study area is a section of the lower Mississippi River valley in the Southern USA, where earthen flood control levees are maintained by the US Army Corps of Engineers. PMID:27322270

  7. Geophysical characterization of the Lollie Levee near Conway, Arkansas, using capacitively coupled resistivity, coring, and direct push logging

    USGS Publications Warehouse

    Gillip, Jonathan A.; Payne, Jason D.

    2011-01-01

    A geophysical characterization of Lollie Levee near Conway, Arkansas, was conducted in February 2011. A capacitively coupled resistivity survey (using Geometric's OhmMapper) was completed along the top and toe of the 6.7-mile levee. Two-dimensional inversions were conducted on the geophysical data. As a quality-control measure, cores and direct push logs were taken at approximately 1-mile intervals along the levee. The capacitively coupled resistivity survey, the coring, and the direct push logs were used to characterize the geologic materials. Comparison of the cores and the direct push log data, along with published resistivity values, indicates that resistivity values of 200 Ohm-meters or greater represent relatively clean sand, with decreasing resistivity values occurring with increasing silt and clay content. The cores indicated that the levee is composed of a heterogeneous mixture of sand, silt, and clay. The capacitively coupled resistivity sections confirm that the levee is composed of a heterogeneous mixture of high and low resistivity materials and show that the composition of the levee varies spatially. The geologic materials underlying the levee vary spatially as a result of the geologic processes that deposited them. In general, the naturally deposited geologic materials underlying the levee contain a greater amount of low resistivity materials in the southern extent of the levee.

  8. California Levee Risk, Now and in the Future:Identifying Research and Tool Development Needs

    SciTech Connect

    Newmark, R L; Hanemann, M; Farber, D

    2006-11-28

    The Center for Catastrophic Risk Management (CCRM) and the California Center for Environmental Law and Policy (CCELP) at UC Berkeley and the Lawrence Livermore National Laboratory (LLNL) joined together to cosponsor a workshop to define research requirements to mitigate the hazards facing the Sacramento-San Joaquin Delta Levee system. The Workshop was intended to provide a forum to (1) Report assessments of current vulnerabilities facing the levees, such as structural failure, seismic loading, flooding, terrorism; (2) Consider longer term challenges such as climate change, sea level rise; and (3) Define research requirements to fill gaps in knowledge and reduce uncertainties in hazard assessments.

  9. The impact of different soil bioengineering techniques on the surface erosion of levees

    NASA Astrophysics Data System (ADS)

    Lammeranner, W.; Meixner, H.; Florineth, F.

    2009-04-01

    The recent flood events have once more drawn attention to the stability and maintenance of river levees. Subsequently, the attention has also been focused on the prevention of erosion by hydraulic forces in case of flooding or overtopping. Vegetation can limit the soil detaching capacity of flowing water, by their retarding effects on runoff and velocity as well as the physical protection of the levee surface. At low discharge intensity vegetation stands rigid and unsubmerged, reducing velocity below required for soil particle entrainment (Coppin and Richards, 1990). At higher discharge capacities flexible vegetation tend to lay down, dissipating energy and providing resistance to scour (Henderson and Shields, 1984). Roots increase the shear strength of the soil (Schiechtl, 1980) and can create a fibrous mat that resists detachment of the surrounding soil matrix (Henderson and Shields, 1984). The erosive capacity of surface water flow is dependant to type and pattern of vegetation. The denser the vegetation, the better the soil surface is protected against erosion. Sets of regulations regard compact turf to be the best vegetation cover for river levees. A contentious issue are woody plants, and many guidelines (DIN 19712, 1997; FEMA, 2005; USACE, 2000) ban woody vegetation from levees for several reasons. So, the planting of woody plants is not an accepted policy by any agency. Within the frame of a research project carried out by the Institute of Soil Bioengineering and Landscape Construction (University of Natural Resources and Applied Life Sciences, Vienna), focusing on woody plants on levees, the effects of small to medium growing woody (shrubby) plants on erosion while hydraulic forces (overtopping) are tested. Data are drawn from two natural-scaled research levees. The homogenous levees consist of a mineral silt-sand-gravel and have a fill height of 2.7 m and a slope inclination of 2:3. The tests investigate erosion resistance with respect to four different

  10. 76 FR 25310 - Intent To Prepare an Environmental Impact Statement for the Zoar Levee and Diversion Dam, Dam...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ... Levee and Diversion Dam, Dam Safety Modification Study, Tuscarawas County, OH AGENCY: Department of the... with Zoar Levee and Diversion Dam. These high hazard structures do not meet current performance... . SUPPLEMENTARY INFORMATION: 1. Authority: Investigation and justification of modifications for dam...

  11. Level-I Trauma Center Effects on Return-to-Work Outcomes

    ERIC Educational Resources Information Center

    Prada, Sergio I.; Salkever, David; MacKenzie, Ellen J.

    2012-01-01

    Background: Injury is the leading cause of death for persons aged 1-44 years in the United States. Injuries have a substantial economic cost. For that reason, regional systems of trauma care in which the more acutely injured patients are transported to Level-I (L-I) trauma centers (TCs) has been widely advocated. However, the cost of TC care is…

  12. 76 FR 78015 - Revised Analysis and Mapping Procedures for Non-Accredited Levees

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-15

    ... SECURITY Federal Emergency Management Agency Revised Analysis and Mapping Procedures for Non-Accredited Levees AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice. SUMMARY: The Federal Emergency... Division, Office of Chief Counsel, Federal Emergency Management Agency, Room 835, 500 C Street...

  13. Agricultural aircraft and thermal imaging - from detecting sand boils at the levee to irrigation management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermal imaging has many potential uses from aerial platforms. A thermal imaging camera was brought into service to detect potential leakage and sand boils at the Mississippi River levee during the flood period of April and May, 2011. This camera was mounted on an agricultural aircraft and operated ...

  14. 75 FR 11147 - Process for Requesting a Variance From Vegetation Standards for Levees and Floodwalls

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-10

    ... period. SUMMARY: In the February 9, 2010 issue of the Federal Register (75 FR 6364), the U.S. Army Corps... Department of the Army, Corps of Engineers Process for Requesting a Variance From Vegetation Standards for... from vegetation standards for levees and floodwalls for public comment. In that notice, the...

  15. The use of seismic tomograms for the identification of internal problems with earthen dams and levees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    According to the National Inventory of dams (NID, 2009), out of the 84,134 dams in the US, more than 87% (73,423) are earthen dams. The majority of these earthen dams are past or approaching their design life expectancy of 50 years. According to the National committee on Levee Safety (NCLS, 2009),...

  16. Grain-size segregation and levee formation in geophysical mass flows

    USGS Publications Warehouse

    Johnson, C.G.; Kokelaar, B.P.; Iverson, R.M.; Logan, M.; LaHusen, R.G.; Gray, J.M.N.T.

    2012-01-01

    Data from large-scale debris-flow experiments are combined with modeling of particle-size segregation to explain the formation of lateral levees enriched in coarse grains. The experimental flows consisted of 10 m3 of water-saturated sand and gravel, which traveled ~80 m down a steeply inclined flume before forming an elongated leveed deposit 10 m long on a nearly horizontal runout surface. We measured the surface velocity field and observed the sequence of deposition by seeding tracers onto the flow surface and tracking them in video footage. Levees formed by progressive downslope accretion approximately 3.5 m behind the flow front, which advanced steadily at ~2 m s-1 during most of the runout. Segregation was measured by placing ~600 coarse tracer pebbles on the bed, which, when entrained into the flow, segregated upwards at ~6–7.5 cm s-1. When excavated from the deposit these were distributed in a horseshoe-shaped pattern that became increasingly elevated closer to the deposit termination. Although there was clear evidence for inverse grading during the flow, transect sampling revealed that the resulting leveed deposit was strongly graded laterally, with only weak vertical grading. We construct an empirical, three-dimensional velocity field resembling the experimental observations, and use this with a particle-size segregation model to predict the segregation and transport of material through the flow. We infer that coarse material segregates to the flow surface and is transported to the flow front by shear. Within the flow head, coarse material is overridden, then recirculates in spiral trajectories due to size-segregation, before being advected to the flow edges and deposited to form coarse-particle-enriched levees.

  17. Flow and solute transport through a levee separating fluids with different densities

    NASA Astrophysics Data System (ADS)

    Brooker, Andrew M. H.; Townley, Lloyd R.

    1994-06-01

    Steady seepage through a levee or a dam separating reservoirs with different levels and densities is shown to result in five possible flow configurations. If densities are equal, the problem reduces to the classical problem of flow through a dam. If the lower reservoir is less dense, a stationary wedge may or may not form inside the levee near the downgradient reservoir level. If the lower reservoir is more dense, a wedge forms near the toe of the levee, as in the classical problem of saltwater intrusion. Another possibility is that the dense wedge can connect the two reservoirs, thus allowing bidirectional flow. Conditions are derived which define when these different flow configurations occur. For the case of a rectangular dam with vertical walls a closed form solution is obtained for the net mass flux between the reservoirs. Net volumetric flux is determined analytically for all flow configurations except the case of bidirectional flow. The expression for volumetric flux is a generalization of a result based on the Dupuit assumption for the case of constant density. A range of parameters is identified in which net volumetric flux is in one direction and net mass flux in the other. A numerical model based on the boundary integral equation method allows calculation of net volumetric flux for the case of bidirectional flow and also allows simulation of more complex levee geometries. The solution has direct application to levees separating ponds in solar salt production, to the causeway across the Great Salt Lake in Utah, and to the role of exchange flows in the genesis of evaporites in nearshore lagoons.

  18. Shallow (0-10) seismic investigation of a distressed earthen levee, New Orleans, USA

    NASA Astrophysics Data System (ADS)

    Lorenzo, J. M.; Hicks, J.; Vera, E. E.

    2009-12-01

    Both deep- and near-surface hydrogeologic processes can contribute to the structural failure of artificial earthen levees. Recently, seismic geophysical methods have attempted to develop a proxy for engineering shear strength, by mapping changes in the transmission velocity of shear waves. High fluid content may indicate both weak, under-compacted materials and/or organic-rich sediments. In the absence of electromagnetic methods, Vp/Vs ratios can be used as good indicators of variations in the fluid (water, and air or gas) saturation. Cone penetration borehole tests measure the resistance of soils to penetration of the cone tip and its frictional sliding that can be correlated to sediment types and their physical properties. A distressed section of an artificial earthen levee, suitable for seismic investigation, lies ~15 km S of the city of New Orleans, Louisiana, USA. Open curvilinear fissures, 10 cm wide, 30 cm deep, and up to 100 m in length, exist along the crest at two sites. Between September 2007 and February 2008 we collect horizontally (SH) polarized shear and compressional wave (P) data in pseudo-walkaway tests for the upper 100 m of the subsurface along the protected (west) side of the earthen levee, within 30 m of its crest. One profile lies parallel and adjacent to the damaged levee crest and, for reference, two profiles lie nearby adjacent to undamaged portions of the artificial earthen levee. In the first ~30 m of sediment below the lower delta plain of the Greater New Orleans area, a complex and dynamic interaction of freshwater and marine sedimentary environments juxtaposes a diverse set of facies. We combine of Vp and Vs velocity maps, sedimentary environment interpretations, and cone-penetration-derived sediment/soil and laboratory-derived physical properties to locate possible zones of high fluid concentration, (and perhaps seepage), weak engineering materials, and natural foundation soil shear strength. Under the distressed portion of the

  19. Ground-water flow beneath levee 35A from conservation area 2B, Broward County, Florida

    USGS Publications Warehouse

    Swayze, L.J.

    1988-01-01

    Conservation Area 2B is an area of recharge for the surficial aquifer system in Broward County. Water stored in the conservation area provides the hydraulic potential for downward flow to the high permeability zone of the Biscayne aquifer. A 5.64 ft head differential (average for the period of record) between water levels in Conservation Area 2B and water levels in the adjacent levee 35A borrow canal causes water to leak into the canal at an average rate of about 0.0022 cu ft per sec per lineal foot of canal and accounts for a loss of 0.013 foot per day of surface water from Conservation Area 2B. Amounts of canal leakage and underflow are constantly changing and are dependent upon the head differential between Conservation Area 2B and the levee 35A borrow canal. (Author 's abstract)

  20. Relationship between canal and levee density and coastal land loss in Louisiana

    SciTech Connect

    Turner, R.E.

    1987-12-01

    Nearly 1% of Louisiana's coastal land becomes water each year. This land loss affects everything from wildlife, fisheries, and recreation to the economy and culture. A part of this loss results from natural, unmanageable factors, but manageable factors are also responsible. This report discusses one of the manageable factors: canals and their dredged-material levees. In coastal Louisiana wetlands, canals are constructed primarily to facilitate navigation and oil and gas recovery. The density of canals in this region is now about equal to the natural network of bayous and creeks. The primary effect of these canals and associated levees is to alter the process of flooding and drainage. The influence of canals and their levees on coastal Louisiana erosion rates are modified by local geologic, hydrologic, and biologic interactions. The empirical relationship between canals and erosion is, however, clear; land loss is directly related to canal density. Comparisons with mosquito ditches, which are smaller analogues of canals, reveal similar patterns of wetland changes and suggest management options.

  1. Fine-grained linings of leveed channels facilitate runout of granular flows

    NASA Astrophysics Data System (ADS)

    Kokelaar, B. P.; Graham, R. L.; Gray, J. M. N. T.; Vallance, J. W.

    2014-01-01

    Catastrophic dense granular flows, such as occur in rock avalanches, debris flows and pyroclastic flows, move as fully shearing mixtures that have approximately 60 vol.% solids and tend to segregate to form coarse-grained fronts and leveed channels. Levees restrict spreading of unconfined flows and form as coarse particles that become concentrated in the top of the flow are transported to the front and then advect to the sides in the flow head. Channels from which most material has drained away down slope are commonly lined with fine-grained deposit, widely thought to remain from the tail of the waning flow. We show how segregation in experimental dense flows of carborundum or sand (300-425 μm) mixed with spherical fine ballotini (150-250 μm), on rough slopes of 27-29°, produces fine-grained channel linings that are deposited with the levees, into which they grade laterally. Maximum runout distance is attained with mixtures containing 30-40% sand, just sufficient to segregate and form levees that are adequately robust to restrict the spreading attributable to the low-friction fines. Resin impregnation and serial sectioning of deliberately arrested experimental flows shows how fines-lined levees form from the flow head; the flows create their own stable ‘conduit’ entirely from the front, which in a geophysical context can play an important mechanistic role in facilitating runout. The flow self-organization ensures that low-friction fines at the base of the segregated channel flow shear over fine-grained substrate in the channel, thus reducing frictional energy losses. We propose that in pyroclastic flows and debris flows, which have considerable mobility attributable to pore-fluid pressures, such fine-grained flow-contact zones form similarly and not only reduce frictional energy losses but also reduce flow-substrate permeability so as to enhance pore-fluid pressure retention. Thus the granular flow self-organization that produces fine-grained channel linings

  2. Natural levee formation along a large and regulated river: The Danube in the National Park Donau-Auen, Austria

    NASA Astrophysics Data System (ADS)

    Klasz, Gerhard; Reckendorfer, Walter; Gabriel, Hannes; Baumgartner, Christian; Schmalfuss, Roland; Gutknecht, Dieter

    2014-06-01

    We investigated overbank deposition and natural levee formation along the Danube east of Vienna based on airborne laserscan data (ALS) combined with historical information. The analyses of equally spaced cross sections, hypsographic curves and point elevations revealed the significance of the distance from the river bank, the floodplain width and the floodplain flow situation (inflow/outflow sections) for the spatial variability of sediment deposition. Deposition was high near the banks (natural levee formation), in wide floodplain sections and in inflow areas. The overall pattern was modified by the presence of side-channels and the micro-relief of the floodplain. From the derived sedimentation rates (averaged for the past 120 years over the reach) of about 11.0 mm yr- 1 at the natural levee and about 0.3 mm yr- 1 at the flood protection dyke, we can estimate an overbank deposit rate of 416,000 m3 yr- 1 for the entire free-flowing reach (between river-km 1921 and 1880), that is, between 18 and 20% of the annual transported suspended load. An analysis of historical cross sections showed that there was no natural levee along the riverbanks shortly after the regulation, about 100 years ago. We thus assume that natural levee formation is a consequence of the Danube regulation in the late 19th century. Under natural conditions overbank deposition was balanced and limited by side erosion and lateral channel migration. After stabilization of the banks the overbank deposits were not eroded, and distinct ‘natural’ levees formed. These levees will develop and grow further and affect flood protection and floodplain ecology. We discuss the interplay between floodplain deposition and lateral bank migration under the concept of dynamic equilibrium.

  3. Combined Resistivity and Shear Wave Velocity Soil-type Estimation Beneath a Coastal Protection Levee.

    NASA Astrophysics Data System (ADS)

    Lorenzo, J. M.; Goff, D.; Hayashi, K.

    2015-12-01

    Unconsolidated Holocene deltaic sediments comprise levee foundation soils in New Orleans, USA. Whereas geotechnical tests at point locations are indispensable for evaluating soil stability, the highly variable sedimentary facies of the Mississippi delta create difficulties to predict soil conditions between test locations. Combined electrical resistivity and seismic shear wave studies, calibrated to geotechnical data, may provide an efficient methodology to predict soil types between geotechnical sites at shallow depths (0- 10 m). The London Avenue Canal levee flank of New Orleans, which failed in the aftermath of Hurricane Katrina, 2005, presents a suitable site in which to pioneer these geophysical relationships. Preliminary cross-plots show electrically resistive, high-shear-wave velocity areas interpreted as low-permeability, resistive silt. In brackish coastal environments, low-resistivity and low-shear-wave-velocity areas may indicate both saturated, unconsolidated sands and low-rigidity clays. Via a polynomial approximation, soil sub-types of sand, silt and clay can be estimated by a cross-plot of S-wave velocity and resistivity. We confirm that existent boring log data fit reasonably well with the polynomial approximation where 2/3 of soil samples fall within their respective bounds—this approach represents a new classification system that could be used for other mid-latitude, fine-grained deltas.

  4. Topographic effect on Radio-Magnetotelluric and Slingram signals: application to a levee along the Loire river, France.

    NASA Astrophysics Data System (ADS)

    Duval, Rodolphe; Fauchard, Cyrille; Antoine, Raphael

    2014-05-01

    We study the influence of the topography of a levee on the electric and magnetic signals obtained with the Radio-Magnetotelluric method (RMT) and the Slingram method, respectively. For the RMT method, field measurements have been modelled with a finite element commercial software (AC/DC and Radio-Frequency modules of Comsol Multiphysics). A levee situated in Orléans (France) along the Loire river has been considered in order to design a model taking into account the skin depth and the incident wavelength. The effect of the incident electromagnetic field direction has been assessed with two different incident wave directions: BBC 5 from Salford (UK) and France-Inter from Allouis (France). The simulations highlight the tri-dimensional effects of the topography in the apparent resistivity, observed on the crest of the levee, depending on the incident field direction and topography. For the Slingram method, the magnetic field has been simulated using the AC/DC module of Comsol. The ratio of the primary magnetic field on the secondary one, received in a loop is determined above a straight levee. The study aims to show the various responses obtained in function of both vertical and horizontal coil configurations. We show that the signal also depends on the topography and the right configuration of the coils alignment with respect to the levee stretch direction. In this study, a buried gas pipe is also characterized by the two methods. Numerical modelling of 3D electromagnetic effects on geophysical signals helps to interpret the field measurements and offers to the stakeholder an optimized methodology for geophysical surveys on levees.

  5. Geomorphic Response to Global Warming in the Anthropocene: Levee Breaches in California's Sacramento-San Joaquin Watershed

    NASA Astrophysics Data System (ADS)

    Florsheim, J. L.; Dettinger, M.; Malamud-Roam, F.; Ingram, B.; Mount, J.

    2006-12-01

    Geomorphic processes in rivers are likely to be influenced by global warming through alterations of flood, erosion, and sedimentation processes and rates. In California's Sierra Nevada, warming scenarios imply future increases in magnitudes and durations (and changes in timing) of floods as snow packs diminish and rainfall runoff increasingly dominates flow into the Central Valley fluvial system. Geomorphic processes are likely to differ from processes that dominated during the Holocene due to the influence both of projected global warming and land use alterations including levee construction that narrows and separates Sacramento-San Joaquin Rivers and tributaries from floodplains and flow regulation downstream of numerous large dams. Whereas Holocene floods induced overbank flow and avulsion processes that led to vertical floodplain accretion and variability of stages in aggrading multiple-channel systems, modern floods largely transport flow and sediment within incised channels confined by levees. Because the scenarios of warming are developed at coarse scales, only an understanding of the relations between large-scale hydrology and climate on the one hand, and the incidence of levee breaches on the other, will make it possible to project likely geomorphic responses to future warming and flooding. A historical record of catastrophic levee breaks on the Sacramento and San Joaquin Rivers has been developed to allow analyses of these connections. In the current work, we develop statistical relations between historical levee break events and flow discharge, as well as with climatic phenomena such as El Nino and La Nina phases of the ENSO cycle, positive and negative phases of the Pacific Decadal Oscillation, and seasonal propensities towards "pineapple-express" storms. Preliminary results suggest strong relations between levee breaches and discharge, but poor relations to ENSO. Further investigation of these data will provide insight to help inform models and river

  6. The influence of woody plants on the seepage of flood protection levees: Experiences from a test site

    NASA Astrophysics Data System (ADS)

    Lammeranner, W.; Meixner, H.; Florineth, F.

    2009-04-01

    The past flood events have once more drawn the attention to the stability and maintenance of flood protection levees. The attention has also been focused on the relationship between vegetation and the structural integrity of dikes. Current standards regard dense turf to be safest vegetation cover for dikes. Many guidelines ban woody vegetation from dikes and levees to provide structural integrity, visual inspection and unhindered flood-fight access. The refusal of woody plants is mainly based on the argument that root penetration of woody plants facilitates water movement along their path. Within the frame of a research project carried out by the Institute of Soil Bioengineering and Landscape Construction (University of Natural Resources and Applied Life Sciences, Vienna), focusing on woody plants on levees, the effects of small to medium growing woody (shrubby) plants on the seepage are tested. Data are drawn from two natural-scaled research levees. The homogenous levees consist of a mineral silt-sand-gravel and have a fill height of 2.7 m and a slope inclination of 2:3. The tests investigate the impact of woody plants (living brush mattress - transversal) in comparison to compact turf (jute netting mulch seeding). Measured plant parameters, characterising the vegetation structures were shoot lengths, shoot diameters, and above ground biomass. Root growth is investigated in an extra plot area allowing excavation of the plants. Percolation is monitored using seepage monitoring pipes, soil moisture sensors and soil temperature probes, which were build into the embankment during construction. The proposed contribution discusses the effects of woody plants (shrubs) on seepage of flood protection levees. Methodology of research and results after three initial seepage tests are presented.

  7. Geophysical Characterization of the American River Levees, Sacramento, California, using Electromagnetics, Capacitively Coupled Resistivity, and DC Resistivity

    USGS Publications Warehouse

    Asch, Theodore H.; Deszcz-Pan, Maria; Burton, Bethany L.; Ball, Lyndsay B.

    2008-01-01

    A geophysical characterization of a portion of American River levees in Sacramento, California was conducted in May, 2007. Targets of interest included the distribution and thickness of sand lenses that underlie the levees and the depth to a clay unit that underlies the sand. The concern is that the erosion of these sand lenses can lead to levee failure in highly populated areas of Sacramento. DC resistivity (Geometric?s OhmMapper and Advanced Geosciences, Inc.?s SuperSting R8 systems) and electromagnetic surveys (Geophex?s GEM-2) were conducted over a 6 mile length of the levee on roads and bicycle and horse trails. 2-D inversions were conducted on all the geophysical data. The OhmMapper and SuperSting surveys produced consistent inversion results that delineated potential sand and clay units. GEM-2 apparent resistivity data were consistent with the DC inversion results. However, the GEM-2 data could not be inverted due to low electromagnetic response levels, high ambient electromagnetic noise, and large system drifts. While this would not be as large a problem in conductive terrains, it is a problem for a small induction number electromagnetic profiling system such as the GEM-2 in a resistive terrain (the sand lenses). An integrated interpretation of the geophysical data acquired in this investigation is presented in this report that includes delineation of those areas consisting of predominantly sand and those areas consisting predominantly of clay. In general, along most of this part of the American River levee system, sand lenses are located closest to the river and clay deposits are located further away from the river. The interpreted thicknesses of the detected sand deposits are variable and range from 10 ft up to 60 ft. Thus, despite issues with the GEM-2 inversion, this geophysical investigation successfully delineated sand lenses and clay deposits along the American River levee system and the approximate depths to underlying clay zones. The results of

  8. Characterizing land surface change and levee stability in the Sacramento-San Joaquin Delta using UAVSAR radar imagery

    USGS Publications Warehouse

    Jones, C.; Bawden, G.; Deverel, S.; Dudas, J.; Hensley, S.

    2011-01-01

    The islands of the Sacramento-San Joaquin Delta have been subject to subsidence since they were first reclaimed from the estuary marshlands starting over 100 years ago, with most of the land currently lying below mean sea level. This area, which is the primary water resource of the state of California, is under constant threat of inundation from levee failure. Since July 2009, we have been imaging the area using the quad-polarimetric UAVSAR L-band radar, with eighteen data sets collected as of April 2011. Here we report results of our polarimetric and differential interferometric analysis of the data for levee deformation and land surface change. ?? 2011 IEEE.

  9. Analyses of water, core material, and elutriate samples collected near Sicily Island, Louisiana (Sicily Island area levee project)

    USGS Publications Warehouse

    Demcheck, Dennis K.; Dupuy, Alton J.

    1980-01-01

    Samples consisting of composited core material were collected from five areas by the U.S. Army Corps of Engineers and analyzed by the U.S. Geological Survey to provide data on the impact of proposed channel excavation and levee construction in the Sicily Island area, Louisiana. Samples of receiving water from the five areas, selected to represent the water that will contact the proposed dredged material of the levee fill material, also were collected. Chemical and physical analyses were performed on samples of core material and native water and on elutriate samples of specific core material-receiving water mixtures. The results of these analyses are presented without interpretation. (USGS)

  10. Capacitively coupled resistivity survey of the levee surrounding the Omaha Public Power District Nebraska City Power Plant, June 2011

    USGS Publications Warehouse

    Burton, Bethany L.; Cannia, James C.

    2011-01-01

    This report is a release of digital data from a capacitively coupled resistivity survey conducted on June 13, 2011, on the flood-protection levees surrounding the Omaha Public Power District Nebraska City power plant. The U.S. Geological Survey Crustal Geophysics and Geochemistry Science Center and the Nebraska Water Science Center performed the survey in response to a flood on the Missouri River. A single line of resistivity profiling was completed along the center line of the section of levee 573 that surrounds the power plant.

  11. Utilizing Radar Remote Sensing to Assess the Water Extent along River Levees

    NASA Astrophysics Data System (ADS)

    Laygo, K.; Madson, A.; O'Connell, K.; Jones, C. E.; Holt, B.

    2012-12-01

    Every spring, precipitation and snowmelt in the central U.S. leads to high water levels in the Mississippi River and its tributaries, with concurrent flooding and levee damage a near-yearly event. In the spring of 2011, historic water levels led to extensive flooding from Mississippi County, Missouri, to southern Louisiana, necessitating the opening of three major spillways, including the Morganza Spillway north of New Orleans, which diverts water from the Mississippi River through the Atchafalaya Basin of central Louisiana and had not been used since 1973. There is value to NOAA, the agency responsible for flood prediction, and the Army Corp. of Engineers, the agency responsible for flood control, in the application of remote sensing to flood mapping and soil moisture mapping, both along the main rivers and levee systems. We plan to use high resolution radar (NASA UAVSAR - Uninhabited Aerial Vehicle Synthetic Aperture Radar), with a particular focus on increased soil moisture mapping in order to determine how quickly and accurately areas of increased soil moisture content associated with levee seepage and sandboils can be delineated. We have several UAVSAR data sets collected along the Mississippi River during June 2009, April and June 2011, which we have analyzed for soil moisture detection algorithm development during the Spring 2012 term. Our goal for part 2 of the study is to develop an algorithm to detect areas of increased soil moisture, and to finalize flood map end products for decision makers based on an easily applied algorithm that utilizes a standard analysis package for water extent measurement along waterways, which will be usable by non-experts with widely available software.River Gage Datat; As mentioned in the section above, river gage data was utilized to help determine the best UAVSAR datset to use for algorithm and processing methodology creation. The table below shows river gage readings with their corresponding UAVSAR flight ID. The datasets

  12. Variability in form and growth of sediment waves on turbidite channel levees

    USGS Publications Warehouse

    Normark, W.R.; Piper, D.J.W.; Posamentier, H.; Pirmez, C.; Migeon, S.

    2002-01-01

    Fine-grained sediment waves have been observed in many modern turbidite systems, generally restricted to the overbank depositional element. Sediment waves developed on six submarine fan systems are compared using high-resolution seismic-reflection profiles, sediment core samples (including ODP drilling), multibeam bathymetry, 3D seismic-reflection imaging (including examples of burried features), and direct measurements of turbidity currents that overflow their channels. These submarine fan examples extend over more than three orders of magnitude in physical scale. The presence or absence of sediment waves is not simply a matter of either the size of the turbidite channel-levee systems or the dominant initiation process for the turbidity currents that overflow the channels to form the wave fields. Both sediment-core data and seismic-reflection profiles document the upslope migration of the wave forms, with thicker and coarser beds deposited on the up-current flank of the waves. Some wave fields are orthogonal to channel trend and were initiated by large flows whose direction was controlled by upflow morphology, whereas fields subparallel to channel levees resulted from local spillover. In highly meandering systems, sediment waves may mimic meander planform. Larger sediment waves form on channel-levee systems with thicker overflow of turbidity currents, but available data indicate that sediment waves can be maintaned during conditions of relatively thin overflow. Coarser-grained units in sediment waves are typically laminated and thin-bedded sand as much as several centimetres thick, but sand beds as thick as several tens of centimetres have been documented from both modern and buried systems. Current production of hydrocarbons from sediment-wave deposits suggests that it is important to develop criteria for recognising this overbank element in outcrop exposures and borehole data, where the wavelength of typical waves (several kilometres) generally exceeds outcrop

  13. Sediment waves on the Monterey fan levee: a preliminary physical interpretation.

    USGS Publications Warehouse

    Normark, W.R.; Hess, G.R.; Stow, D.A.V.; Bowen, A.J.

    1980-01-01

    A detailed survey of a 30 km2 area of abyssal-depth sediment waves associated with the levee of the Monterey fan valley shows a pattern of sinuous crests and troughs with parallel, well-bedded internal structure. Material in the upper 1 m of sediment consists predominantly of bioturbated, muddy coccolith ooze. A single thin, silty horizon can be correlated between adjoining waves. The sediment waves are considered to be formed most likely by low-velocity (10 cm/s), low-concentration turbidity flows approximately 100-800 m thick. This interpretation emphasizes the role of low-speed, low-concentration turbidity currents in the downslope movement of fine-grained material.- from Authors

  14. Possibilities for Using LIDAR and Photogrammetric Data Obtained with AN Unmanned Aerial Vehicle for Levee Monitoring

    NASA Astrophysics Data System (ADS)

    Bakuła, K.; Ostrowski, W.; Szender, M.; Plutecki, W.; Salach, A.; Górski, K.

    2016-06-01

    This paper presents the possibilities for using an unmanned aerial system for evaluation of the condition of levees. The unmanned aerial system is equipped with two types of sensor. One is an ultra-light laser scanner, integrated with a GNSS receiver and an INS system; the other sensor is a digital camera that acquires data with stereoscopic coverage. Sensors have been mounted on the multirotor, unmanned platform the Hawk Moth, constructed by MSP company. LiDAR data and images of levees the length of several hundred metres were acquired during testing of the platform. Flights were performed in several variants. Control points measured with the use of the GNSS technique were considered as reference data. The obtained results are presented in this paper; the methodology of processing the acquired LiDAR data, which increase in accuracy when low accuracy of the navigation systems occurs as a result of systematic errors, is also discussed. The Iterative Closest Point (ICP) algorithm, as well as measurements of control points, were used to georeference the LiDAR data. Final accuracy in the order of centimetres was obtained for generation of the digital terrain model. The final products of the proposed UAV data processing are digital elevation models, an orthophotomap and colour point clouds. The authors conclude that such a platform offers wide possibilities for low-budget flights to deliver the data, which may compete with typical direct surveying measurements performed during monitoring of such objects. However, the biggest advantage is the density and continuity of data, which allows for detection of changes in objects being monitored.

  15. Losses of surface runoff, total solids, and nitrogen during bermudagrass establishment on levee embankments.

    PubMed

    Burwell, Robert W; Beasley, Jeffrey S; Gaston, Lewis A; Borst, Steven M; Sheffield, Ron E; Strahan, Ron E; Munshaw, Gregg C

    2011-01-01

    Nutrient and sediment runoff from newly constructed levee embankments pose a threat to water quality during soft armor vegetation establishment. Research was initiated in 2008 and 2009 to evaluate the effect of bermudagrass ( L.) coverage and N source on nutrient and sediment runoff from levee embankments during establishment. Bermudagrass plots were seeded at 195.3 kg pure live seed ha and fertilized at 50 kg N ha using a water-soluble N source, urea or NH-NO, or slow-release N source, S-coated urea (SCU) or urea formaldehyde (UF), with controls unfertilized. Vegetative cover percentage, time until the onset of runoff, runoff volume, and total solids (TS), NO-N, and NH-N concentrations were measured from simulated and natural rainfall events for 70 d in 2008 and 56 d in 2009. Bermudagrass at 90% grass cover delayed the onset of runoff an additional 441 to 538 s and reduced runoff volumes 74 to 84% of that exhibited at 10% grass cover. Nitrogen fertilizers did not accelerate bermudagrass growth sufficiently, however, to reduce TS loading compared with unfertilized bermudagrass in either year of the study. The application of urea and SCU resulted in cumulative N losses of 2.45 and 3.13 kg ha compared with 1.59 kg ha from the unfertilized bermudagrass in 2008, and 1.73 kg ha from NH-NO vs. 0.24 kg ha from controls in 2009. Only UF increased bermudagrass establishment without increasing cumulative N losses compared with unfertilized bermudagrass. Therefore, the benefit of greater erosion and runoff resistance expected from N-accelerated vegetative growth did not occur but had the unintended consequence of higher N losses when water-soluble N and SCU fertilizers were applied. PMID:21712593

  16. Losses of surface runoff, total solids, and nitrogen during bermudagrass establishment on levee embankments.

    PubMed

    Burwell, Robert W; Beasley, Jeffrey S; Gaston, Lewis A; Borst, Steven M; Sheffield, Ron E; Strahan, Ron E; Munshaw, Gregg C

    2011-01-01

    Nutrient and sediment runoff from newly constructed levee embankments pose a threat to water quality during soft armor vegetation establishment. Research was initiated in 2008 and 2009 to evaluate the effect of bermudagrass ( L.) coverage and N source on nutrient and sediment runoff from levee embankments during establishment. Bermudagrass plots were seeded at 195.3 kg pure live seed ha and fertilized at 50 kg N ha using a water-soluble N source, urea or NH-NO, or slow-release N source, S-coated urea (SCU) or urea formaldehyde (UF), with controls unfertilized. Vegetative cover percentage, time until the onset of runoff, runoff volume, and total solids (TS), NO-N, and NH-N concentrations were measured from simulated and natural rainfall events for 70 d in 2008 and 56 d in 2009. Bermudagrass at 90% grass cover delayed the onset of runoff an additional 441 to 538 s and reduced runoff volumes 74 to 84% of that exhibited at 10% grass cover. Nitrogen fertilizers did not accelerate bermudagrass growth sufficiently, however, to reduce TS loading compared with unfertilized bermudagrass in either year of the study. The application of urea and SCU resulted in cumulative N losses of 2.45 and 3.13 kg ha compared with 1.59 kg ha from the unfertilized bermudagrass in 2008, and 1.73 kg ha from NH-NO vs. 0.24 kg ha from controls in 2009. Only UF increased bermudagrass establishment without increasing cumulative N losses compared with unfertilized bermudagrass. Therefore, the benefit of greater erosion and runoff resistance expected from N-accelerated vegetative growth did not occur but had the unintended consequence of higher N losses when water-soluble N and SCU fertilizers were applied.

  17. Elemental chemistry of sand-boil discharge used to trace variable pathways of seepage beneath levees during the 2011 Mississippi River flood

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water samples were collected from the Mississippi River, from sand boils near the toe of the levee on the Mississippi side of the river, and from actively flowing relief wells shortly after peak stage of the 2011 Mississippi River flood. Two distinct pathways for seepage under the levee were identif...

  18. Improvements in the Weeding of Levee Slope of Terraced Paddy Fields with Statutory Regulation of Places of Scenic Beauty

    NASA Astrophysics Data System (ADS)

    Uchikawa, Yoshiyuki; Kimura, Kazuhiro; Hirata, Ayumi

    A growing number of terraced paddy fields in Japan are being conserved as cultural assets like places of scenic beauty. This has meant that the task of weeding levee slope of these terraced paddy fields has become increasingly important, not only for general maintenance of the terraced paddy fields, but also because of the impact landscape, vegetation and the surrounding environment. However, the steep gradient of the levee slope and lack of footholds mean that the workability and safety associated with this weeding work is problematic. In addition, in the event that an area has been designated as a cultural asset, there are restrictions regarding how it can be modified and local farmers are reluctant to change their traditional farming methods in such cases. This study therefore sought to clarify the actual condition of the levee slope weeding work undertaken in the places of scenic beauty Obasute Tanada district. Empirical validations of potential measures for reforming the work environment were evaluated based on the findings of this investigation. We demonstrated that it is possible to modify current work practices while still maintaining and preserving the terraced paddy fields, even in designated scenic locations. To improve the working environment for levee slope weeding, we propose creating berms to serve as footholds at the toes of slopes.

  19. Application of ground penetrating radar in detecting the hazards and risks of termites and ants in soil levees.

    PubMed

    Yang, Xiuhao; Henderson, Gregg; Mao, Lixin; Evans, Ahmad

    2009-08-01

    A ground penetrating radar (GPR) technique was used to detect Formosan subterranean termite (Coptotermes formosanus) and red imported fire ant (Solenopsis invicta) hazards and risks (targets) in a soil levee at the London Avenue Canal in New Orleans, LA. To make this assessment, GPR signal scans were examined for features produced by termite or ant activities and potential sources of food and shelter such as nests, tree roots, and voids (tunnels). The total scanned length of the soil levee was 4,125 m. The average velocity and effective depth of the radar penetration was 0.080 m/ns and 0.61 m, respectively. Four hundred twenty-seven targets were identified. Tree roots (38), voids (31), fire ant nests (209), and metal objects (149) were detected, but no Formosan termite carton nests were identified. The lack of identified termite nests may be related to drowning events at the time to the flood. Based on the target density (TD), the two new floodwall and levee sections that were rebuilt or reinforced after they were destroyed by Hurricane Katrina in 2005 were determined to be at low potential risk from termites and ants. A merging target density (MTD) method indicated a high potential risk near one of the breached sections still remains. Foraging and nesting activity of Formosan subterranean termites and red imported fire ants may be a contributory factor to the levee failure at the London Avenue Canal. PMID:19689906

  20. The Routing and Re-Routing of Difficult Knowledge: Social Studies Teachers Encounter "When the Levees Broke"

    ERIC Educational Resources Information Center

    Garrett, H. James

    2011-01-01

    The author explores the articulations of six social studies student/teachers after a viewing of "When the Levees Broke: A Requiem in Four Acts". The film, a documentary about the aftermath of Hurricane Katrina on the people in and around New Orleans, constitutes an encounter with what Deborah Britzman (1998) calls "difficult…

  1. BUDDA (Bulge/Disk Decomposition Analysis) - um novo programa para análise estrutural de galáxias

    NASA Astrophysics Data System (ADS)

    Gadotti, D. A.; de Souza, R. E.; Dos Anjos, S.

    2003-08-01

    Tem sido prática comum nos últimos anos estudar a distribuição de luminosidade em galáxias fazendo uso da informação contida em toda a imagem da galáxia, já que esta técnica tem se mostrado muito mais confiável do que o simples ajuste de perfis radiais de luminosidade. Através destes estudos bidimensionais, melhores resultados tem sido obtidos na análise e.g. do Plano Fundamental, de correlações entre os parâmetros estruturais de galáxias, de sub-estruturas como barras e anéis nucleares etc. Apresentamos um novo código bidimensional, o BUDDA, de análise estrutural de galáxias, que será disponibilizado para a comunidade. Desenvolvido por nós, o código determina os parâmetros estruturais de galáxias de forma prática e robusta, e pode ser aplicado genericamente em qualquer estudo sobre a formação, evolução e estrutura de galáxias. O programa ainda permite a avaliação direta de sub-estruturas, através de imagens residuais que são obtidas ao se subtrair, das imagens originais, bojo e disco sintéticos que melhor representam essas componentes da galáxia sob consideração. Será apresentada a forma de utilização do código, bem como séries de testes que atestam a sua funcionalidade. Além disso, os resultados da aplicação do código em uma amostra de 51 galáxias serão expostos como exemplo prático, e do seu enorme potencial de uso.

  2. Evaluation of the use of reach transmissivity to quantify leakage beneath Levee 31N, Miami-Dade County, Florida

    USGS Publications Warehouse

    Nemeth, Mark S.; Wilcox, Walter M.; Solo-Gabriele, Helena M.

    2000-01-01

    A coupled ground- and surface-water model (MODBRANCH) was developed to estimate ground-water flow beneath Levee 31N in Miami-Dade County, Florida, and to simulate hydrologic conditions in the surrounding area. The study included compilation of data from monitoring stations, measurement of vertical seepage rates in wetlands, and analysis of the hydrogeologic properties of the ground-water aquifer within the study area. In addition, the MODBRANCH code was modified to calculate the exchange between surface-water channels and ground water using a relation based on the concept of reach transmissivity. The modified reach-transmissivity version of the MODBRANCH code was successfully tested on three simple problems with known analytical solutions. It was also tested and determined to function adequately on one field problem that had previously been solved using the unmodified version of the software. The modified version of MODBRANCH was judged to have performed satisfactorily, and it required about 60 percent as many iterations to reach a solution. Additionally, its input parameters are more physically-based and less dependent on model-grid spacing. A model of the Levee 31N area was developed and used with the original and modified versions of MODBRANCH, which produced similar output. The mean annual modeled ground-water heads differed by only 0.02 foot, and the mean annual canal discharge differed by less than 1.0 cubic foot per second. Seepage meters were used to quantify vertical seepage rates in the Everglades wetlands area west of Levee 31N. A comparison between results from the seepage meters and from the computer model indicated substantial differences that seemed to be a result of local variations in the hydraulic properties in the topmost part of the Biscayne aquifer. The transmissivity of the Biscayne aquifer was estimated to be 1,400,000 square feet per day in the study area. The computer model was employed to simulate seepage of ground water beneath Levee 31N

  3. Effect of a levee setback on aquatic resources using two-dimensional flow and bioenergetics models

    USGS Publications Warehouse

    Black, Robert W.; Czuba, Christiana R.; Magirl, Christopher S.; McCarthy, Sarah; Berge, Hans; Comanor, Kyle

    2016-04-05

    Watershed restoration is the focus of many resource managers and can include a multitude of restoration actions each with specific restoration objectives. For the White River flowing through the cities of Pacific and Sumner, Washington, a levee setback has been proposed to reconnect the river with its historical floodplain to help reduce flood risks, as well as provide increased habitat for federally listed species of salmonids. The study presented here documents the use of a modeling framework that integrates two-dimensional hydraulic modeling with process-based bioenergetics modeling for predicting how changes in flow from reconnecting the river with its floodplain affects invertebrate drift density and the net rate of energy intake of juvenile salmonids. Modeling results were calculated for flows of 25.9 and 49.3 cubic meters per second during the spring, summer, and fall. Predicted hypothetical future mean velocities and depths were significantly lower and more variable when compared to current conditions. The abundance of low energetic cost and positive growth locations for salmonids were predicted to increase significantly in the study reach following floodplain reconnection, particularly during the summer. This modeling framework presents a viable approach for evaluating the potential fisheries benefits of reconnecting a river to its historical floodplain that integrates our understanding of hydraulic, geomorphology, and organismal biology.

  4. Three-dimensional imaging, change detection, and stability assessment during the centerline trench levee seepage experiment using terrestrial light detection and ranging technology, Twitchell Island, California, 2012

    USGS Publications Warehouse

    Bawden, Gerald W.; Howle, James; Bond, Sandra; Shriro, Michelle; Buck, Peter

    2014-01-01

    A full scale field seepage test was conducted on a north-south trending levee segment of a now bypassed old meander belt on Twitchell Island, California, to understand the effects of live and decaying root systems on levee seepage and slope stability. The field test in May 2012 was centered on a north-south trench with two segments: a shorter control segment and a longer seepage test segment. The complete length of the trench area measured 40.4 meters (m) near the levee centerline with mature trees located on the waterside and landside of the levee flanks. The levee was instrumented with piezometers and tensiometers to measure positive and negative porewater pressures across the levee after the trench was flooded with water and held at a constant hydraulic head during the seepage test—the results from this component of the experiment are not discussed in this report. We collected more than one billion three-dimensional light detection and ranging (lidar) data points before, during, and after the centerline seepage test to assess centimeter-scale stability of the two trees and the levee crown. During the seepage test, the waterside tree toppled (rotated 20.7 degrees) into the water. The landside tree rotated away from the levee by 5 centimeters (cm) at a height of 2 m on the tree. The paved surface of the levee crown had three regions that showed subsidence on the waterside of the trench—discussed as the northern, central, and southern features. The northern feature is an elongate region that subsided 2.1 cm over an area with an average width of 1.35 m that extends 15.8 m parallel to the trench from the northern end of the trench to just north of the trench midpoint, and is associated with a crack 1 cm in height that formed during the seepage test on the trench wall. The central subsidence feature is a semicircular region on the waterside of the trench that subsided by as much as 6.2 cm over an area 3.4 m wide and 11.2 m long. The southern feature is an elongate

  5. Characterizing Land Surface Change and Levee Stability in the Sacramento-San Joaquin Delta Using UAVSAR Radar Imagery

    NASA Technical Reports Server (NTRS)

    Jones, Cathleen; Bawden, Gerald; Deverel, Steven; Dudas, Joel; Hensley, Scott

    2011-01-01

    The Sacramento-San Joaquin Delta is one of the primary water sources for the state of California and represents a complex geographical area comprised of tidal marshland, levee rimmed islands that are used primarily for agriculture, and urban encroachment. Land subsidence has dropped many of the Delta islands 3 to >7 meters below mean sea level and requires nearly 1700 km of levees to maintain the integrity of the islands and flow of water through the Delta. The current average subsidence rates for each island varies, with 1.23 cm/yr on Sherman Island and 2.2 cm/yr for Bacon Island, as determined by ground-based instruments located at isolated points in the Delta. The Delta's status as the most critical water resource for the state, an endangered ecosystem, and an area continuously threatened with levee breakage from hydrostatic pressure and the danger of earthquakes on several major faults in the San Francisco area make it a focus of monitoring efforts by both the state and national government. This activity is now almost entirely done by ground-based efforts, but the benefits of using remote sensing for wide scale spatial coverage and frequent temporal coverage is obvious. The UAVSAR airborne polarimetric and differential interferometric L-band synthetic aperture radar system has been used to collected monthly images of the Sacramento-San Joaquin Delta and much of the adjacent Suisun Marsh since July 2009 to characterize levee stability, image spatially varied subsidence, and assess how well the UAVSAR performs in an area with widespread agriculture production.

  6. Evaluating the Effects of Constriction by Levees on a Dynamic Gravel-Bed River through Morphological Sediment Budgeting and Bed Mobility Studies, Snake River, WY

    NASA Astrophysics Data System (ADS)

    Leonard, C.; Legleiter, C. J.

    2014-12-01

    High-energy gravel-bed rivers are subject to a range of management practices used to control the system's dynamic behavior. The Snake River, near Jackson, WY, offers an opportunity to study the morphological effects of management practices through a comparison of a reach confined by levees to an unmanaged reach just upstream within Grand Teton National Park (GTNP). I hypothesize that levees have reduced sediment supply by disconnecting the river from its banks and increased transport capacity by increasing flow velocity. Together, these effects accentuate the sediment deficit in the leveed reach. To test this I am developing a morphological sediment budget from GTNP to Wilson, WY, using LiDAR data from 2007 and 2012. This analysis will yield insight as to how sediment transport varies between the relatively natural reach in GTNP and the leveed reach downstream. A problem inherent to morphological budgets is the inability to decipher when change occurs within the budget timeframe. To combat this, a partial mobility study was executed using 300 PIT tagged gravels within the leveed reach. Gravels were relocated to decipher how bed mobility and sediment transport varied with grain size under a range of hydraulic conditions. These results are then used to estimate a critical discharge representing the inception of bed motion and geomorphic change. The critical discharge will be used to reconstruct the timing of bed mobility based on streamflow records and thus deconvolve when morphological change occurred during the sediment budget period. I further hypothesize that a greater imbalance between transport capacity and sediment supply in the leveed reach causes the bed to armor, resulting in larger critical shear stresses and implying that the bed will be mobilized only during greater discharge events. To test this hypothesis I will measure armor ratios within the leveed reach and examine how bed mobility differs between the two reaches by comparing the results of our

  7. Application of Ground Penetrating Radar Surveys and GPS Surveys for Monitoring the Condition of Levees and Dykes

    NASA Astrophysics Data System (ADS)

    Tanajewski, Dariusz; Bakuła, Mieczysław

    2016-08-01

    This paper analyses the possibility of using integrated GPS (Global Positioning System) surveys and ground penetrating radar surveys to precisely locate damages to levees, particularly due to the activity of small fossorial mammals. The technology of intercommunication between ground penetrating radar (GPR) and an RTK (Real-Time Kinematic) survey unit, and the method of data combination, are presented. The errors which may appear during the survey work are also characterized. The procedure for processing the data so that the final results have a spatial character and are ready to be implemented in digital maps and geographic information systems (GIS) is also described.

  8. An experimental investigation of the dynamics of submarine leveed channel initiation as sediment-laden density currents experience sudden unconfinement

    SciTech Connect

    Rowland, Joel C; Hilley, George E; Fildani, Andrea

    2009-01-01

    Leveed submarine channels play a critical role in the transfer of sediment from the upper continental slopes to interslope basins and ultimately deepwater settings. Despite a reasonable understanding of how these channels grow once established, how such channels initiate on previously unchannelized portions of the seafloor remains poorly understood. We conducted a series of experiments that elucidate the influence of excess density relative to flow velocity on the dynamics of, and depositional morphologies arising from, density currents undergoing sudden unconfinement across a sloped bed. Experimental currents transported only suspended sediment across a non-erodible substrate. Under flow conditions ranging from supercritical to subcritical (bulk Richardson numbers of 0.02 to 1.2) our experiments failed to produce deposits resembling or exhibiting the potential to evolve into self-formed leveed channels. In the absence of excess density, a submerged sediment-laden flow produced sharp crested lateral deposits bounding the margins of the flow for approximately a distance of two outlet widths down basin. These lateral deposits terminated in a centerline deposit that greatly exceeded marginal deposits in thickness. As excess density increased relative to the outlet velocity, the rate of lateral spreading of the flow increased relative to the downstream propagation of the density current, transitioning from a narrow flow aligned with the channel outlet to a broad radially expanding flow. Coincident with these changes in flow dynamics, the bounding lateral deposits extended for shorter distances, had lower, more poorly defined crests that were increasingly wider in separation than the initial outlet, and progressively became more oblong rather than linear. Based on our results, we conclude that leveed channels cannot initiate from sediment-laden density currents under strictly depositional conditions. Partial confinement of these currents appears to be necessary to

  9. Vertical Accretion of the Rain Forest Floodplains and Levees: the Formation of Rias from Interaction of Black and White River Types in the Amazon River System.

    NASA Astrophysics Data System (ADS)

    Ori, G.; Franzinelli, E.

    2006-12-01

    The Amazon river system is dominated by the presence of rias, that is plaeovalleys paretially filled by sediment and harbouring almost standing bodies of water. Since the seminal work of Harald Sioli, it has been clear the paleovalleys have been formed in rivers (black type) poor in sediment and rich in organic matter during low stand periods of the sea level. Subsequently, the rivers rich in sediment (white type) damming of their mouths by the vertical accretion of the rivers rich in sediments (white type). This pattern is present in other rain forest fluvial systems and a good example is the Murray Lake in Papua New Guinea. These relations show that of the flood plain in tropical rain forest systems is strongly dominated by vertical accretion. This fact is also confirmed by the ubiquitous presence of levees inside channels (e.g. Rio Trombettas). Levees accrete vertically by the addition of single layers of sediment mostly entrapped by vegetation. The formation of permanent crevasse splays is also contributing to the levee accretion. Secondary channels are perched over the floodplain interface and totally bounded by levees. Consequently, the floodplain is dominated by lakes, permanent crevasse splays and levees assembled in vertical stacked bodies. The geological record shows examples of rain forest floodplains with similar facies and stratigraphic patterns..

  10. The Transition of Benthic Nutrient Sources after Planned Levee Breaches Adjacent to Upper Klamath and Agency Lakes, Oregon

    USGS Publications Warehouse

    Kuwabara, James S.; Topping, Brent R.; Carter, James L.; Parcheso, Francis; Cameron, Jason M.; Asbill, Jessica R.; Fend, Steven V.; Duff, John H.; Engelstad, Anita C.

    2010-01-01

    Four sampling trips were coordinated after planned levee breaches that hydrologically reconnected both Upper Klamath Lake and Agency Lake, Oregon, to adjacent wetlands. Sets of nonmetallic pore-water profilers were deployed during these trips in November 2007, June 2008, May 2009, and July 2009. Deployments temporally spanned the annual cyanophyte bloom of Aphanizomenon flos-aquae (AFA) and spatially involved three lake and four wetland sites. Profilers, typically deployed in triplicate at each lake or wetland site, provided high-resolution (centimeter-scale) estimates of the vertical concentration gradients for diffusive-flux determinations. Estimates based on molecular diffusion may underestimate benthic flux because solute transport across the sediment-water interface can be enhanced by processes including bioturbation, bioirrigation and groundwater advection. Water-column and benthic samples were also collected to help interpret spatial and temporal trends in diffusive-flux estimates. Data from these samples complement taxonomic and geochemical analyses of bottom-sediments taken from Upper Klamath Lake (UKL) in prior studies. This ongoing study provides information necessary for developing process-interdependent solute-transport models for the watershed (that is, models integrating physical, geochemical, and biological processes) and supports efforts to evaluate remediation or load-allocation strategies. To augment studies funded by the U.S. Bureau of Reclamation (USBR), the Department of the Interior supported an additional full deployment of pore-water profilers in November 2007 and July 2009, immediately following the levee breaches and after the crash of the annual summer AFA bloom. As observed consistently since 2006, benthic flux of 0.2-micron filtered, soluble reactive phosphorus (that is, biologically available phosphorus, primarily as orthophosphate; SRP) was consistently positive (that is, out of the sediment into the overlying water column) and

  11. First discovery of channel-levee complexes in a modern deep-water carbonate slope environment in Bahamas

    NASA Astrophysics Data System (ADS)

    Mulder, Thierry; Ducassou, Emmanuelle; Gillet, Hervé; Hanquiez, Vincent; Principaud, Mélanie; Eberli, Gregor; Kindler, Pascal; Chabaud, Ludivine; Gonthier, Eliane; Fournier, François; Léonide, Philippe; Borgomano, Jean

    2014-05-01

    New high-quality very-high-resolution seismic data along the western slope of the Great Bahama Bank reveals the presence of the first modern channel-levee complex developed in a pure carbonate setting along the western slope of the Gran Bahama Bank (Andros Island, Bahamas). This complex has presently a very subtle morphology on the actual seafloor. The last complex grew over two buried complexes separated by erosion surfaces suggesting both the continuity of downslope gravity-driven processes along this carbonate slope, and the channel migration through avulsion processes similar to what happens along a siliciclastic slope. Complex morphology and geometry are similar to analogs described in siliciclastic systems but size of the presented carbonate complex is substantially smaller (length = 9 km; width = 4 km). Both high-resolution seismics and core studies show that this complex was built by the stacking of gravity-flow deposits, including turbidites, but it is presently inactive and buried by deposits resulting from hemipelagic fallout or low-energy density processes channeled by the gully network, which are permanently reworked by along-slope bottom currents dominated by internal tides. The channel-levee surface is now covered with antidune-like bedforms probably related to density-cascading-induced downslope currents. The recent and present channel dissymmetry is probably related to the activity of the northward moving Santaren current. The discovery of channel-levee complexes has major implications both on the conceptual models describing the behavior of carbonate slope systems and on hydrocarbon exploration by enhancing the reservoir-bearing potential of carbonate slopes. In addition, these finding can have impact on living benthic biologic community (such as those occupying deep-sea carbonate mound, because a part of nutriments could be supplied by turbidity. Finally, importance of turbidity currents in remolding carbonate slope can also impact the Global

  12. Morphological Analyses and Simulated Flood Elevations in a Watershed with Dredged and Leveed Stream Channels, Wheeling Creek, Eastern Ohio

    USGS Publications Warehouse

    Sherwood, James M.; Huitger, Carrie A.; Ebner, Andrew D.; Koltun, G.F.

    2008-01-01

    The USGS, in cooperation with the Ohio Emergency Management Agency, conducted a study in the Wheeling Creek Basin to (1) evaluate and contrast land-cover characteristics from 2001 with characteristics from 1979 and 1992; (2) compare current streambed elevation, slope, and geometry with conditions present in the late 1980s; (3) look for evidence of channel filling and over widening in selected undredged reaches; (4) estimate flood elevations for existing conditions in both undredged and previously dredged reaches; (5) evaluate the height of the levees required to contain floods with selected recurrence intervals in previously dredged reaches; and (6) estimate flood elevations for several hypothetical dredging and streambed aggradation scenarios in undredged reaches. The amount of barren land in the Wheeling Creek watershed has decreased from 20 to 1 percent of the basin area based on land-cover characteristics from 1979 and 2001. Barren lands appear to have been converted primarily to pasture, presumably as a result of surface-mine reclamation. Croplands also decreased from 13 to 8 percent of the basin area. The combined decrease in barren lands and croplands is approximately offset by the increase in pasture. Stream-channel surveys conducted in 1987 and again in 2006 at 21 sites in four previously dredged reaches of Wheeling Creek indicate little change in the elevation, slope, and geometry of the channel at most sites. The mean change in width-averaged bed and thalweg elevations for the 21 cross sections was 0.1 feet. Bankfull widths, mean depths, and cross-sectional areas measured at 12 sites in undredged reaches were compared to estimates determined from regional equations. The mean percentage difference between measured and estimated bankfull widths was -0.2 percent, suggesting that bankfull widths in the Wheeling Creek Basin are generally about the same as regional averages for undisturbed basins of identical drainage area. For bankfull mean depth and cross

  13. Actual Condition of Paddy Field Levee Maintenance by Various Farm Households including Large-scale Farming in the Developed Land Renting Area

    NASA Astrophysics Data System (ADS)

    Sakata, Yasuyo

    The survey of interview, resource acquisition, photographic operation, and questionnaire were carried out in the “n” Community in the “y” District in Hakusan City in Ishikawa Prefecture to investigate the actual condition of paddy field levee maintenance in the area where land-renting market was proceeding, large-scale farming was dominant, and the problems of geographically scattered farm-land existed. In the study zone, 1) an agricultural production legal person rent-cultivated some of the paddy fields and maintained the levees, 2) another agricultural production legal person rent-cultivated some of the soy bean fields for crop changeover and land owners maintained the levees. The results indicated that sufficient maintenance was executed on the levees of the paddy fields cultivated by the agricultural production legal person, the soy bean fields for crop changeover, and the paddy fields cultivated by the land owners. Each reason is considered to be the managerial strategy, the economic incentive, the mutual monitoring and cross-regulatory mechanism, etc.

  14. Transition of Benthic Nutrient Sources after Engineered Levee Breaches Adjacent to Upper Klamath and Agency Lakes, Oregon

    NASA Astrophysics Data System (ADS)

    Kuwabara, J. S.; Topping, B. R.; Carter, J. L.; Parchaso, F.; Cameron, J. M.; Asbill, J. R.; Carlson, R. A.; Fend, S. V.; Engelstad, A. C.

    2010-12-01

    Nonmetallic pore-water profilers were deployed during four sampling trips between November 2007 and July 2009 after engineered levee breaches on 30 October 2007, hydrologically reconnected both Upper Klamath Lake and Agency Lake, Oregon, to adjacent wetlands. Centimeter-scale measurements of the vertical dissolved-nutrient concentration gradients from the profilers served as the basis for diffusive-flux determinations. Wetland areas undergoing restoration and those being used for water storage around these lakes function very differently than nearby established wetlands within the Upper Klamath National Wildlife Refuge. Consistent with previous results from Upper Klamath Lake, benthic flux of soluble reactive phosphorus (SRP) in the wetlands was consistently positive, and when areally and seasonally averaged over the 13 km2 newly restored wetlands, an SRP flux to the overlying water column (~87,000 kg over the 3-month cyanophyte bloom of Aphanizomenon flos-aquae (AFA)) exceeded the magnitude of riverine inputs (42,000 kg for that season). SRP benthic flux at a site within the restored wetland area ~0.5 km from the breach was elevated relative to all other lake and wetland sites (including another wetland site <0.1 km from the breached levee) in 2009 suggests that the restored wetlands, at least chemically, remain in a transition period following the hydrologic reconnection of the lake and wetland environments. Ammonium fluxes to the water column remained consistently positive throughout the sampling period, generating a toxicological concern for endangered fish populations at elevated summer pH. Soluble reactive phosphorus (SRP) concentrations were lower than detection limits (<0.03 mg-P/L) at all lake and wetland sites following the levee breaches. As indicated in previous studies, SRP concentrations for 2009 sampling trips indicated higher concentrations at the end of the annual AFA bloom relative to its beginning, suggesting a limiting factor or factors other

  15. Total flavonoid of Litsea coreana leve exerts anti-oxidative effects and alleviates focal cerebral ischemia/reperfusion injury

    PubMed Central

    Dong, Shuying; Tong, Xuhui; Li, Jun; Huang, Cheng; Hu, Chengmu; Jiao, Hao; Gu, Yuchen

    2013-01-01

    In this study, we hypothesized that total flavonoid of Litsea coreana leve (TFLC) protects against focal cerebral ischemia/reperfusion injury. TFLC (25, 50, 100 mg/kg) was administered orally to a rat model of focal ischemia/reperfusion injury, while the free radical scavenging agent, edaravone, was used as a positive control drug. Results of neurological deficit scoring, 2,3,5-triphenyl tetrazolium chloride staining, hematoxylin-eosin staining and biochemical tests showed that TFLC at different doses significantly alleviated cerebral ischemia-induced neurological deficits and histopathological changes, and reduced infarct volume. Moreover, it suppressed the increase in the levels of nitrates plus nitrites, malondialdehyde and lactate dehydrogenase, and it diminished the reduction in gluta-thione, superoxide dismutase and catalase activities induced by cerebral ischemia/reperfusion in-jury. Compared with edaravone, the protective effects of TFLC at low and medium doses (25, 50 mg/kg) against cerebral ischemia/reperfusion injury were weaker, while the protective effects at high dose (100 mg/kg) were similar. Our experimental findings suggest that TFLC exerts neuroprotective effects against focal cerebral ischemia/reperfusion injury in rats, and that the effects may be asso-ciated with its antioxidant activities. PMID:25206640

  16. The possible role of Coriolis forces in structuring large-scale sinuous patterns of submarine channel-levee systems.

    PubMed

    Wells, Mathew; Cossu, Remo

    2013-01-01

    Submarine channel-levee systems are among the largest sedimentary structures on the ocean floor. These channels have a sinuous pattern and are the main conduits for turbidity currents to transport sediment to the deep ocean. Recent observations have shown that their sinuosity decreases strongly with latitude, with high-latitude channels being much straighter than similar channels near the Equator. One possible explanation is that Coriolis forces laterally deflect turbidity currents so that at high Northern latitudes both the density interface and the downstream velocity maximum are deflected to the right-hand side of the channel (looking downstream). The shift in the velocity field can change the locations of erosion and deposition and introduce an asymmetry between left- and right-turning bends. The importance of Coriolis forces is defined by two Rossby numbers, RoW=U/Wf and RoR=U/Rf, where U is the mean downstream velocity, W is the width of the channel, R is the radius of curvature and f is the Coriolis parameter. In a bending channel, the density interface is flat when RoR∼-1, and Coriolis forces start to shift the velocity maximum when |RoW|<5. We review recent experimental and field observations and describe how Coriolis forces could lead to straighter channels at high latitudes.

  17. The possible role of Coriolis forces in structuring large-scale sinuous patterns of submarine channel-levee systems.

    PubMed

    Wells, Mathew; Cossu, Remo

    2013-12-13

    Submarine channel-levee systems are among the largest sedimentary structures on the ocean floor. These channels have a sinuous pattern and are the main conduits for turbidity currents to transport sediment to the deep ocean. Recent observations have shown that their sinuosity decreases strongly with latitude, with high-latitude channels being much straighter than similar channels near the Equator. One possible explanation is that Coriolis forces laterally deflect turbidity currents so that at high Northern latitudes both the density interface and the downstream velocity maximum are deflected to the right-hand side of the channel (looking downstream). The shift in the velocity field can change the locations of erosion and deposition and introduce an asymmetry between left- and right-turning bends. The importance of Coriolis forces is defined by two Rossby numbers, Ro(W) = U/Wf and Ro(R) = U/Rf, where U is the mean downstream velocity, W is the width of the channel, R is the radius of curvature and f is the Coriolis parameter. In a bending channel, the density interface is flat when Ro(R) - -1, and Coriolis forces start to shift the velocity maximum when [Row] < 5. We review recent experimental and field observations and describe how Coriolis forces could lead to straighter channels at high latitudes.

  18. Pliocene facies trends and controls on deposition of lower gusher shallow gas reservoirs, North Coles Levee Field, San Joaquin Basin, California

    SciTech Connect

    Steward, D.C.; Gillespie, J.M. )

    1994-04-01

    Net sand isochore maps of three Pliocene-age Lower Gusher sands in the Etchegoin Formation at North Coles Levee field, southern San Joaquin basin, California display geometries suggestive of deposition in delta front settings. The north-south depositional strike of these sands approximately parallels the orientation of the paleoshoreline. The sands thicken and display greater lateral continuity near distributary channel sands, which are oriented east-northeast approximately perpendicular to the shoreline. A comparison of the isochore maps of each of the three sand bodies show that they are stacked vertically above each other, indicating that the position of the shoreline remained stationary during deposition of the Gusher interval. This apparent stillstand of the shoreline is superimposed on an overall regression of the sea from the San Joaquin basin during the Pliocene. Therefore, we believe that the Lower Gusher sands were deposited during a period of relatively rapid basin subsidence, which negated the effects of the marine regression and caused vertical aggradation of shoreline facies in the North Coles Levee area. The Lower Gusher interval at North and South Coles Levee contains the most prolific shallow gas reservoirs on the Bakersfield Arch. A thorough knowledge of depositional trends in the Lower Gusher interval increases the probability of encountering reservoir-quality facies in exploration programs focusing on Pliocene gas.

  19. Large-scale flooding analysis in the suburbs of Tokyo Metropolis caused by levee breach of the Tone River using a 2D hydrodynamic model.

    PubMed

    Hai, Pham T; Magome, J; Yorozuya, A; Inomata, H; Fukami, K; Takeuchi, K

    2010-01-01

    In order to assess the effects of climate change on flood disasters in urban areas, we applied a two dimensional finite element hydrodynamic model (2D-FEM) to simulate flood processes for the case analysis of levee breach caused by Kathleen Typhoon on 16 September 1947 in Kurihashi reach of Tone River, upstream of Tokyo area. The purpose is to use the model to simulate flood inundation processes under the present topography and land-use conditions with impending extreme flood scenarios due to climate change for mega-urban areas like Tokyo. Simulation used 100 m resolution topographic data (in PWRI), which was derived from original LiDAR (Light Detection and Ranging) data, and levee breach hydrographic data in 1947. In this paper, we will describe the application of the model with calibration approach and techniques when applying for such fine spatial resolution in urban environments. The fine unstructured triangular FEM mesh of the model appeared to be the most capable of introducing of constructions like roads/levees in simulations. Model results can be used to generate flood mapping, subsequently uploaded to Google Earth interface, making the modeling and presentation process much comprehensible to the general public.

  20. Monitoring of levees, bridges, pipelines, and other critical infrastructure during the 2011 flooding in the Mississippi River Basin: Chapter J in 2011 floods of the central United States

    USGS Publications Warehouse

    Densmore, Brenda K.; Burton, Bethany L.; Dietsch, Benjamin J.; Cannia, James C.; Huizinga, Richard J.

    2014-01-01

    During the 2011 Mississippi River Basin flood, the U.S. Geological Survey evaluated aspects of critical river infrastructure at the request of and in support of local, State, and Federal Agencies. Geotechnical and hydrographic data collected by the U.S. Geological Survey at numerous locations were able to provide needed information about 2011 flood effects to those managing the critical infrastructure. These data were collected and processed in a short time frame to provide managers the ability to make a timely evaluation of the safety of the infrastructure and, when needed, to take action to secure and protect critical infrastructure. Critical infrastructure surveyed by the U.S. Geological Survey included levees, bridges, pipeline crossings, power plant intakes and outlets, and an electrical transmission tower. Capacitively coupled resistivity data collected along the flood-protection levees surrounding the Omaha Public Power District Nebraska City power plant (Missouri River Levee Unit R573), mapped the near-subsurface electrical properties of the levee and the materials immediately below it. The near-subsurface maps provided a better understanding of the levee construction and the nature of the lithology beneath the levee. Comparison of the capacitively coupled resistivity surveys and soil borings indicated that low-resistivity value material composing the levee generally is associated with lean clay and silt to about 2 to 4 meters below the surface, overlying a more resistive layer associated with sand deposits. In general, the resistivity structure becomes more resistive to the south and the southern survey sections correlate well with the borehole data that indicate thinner clay and silt at the surface and thicker sand sequences at depth in these sections. With the resistivity data Omaha Public Power District could focus monitoring efforts on areas with higher resistivity values (coarser-grained deposits or more loosely compacted section), which typically are

  1. Monitoring of levees, bridges, pipelines, and other critical infrastructure during the 2011 flooding in the Mississippi River Basin: Chapter J in 2011 floods of the central United States

    USGS Publications Warehouse

    Densmore, Brenda K.; Burton, Bethany L.; Dietsch, Benjamin J.; Cannia, James C.; Huizinga, Richard J.

    2014-01-01

    During the 2011 Mississippi River Basin flood, the U.S. Geological Survey evaluated aspects of critical river infrastructure at the request of and in support of local, State, and Federal Agencies. Geotechnical and hydrographic data collected by the U.S. Geological Survey at numerous locations were able to provide needed information about 2011 flood effects to those managing the critical infrastructure. These data were collected and processed in a short time frame to provide managers the ability to make a timely evaluation of the safety of the infrastructure and, when needed, to take action to secure and protect critical infrastructure. Critical infrastructure surveyed by the U.S. Geological Survey included levees, bridges, pipeline crossings, power plant intakes and outlets, and an electrical transmission tower. Capacitively coupled resistivity data collected along the flood-protection levees surrounding the Omaha Public Power District Nebraska City power plant (Missouri River Levee Unit R573), mapped the near-subsurface electrical properties of the levee and the materials immediately below it. The near-subsurface maps provided a better understanding of the levee construction and the nature of the lithology beneath the levee. Comparison of the capacitively coupled resistivity surveys and soil borings indicated that low-resistivity value material composing the levee generally is associated with lean clay and silt to about 2 to 4 meters below the surface, overlying a more resistive layer associated with sand deposits. In general, the resistivity structure becomes more resistive to the south and the southern survey sections correlate well with the borehole data that indicate thinner clay and silt at the surface and thicker sand sequences at depth in these sections. With the resistivity data Omaha Public Power District could focus monitoring efforts on areas with higher resistivity values (coarser-grained deposits or more loosely compacted section), which typically are

  2. Integrating remotely acquired and field data to assess effects of setback levees on riparian and aquatic habitat in glacial-melt water rivers

    USGS Publications Warehouse

    Konrad, C.P.; Black, R.W.; Voss, F.; Neale, C. M. U.

    2008-01-01

    Setback levees, in which levees are reconstructed at a greater distance from a river channel, are a promising restoration technique particularly for alluvial rivers with broad floodplains where river-floodplain connectivity is essential to ecological processes. Documenting the ecological outcomes of restoration activities is essential for assessing the comparative benefits of different restoration approaches and for justifying new restoration projects. Remote sensing of aquatic habitats offers one approach for comprehensive, objective documentation of river and floodplain habitats, but is difficult in glacial rivers because of high suspended-sediment concentrations, braiding and a lack of large, well-differentiated channel forms such as riffles and pools. Remote imagery and field surveys were used to assess the effects of recent and planned setback levees along the Puyallup River and, more generally, the application of multispectral imagery for classifying aquatic and riparian habitats in glacial-melt water rivers. Airborne images were acquired with a horizontal ground resolution of 0.5 m in three spectral bands (0.545-0.555, 0.665-0.675 and 0.790-0.810 ??m) spanning from green to near infrared (NIR) wavelengths. Field surveys identified river and floodplain habitat features and provided the basis for a comparative hydraulic analysis. Broad categories of aquatic habitat (smooth and rough water surface), exposed sediment (sand and boulder) and vegetated surfaces (herbaceous and deciduous shrub/forest) were classified accurately using the airborne images. Other categories [e.g. conifers, boulder, large woody debtis (LWD)] and subdivisions of broad categories (e.g. riffles and runs) were not successfully classified either because these features did not form large patches that could be identified on the imagery or their spectral reflectances were not distinct from those of other habitat types. Airborne imagery was critical for assessing fine-scale aquatic habitat

  3. Time scales of change in chemical and biological parameters after engineered levee breaches adjacent to Upper Klamath and Agency Lakes, Oregon

    USGS Publications Warehouse

    Kuwabara, James S.; Topping, Brent R.; Carter, James L.; Wood, Tamara M.; Parcheso, Francis; Cameron, Jason M.; Asbill, Jessica R.; Carlson, Rick A.; Fend, Steven V.

    2012-01-01

    Eight sampling trips were coordinated after engineered levee breaches hydrologically reconnected both Upper Klamath Lake and Agency Lake, Oregon, to adjacent wetlands. The reconnection, by a series of explosive blasts, was coordinated by The Nature Conservancy to reclaim wetlands that had for approximately seven decades been leveed for crop production. Sets of nonmetallic porewater profilers (U.S. Patent 8,051,727 B1; November 8, 2011; http://www.uspto.gov/web/patents/patog/ week45/OG/html/1372-2/US08051727-20111108.html.) were deployed during these trips in November 2007, June 2008, May 2009, July 2009, May 2010, August 2010, June 2011, and July 2011 (table 1). Deployments temporally spanned the annual cyanophyte bloom of Aphanizomenon flos-aquae and spatially involved three lake and four wetland sites. Spatial and temporal variation in solute benthic flux was determined by the field team, using the profilers, over an approximately 4-year period beginning 3 days after the levee breaches. The highest flux to the water column of dissolved organic carbon (DOC) was detected in the newly flooded wetland, contrasting negative or insignificant DOC fluxes at adjacent lake sites. Over the multiyear study, DOC benthic fluxes dissipated in the reconnected wetlands, converging to values similar to those for established wetlands and to the adjacent lake (table 2). In contrast to DOC, benthic sources of soluble reactive phosphorus, ammonium, dissolved iron and manganese from within the reconnected wetlands were consistently elevated (that is, significant in magnitude relative to riverine and established-wetland sources) indicating a multi-year time scale for certain chemical changes after the levee breaches (table 2). Colonization of the reconnected wetlands by aquatic benthic invertebrates during the study trended toward the assemblages in established wetlands, providing further evidence of a multiyear transition of this area to permanent aquatic habitat (table 3). Both the

  4. Modes of development of slope canyons and their relation to channel and levee features on the Ebro sediment apron, off-shore northeastern Spain

    USGS Publications Warehouse

    O'Connell, S.; Ryan, William B. F.; Normark, W.R.

    1987-01-01

    Six submarine slope canyons in an area of the northwestern Mediterranean, offshore from the Ebro River and Delta, were surveyed with bathymetric swathmapping (SeaBeam) and mid-range side-looking sonar (SeaMARC I). All of the canyons have slightly winding paths with concave-upwards gradients that are relatively steep shallower than 1,200 m. Two major types of canyons are identified on the basis of their morphologic character at the base of the slope; Type-I canyons lead to an unchannelled base-of-slope deposit and Type-II canyons are continuous with channel-levee systems that cross the rise. Four Type-I canyons were surveyed in the area. Two of these are broad, U-shaped, steep (average gradients of 1:14), do not indent the shelf, and terminate downslope at debris-flow deposits. These two canyons, the most northern in the area, have rounded heads with extensive gullies separated by knife-edge ridges. Relief of the canyon walls is about equal on both sides of the canyons, although the right-hand walls (looking downslope) are generally steeper. The other two Type-I canyons in the area are similar in that they do not indent the shelf, but they are much smaller and shallower and coalesce before terminating in the base-of-slope region. The two Type-II canyons that feed leveed-channels are U-shaped with flatter floors, longer profiles and gentler gradients than Type-I canyons. They are closer to the Valencia Valley and have relatively small cross-sectional areas. We propose a four-stage evolutionary sequence to explain the development of the canyons observed in this section on the prograding Ebro margin. During the initial stage, slumping and erosion on the slope creates a network of small gullies. During the next stage, headward growth of one (or more) gully leads to a major indentation of the shelf. This is the critical factor for developing a channel that will incise the slope and provide a major conduit for moving sediment to the basin. Stage 3 is characterized by the

  5. Mississippi River Flood of 2011 and the Activation of the Birds Point-New Madrid Floodway: Observations and Modeling of a Levee Breach

    NASA Astrophysics Data System (ADS)

    Holmes, R. R.; Koenig, T. A.; McDonald, R. R.; Nelson, J. M.; Simoes, F. J.

    2011-12-01

    During 2011, record flooding has occurred in many parts of the central United States. As the flooding reached record levels for the Mississippi-Ohio River confluence at Cairo, Illinois, the 61 kilometer long and 8 kilometer wide Birds Point-New Madrid Floodway (Floodway) was activated to provide a lowering of upstream water levels through a controlled demolition of approximately 3,300 meters of levee at 10:00 PM on May 2, 2011. Prior to activation of the Floodway, the U.S. Geological Survey (USGS) deployed 38 self-contained stage sensors throughout the Floodway to capture the change in water elevation through time at various locations. From April 29, 2011 to May 24, 2011, daily streamflow measurements were made upstream of the confluence of the Ohio and Mississippi Rivers, within the Floodway opening and outlets, and on the Mississippi River downstream of the Floodway opening. Additionally, velocity and bathymetric data were collected immediately downstream of the Floodway opening at Birds Point to characterize scour in the Floodway. The data provide a unique look at the impact of a controlled levee breach on river flows and hydraulics. The activation of the Floodway lowered the water level at Cairo, Illinois by 0.44 meters in the first 14 hours, while increasing the streamflow of the Mississippi and Ohio Rivers in vicinity of Cairo, Illinois by 9,200 cubic meters per second. On May 2, prior to the activation of the Floodway, the measured combined streamflow of the upper Mississippi and Ohio Rivers at Cairo, Illinois was 52,900 cubic meters per second with the Ohio River contributing 27,700 cubic meters per second. Following the controlled breach of the Birds Point levee (immediately downstream of Cairo, Illinois on the right descending bank) the night of May 2, 2011, the measured combined streamflow at Cairo, Illinois on May 3, 2011 increased to 62,100 cubic meters per second with the Ohio River increasing to 38,100 cubic meters per second, an increase of 10

  6. Depositional environments of late glacial to Holocene sediments on the deep water levees of Setúbal and Nazaré Canyons, offshore Portugal: preliminary results

    NASA Astrophysics Data System (ADS)

    Pascoletti, F. C.; Masson, D.; Innocenti, C.

    2010-12-01

    The west Iberian margin is indented by a network of submarine canyons that create rugged seafloor morphology and act as major pathways for the transport of sediment from land to the abyssal plains. The Setúbal and Nazaré Canyons are part of this complex environment and strongly influence sediment distribution, capturing sediments from the Tagus River and the littoral cell transport respectively. Deep submarine sedimentary sequences thus reflect changes in sediment input and depositional environments. The high-resolution sedimentological study here presented was applied in four cores of the deep water levees of Nazaré and Setúbal Canyons in order to explore how sediment input to the canyons changed during the last glacial - interglacial transition, and how this reflects changing environmental conditions on land. By means of non-destructive corelogger measurements and analyses of spectral signatures, geochemical compositions and colour variations, it was possible to identify ice-rafted debris (IRD) deposits, to characterize hemipelagic and turbidite layers and to investigate terrestrial-derived sediments input variation during the last 26 ka. Preliminary results from the sedimentological and turbidite frequency analyses show that highest turbidite occurrence is recorded during the glacial stage, confirming that the generation of turbidity flows in submarine canyons is tightly related to low sea-level stands. We found that major peaks in frequency and thickness of turbidite deposits in the deep Portuguese margin are mainly coeval with abrupt climatic (H2 and 1) and sea-level changes (~ 19 and ~ 23 ka BP), as a consequence of which a major amount of continentally-derived material was transported into the deep sea. During the Holocene, the inception of sea-level rises, independent of their magnitude, has been found to be sufficient to generate turbidity currents, particularly in the Nazaré system. Moreover, a multiple regression analysis was attempted in order to

  7. Novel insights into the genetics of smoking behaviour, lung function, and chronic obstructive pulmonary disease (UK BiLEVE): a genetic association study in UK Biobank

    PubMed Central

    Wain, Louise V; Shrine, Nick; Miller, Suzanne; Jackson, Victoria E; Ntalla, Ioanna; Artigas, María Soler; Billington, Charlotte K; Kheirallah, Abdul Kader; Allen, Richard; Cook, James P; Probert, Kelly; Obeidat, Ma'en; Bossé, Yohan; Hao, Ke; Postma, Dirkje S; Paré, Peter D; Ramasamy, Adaikalavan; Mägi, Reedik; Mihailov, Evelin; Reinmaa, Eva; Melén, Erik; O'Connell, Jared; Frangou, Eleni; Delaneau, Olivier; Freeman, Colin; Petkova, Desislava; McCarthy, Mark; Sayers, Ian; Deloukas, Panos; Hubbard, Richard; Pavord, Ian; Hansell, Anna L; Thomson, Neil C; Zeggini, Eleftheria; Morris, Andrew P; Marchini, Jonathan; Strachan, David P; Tobin, Martin D; Hall, Ian P

    2015-01-01

    Summary Background Understanding the genetic basis of airflow obstruction and smoking behaviour is key to determining the pathophysiology of chronic obstructive pulmonary disease (COPD). We used UK Biobank data to study the genetic causes of smoking behaviour and lung health. Methods We sampled individuals of European ancestry from UK Biobank, from the middle and extremes of the forced expiratory volume in 1 s (FEV1) distribution among heavy smokers (mean 35 pack-years) and never smokers. We developed a custom array for UK Biobank to provide optimum genome-wide coverage of common and low-frequency variants, dense coverage of genomic regions already implicated in lung health and disease, and to assay rare coding variants relevant to the UK population. We investigated whether there were shared genetic causes between different phenotypes defined by extremes of FEV1. We also looked for novel variants associated with extremes of FEV1 and smoking behaviour and assessed regions of the genome that had already shown evidence for a role in lung health and disease. We set genome-wide significance at p<5 × 10−8. Findings UK Biobank participants were recruited from March 15, 2006, to July 7, 2010. Sample selection for the UK BiLEVE study started on Nov 22, 2012, and was completed on Dec 20, 2012. We selected 50 008 unique samples: 10 002 individuals with low FEV1, 10 000 with average FEV1, and 5002 with high FEV1 from each of the heavy smoker and never smoker groups. We noted a substantial sharing of genetic causes of low FEV1 between heavy smokers and never smokers (p=2·29 × 10−16) and between individuals with and without doctor-diagnosed asthma (p=6·06 × 10−11). We discovered six novel genome-wide significant signals of association with extremes of FEV1, including signals at four novel loci (KANSL1, TSEN54, TET2, and RBM19/TBX5) and independent signals at two previously reported loci (NPNT and HLA-DQB1/HLA-DQA2). These variants also showed

  8. Hydrogen bonds in concreto and in computro

    NASA Astrophysics Data System (ADS)

    Stouten, Pieter F. W.; Kroon, Jan

    1988-07-01

    Molecular dynamics simulations of liquid water and liquid methanol have been carried out. For both liquids an effective pair potential was used. The models were fitted to the heat of vaporization, pressure and various radial distribution functions resulting from diffraction experiments on liquids. In both simulations 216 molecules were put in a cubic periodical ☐. The system was loosely coupled to a temperature bath and to a pressure bath. Following an initial equilibration period relevant data were sampled during 15 ps. The distributions of oxygen—oxygen distances in hydrogen bonds obtained from the two simulations are essentially the same. The distribution obtained from crystal data is somewhat different: the maximum has about the same position, but the curve is much narrower, which can be expected merely from the fact that diffraction experiments only supply average atomic positions and hence average interatomic distances. When thermal motion is taken into account a closer likeness is observed.

  9. Haine v. Leves, 7 April 1987.

    PubMed

    1987-01-01

    The Court ruled that where pupils coming from within a local community were segregated into single sex schools with differences in their curricula that resulted in a variation in educational qualification such that the school qualification of boys for tertiary education and employment was greater than that of girls, the Equal Opportunity Tribunal could conclude that the girls were being discriminated against under Section 31A of the Anti-Discrimination Act 1977. PMID:12346613

  10. Levee Vegetation Review Act of 2013

    THOMAS, 113th Congress

    Rep. Matsui, Doris O. [D-CA-6

    2013-01-23

    01/24/2013 Referred to the Subcommittee on Water Resources and Environment. (All Actions) Notes: For further action, see H.R.3080, which became Public Law 113-121 on 6/10/2014. Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  11. Cibola High Levee Pond annual report 2004

    USGS Publications Warehouse

    Mueller, Gordon A.; Carpenter, Jeanette; Marsh, Paul C.

    2005-01-01

    Remaining work will be finished this coming summer and a final report describing CHLP and the ecology of these fish will be completed by the end of 2005. We offer our assistance to the Fish and Wildlife Service in the pond’s renovation and support for the creation of additional refuge ponds. Funding for this work ends September 2005.

  12. Managing Enrollments When the Levee Breaks

    ERIC Educational Resources Information Center

    Whiteside, Richard

    2006-01-01

    This article features the text of a speech by Richard Whiteside, Vice President for Enrollment Management and Dean of Admission at Tulane University in New Orleans, that was presented during AACRAO's Strategic Enrollment Management (SEM) Conference, November 15, 2005, in Chicago. In his speech, Whiteside recounts his personal story of living…

  13. Falling towers, crumbling levees, and viral mutations.

    PubMed

    Chalfin, Donald B

    2006-02-01

    Hurricanes Katrina and Rita destroyed an entire beloved city and shattered a large part of the US Gulf Coast. Unlike the destruction of 9/11, it is difficult to say at the time of this writing whether or not this region will ever be fully restored. In light of these and other man-made and natural disasters, the world needs to revisit its approach to disaster planning and preparedness to insure that we can best meet the needs of those likely to be affected by future calamities.

  14. Hydrogen bonds in concreto and in computro: the sequel

    NASA Astrophysics Data System (ADS)

    Stouten, Pieter F. W.; Van Eijck, Bouke P.; Kroon, Jan

    1991-02-01

    In the framework of our comparative research concerning hydrogen bonding in the crystalline and liquid phases we have carried out molecular dynamics (MD) simulations of liquid methanol. Six different rigid three site models are compared. Five of them had been reported in the literature and one (OM2) we developed by a fit to the experimental molar volume, heat of vaporization and neutron weighted radial distribution function. In general the agreement with experiment is satisfactory for the different models. None of the models has an explicit hydrogen bond potential, but five of the six models show a degree of hydrogen bonding comparable to experiments on liquid methanol. The analysis of the simulation hydrogen bonds indicates that there is a distinct preference of the O⋯O axis to lie in the acceptor lone pairs plane, but hardly any for the lone pair directions. Ab initio calculations and crystal structure statistics of OH⋯O hydrogen bonds agree with this observation. The O⋯O hydrogen bond length distributions are similar for most models. The crystal structures show a sharper O⋯O distribution. Explicit introduction of harmonic motion with a quite realistic root mean square amplitude of 0.08 Å to the thermally averaged crystal distribution results in a distribution comparable to OM2 although the maximum of the former is found at shorter distance. On the basis of the analysis of the static properties of all models we conclude that our OM2, Jorgenson's OPLS and Haughney, Ferrario and McDonald's HFM1 models are good candidates for simulations of liquid methanol under isothermal, isochoric conditions. Partly flexible and completely rigid OM2 are simulated at constant pressure and with fixed volume. The flexible simulations give essentially the same (correct) results under both conditions, which is not surprising because the flexible form was fitted under both conditions. Rigid OM2 has a similar potential energy but larger pressure in the isochoric case and larger energy and far larger volume in the isobaric case. Radial distribution functions and hydrogen bond geometries are very similar for all four cases. Only in the case of the osobaric rigid methanol does the volume expansion seem to be accompanied by a slight preference for tetrahedrality around the oxygen atom.

  15. Biogeochemical implications of levee confinement in the lowermost Mississippi River

    NASA Astrophysics Data System (ADS)

    Galler, J. J.; Bianchi, T. S.; Alison, M. A.; Wysocki, L. A.; Campanella, R.

    With the recent formation of the Center for River-Ocean Studies (CeROS) at Tulane University in Louisiana (see http://www.tulane.edu/~ceros) and the emerging state-federal partnership that is creating river diversions to combat coastal land loss, increased attention is being paid to the lowermost Mississippi River, from Baton Rouge to the Gulf of Mexico, as a critical juncture and storage area for sediment particles and bio-active compounds.CeROS scientists, working with the US. Geological Survey and the National Oceanic and Atmospheric Administration, have undertaken a detailed re-assessment of the channel floor and water column of this region using geophysical and biogeochemical data collection, combined with historical data sets.

  16. Probabilistic seasonal Forecasts to deterministic Farm Leve Decisions: Innovative Approach

    NASA Astrophysics Data System (ADS)

    Mwangi, M. W.

    2015-12-01

    Climate change and vulnerability are major challenges in ensuring household food security. Climate information services have the potential to cushion rural households from extreme climate risks. However, most the probabilistic nature of climate information products is not easily understood by majority of smallholder farmers. Despite the probabilistic nature, climate information have proved to be a valuable climate risk adaptation strategy at the farm level. This calls for innovative ways to help farmers understand and apply climate information services to inform their farm level decisions. The study endeavored to co-design and test appropriate innovation systems for climate information services uptake and scale up necessary for achieving climate risk development. In addition it also determined the conditions necessary to support the effective performance of the proposed innovation system. Data and information sources included systematic literature review, secondary sources, government statistics, focused group discussions, household surveys and semi-structured interviews. Data wasanalyzed using both quantitative and qualitative data analysis techniques. Quantitative data was analyzed using the Statistical Package for Social Sciences (SPSS) software. Qualitative data was analyzed using qualitative techniques, which involved establishing the categories and themes, relationships/patterns and conclusions in line with the study objectives. Sustainable livelihood, reduced household poverty and climate change resilience were the impact that resulted from the study.

  17. Five Years after the Levees Broke: Bearing Witness through Poetry

    ERIC Educational Resources Information Center

    Watson, Renee

    2010-01-01

    As a teaching artist in public schools, the author is paired with classroom teachers to teach poetry and to give students an opportunity to experience their academic curriculum through the arts. At the beginning of the school year, she gave her students the on-going, yearlong assignment to watch the news, to pay attention. Knowing many of them…

  18. 44 CFR 65.10 - Mapping of areas protected by levee systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... requirement described in paragraph (b)(1)(i) of this section, may be approved. Appropriate engineering... paragraph (b)(1)(iii) of this section, may be approved. Appropriate engineering analyses demonstrating... are structural parts of the system during operation and design according to sound engineering...

  19. Reintroduction of flooding and change in denitrification rates on a leveed Midwestern floodplain

    NASA Astrophysics Data System (ADS)

    Orr, C. H.; Stanley, E.; Wilson, K.; Finlay, J.

    2005-05-01

    We examined the response of soil denitrification to a floodplain restoration project that reintroduced controlled flooding to a previously isolated 900 hectare site adjacent to the Baraboo River, Wisconsin. Monthly June-August for one year prior and two years post restoration we measured denitrification in static cores (SC μgN2O-N/kgsoil-hr) and potential denitrification in carbon and nitrate amended soil slurry samples (DEA μgN2O-N/kgsoil-hr). Rates showed high temporal and spatial variability. Individual sample SC rates ranged widely (0.00 to 16.7) with a mean value of 1.10 (SD = 3.02). DEA rates were in the same general range (0.00 to 15.0) but with a slightly higher mean (mean 1.41, comparison p<0.05). Denitrification was not highly correlated with soil nutrient content. However, the difference in rates between SC and DEA samples pre-restoration was higher than post-restoration, suggesting that denitrification was less limited after the reintroduction of flooding. Vegetation type and history of flooding were better predictors of denitrification than current soil water content. Despite large variability in measured rates, these results demonstrate that there is potential for denitrification to remove significant amounts nitrate from river systems. Management of water levels to provide adequate exchange between river and floodplain is important to this process.

  20. WHEN THE LEVEE BREAKS: TREATING ADOLESCENTS AND FAMILIES IN THE AFTERMATH OF HURRICANE KATRINA

    PubMed Central

    Rowe, Cynthia L.; Liddle, Howard A.

    2008-01-01

    Hurricane Katrina brought to the surface serious questions about the capacity of the public health system to respond to community-wide disaster. The storm and its aftermath severed developmentally protective family and community ties; thus its consequences are expected to be particularly acute for vulnerable adolescents. Research confirms that teens are at risk for a range of negative outcomes under conditions of life stress and family disorganization. Specifically, the multiple interacting risk factors for substance abuse in adolescence may be compounded when families and communities have experienced a major trauma. Further, existing service structures and treatments for working with young disaster victims may not address their risk for co-occurring substance abuse and traumatic stress reactions because they tend to be individually or peer group focused, and fail to consider the multi-systemic aspects of disaster recovery. This article proposes an innovative family-based intervention for young disaster victims, based on an empirically supported model for adolescent substance abuse, Multidimensional Family Therapy (MDFT; Liddle, 2002). Outcomes and mechanisms of the model’s effects are being investigated in a randomized clinical trial with clinically referred substance-abusing teens in a New Orleans area community impacted by Hurricane Katrina. PMID:18412822

  1. Native fish sanctuaries of the lower Colorado River: Cibola High Levee Pond, Desert Pupfish Pond

    USGS Publications Warehouse

    Mueller, G.

    2005-01-01

    Isolated by high mountains and harsh deserts, its fish community developed unique and specialized traits that helped them survive raging floods and prolonged droughts. Conditions were so unique that three quarters of the fish species are found nowhere else in the world?|

  2. Applications of the JARS method to study levee sites in southern Texas and southern New Mexico

    USGS Publications Warehouse

    Ivanov, J.; Miller, R.D.; Xia, J.; Dunbar, J.B.

    2007-01-01

    We apply the joint analysis of refractions with surface waves (JARS) method to several sites and compare its results to traditional refraction-tomography methods in efforts of finding a more realistic solution to the inverse refraction-traveltime problem. The JARS method uses a reference model, derived from surface-wave shear-wave velocity estimates, as a constraint. In all of the cases JARS estimates appear more realistic than those from the conventional refraction-tomography methods. As a result, we consider, the JARS algorithm as the preferred method for finding solutions to the inverse refraction-tomography problems. ?? 2007 Society of Exploration Geophysicists.

  3. 44 CFR 65.10 - Mapping of areas protected by levee systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., the freeboard must be established at one foot above the height of the one percent wave or the maximum wave runup (whichever is greater) associated with the 100-year stillwater surge elevation at the site.... Particular emphasis must be placed on the effects of wave attack and overtopping on the stability of...

  4. 44 CFR 65.10 - Mapping of areas protected by levee systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., the freeboard must be established at one foot above the height of the one percent wave or the maximum wave runup (whichever is greater) associated with the 100-year stillwater surge elevation at the site.... Particular emphasis must be placed on the effects of wave attack and overtopping on the stability of...

  5. 44 CFR 65.10 - Mapping of areas protected by levee systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., the freeboard must be established at one foot above the height of the one percent wave or the maximum wave runup (whichever is greater) associated with the 100-year stillwater surge elevation at the site.... Particular emphasis must be placed on the effects of wave attack and overtopping on the stability of...

  6. 44 CFR 65.10 - Mapping of areas protected by levee systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., the freeboard must be established at one foot above the height of the one percent wave or the maximum wave runup (whichever is greater) associated with the 100-year stillwater surge elevation at the site.... Particular emphasis must be placed on the effects of wave attack and overtopping on the stability of...

  7. When the Levee Breaks: Treating Adolescents and Families in the Aftermath of Hurricane Katrina

    ERIC Educational Resources Information Center

    Rowe, Cynthia L.; Liddle, Howard A.

    2008-01-01

    Hurricane Katrina brought to the surface serious questions about the capacity of the public health system to respond to community-wide disaster. The storm and its aftermath severed developmentally protective family and community ties; thus its consequences are expected to be particularly acute for vulnerable adolescents. Research confirms that…

  8. CONSEQUENCES OF HUMAN-ALTERED FLOODS: LEVEES, FLOODS, AND FLOODPLAIN FORESTS ALONG THE WISCONSIN RIVER. (R826600)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  9. A bill to allow a State or local government to construct levees on certain properties otherwise designated as open space lands.

    THOMAS, 112th Congress

    Sen. Hoeven, John [R-ND

    2012-01-26

    07/23/2012 On motion to suspend the rules and pass the bill Failed by the Yeas and Nays: (2/3 required): 126 - 254 (Roll no. 500). (text: CR H5105) (All Actions) Tracker: This bill has the status Failed HouseHere are the steps for Status of Legislation:

  10. When the levee breaks - public policy and holistic risk management - lessons from Katrina for coastal cities faced with rising storm surge flood risk

    NASA Astrophysics Data System (ADS)

    Muir-Wood, R.

    2009-04-01

    In a period of accelerating sea level rise and increased tropical cyclone intensities, extreme 100 year coastal flood levels are rising rapidly along a number of tropical and subtropical coastlines. Meanwhile, whether from natural megadelta consolidation, post glacial rebound or overpumping of shallow aquifers, many coastal cities are sinking even faster than mean sea level is rising. Without significant investment in continually improved flood defence inevitably this means the risk of catastrophic flooding is rising, for many cities quite steeply. The experience of Hurricane Katrina and New Orleans may become seen as iconic for 21st Century catastrophe risk as more and more coastal cities are subject to similar calamities. The story of New Orleans also highlights many aspects of catastrophe risk management failures before and after extreme events. The city of New Orleans had already been flooded three times by storm surges in the 100 years before Katrina. After each flood, investments were made in improved flood defences but these investments dwindled through time as there appeared to be a reduced imperative to divert money to support abstract risk reduction. Meanwhile land subsidence and rising sea levels and storm surges meant that risk levels continued to rise, until the inevitable time when the city once again was flooded. As the city increasingly sinks below mean sea level the impact of each flood has become increasingly catastrophic, both in terms of areas flooded, property damage and casualties. While a major program of investment in improved flood defences has once again followed the catastrophic 2005 flood, Federal government agencies have given no assurance that levels of flood risk will be maintained below some designated threshold long term. Therefore another cycle of rising flood risk has now started that will inevitably eventually to lead to the city becoming reflooded. This cycle can only end with the eventual abandonment of much of the city area - an outcome that is deemed politically unacceptable. The loss consequences of rising levels of risk, improvements or degradation in flood defences and the potential outcomes of different catastrophic storm surges can only be explored in a Catastrophe loss model.

  11. To ensure that Federal assistance provided under the Robert T. Stafford Disaster Relief and Emergency Assistance Act for the construction of certain emergency levees is not conditioned on the subsequent dismantlement of those levees, except as provided for in a status certificate, and for other purposes.

    THOMAS, 112th Congress

    Rep. Kline, John [R-MN-2

    2011-10-24

    10/25/2011 Referred to the Subcommittee on Economic Development, Public Buildings and Emergency Management. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  12. Costura Basica (Principios Basicos para el Estudiante con Impedimentos Leves y Moderados) Documento de Trabajo Guia Curricular para el Curso. Basic Sewing (Basic Principles for the Student with Light and Moderate Disabilities. Course Curriculum Guide. Working Document).

    ERIC Educational Resources Information Center

    Puerto Rico State Dept. of Education, Hato Rey. Office of Special Education.

    This guide has been prepared by the Puerto Rico Department of Public Instruction for special education teachers teaching domestic sewing. It includes informative and easy to comprehend material for students of both sexes with mild to moderate disabilities. The material is developed through varied strategies and activities that relate to the…

  13. Cuaderno de Recetas Ilustradas para Jovenes con Impedimentos--Para Estudiantes con Impedimentos Leves v Moderados (Notebook of Illustrated Recipes for Youth with Disabilities--For Students with Light and Moderate Disabilities).

    ERIC Educational Resources Information Center

    Puerto Rico State Dept. of Education, Hato Rey. Office of Special Education.

    This collection of recipes has been prepared with attention to the needs of students with disabilities who lack reading skills sufficient to be able to use ordinary cookbooks. Presentation in this illustrated form helps them understand the processes of food preparation as it introduces a basic culinary vocabulary. The teacher can use this…

  14. Anatomy and growth pattern of Amazon deep-sea fan as revealed by long-range side-scan sonar (GLORIA) and high-resolution seismic studies

    SciTech Connect

    Damuth, J.E.; Flood, R.D.; Kowsmann, R.O.; Belderson, R.H.; Gorini, M.A.

    1988-08-01

    Imaging of the Amazon deep-sea fan with long-range side-scan sonar (GLORIA) has, for the first time, revealed the anatomy, trends, and growth pattern of distributary channels on this fan. Only one channel-levee system was active at any given time and extended from the Amazon Submarine Canyon downslope onto the lower fan (> 4,200 m). Formation of new channel-levee systems occurred when a currently active channel-levee system was cut off and abandoned through avulsion, and a new channel-levee system was established nearby. Through time, successive channel-levee formation and abandonment built two broad levee complexes consisting of groups of overlapping, coalescing segments of channel-levee systems across the present fan surface. These, plus older, now buried levee complexes, indicate that fan growth is radially outward and downslope through development of successive levee complexes. The most striking characteristic of the distributary channels is their intricate, often recurving, meanders with sinuosities of up to 2.5. Cutoffs and abandoned meander loops indicate that the channels migrate laterally through time. Channel bifurcation results predominantly from avulsion when flows breach a channel levee, thereby abandoning the present channel and establishing a new channel-levee segment nearby. No clear evidence of channel branching (i.e., division of a single channel into two active segments) or braiding was observed. 22 figs.

  15. Hydrologic conditions: Dade County, Florida

    USGS Publications Warehouse

    Kohout, Francis Anthony; Klein, Howard; Sherwood, C.B.; Leach, Stanley D.

    1964-01-01

    Thin layers of dense limestone of low permeability that occur near the top of the Biscayne aquifer in the vicinity of the north end of Levee 30 in Dade County, Florida are of hydrologic importance because they retard the downward infiltration of ponded water in Conservation Area No. 3. This retarding effect frequently results in high head differentials across the levee. Tests made in a small area adjacent to Levee 30 indicate that the coefficient of transmissibility of the aquifer is 3,600,000 gpd (gallons per day) per foot, and the coefficient of vertical permeability of the dense limestones is 13 gpd per square foot. If ground-water flow beneath the levee is laminar, the total inflow to the Levee 30 Canal from Conservation Area No. 3 will be about 350 mgd (million gallons per day), or 540 cfs (cubic feet per second), per mile length of levee when the head difference across the levee is 10 feet.

  16. Principios de Nutricion y Alimentacion del Adolescente (Para Estudiantes con Impedimentos Leves y Moderados). Guia Curricular para el Curso Documento de Trabajar. Principles of Nutrition and Food for the Adolescent (For Students with Light and Moderate Disabilities. Course Curriculum Guide. Working Document).

    ERIC Educational Resources Information Center

    Puerto Rico State Dept. of Education, Hato Rey. Office of Special Education.

    This curriculum guide, in Spanish, consists of a compilation of concepts, activities, and skills for the student with disabilities who receives services from the special education programs of Puerto Rico. Lesson plans cover the basic principles of nutrition, food handling, and food preparation for adolescents. The following units are presented…

  17. 26 CFR 1.103-1 - Interest upon obligations of a State, territory, etc.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... this section, include special assessment districts so created, such as road, water, sewer, gas, light, reclamation, drainage, irrigation, levee, school, harbor, port improvement, and similar districts...

  18. 26 CFR 1.103-1 - Interest upon obligations of a State, territory, etc.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... this section, include special assessment districts so created, such as road, water, sewer, gas, light, reclamation, drainage, irrigation, levee, school, harbor, port improvement, and similar districts...

  19. 7 CFR 701.5 - Land eligibility.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... other political subdivisions of a State; (3) Protected by a levee or dike that was not effectively and... dike not built to U.S. Army Corps of Engineers, NRCS, or comparable standards; (4) Adjacent to water... which levees or dikes are located; (6) Subject to frequent damage or susceptible to severe...

  20. 1. OVERALL VIEW OF INTAKE PIER AND ACCESS BRIDGE, LOOKING ...

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

    1. OVERALL VIEW OF INTAKE PIER AND ACCESS BRIDGE, LOOKING NORTHEAST FROM WESTERN LEVEE OF THE SACRAMENTO RIVER. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  1. 5. OBLIQUE VIEW OF INTAKE PIER AND ACCESS BRIDGE, LOOKING ...

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

    5. OBLIQUE VIEW OF INTAKE PIER AND ACCESS BRIDGE, LOOKING SOUTHWEST, FROM THE EASTERN LEVEE. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  2. 7. DETAIL OF INTAKE PIER, LOOKING SOUTHWEST FROM EASTERN SACRAMENTO ...

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

    7. DETAIL OF INTAKE PIER, LOOKING SOUTHWEST FROM EASTERN SACRAMENTO LEVEE. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  3. 75 FR 21252 - Notice of Intent To Prepare an Environmental Impact Statement/Environmental Impact Report for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-23

    ... project. Portions of the RD 17 levee system including the section of levee along the south bank of French Camp Slough, along the east bank of the San Joaquin River, and along the northerly bank of Walthall... Protection Board. Under Section 404, the District Engineer permits the discharge of dredged or fill...

  4. 7 CFR 701.105 - Land eligibility.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) Between any levee or dike and a stream, river, or body of water, including land between two or more levees or dikes; (9) Located in an old or new channel of a stream, creek, river or other similar body of... Deputy Administrator determines that the canal is not a channel subject to flooding; (10) In...

  5. 29 CFR 776.29 - Instrumentalities and channels of interstate commerce.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., dams, reservoirs and similar projects; also the removal of debris and other impediments in the waterway... navigable channel of the river, since levees, dams, dikes and like structures, which hold back the waters in... its tributaries. (2) Basis of coverage. (i) The construction of a levee, dam or other improvement...

  6. 29 CFR 776.29 - Instrumentalities and channels of interstate commerce.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., dams, reservoirs and similar projects; also the removal of debris and other impediments in the waterway... navigable channel of the river, since levees, dams, dikes and like structures, which hold back the waters in... its tributaries. (2) Basis of coverage. (i) The construction of a levee, dam or other improvement...

  7. 7 CFR 701.105 - Land eligibility.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AGRICULTURAL CONSERVATION PROGRAM EMERGENCY CONSERVATION PROGRAM, EMERGENCY FOREST RESTORATION PROGRAM, AND...) Between any levee or dike and a stream, river, or body of water, including land between two or more levees or dikes; (9) Located in an old or new channel of a stream, creek, river or other similar body...

  8. 7 CFR 701.105 - Land eligibility.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AGRICULTURAL CONSERVATION PROGRAM EMERGENCY CONSERVATION PROGRAM, EMERGENCY FOREST RESTORATION PROGRAM, AND...) Between any levee or dike and a stream, river, or body of water, including land between two or more levees or dikes; (9) Located in an old or new channel of a stream, creek, river or other similar body...

  9. Geophysical methods for the assessment of earthen dams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dams and levees are an integral part of the fluvial system in watersheds. Their stability is of utmost concern to the Nation and to those directly impacted should failure occur. There are some 88,000 dams and 110,000 miles of levees in the USA. Many of those are earthen embankments and structures su...

  10. 75 FR 18238 - United States Section; Final Environmental Impact Statement, Flood Control Improvements and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-09

    ..., overtopping, piping/sand boils, under-seepage, and severe surface and slope erosion. The flooding also potentially compromised the integrity of the levee foundation within several levee segments, primarily at... extensive flooding. In response to the September 2008 flooding damage, the USIBWC developed...

  11. 27 CFR 9.163 - Salado Creek.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the levee on the east bank of the Delta-Mendota Canal in section 35, T5S, R7E; then (3) Proceed southeast approximately 0.3 miles along the Delta-Mendota Canal levee road to its intersection with...

  12. 78 FR 6814 - Notice of Intent to Prepare an Environmental Impact Statement for the Sacramento-San Joaquin...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-31

    ... for the Sacramento-San Joaquin Delta Islands and Levees Feasibility Study AGENCY: Department of the... the preparation of an environmental impact statement (EIS) for the Sacramento-San Joaquin Delta Islands and Levees Feasibility Study (Delta Study). The EIS will be prepared in accordance with...

  13. 27 CFR 9.163 - Salado Creek.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... the levee on the east bank of the Delta-Mendota Canal in section 35, T5S, R7E; then (3) Proceed southeast approximately 0.3 miles along the Delta-Mendota Canal levee road to its intersection with...

  14. 27 CFR 9.163 - Salado Creek.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the levee on the east bank of the Delta-Mendota Canal in section 35, T5S, R7E; then (3) Proceed southeast approximately 0.3 miles along the Delta-Mendota Canal levee road to its intersection with...

  15. Laboratory measurements of acoustic, electrical resistivity, and erodibility of soils as a function of compaction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Catastrophic floods resulting from the failure of dam and levee infrastructures can paralyze the economy and social life of large populations for long periods of time. The United States has over 100,000 miles of levees and the National Inventory of Dams lists approximately 79,000 U.S. dams. The de...

  16. Cyclic sediment deposition within Amazon deep-sea fan

    SciTech Connect

    Manley, P.L.; Flood, R.D.

    1988-08-01

    The Upper and middle Amazon Fan has grown in a cyclic fashion. An individual deposition cycle consists of (1) a widespread basal, acoustically transparent seismic unit (interpreted as debris-flow deposits) that fills and levels preexisting topographic lows, and (2) a levee complex built of overlapping channel-levee systems. Two and possibly three cycles have been identified within the Amazon Fan. The levee complex beneath one debris flow originated from a different submarine canyon than did the levee complex above the debris flow, suggesting that these levee complexes formed during different sea level lowstands. Calculations based on present sediment discharge of the Amazon River suggest that an entire levee complex can form within the time span of a single glacial stage, such as the Wisconsin; however, the levee complex probably could not have formed during the relatively short time interval when sea level rose rapidly at the end of a glacial stage. The basal seismic units (debris-flow deposits) may have been deposited at any time during sea level fluctuations. Although seismic evidence suggests that this cyclic sedimentation pattern may be related to glacio-eustatic sea level variations, cyclic fan growth may be attributed to other processes as well. For example, a bottom-simulating reflector (BSR) observed within the upper fan appears to be a gas hydrate. Migration of the hydrate phase boundary during sea level fluctuations and diapiric activity may be mechanisms for initiating widespread debris flows. 10 figs.

  17. Comparison of shallow-water and marsh-surface habitats associated with pipeline canals and natural channels in Louisiana salt marshes

    SciTech Connect

    Rozas, L.P.

    1992-11-01

    The primary objective of the study was to assess the effects of pipeline canals on the habitat function of inside-levee marshes. The degree to which inside-levee marshes function as nursery habitat for nekton residing in canals was examined by comparing densities of nekton on marshes adjacent to pipeline canals (inside-levee marshes) and natural tidal creeks. In addition, shallow subtidal habitats in the two environments (canals and natural channels) were compared by sampling nekton along the marsh edge at low tide and measuring predator encounter rates in both habitats.

  18. Time-frequency methods for structural health monitoring.

    PubMed

    Pyayt, Alexander L; Kozionov, Alexey P; Mokhov, Ilya I; Lang, Bernhard; Meijer, Robert J; Krzhizhanovskaya, Valeria V; Sloot, Peter M A

    2014-03-12

    Detection of early warning signals for the imminent failure of large and complex engineered structures is a daunting challenge with many open research questions. In this paper we report on novel ways to perform Structural Health Monitoring (SHM) of flood protection systems (levees, earthen dikes and concrete dams) using sensor data. We present a robust data-driven anomaly detection method that combines time-frequency feature extraction, using wavelet analysis and phase shift, with one-sided classification techniques to identify the onset of failure anomalies in real-time sensor measurements. The methodology has been successfully tested at three operational levees. We detected a dam leakage in the retaining dam (Germany) and "strange" behaviour of sensors installed in a Boston levee (UK) and a Rhine levee (Germany).

  19. 9. VIEW OF THE PRESSURE CULVERT STILLING BASIN, LOOKING NORTH. ...

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

    9. VIEW OF THE PRESSURE CULVERT STILLING BASIN, LOOKING NORTH. NOTE THE LEVEE TO THE RIGHT. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

  20. 76 FR 19124 - United States Section, Notice of Availability of a Draft Supplemental Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-06

    ... Supplemental Environmental Assessment and Finding of No Significant Impact for Improvements to the Mission Levee Protective System in Hidalgo County, Texas AGENCY: United States Section, International Boundary... Supplemental Environmental Assessment (SEA) and Finding of No Significant Impact (FONSI). SUMMARY: Pursuant...

  1. 33 CFR 334.778 - Pensacola Bay and waters contiguous to the Naval Air Station, Pensacola, FL; restricted area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., motorized, and/or rowed or self-propelled), private and commercial fishing vessels, other commercial vessels... within the above described area, or within 500 feet of any quay, pier, wharf, or levee along the...

  2. Sacramento River Water Treatment Plant Intake Pier & Access Bridge, ...

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

    Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  3. 12 CFR 745.1 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., the Panama Canal Zone, any territory or possession of the United States, any county, municipality, or..., levee, sanitary, school or power districts and bridge or port authorities, and other special...

  4. 76 FR 27030 - Intent To Prepare a Supplemental Environmental Impact Statement for the Indianapolis, White River...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ..., economics, biological and cultural resources, public safety, and water supply. Public Participation: The...) Clearing of all woody vegetation 20 ft on each side of the toe of the existing levee, (2) a...

  5. Time-Frequency Methods for Structural Health Monitoring †

    PubMed Central

    Pyayt, Alexander L.; Kozionov, Alexey P.; Mokhov, Ilya I.; Lang, Bernhard; Meijer, Robert J.; Krzhizhanovskaya, Valeria V.; Sloot, Peter M. A.

    2014-01-01

    Detection of early warning signals for the imminent failure of large and complex engineered structures is a daunting challenge with many open research questions. In this paper we report on novel ways to perform Structural Health Monitoring (SHM) of flood protection systems (levees, earthen dikes and concrete dams) using sensor data. We present a robust data-driven anomaly detection method that combines time-frequency feature extraction, using wavelet analysis and phase shift, with one-sided classification techniques to identify the onset of failure anomalies in real-time sensor measurements. The methodology has been successfully tested at three operational levees. We detected a dam leakage in the retaining dam (Germany) and “strange” behaviour of sensors installed in a Boston levee (UK) and a Rhine levee (Germany). PMID:24625740

  6. Community implementation dynamics: nutrient management in the New York City and Chesapeake Bay watersheds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation of natural resources has implications for international, national, and local citizens. The creation of natural resource management and conservation strategies can be affected by engagement with local citizens and competing interests between agencies and stakeholders at the varying leve...

  7. 76. Photocopy of photograph (original print in the Minnesota Historical ...

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

    76. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, 1860. #22358.) UPPER LEVEE FROM CHESTNUT STREET, 1860 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

  8. 77. Photocopy of photograph (original print in the Minnesota Historical ...

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

    77. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, 1859. #377. Photographer: Illingworth.) LOWER LEVEE FROM JACKSON STREET, 1859 - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

  9. Delgada Fan: Preliminary interpretation of channel development

    USGS Publications Warehouse

    Normark, W.R.; Gutmacher, C.E.

    1984-01-01

    The Delgada Fan, an irregularly shaped turbidite deposit extending more than 350 km offshore from northern California, consists of two large leveed-valley units each fed by a separate complex of coalescing submarine canyons and slope gullies. Although the leveed-valley units head within 25 km of each other, both appear to have developed independently during fan growth. The larger southern leveed-valley system has not developed middle-fan distributary channels and appears to illustrate a period of progressive valley abandonment. Although the lower-fan area is underlain by sandy sediments, little sand has been recovered in piston cores from the leveed-valley unit. ?? 1984 Springer-Verlag New York Inc.

  10. Comparing Denitrification Rates and Carbon Sources in Commercial Scale Upflow Denitrification Biological Filters in Aquaculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerobic biological filtration systems employing nitrifying bacteria to remediate excess ammonia and nitrite concentrations are common components of recirculating aquaculture systems (RAS). However, significant water exchange may still be necessary to reduce nitrate concentrations to acceptable leve...

  11. The Ebro Deep-Sea Fan system

    USGS Publications Warehouse

    Nelson, C.H.; Maldonado, A.; Coumes, F.; Got, H.; Manaco, A.

    1984-01-01

    The Ebro Fan System consists of en echelon channel-levee complexes, 50??20 km in area and 200-m thick. A few strong reflectors in a generally transparent seismic facies identify the sand-rich channel floors and levee crests. Numerous continuous acoustic reflectors characterize overbank turbidites and hemipelagites that blanket abandoned channel-levee complexes. The interlobe areas between channel complexes fill with homogeneous mud and sand from mass flow and overbank deposition; these exhibit a transparent seismic character. The steep continental rise and sediment 'drainage' of Valencia Trough at the end of the channel-levee complexes prevent the development of distributary channels and midfan lobe deposits. ?? 1984 Springer-Verlag New York Inc.

  12. 88. (Credit CBF) Twelve Mile Bayou Pumping Station and force ...

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

    88. (Credit CBF) Twelve Mile Bayou Pumping Station and force main for pumping water over levee and into the canal (Blind Bayou), March 1913. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  13. ISOTOPIC EVIDENCE FOR NATURALLY OCCURRING SULFATE PONDS IN THE KANKAKEE RIVER BASIN, ILLINOIS-INDIANA

    EPA Science Inventory

    Design of constructed wetlands in the Kankakee watershed, Indiana, include pumping and distribution ditches leaving former channelized river levees intact. Resultant changes in shallow ground water - surface water interactions may be contributing elevated sulfate to wetland ponds...

  14. Case study of slope failures at Spilmans Island

    SciTech Connect

    Kayyal, M.K.; Hasen, M.

    1998-11-01

    This paper presents a case study for a dredge disposal site called Spilmans Island, located along the Houston-Galveston Ship Channel, east of Houston. Initially classified as a sand bar in the San Jacinto River, Spilmans Island evolved in recent years with the construction of perimeter levees to contain the flow of materials produced from dredging operations. These levees were often constructed on soft dredged sediments, and as the levees were raised, occasionally slope failures occurred. The objectives of this paper are to illustrate the importance of reconstructing the history of a site as a basis for geotechnical analyses, and to demonstrate the significance of keeping accurate records of past investigations, construction activities, slope failures and subsequent remedial measures. The results of the geotechnical investigation described in this paper offer a clear example of how such data can be used to provide reliable predictions on the stability conditions of raised levees.

  15. Modeling flood dynamics along the superelevated channel belt of the Yellow River over the last 3000 years

    NASA Astrophysics Data System (ADS)

    Chen, Yunzhen; Overeem, Irina; Kettner, Albert J.; Gao, Shu; Syvitski, James P. M.

    2015-07-01

    The Yellow River, China, experienced >1000 levee breaches during the last 3000 years. A reduced-complexity model is developed in this study to explore the effects of climate change and human activity on flood levels, levee breaches, and river avulsions. The model integrates yearly morphological change along a channel belt with daily river fluxes and hourly evolution of levee breaches. Model sensitivity analysis reveals that under natural conditions, superelevation of the channel belt dominates flood frequency. When there is significant human-accelerated basin erosion and breach repair, the dominant factors shift to a combination of mean annual precipitation, superelevation, critical shear stress of weak channel banks, and the time interval between breach initiation and its repair. The effect of precipitation on flood frequency is amplified by land use changes in the hinterland, particularly in the erodible Loess Plateau. Uncertainty analysis estimates the most likely values of the dominant factors for six historical periods between 850 B.C. and A.D. 1839, which are used to quantitatively reconstruct flood dynamics. During 850 B.C. to A.D. 1839, when the sediment load increased fourfold, the breach recurrence interval was shortened from more than 500 years to less than 6 years, and the breach outflow rate increased ~27 times. River management practices during A.D. 1579 to A.D. 1839 focused on levees and triggered a severe positive feedback of increased levee heights and flood hazard exacerbation. Raising the levee heights proved to be ineffective for sustainable flood management.

  16. Strategic floodplain reconnection for the Lower Tisza River, Hungary: Opportunities for flood-height reduction and floodplain-wetland reconnection

    NASA Astrophysics Data System (ADS)

    Guida, Ross J.; Swanson, Taylor L.; Remo, Jonathan W. F.; Kiss, Timea

    2015-02-01

    During the late 19th Century, the Tisza River's vast floodplain-wetland system was largely disconnected by levees, facilitating "reclamation" for agriculture and resulting in an estimated loss of over 90% of historical wetlands. While levees have been successful in preventing catastrophic flooding for a century, Lower Tisza flood stage records have been set repeatedly during the last 15 years. The decrease in the Tisza's current floodway carrying capacity has reduced the flood-protection level of the Tisza's aging levee system. Recently in Hungary, "Room for the River" policies have gained more prominence. To explore the possibilities of a room for the river approach along the Lower Tisza, we assess eight potential floodplain-reconnection scenarios between Csongrád, Hungary and the Hungary-Serbia border. A novel framework using hydrodynamic and geospatial modeling was used to perform planning-level evaluations of the tradeoffs between floodplain-reconnection scenarios and enhancement of the existing levee system. The scenarios evaluated include levee removal and levee setbacks to strategically reconnect significant historical wetlands while reducing flood levels. Scenario costs and human population impacts are also assessed. Impacts of reconnecting the Lower Tisza floodplain are compared to heightening levees, the prevailing strategy over the previous century. From a purely construction-cost perspective, heightening Lower Tisza levees is potentially the most cost-effective and politically expedient solution (i.e., impacts the least number of people). However, levee-heightening does not solve the long-term problem of reduced flood conveyance, which has been attributed to aggradation and increased floodplain roughness, nor does it result in wetland reconnection or enhancement of other floodplain ecosystem services. The suite of reconnection options we evaluate provides engineers, planners, and decision makers a framework from which they can further evaluate

  17. Debates—Perspectives on socio-hydrology: Capturing feedbacks between physical and social processes

    NASA Astrophysics Data System (ADS)

    Di Baldassarre, Giuliano; Viglione, Alberto; Carr, Gemma; Kuil, Linda; Yan, Kun; Brandimarte, Luigia; Blöschl, Günter

    2015-06-01

    In flood risk assessment, there remains a lack of analytical frameworks capturing the dynamics emerging from two-way feedbacks between physical and social processes, such as adaptation and levee effect. The former, "adaptation effect", relates to the observation that the occurrence of more frequent flooding is often associated with decreasing vulnerability. The latter, "levee effect", relates to the observation that the non-occurrence of frequent flooding (possibly caused by flood protection structures, e.g. levees) is often associated to increasing vulnerability. As current analytical frameworks do not capture these dynamics, projections of future flood risk are not realistic. In this paper, we develop a new approach whereby the mutual interactions and continuous feedbacks between floods and societies are explicitly accounted for. Moreover, we show an application of this approach by using a socio-hydrological model to simulate the behavior of two main prototypes of societies: green societies, which cope with flooding by resettling out of flood-prone areas; and technological societies, which deal with flooding also by building levees or dikes. This application shows that the proposed approach is able to capture and explain the aforementioned dynamics (i.e. adaptation and levee effect) and therefore contribute to a better understanding of changes in flood risk, within an iterative process of theory development and empirical research.

  18. Influence of hydrologic modifications on Fraxinus pennsylvanica in the Mississippi River Alluvial Valley, USA

    USGS Publications Warehouse

    Gee, Hugo K.W.; King, Sammy L.; Keim, Richard F.

    2015-01-01

    We used tree-ring analysis to examine radial growth response of a common, moderately flood-tolerant species (Fraxinus pennsylvanica Marshall) to hydrologic and climatic variability for > 40 years before and after hydrologic modifications affecting two forest stands in the Mississippi River Alluvial Valley (USA): a stand without levees below dams and a stand within a ring levee. At the stand without levees below dams, spring flood stages decreased and overall growth increased after dam construction, which we attribute to a reduction in flood stress. At the stand within a ring levee, growth responded to the elimination of overbank flooding by shifting from being positively correlated with river stage to not being correlated with river stage. In general, growth in swales was positively correlated with river stage and Palmer Drought Severity Index (an index of soil moisture) for longer periods than flats. Growth decreased after levee construction, but swales were less impacted than flats likely because of differences in elevation and soils provide higher soil moisture. Results of this study indicate that broad-scale hydrologic processes differ in their effects on the flood regime, and the effects on growth of moderately flood-tolerant species such as F. pennsylvanica can be mediated by local-scale factors such as topographic position, which affects soil moisture.

  19. Post-Katrina Fecal Contamination in Violet Marsh near New Orleans

    PubMed Central

    Furey, John S.; Fredrickson, Herbert; Foote, Chris; Richmond, Margaret

    2007-01-01

    Fecal material entrained in New Orleans flood waters was pumped into the local environment. Violet Marsh received water pumped from St. Bernard Parish and the Lower Ninth Ward. Sediment core samples were collected from canals conducting water from these areas to pump stations and from locations within Violet Marsh. Viable indicator bacteria and fecal sterols were used to assess the levels of fecal material in sediment deposited after the levee failures and deeper sediments deposited before. Most of the cores had fecal coliform levels that exceed the biosolids criterion. All of the cores had fecal sterols that exceeded the suggested environmental quality criterion. Our data show both a long history of fecal contamination in Violet Marsh and an increase in fecal loading corresponding to the failure of the levee system. The work was performed as part of the Interagency Performance Evaluation Task Force investigation into the consequences of the failures of the New Orleans levee system. PMID:17617670

  20. Post-Katrina fecal contamination in Violet Marsh near New Orleans.

    PubMed

    Furey, John S; Fredrickson, Herbert; Foote, Chris; Richmond, Margaret

    2007-06-01

    Fecal material entrained in New Orleans flood waters was pumped into the local environment. Violet Marsh received water pumped from St. Bernard Parish and the Lower Ninth Ward. Sediment core samples were collected from canals conducting water from these areas to pump stations and from locations within Violet Marsh. Viable indicator bacteria and fecal sterols were used to assess the levels of fecal material in sediment deposited after the levee failures and deeper sediments deposited before. Most of the cores had fecal coliform levels that exceed the biosolids criterion. All of the cores had fecal sterols that exceeded the suggested environmental quality criterion. Our data show both a long history of fecal contamination in Violet Marsh and an increase in fecal loading corresponding to the failure of the levee system. The work was performed as part of the Interagency Performance Evaluation Task Force investigation into the consequences of the failures of the New Orleans levee system.

  1. [Molecular characterisation and phenotypic description of two patients with reciprocal chromosomal aberrations in the region of the 3q29 microdeletion/microduplication syndromes].

    PubMed

    Quintela, I; Barros-Angueira, F; Perez-Gay, L; Dacruz, D; Castro-Gago, M; Carracedo, A; Eiris-Punal, J

    2015-09-16

    Introduccion. Los sindromes de microdelecion y microduplicacion 3q29 se caracterizan por una marcada heterogeneidad fenotipica, y el retraso del desarrollo y la discapacidad intelectual de grado leve-moderado son las manifestaciones clinicas mas frecuentes. Casos clinicos. Dos pacientes con aberraciones cromosomicas reciprocas en la region 3q29. La paciente con la microdelecion 3q29 presenta dificultades de aprendizaje, microcefalia limite, dismorfismo facial leve, deficit atencional e impulsividad, y rasgos ansiosos y obsesivos. El paciente con la microduplicacion 3q29 reciproca presenta dificultades de aprendizaje, dismorfismo facial leve y un perfil conductual disruptivo no asociado previamente con esta duplicacion. Conclusion. Se comparan los fenotipos de estos pacientes y se revisa la bibliografia de pacientes pediatricos con microdeleciones y microduplicaciones 3q29.

  2. Exposed salt marsh morphodynamics: An example from the Danish Wadden Sea

    NASA Astrophysics Data System (ADS)

    Pedersen, Jørn B. T.; Bartholdy, Jesper

    2007-10-01

    In the Danish Wadden Sea, exposed salt marshes grow in the form of sequences of salt marsh platforms which terminate at the tidal flat with an erosional cliff. On the tidal flat adjacent to the salt marsh, a marsh-parallel small depression is usually formed which acts as a tidal channel (landpriel) creating levees on its landward side, on which salt marsh from the mainland spreads seaward with an uneven topography. On the seaward side of the landpriel, patches of slightly higher elevations form as a result of wave action. As plants get a foothold on these patches salt marsh growth is initiated. Along with this process a salt marsh cliff develops against wave attack from the tidal flat during storms. The unit consisting of levee, landpriel and patches of higher elevation eventually silts up and buries the former cliff on top of the levee, so this now stands as a small (≈ 0.25 m) ridge separating the new platform from the older one. Thus, the salt marsh accretes through a sequence of salt marsh platforms, each with its own landpriel, levee and erosional cliff. The landpriel and levee can be recognised later as topographic lows and highs, respectively, in the sand beneath the fine-grained salt marsh sediments, while the erosional cliff can be recognised in the salt marsh topography. Based on these observations, a conceptual evolutionary/accretionary model for exposed salt marshes with associated erosional cliff, landpriel and levee is presented. The deposition across the salt marsh platform decreases in an exponential manner away from the salt marsh edge at a lower rate than that found on a lee side salt marsh at the Skallingen backbarrier north of the study area. This is interpreted as a result of wave action.

  3. Channel systems and lobe construction in the Mississippi Fan

    USGS Publications Warehouse

    Garrison, L. E.; Kenyon, Neil H.; Bouma, A.H.

    1982-01-01

    Morphological features on the Mississippi Fan in the eastern Gulf of Mexico were mapped using GLORIA II, a long-range side-scan sonar system. Prominent is a sinuous channel flanked by well-developed levees and occasional crevasse splays. The channel follows the axis and thickest part of the youngest fan lobe; seismic-reflection profiles offer evidence that its course has remained essentially constant throughout lobe development. Local modification and possible erosion of levees by currents indicates a present state of inactivity. Superficial sliding has affected part of the fan lobe, but does not appear to have been a factor in lobe construction. ?? 1982 A. M. Dowden, Inc.

  4. Sedimentation, accretion, and subsidence in marshes of Barataria Basin, Louisiana

    SciTech Connect

    Hatton, R.S.; DeLaune, R.D.; Patrick, W.H. Jr.

    1983-05-01

    Vertical accretion and sediment accumulation rates were determined from the distribution of /sup 137/Cs in cores collected from fresh water, intermediate, brackish, and salt marshes in the Barataria Basin, Louisiana. Vertical accretion rates vary from about 1.3 cm.yr/sup -1/ in levee areas to 0.7 in backmarshes. Mineral sediment content of the marsh soil profile decreased with distance from the coast. Except in natural levee areas, marsh accretion rates are less than subsidence measured by water level data, however this alone cannot account for observed land-loss patterns in the basin area.

  5. Architecture and depositional pattern of the Bengal Fan with respect to shelf distance imaged with high-resolution seismic data

    NASA Astrophysics Data System (ADS)

    Schwenk, T.; Spiess, V.; Breitzke, M.; Huebscher, C.

    2003-04-01

    Large submarine fans were recently the target of investigations to evaluate both, their hydrocarbon reservoir potential and their potential as recorder of long- and short-term climatic changes. For both objectives a detailed knowledge of the specific architectural elements is required. The Bengal Fan (the largest submarine fan on Earth) covers the whole Bay of Bengal and is fed by the Ganges and Brahmaputra river sediments, which derived from the drainage of the Himalayan. The amount and nature of these river sediments reacts to tectonic and climatic changes on land, making the Bengal Fan a suitable study area for the link of land and marine processes. The sediments reach the deep sea through a canyon deeply incised into the shelf, also acting as temporary trap. Turbidity currents transport the sediments episodically from the canyon onto the fan, building successively a stack of channel-levee systems, with only one active channel at a time though. In 1997 during R/V Sonne Cruise SO 125 to the Bay of Bengal, the morphology and structure of the Bengal Fan were studied with high-resolution seismics. On four long W-E latitudinal transects at 17°, 14°, 11° and 8°N, the southernmost crossing DSDP Site 218, seismic data were collected to characterise the distribution and character of fan deposits as a function of distance to the shelf. Here we present GI Gun data (100-500 Hz) from these transects to discuss the vertical sequence of architectural elements in occurrence, size and shape as well as downfan changes. Basically, the Bengal Fan consists of numerous channel-levee systems intercalated by High Amplitude Reflector Packets (HARPS). Whereas the channel-levee systems were building up by channelized turbidity currents, the HARPS are deposited by unchannelized turbidity currents, either as a result of levee avulsions or as a result of terminating channel-levee systems. Large mass-flow deposits as slumps or debris flows could not be identified. In particular, the

  6. Analyses of water, core material, and elutriate samples collected near Galliano, Louisiana: Larose to Golden Meadow, Louisiana, Hurricane Protection Project

    USGS Publications Warehouse

    Leone, Harold L.

    1977-01-01

    Seven core-material-sampling sites were chosen by the U.S. Army Corps of Engineers as possible borrow areas for fill material to be used in levee construction near Galliano La. Four receiving-water sites also were selected to represent the water that will contact the proposed levees. Analyses of selected nutrients, metals, pesticides, and other organic constituents were performed upon these bed-material and native-water samples as well as upon elutriate samples of specific core material-receiving water systems. The results of these analyses are presented without interpretation. (Woodard-USGS)

  7. Analyses of water, core material, and elutriate samples collected near Buras, Louisiana (New Orleans to Venice, Louisiana, Hurricane Protection Project)

    USGS Publications Warehouse

    Leone, Harold A.

    1977-01-01

    Eight core-material-sampling sites were chosen by the U.S. Army Corps of Engineers as possible borrow areas for fill material to be used in levee contruction near Buras, La. Eleven receiving-water sites also were selected to represent the water that will contact the porposed levees. Analyses of selected nutrients, metals, pesticides, and other organic constitutents were performed upon these bed-material and native-water samples as well as upon elutriate samples of specific core material-receiving water systems. The results of these analyses are presented without interpretation. (Woodard-USGS)

  8. Morphology of the Ebro fan valleys from SeaMARC and sea beam profiles

    USGS Publications Warehouse

    Alonso, B.; Kastens, K.A.; Maldonado, A.; Malinverno, A.; Nelson, C.H.; O'Connell, S.; Palanques, A.; Ryan, William B. F.

    1985-01-01

    The northern continental slope off the Ebro Delta has a badland topography indicating major slope erosion and mass movement of material that deposits sediment into a ponded lobe. The southern slope has a low degree of mass movement activity and slope valleys feed channel levee-complexes on a steep continental rise. The last active fan valley is V-shaped with little meandering and its thalweg merges downstream with the Valencia Valley. The older and larger inactive channel-levee complex is smoother, U-shaped, and meanders more than the active fan valley. ?? 1985 Springer-Verlag New York Inc.

  9. Earthen embankment breaching

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A large number of embankment structures, including dams, levees, dikes, and barriers, have been built by humans. These structures play a very important role in flood defense, while many are also used for water supply, power generation, transportation, sediment retention, etc. Since these structure...

  10. Earthen embankment erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A large number of embankment structures, including dams, levees, dikes, and barriers, have been built by humans or formed naturally along rivers, lakes, and coastal lines around the world. These structures play very important roles in flood defense, while many are also used for water supply, power g...

  11. 14. PROJECT PLAN, INTAKE PIER, RAW WATER CONDUITS, PUMPING STATION ...

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

    14. PROJECT PLAN, INTAKE PIER, RAW WATER CONDUITS, PUMPING STATION FORCE MAINS, TREATED WATER PIPELINES, AND FILTRATION PLANT, SHEET 1 OF 117, 1920. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  12. 76 FR 69283 - Notice of Availability of the Final Supplemental Environmental Assessment and Finding of No...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... Environmental Assessment and Finding of No Significant Impact for Improvements to the Mission Levee Protective System in Hidalgo County, TX AGENCY: United States Section, International Boundary and Water Commission, United States and Mexico (USIBWC). ACTION: Notice of Availability of the Final Supplemental...

  13. 9. VIEW OF INTAKE PIER AND MAIN SPAN OF ACCESS ...

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

    9. VIEW OF INTAKE PIER AND MAIN SPAN OF ACCESS BRIDGE FROM WATER LEVEL, LOOKING NORTHWEST. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  14. Katrina and the Privilege of Despair: Welch's Model of Connection in Teaching for Social Justice

    ERIC Educational Resources Information Center

    Brown, Alicia D.; Brooks, Julia G.; Gunzenhauser, Michael G.

    2008-01-01

    In this essay, the authors note a particular air of apathy in relation to the post-Katrina era expressed in teacher education classes. They are concerned with what the cultural levees mean for justice-oriented educators. How might they find ways to foster in their students connections of empathy and solidarity with those experiencing these…

  15. Clay mineral variations in Four-Point Bayou, Terrebonne Parish, Louisiana

    SciTech Connect

    Baxter, P.; Ferrell, R.E.

    1987-05-01

    Cores of unconsolidated sediments from the Four-Point Bayou area, representing an interdistributary basin deposit less than 1000 years old, were examined for variations in clay mineralogy. Two specific environments of deposition, interpreted from grain-size analyses and sedimentary structures, were compared: a sand-rich natural levee deposit and an overlying clay-rich interdistributary bay. Analyses of the < 2 ..mu..m clay fraction using Schultz's method show smectite to be the predominant clay in both environments. The relative abundance of kaolinite:illite:smectite in the natural levee, near-channel deposits is 1:3:6. In bay deposits, it is 2:3:5. Hydraulic fractionation of clays during deposition should result in a high K/I ratio in natural levees and a low ratio in bay deposits, the reverse of what was observed. Kaolinite should have been enriched in natural levees at the expense of illite. Other processes must have been operative either at the time of deposition or during early diagenesis of these deposits. Possible mechanisms include localized redistribution and sorting or chemical equilibration with early pore fluids associated with saltwater intrusion. The mixing of clays from different sources could also account for the observed differences.

  16. Design and fish culture considerations for catfish farming in split ponds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Split ponds are simple, pond-based aquaculture systems constructed by dividing an existing catfish pond into two unequal basins with an earthen levee. Fish are confined in the smaller basin (usually about 15-20% of total water area) while the larger basin serves as a waste-treatment lagoon. A high-v...

  17. 76 FR 53827 - Safety Zone; Big Sioux River From the Military Road Bridge North Sioux City to the Confluence of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... destruction, and loss or injury due to the hazards associated with flood water. The impacts on routine... or injury due to the hazards associated with flood water. If you are a small business entity and are... continued and uninterrupted protection of levees and personnel involved in ongoing high water...

  18. Public Opinion on Long Island about the Vietnam War: A School Year Project Using Local Sources and Perspectives in the Classroom and in Student Research Papers

    ERIC Educational Resources Information Center

    Howlett, Charles

    2004-01-01

    A school-year research experiment using primary resources to teach an important national issue--protest movements against the Vietnam War at the local level--is an excellent way to motivate students and energize classroom teaching. Every local community in America has its own story to tell about the war in Vietnam. Whether it is about a local son…

  19. 76 FR 80366 - Clean Water Act Section 303(d): Availability of One Total Maximum Daily Load (TMDL) in Louisiana

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-23

    ... AGENCY Clean Water Act Section 303(d): Availability of One Total Maximum Daily Load (TMDL) in Louisiana...: Comments on the one TMDL should be sent to Diane Smith, Environmental Protection Specialist, Water Quality... Waterbody name Pollutant 041401 New Orleans East Leveed Dissolved oxygen. Waterbodies (Estuarine). The...

  20. Three dimensional numerical modeling of flow and pollutant transport in a flooding area of 2008 US Midwest Flood

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper presents the development and application of a three-dimensional numerical model for simulating the flow field and pollutant transport in a flood zone near the confluence of the Mississippi River and Iowa River in Oakville, Iowa. Due to a levee breaching along the Iowa River during the US ...

  1. 18. INTAKE PIER, BRIDGE DETAILS, SHEET 9 OF 117, 1920. ...

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

    18. INTAKE PIER, BRIDGE DETAILS, SHEET 9 OF 117, 1920. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  2. 13. INTERIOR VIEW OF GATE OPERATOR ROOM, SHOWING UNFINISHED CONCRETE ...

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

    13. INTERIOR VIEW OF GATE OPERATOR ROOM, SHOWING UNFINISHED CONCRETE WALLS AND SLIDE GATE OPERATORS, LOOKING NORTH. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  3. 21. COMPLETION OF INTAKE CONDUITS REVISED, PIPE SECTIONS AND PLANS, ...

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

    21. COMPLETION OF INTAKE CONDUITS REVISED, PIPE SECTIONS AND PLANS, SHEET 117 OF 117, 1922. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  4. 19. INTAKE CONDUITS, PROFILE, SECTIONS, AND DETAILS, SHEET 10 OF ...

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

    19. INTAKE CONDUITS, PROFILE, SECTIONS, AND DETAILS, SHEET 10 OF 117, 1920. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  5. 8. VIEW OF ACCESS BRIDGE AND INTAKE PIER FROM THE ...

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

    8. VIEW OF ACCESS BRIDGE AND INTAKE PIER FROM THE BRIDGE PIER ABUTMENT, LOOKING NORTHEAST. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  6. 6. VIEW OF APPROACH SPAN AND MAIN SPAN OF THE ...

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

    6. VIEW OF APPROACH SPAN AND MAIN SPAN OF THE ACCESS BRIDGE AND INTAKE PIER, LOOKING SOUTHWEST. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  7. 11. DETAIL VIEW OF APPROACH TO INTAKE PIER FROM ACCESS ...

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

    11. DETAIL VIEW OF APPROACH TO INTAKE PIER FROM ACCESS BRIDGE, SHOWING DOOR TO INTERIOR GATE OPERATOR ROOM, LOOKING WEST. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  8. 4. DETAIL OF THE BRIDGE PIER SHOWING THE SUSPENSION CABLE, ...

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

    4. DETAIL OF THE BRIDGE PIER SHOWING THE SUSPENSION CABLE, LOOKING SOUTHWEST. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  9. 15. SUPERSTRUCTURE PLANS, ELEVATION AND DETAILS, SHEET 4 OF 117, ...

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

    15. SUPERSTRUCTURE PLANS, ELEVATION AND DETAILS, SHEET 4 OF 117, 1920. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  10. 3. APPROACH TO THE ACCESS BRIDGE AND INTAKE PIER, LOOKING ...

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

    3. APPROACH TO THE ACCESS BRIDGE AND INTAKE PIER, LOOKING SOUTHWEST. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  11. 2. OVERALL VIEW OF INTAKE PIER AND ACCESS BRIDGE, LOOKING ...

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

    2. OVERALL VIEW OF INTAKE PIER AND ACCESS BRIDGE, LOOKING NORTH. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  12. 20. COMPLETION OF INTAKE CONDUITS, PLANS, PROFILES, AND DETAILS, SHEET ...

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

    20. COMPLETION OF INTAKE CONDUITS, PLANS, PROFILES, AND DETAILS, SHEET 115 OF 117, 1922. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  13. 16. INTAKE PIER, PLANS ELEVATIONS, AND SECTIONS, SHEETS 5 OF ...

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

    16. INTAKE PIER, PLANS ELEVATIONS, AND SECTIONS, SHEETS 5 OF 117, 1920. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  14. 12. INTERIOR VIEW OF GATE OPERATOR ROOM, SHOWING SLIDES GATE ...

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

    12. INTERIOR VIEW OF GATE OPERATOR ROOM, SHOWING SLIDES GATE OPERATORS, LOOKING NORTHWEST. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  15. The Kabu-ido system: a pioneering solution for uncoordinated groundwater pumping in Japan

    NASA Astrophysics Data System (ADS)

    Endo, T.

    2015-11-01

    The Kabu-ido system was a customary institution for groundwater management in a ring levee area of the Tokai region in Japan. It consists of three programs, a permit system for groundwater pumping, groundwater pricing, and economic compensation. The purpose of this paper is to clarify characteristics of the Kabu-ido as a groundwater management institution.

  16. Characterizing the Exposure of Regional-Scale Air Quality in the Northeastern United States

    EPA Science Inventory

    The Clean Air Act (CAA) requires that the United States (U.S.) Environmental Protection Agency (EPA) set National Ambient Air Quality Standards (NAAQS) for pollutants considered harmful to human health and the environment. Previous research has shown that high ambient ozone leve...

  17. Internal erosion and impact of erosion resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The two most common causes of earthen embankment and levee failure are embankment overtopping and internal erosion. Internal erosion occurs when water flows through a cavity, crack, and/or other opening within the embankment. These openings may be a result of inadequate compaction during construct...

  18. Erodibility characteristics of embankment materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Erosion is one of the least reliably defined elements of many hydraulic projects. Earthen embankments (i.e. dams and levees) are an example of hydraulic projects in which erosion and material erodibility have not been reliably defined in the past. Recent as well as past embankment failures have he...

  19. Hyperspectral image classification and development of fluorescence index for single corn kernels infected with Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins are toxic secondary metabolites predominantly produced by the fungi Aspergillus flavus and A. parasiticus. Aflatoxin contaminated corn is toxic to domestic animals when ingested in feed and is a known carcinogen associated with liver and lung cancer in humans. Consequently, aflatoxin leve...

  20. Single Aflatoxin Contaminated Corn Kernel Analysis with Fluorescence Hyperspectral Image

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins are toxic secondary metabolites of the fungi Aspergillus flavus and Aspergillus parasiticus, among others. Aflatoxin contaminated corn is toxic to domestic animals when ingested in feed and is a known carcinogen associated with liver and lung cancer in humans. Consequently, aflatoxin leve...

  1. Katrina's Children: Social Policy Considerations for Children in Disasters. Social Policy Report. Volume 21, Number 1

    ERIC Educational Resources Information Center

    Osofsky, Joy D.; Osofsky, Howard J.; Harris, William W.

    2007-01-01

    Hurricane Katrina resulted in a disaster of proportions not previously known in the United States. The traumatic experiences of children and families during Hurricane Katrina, the flooding that resulted from the breach of the levees, the evacuation, and the aftermath are unprecedented. In responding to the enormous mental health needs of children…

  2. Cigarrillos de mentol | Smokefree Español

    Cancer.gov

    ¿Qué es el mentol? El mentol es una sustancia encontrada naturalmente en las plantas de menta, tales como la menta fresca y la hierbabuena. Deja una sensación refrescante y se usa frecuentemente para aliviar el dolor y la irritación leve, y para prevenir infecciones [1].

  3. 75. Photocopy of photograph (original print in the Minnesota Historical ...

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

    75. Photocopy of photograph (original print in the Minnesota Historical Society, St. Paul, Minnesota, ca. 1870s. #22006. Photographer: Illingworth.) VIEW TO SOUTHEAST, SHOWING THE UPPER LEVEE AND BLUSS (on left) TO WHICH THE HIGH BRIDGE WAS BUILT - Smith Avenue High Bridge, Smith Avenue between Cherokee Avenue & Cliff Street, Saint Paul, Ramsey County, MN

  4. Relationship between the erosion properties of soils and other parameters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil parameters are essential for erosion process prediction and ultimately improved model development, especially as they relate to dam and levee failure. Soil parameters including soil texture and structure, soil classification, soil compaction, moisture content, and degree of saturation can play...

  5. Starting Anew

    ERIC Educational Resources Information Center

    Lum, Lydia

    2006-01-01

    Hundreds of higher education faculty lost their jobs in the aftermath of Hurricane Katrina. New Orleans' colleges and universities were forced to cancel fall semester classes after the city's levee system failed, submerging 80 percent of the city just weeks before the academic year began. Damage assessments began even before the deadly storm's…

  6. Civic Engagement about Climate Change: A Case Study of Three Educators and Their Practice

    ERIC Educational Resources Information Center

    Chandler, Thomas; Marri, Anand R.

    2012-01-01

    This collective case study examined how three educators (a high school social studies teacher, a university social studies teacher educator, and minister teaching an adult population) used a multimedia based curriculum guide, "Teaching the Levees", to teach about climate change to examine public priorities in relation to the environment.…

  7. Simulated response and effects to oil exposure in an estuarine fish species

    EPA Science Inventory

    Experimental toxicity data alone lack ecological relevance to assess more realistic situations, such as variable exposure to a contaminant and long-term impact. Evaluating the implications of sublethal effects or behavioral response to exposure requires long-term, population-leve...

  8. Downstream on the Mississippi.

    ERIC Educational Resources Information Center

    Parfit, Michael

    1993-01-01

    Recounts a trip down the Lower Mississippi River starting in Memphis, describing the features of the river at different stops along the way. Aspects of life along the river discussed include the levee system built to contain the waters, flooding on the river, and travel on the river. (MDH)

  9. Making Ethnic Citizens: The Politics and Practice of Education in Malaysia

    ERIC Educational Resources Information Center

    Brown, Graham K.

    2007-01-01

    This paper examines the politics and practice of education in Malaysia within the context of ethnicity and nation building. Public education in Malaysia--particularly, but not exclusively, at the pre-university level--is promoted as a nation-building tool, seeking to inculcate a sense of Malaysian-ness and patriotism. Simultaneously, however,…

  10. Nocturnal intermittency in surface CO2 concentrations in sub-Saharan Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Data obtained over four adjacent fields of differing management practices in Zimbabwe illustrate the role of atmospheric intermittency as a mechanism for transferring CO2 between the surface and the atmosphere above. At night, limited atmospheric mixing permits CO2 concentrations to increase to leve...

  11. Necessarily Cumbersome, Messy, and Slow: Community Collaborative Work within Art Institutions

    ERIC Educational Resources Information Center

    Filipovic, Yaël

    2013-01-01

    Building relationships and community collaborations--especially on an institutional level--is a slow and long-term process. These types of innovative, experimental, and long-term collaborations with community organizations and groups often lead art institutions to reflect on the value and place of their institutional structures when engaging in…

  12. 75 FR 77662 - United States Section; Notice of Availability of a Final Environmental Assessment and Finding of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-13

    ... Procedures for Implementing Section 102 of NEPA, published in the Federal Register September 2, 1981, (46 FR... Project in Cameron and Hidalgo Counties, TX AGENCY: United States Section, International Boundary and... for Arroyo Colorado South Levee Rehabilitation Project located in Cameron and Hidalgo Counties,...

  13. 75 FR 21659 - Notice of Availability of a Draft Environmental Assessment and Finding of No Significant Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-26

    ... Procedures for Implementing Section 102 of NEPA, published in the Federal Register September 2, 1981, (46 FR... Project in Cameron and Hidalgo Counties, TX AGENCY: United States Section, International Boundary and... for Arroyo Colorado South Levee Rehabilitation Project located in Cameron and Hidalgo Counties,...

  14. Development and validation of a 2D dam break process model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flooding due to dam or levee breach often results in detrimental impact on the people and their properties in the flooding zone. The embankment breach process is often caused by overtopping or internal erosion due to excessive water in a reservoir or a river. This study is to develop a practical nu...

  15. Delta Subsidence in California: The Sinking Heart of the State

    USGS Publications Warehouse

    Ingebritsen, S.E.; Ikehara, M.E.; Galloway, D.L.; Jones, D.R.

    2000-01-01

    The Sacramento-San Joaquin River Delta of California once was a great tidal freshwater marsh blanketed by peat and peaty alluvium. Beginning in the late 1800s, levees were built along the stream channels, and the land thus protected from flooding was drained, cleared, and planted. Although the Delta is now an exceptionally rich agricultural area (over a $500 million crop value in 1993), its unique value is as a source of freshwater for the rest of the State. It is the heart of a massive north-to-south waterdelivery system. Much of this water is pumped southward for use in the San Joaquin Valley and elsewhere in central and southern California. The leveed tracts and islands help to protect water-export facilities in the southern Delta from saltwater intrusion by displacing water and maintaining favorable freshwater gradients. However, ongoing subsidence behind the levees reduces levee stability and, thus, threatens to degrade water quality in the massive north-to-south water-transfer system.

  16. Out of New Orleans: Race, Class, and Researching the Katrina Diaspora

    ERIC Educational Resources Information Center

    Morris, Jerome E.

    2008-01-01

    The torrential rains from Hurricane Katrina, the breaking of the levees, and the subsequent flooding of New Orleans resulted in another Black Diaspora. This article focuses on Black children and families who were displaced by Hurricane Katrina but now reside in cities, towns, and suburbs outside of the Crescent City. Informed by the author's…

  17. 76 FR 29215 - Notice of Intent To Prepare Draft Environmental Impact Statements/Environmental Impact Reports...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-20

    ...-central California: a Feasibility Study of flood risk management and related water resources problems in... Section 404 of the Clean Water Act (33 U.S.C. 1344), the proposed Feather River West Levee Project (FRWLP... study areas, purpose, potential improvements, potential effects, and involved parties. Therefore,...

  18. Macronutrients use efficiency and changes in chemical properties of an oxisol as influenced by phosphorus fertilization and tropical cover crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover crops are important components of copping systems due to their beneficial effects on soil physical, chemical and biological properties. A green house experiment was conducted to evaluate influence of phosphorus (P) fertilization on nutrient use efficiency of 14 tropical cover crops. The P leve...

  19. 10. DETAIL VIEW OF LOWER LEVEL OF INTAKE PIER SHOWING ...

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

    10. DETAIL VIEW OF LOWER LEVEL OF INTAKE PIER SHOWING THE RIVER HEIGHT INDICATOR, ONE OF THE FIVE GATE OPENINGS, AND MOORINGS, LOOKING SOUTHWEST. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  20. Leadership in Freshman Physics

    ERIC Educational Resources Information Center

    Rebello, Carina M.; Hanuscin, Deborah; Sinha, Somnath

    2011-01-01

    Physics First--a movement to invert the traditional science course sequence to teach physics at the ninth-grade level--is gaining interest. However, there is limited literature exploring how to support teachers in successfully implementing Physics First. To address this, a professional development (PD) program supporting a cadre of teacher-leaders…

  1. Flooding and Schools

    ERIC Educational Resources Information Center

    National Clearinghouse for Educational Facilities, 2011

    2011-01-01

    According to the Federal Emergency Management Agency, flooding is the nation's most common natural disaster. Some floods develop slowly during an extended period of rain or in a warming trend following a heavy snow. Flash floods can occur quickly, without any visible sign of rain. Catastrophic floods are associated with burst dams and levees,…

  2. Leading in the Worst of Times

    ERIC Educational Resources Information Center

    Elliott, Cynthia B.; Taylor, Denny

    2006-01-01

    On Monday, August 29, 2005, Hurricane Katrina and the floodwaters from the breeched levees destroyed all 14 schools in Louisiana's St. Bernard Parish. Although most residents had been evacuated before the hurricane hit, 1,500 men, women, and children rode out the storm in Chalmette High School. The district superintendent and the school leadership…

  3. Good News for New Orleans: Early Evidence Shows Reforms Lifting Student Achievement

    ERIC Educational Resources Information Center

    Harris, Douglas N.

    2015-01-01

    What happened to the New Orleans public schools following the tragic levee breeches after Hurricane Katrina is truly unprecedented. Within the span of one year, all public-school employees were fired, the teacher contract expired and was not replaced, and most attendance zones were eliminated. The state took control of almost all public schools…

  4. From Classroom to Gallery: Building Community and Preserving Heritage

    ERIC Educational Resources Information Center

    Barron, Kate

    2012-01-01

    When the levees broke during Hurricane Katrina in 2005, eighty percent of New Orleans flooded, and the citizens who returned to the evacuated city had to rebuild their homes, cultural institutions, and school system. This article records how The Ogden Museum of Southern Art, University of New Orleans, was able to collaborate with a charter school…

  5. Revisiting the Gulf Coast after Katrina

    ERIC Educational Resources Information Center

    Principal, 2009

    2009-01-01

    In August 2005, the world witnessed one of the most destructive natural disasters on America's mainland. Hurricane Katrina, followed a month later by Hurricane Rita, brought more than broken levees, flooded streets and homes, and destroyed businesses. It caused changes in the dynamics and the demographic and cultural makeup of the region. One of…

  6. 7 CFR 623.5 - Ineligible land.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Ineligible land. 623.5 Section 623.5 Agriculture... AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS RESERVE PROGRAM § 623.5 Ineligible land. Notwithstanding any... conditions; (d) Land located between the pre-flood mainstem levees and the river; or (e) Land that...

  7. Student Mobility and Academic Achievement. ERIC Digest.

    ERIC Educational Resources Information Center

    Rumberger, Russell W.

    Student mobility--students moving from one school to another for reasons other than being promoted to the next school level-is widespread in the United States. This digest examines the research on the academic consequences of mobility for elementary school students and discusses what schools and parents can do to mitigate the possible negative…

  8. 7. CLOSEUP VIEW OF THE PUMP DISCHARGE CHANNEL, AND THE ...

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

    7. CLOSEUP VIEW OF THE PUMP DISCHARGE CHANNEL, AND THE DISCHARGE WEIR OF THE FOR PUMPS NO. 2 AND 3, LOOKING NORTHEAST. THE SERVICE BRIDGE PROVIDED ACCESS TO THE LEVEE OVER TOBY CREEK. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

  9. 4. VIEW OF THE WEST FACADE. NOTE THE BRIDGES FROM ...

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

    4. VIEW OF THE WEST FACADE. NOTE THE BRIDGES FROM THE D.L. & W. R.R. WOODWARD SIDING AND MAIN LINE IN THE LEFT FOREGROUND. PHOTO IS FROM THE LEVEE CROSSING TOBY CREEK FACING EAST. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

  10. 44 CFR 206.346 - Applicability to disaster assistance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... prevent loss of life, prevent damage to improved property and protect public health and safety; (3... of utilities, provision of heat in the season requiring heat, or provision of minimal cooking... bridges; (2) Drainage structures, dams, levees; (3) Buildings and equipment; (4) Utilities...

  11. Pronghorn virus, genomic and antigenic characterization and detection in free ranging ungulates in the US

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: In addition to the recognized/classic species within the pestivirus genus there are putative species. One of these is pronghorn virus (PHV). PHV was first isolated from an immature, blind pronghorn antelope in the state of Wyoming. The objectives of these studies were to determine leve...

  12. Physiological effects of Meloidogyne incognita infection on cotton genotypes with differing levels of resistance in the greenhouse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Greenhouse tests were conducted to evaluate 1) the effect of Meloidogyne incognita infection in cotton on plant growth and physiology including the height-to-node ratio, chlorophyll content, dark adapted quantum yield of photosystem II, and leaf area, and 2) the extent to which moderate or high leve...

  13. 76 FR 53820 - Safety Zone; Missouri River From the Border Between Montana and North Dakota

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... destruction to levees and vessels and tows. DATES: Section 165.T11-0511 temporarily added at 76 FR 37647, June... pursuant to the temporary final Rule at docket USCG-2011-0511 (76 FR 37647) established a safety zone for...; Department of Homeland Security Delegation No. 0170.1. 0 2. Section 165.T11-0511 temporarily added at 76...

  14. 17. INTAKE PIER, BRIDGE STRESS SHEET, SHEET 8 OF 117, ...

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

    17. INTAKE PIER, BRIDGE STRESS SHEET, SHEET 8 OF 117, 1920. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  15. Geotechnical reconnaissance of the Mississippi River Delta flood-protection system after Hurricane Katrina: Chapter 3C in Science and the storms-the USGS response to the hurricanes of 2005

    USGS Publications Warehouse

    Luna, Ronaldo; Summers, David; Hoffman, David; Rogers, J. David; Sevi, Adam; Witt, Emitt C.

    2007-01-01

    This article presents the post-Hurricane Katrina conditions of the flood-protection system of levees and floodwalls that failed in the environs of the Mississippi River Delta and New Orleans, La. Damage conditions and suggested mechanisms of failure are presented from the geotechnical point of view.

  16. Lessons: Katrina and Beginning Anew

    ERIC Educational Resources Information Center

    Kirylo, James D.

    2005-01-01

    New Orleans, fondly known in better days for its spectacular cuisine, cool jazz, and good times, was the leading story on television news broadcasts the world over when a massive hurricane came. As Katrina took its destructive path, culminating in the devastating rupture of ill-prepared levee systems, the world was riveted by stories about the…

  17. Preliminary waste acceptance criteria for the ICPP spent fuel and waste management technology development program

    SciTech Connect

    Taylor, L.L.; Shikashio, R.

    1993-09-01

    The purpose of this document is to identify requirements to be met by the Producer/Shipper of Spent Nuclear Fuel/High-LeveL Waste SNF/HLW in order for DOE to be able to accept the packaged materials. This includes defining both standard and nonstandard waste forms.

  18. Best Practices and Simultaneous Compliance

    EPA Science Inventory

    This wrap-up presentation to the workshop covers several topics concerning how lead and copper compliance under the Lead and Copper Rule should be integrated into an overall “simultaneous compliance” framework with other organizations. The LCR requires “optimization” of lead leve...

  19. 7 CFR 623.5 - Ineligible land.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF... owned or acquired by an agency of the Federal Government; (c) Land already subject to a deed restriction... conditions; (d) Land located between the pre-flood mainstem levees and the river; or (e) Land that...

  20. 78 FR 24382 - Endangered and Threatened Species; Take of Anadromous Fish

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-25

    ... distribution and diversity of anadromous fish species in water bodies adjacent to and within the county's levee... management practice program and establish in-water work windows that would minimize effects on listed fish... pacificus): Threatened southern (S). Green sturgeon (Acipenser medirostris): Threatened southern...

  1. 75 FR 13303 - Notice of Realty Action: Direct Sale of Public Lands in Riverside County, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ... public lands in the N lying south of the Chino Wash Flood Control Levee. The area described contains... Bureau of Land Management Notice of Realty Action: Direct Sale of Public Lands in Riverside County, CA AGENCY: Bureau of Land Management, Interior. ACTION: Notice of Realty Action. SUMMARY: The Bureau of...

  2. Internal geometry, seismic facies, and petroleum potential of canyons and inner fan channels of the Indus submarine fan

    SciTech Connect

    McHargue, T.R.; Webb, J.E.

    1986-02-01

    The Indus Fan, the second largest submarine fan in the world, covers 1,250,000 km/sup 2/ (500,000 mi/sup 2/) and contains sediment more than 7 km (23,000 ft) thick. Multichannel (24-fold) CDP seismic data provide the bases for evaluating the Indus Fan and consist of four seismic facies. Of these, only the high-amplitude, discontinuous (H-D) facies is thought to contain reservoir-quality sandstones. The H-D facies is confined to the axes of leveed channels. Canyon-channel systems that fed the fan in the past can be divided into three zones. The degradational zone is composed of an erosional canyon complex filled by prodelta mud. The transitional zone, located near the canyon mouth, consists of superimposed channels that initially were erosional but eventually aggraded and developed levees. The headward termination of the H-D facies occurs in this zone. The aggradational zone consists of superimposed leveed channels confined solely by their own levees. The proximal termination of the H-D facies near canyon mouths implies the presence of reservoir-quality sandstone surrounded by source/seal mudstone in the transitional zone. This stratigraphic trapping geometry and structural leads may represent a vast, untapped petroleum province.

  3. Connecting the Disconnected: Scholar Activists and Education Reform in Post-Katrina New Orleans

    ERIC Educational Resources Information Center

    Cook, Daniella Ann

    2014-01-01

    When Hurricane Katrina slammed into New Orleans on August 29, 2005, the failure of the levees resulted in the largest single human-made disaster in the United States. In addition to the physical devastation of the city, the landscape of public schools in New Orleans was permanently altered, as was the national dialogue about school reform in the…

  4. In utero glucocorticoid (GLC) exposure and maternal undernutrition reduce fetal skeletal muscle mass by different mechanisms in rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Both maternal undernutrition and exposure of the fetus to above normal levels of GLC impair skeletal muscle growth. The degree to which the effects of maternal undernutrition on fetal skeletal muscle growth are a direct result of nutrient deficit or secondary to the presence of above normal GLC leve...

  5. A large channel system in the western the Riiser Larsen Sea, East Antarctica: Paleoceanographic and sedimentary aspects

    NASA Astrophysics Data System (ADS)

    Hass, H. Christian; Klages, Johann P.; Kuhn, Gerhard; Forwick, Matthias

    2016-04-01

    We investigated seafloor morphology and sedimentary processes at the continental margin in the western Riiser Larsen Sea, Antarctica, to reconstruct processes of channel/levee development, and to evaluate the influence of climate through the past 5 marine isotope stages on these processes. Shallow seismic (parametric subbottom profiler) investigations reveal that channels and associated levees form the principal morphological structures in the western Riiser Larsen Sea. The channels are up to several kilometers wide and hundreds of meters deep. They stretch from the upper continental slope towards the Enderby Abyssal Plain. Sediment cores (taken from levee tops) reveal increased amounts of sand and coarser silt during warmer climate phases (MIS 1, 3, 5). The sand is mainly composed of planktic foraminifers and IRD, both suggesting seasonally open waters (interglacials). The carbonate-free sortable silt mean grain size suggests increased bottom current speed during the warmer climate phases. We postulate, that the occurrence of coastal polynyas and strong sea-ice formation through katabatic winds promote the formation of cold waters and brines. These are channeled on the continental slope and intensify turbidity currents that occur on the steep slopes. Alternatively, the newly formed dense waters can be taken up by westward flowing contour currents and thus support the formation of turbidity currents. It is suggested that either process supports downslope sediment transport and levee growth during warm climate phases. Under cold climates a permanent ice cover is suggested at least for the positions of the sediment cores (seasonally open waters today). These reveal significantly IRD and carbonate-depleted sediments during the cold climate phases. Hence, polynyas may have formed further to the north over deeper waters. The volume of the cooled-down waters and brines was likely smaller and probably not able to reach the sea floor due to mixing with upwelling warmer

  6. Subsurface imaging of flood embankment erosional-piping collapse using a combined MASW and ERI approach

    NASA Astrophysics Data System (ADS)

    Brook, Martin

    2016-04-01

    In recent years, non-destructive investigations and management of civil engineering structures is increasingly improving, and assessments are now supported by national and international standards. However, the literature on the applicability of different geophysical techniques to the problem of levee and river embankment monitoring is still limited. Accurate flood levee embankment stability assessment is critically important because embankments and earth dams are subject to water infiltration and internal erosion, which may lead to mechanical weakness and breaching. This study includes a 2D analysis of the instability of an earthen levee, using multichannel analysis of surface waves (MASW) and electrical resistivity imaging (ERI), along with direct observations of the site engineering geology and geomorphology. Both the modeled Vs and Ω indicate a horizontally-layered subsurface with rapid vertical transitions in both stiffness and conductivity. This conclusion is supported by a covariance analysis of Vs and Ω at varying depths and chainages along the levee. Together with a geomorphic assessment, this indicates that the structure is being destabilized by water infiltration, which is causing erosional-piping, leading to surface subsidence. While the key reason for applying various types of geophysical methods to embankment stability assessment is to undertake a safety examination of the embankment, a secondary reason is to compare and contrast the efficacy of the geophysical methods. To this end, it was found that the integration of covariance analysis of 2D geophysical datasets, alongside sedimentary and topographic data, can help the rapid location of anomalous zones in sub-levee soils between geotechnical boreholes.

  7. Evaluating the role of coastal habitats and sea-level rise in hurricane risk mitigation: An ecological economic assessment method and application to a business decision.

    PubMed

    Reddy, Sheila M W; Guannel, Gregory; Griffin, Robert; Faries, Joe; Boucher, Timothy; Thompson, Michael; Brenner, Jorge; Bernhardt, Joey; Verutes, Gregory; Wood, Spencer A; Silver, Jessica A; Toft, Jodie; Rogers, Anthony; Maas, Alexander; Guerry, Anne; Molnar, Jennifer; DiMuro, Johnathan L

    2016-04-01

    Businesses may be missing opportunities to account for ecosystem services in their decisions, because they do not have methods to quantify and value ecosystem services. We developed a method to quantify and value coastal protection and other ecosystem services in the context of a cost-benefit analysis of hurricane risk mitigation options for a business. We first analyze linked biophysical and economic models to examine the potential protection provided by marshes. We then applied this method to The Dow Chemical Company's Freeport, Texas facility to evaluate natural (marshes), built (levee), and hybrid (marshes and a levee designed for marshes) defenses against a 100-y hurricane. Model analysis shows that future sea-level rise decreases marsh area, increases flood heights, and increases the required levee height (12%) and cost (8%). In this context, marshes do not provide sufficient protection to the facility, located 12 km inland, to warrant a change in levee design for a 100-y hurricane. Marshes do provide some protection near shore and under smaller storm conditions, which may help maintain the coastline and levee performance in the face of sea-level rise. In sum, the net present value to the business of built defenses ($217 million [2010 US$]) is greater than natural defenses ($15 million [2010 US$]) and similar to the hybrid defense scenario ($229 million [2010 US$]). Examination of a sample of public benefits from the marshes shows they provide at least $117 million (2010 US$) in coastal protection, recreational value, and C sequestration to the public, while supporting 12 fisheries and more than 300 wildlife species. This study provides information on where natural defenses may be effective and a replicable approach that businesses can use to incorporate private, as well as public, ecosystem service values into hurricane risk management at other sites.

  8. Linking River Management-Induced Perturbations of Hydrologic and Sediment Regimes to Geomorphic Processes Along a Highly-Dynamic Gravel-Bed River: Snake River, WY.

    NASA Astrophysics Data System (ADS)

    Leonard, C.; Legleiter, C. J.

    2015-12-01

    Encroachment of human development onto river floodplains creates a need to stabilize rivers and provide flood protection. Structural interventions, such as levees, often perturb hydrologic and sediment regimes and thus can initiate morphological responses. An understanding of how human activities affect river morphodynamics and trigger channel change is needed to anticipate future river responses and facilitate effective restoration. This study examines approximately 66 km of the Snake River, WY, USA, and links sediment transport processes to channel form and behavior by developing a morphological sediment budget that spans both a natural, unconfined reach and a reach confined by artificial levees. Sediment transport rates are inferred from the morphological sediment budget and a bed mobility study is used to estimate entrainment thresholds that allow us to link the hydrological regime during the sediment budget period to the observed channel changes. Results indicate that lateral constriction by levees triggers a positive feedback mechanism by incising the bed, focusing flow energy, thus increasing transport capacity, and leading to armoring of the bed. In other systems, armoring promotes widening of the channel but in this case levees prevent widening and the channel instead migrates across the braidplain rapidly, producing further erosion of bars and vegetated islands that is expressed as negative net volumetric changes and increased sediment transport rates. Furthermore, decreased slopes and reduced discharges due to dam regulation in the upstream unconfined reach cause gravel sheets to stall on bars and in other areas of storage, creating a spatial discontinuity in sediment conveyance downstream, and thus contributing to the sediment deficit within the leveed reach.

  9. Evaluating the role of coastal habitats and sea-level rise in hurricane risk mitigation: An ecological economic assessment method and application to a business decision.

    PubMed

    Reddy, Sheila M W; Guannel, Gregory; Griffin, Robert; Faries, Joe; Boucher, Timothy; Thompson, Michael; Brenner, Jorge; Bernhardt, Joey; Verutes, Gregory; Wood, Spencer A; Silver, Jessica A; Toft, Jodie; Rogers, Anthony; Maas, Alexander; Guerry, Anne; Molnar, Jennifer; DiMuro, Johnathan L

    2016-04-01

    Businesses may be missing opportunities to account for ecosystem services in their decisions, because they do not have methods to quantify and value ecosystem services. We developed a method to quantify and value coastal protection and other ecosystem services in the context of a cost-benefit analysis of hurricane risk mitigation options for a business. We first analyze linked biophysical and economic models to examine the potential protection provided by marshes. We then applied this method to The Dow Chemical Company's Freeport, Texas facility to evaluate natural (marshes), built (levee), and hybrid (marshes and a levee designed for marshes) defenses against a 100-y hurricane. Model analysis shows that future sea-level rise decreases marsh area, increases flood heights, and increases the required levee height (12%) and cost (8%). In this context, marshes do not provide sufficient protection to the facility, located 12 km inland, to warrant a change in levee design for a 100-y hurricane. Marshes do provide some protection near shore and under smaller storm conditions, which may help maintain the coastline and levee performance in the face of sea-level rise. In sum, the net present value to the business of built defenses ($217 million [2010 US$]) is greater than natural defenses ($15 million [2010 US$]) and similar to the hybrid defense scenario ($229 million [2010 US$]). Examination of a sample of public benefits from the marshes shows they provide at least $117 million (2010 US$) in coastal protection, recreational value, and C sequestration to the public, while supporting 12 fisheries and more than 300 wildlife species. This study provides information on where natural defenses may be effective and a replicable approach that businesses can use to incorporate private, as well as public, ecosystem service values into hurricane risk management at other sites. PMID:26123999

  10. Perched Lava Pond Complex on South Rift of Axial Volcano Revealed in AUV Mapping

    NASA Astrophysics Data System (ADS)

    Paduan, J. B.; Clague, D. A.; Caress, D. W.; Thomas, H. J.

    2013-12-01

    An extraordinary lava pond complex is located on Axial Volcano's distal south rift. It was discovered in EM300 multibeam bathymetry collected in 1998, and explored and sampled with ROVs Tiburon in 2005 and Doc Ricketts in 2013. It was surveyed with the MBARI Mapping AUV D. Allan B. in 2011, in a complicated mission first flying above the levees at constant depth, then skimming ~5 m over the levees at a different constant depth to survey the floors, then twice switching to constant altitude mode to map outside the ponds. The AUV navigation was adjusted using the MB-System tool mbnavadjust so that bathymetric features match in overlapping and crossing swaths. The ~1-m resolution AUV bathymetry reveals extremely rough terrain, where low-resolution EM300 data had averaged acoustic returns and obscured details of walls, floors, a breach and surrounding flows, and gives context to the ROV observations and samples. The 6 x 1.5 km pond complex has 4 large and several smaller drained ponds with rims 67 to 106 m above the floors. The combined volume before draining was 0.56 km3. The ponds overflowed to build lobate-flow levees with elongate pillows draping outer flanks, then drained, leaving lava veneer on vertical inner walls. Levee rim depths vary by only 10 m and are deeper around the southern ponds. Deep collapse-pits in the levees suggest porosity of pond walls. The eastern levee of the northeastern pond breached, draining the interconnected ponds, and fed thick, rapidly-emplaced, sheet-flows along the complex's east side. These flows travelled at least 5.5 km down-rift and have 19-33 m deep drained ponds. They extended up-rift as well, forming a 10 x 2.5 km ponded flow with level 'bathtub rings' as high as 35 m above the floor marking that flow's high-stand. Despite the breach, at least 0.066 km3 of the molten interior of the large ponds also drained back down the eruptive fissures, as the pond floors are deeper than the sill and sea floor outside the complex. Tumulus

  11. Erosion versus construction: The origin of Venusian channels

    NASA Technical Reports Server (NTRS)

    Bussey, D. B. J.; Guest, J. E.

    1992-01-01

    Lava channels are a common feature in the volcanic regions of the Moon, and have now been observed on Venus. There has been much debate about the origin of lunar channels as to whether they are the result of erosional (either thermal or mechanical) or constructional processes. It is necessary to determine the criteria to distinguish between the different types of channels. The clearest evidence is that the presence of levees indicates that the channel experienced a constructional phase for a period. One example of a channel of this type in the southeast region of Aphrodite Terra appears to show both erosional and constructional characteristics. It is approximately 700 km long with an average width of about 1 km. It drops a distance of 700 m from beginning to end, which means that the average slope is 0.06 degrees. Its source may have been a graben situated at the northwest end of the channel. It appears to have different origins along its length. The lack of levees near the source suggests that the channel is erosional in this region. The presence of levees indicates that a constructional phase has occurred. These are formed by lava repeatedly splashing over the channel sides and solidifying. Evidence of levees is seen further away from the source. However, the presence of levees does not mean that the lava was not also eroding and deepening the channel. Thus, in conclusion, our example channel is very sinuous and there is evidence of erosion. There may also have been overflow here. In its middle reaches it roofs over and has the characteristics of a lava tube. In the lower reaches there is strong evidence for the presence of levees indicating construction. On Earth, limited amounts of erosion may occur in basaltic lava channels, although not nearly on the same scale as on the planets just mentioned. For lava erosion on Earth to occur to a comparable extent, excessive eruption times are required. However, low-viscosity komatiite lava may erode to a larger extent

  12. Influence of anthropogenic alterations on geomorphic response to climate variations and change in San Francisco Bay-Delta and watershed

    USGS Publications Warehouse

    Florsheim, J.L.; Dettinger, M.D.

    2004-01-01

    Global warming and attendant sea-level rise may soon impact geomorphic processes in the Sacramento-San Joaquin River and San Francisco Bay Delta systems. During the past two centuries, dramatic anthropogenic changes in sediment supply and pervasive structural controls on rivers and floodplains have altered geomorphic responses to floods throughout a zone that extends upstream from tidally influenced areas to dams that regulate flow. Current geomorphic responses to floods differ from natural responses due to historical actions that concentrated the pre-disturbance multiple-channel and flood-basin system into single channels isolated by levees from increasingly developed floodplains and flood bypass channels, altered flow and sediment regimes, and caused subsidence of leveed Delta Islands. A review of historic and current geomorphic responses to floods illustrates the dominance of structural controls on geomorphic changes in the lowland part of the Sacramento-San Joaquin system. Current climate-change projections for CA suggest that the total volume of snowmelt runoff that may be shifted from spring and added to winter flows is roughly 5 maf/yr, similar to the volume currently available for flood storage in Sierra Nevadan reservoirs. Changes in timing of reservoir releases to accommodate these changes could add to either the magnitude or duration of winter flood peaks, each causing different geomorphic responses. Increased wintertime flows that accompany already large floods could increase overbank flood extent, erosion, and sedimentation, or alternatively increase the depth and strength of confined flows and increase the risk of levee failures. Runoff released from reservoirs as a relatively constant addition to winter baseflow would increase the duration of bankfull or possibly "levee-full" flows. This scenario could lead to bank and levee failure through increased saturation and seepage erosion. Projected sea level rise of 1-2 m would compound vulnerability of

  13. Effects of the curvature of a lava channel on velocity and stress fields

    NASA Astrophysics Data System (ADS)

    Valerio, Antonella; Tallarico, Andrea; Dragoni, Michele

    2010-05-01

    Bends in lava flows due to local variations in topography are commonly observed in volcanic fields. The curvature of a channel affects the flow surface morphology, as described in literature by Greeley (1971) and Peterson (1994). Where channels make an especially sharp bend, crust plates break and are incorporated within the flow by remelting. In some places, they jam together welding to the sides of the channel and forming a stable roof. We propose a model to explain the effects of the curvature of a channel on velocity, shear stress and formation of solid crust at the surface. Lava is described as a Newtonian, homogeneous, isotropic and incompressible fluid. The steady-state solution of the Navier-Stokes equation is found for a unidirectional flow, in cylindrical polar coordinates, neglecting the gradient of pressure and assuming a dependence of velocity on the radial coordinate only. The flow levees are described as arcs of concentric circumferences, with their centres in the origin of the reference frame. The equation is solved using non-slip boundary conditions at the levees. From the constitutive equation of a Newtonian incompressible fluid we obtain the nonvanishing component of the shear stress. As a consequence of the curvature of the channel, velocity and shear stress show an asymmetric behaviour in respect to the centre of the channel. The gradient of velocity and the shear stress reach larger values close to the levee with the higher curvature. Heat radiation and convection into the atmosphere are considered as the main cooling processes. Solid platforms form at the flow surface during cooling. Crust plates are laterally confined by the shear regions with high stress values. The model analyses the effects of the curvature of a channel on the development and shape of surface solid plates. The dimension and shape of plates are controlled by the competition between the shear stress and crust yield strength, and the degree of crust coverage of the channel

  14. Governing factors to determine types of submarine fans: Consideration from the model of equilibrium profile of submarine channels

    NASA Astrophysics Data System (ADS)

    Naruse, H.

    2015-12-01

    It has been known that submarine fans are diverse in constitutive architectural elements. Leveed channels are common architectural elements of submarine fans but some of submarine fans lack such self-constructive channels. Also, frontal splays that develops at the end of channels cannot be observed in all of submarine fans. Several researches suggested that this diversity of submarine fans is originated from attributes of sediment supply such as ratio between sand and mud. However, quantitative investigation of these phase changes in types of submarine fans has not been explored yet. Here, this study aims to consider deterministic parameters that govern types of submarine fans, using a theoretical model that assumes submarine channel are in equilibrium condition. The model is based on the 4 equation model of turbidity currents that considers conservation of turbulent kinetic energy. The equilibrium profile is here defined as profiles where turbidity currents are bypassing or depositing uniformly. 1D momentum conservation is considered, and grain-size distribution is approximated to two size classes: channel-forming sands and levee-forming muddy sediments. Widths of channel and levees are calculated from empirical hydraulic geometry. The model predicts length of leveed channels in the equilibrium condition and hydraulic conditions at downstream end of the channels. As a result, depending on boundary condition at upstream end of channels, three possible cases were recognized: (A) submarine channels in which levee-forming muddy sediments are run out at the end of channel, (B) submarine channels in which sandy sediments are run out, and (C) no possible equilibrium profiles that satisfy empirical hydraulic geometry for given boundary conditions. It can be interpreted that these types of results correspond to submarine channels with/without frontal splays and submarine fans without leveed channels. Essentially three parameters are significant to determine types of

  15. Flood trends and river engineering on the Mississippi River system

    USGS Publications Warehouse

    Pinter, N.; Jemberie, A.A.; Remo, J.W.F.; Heine, R.A.; Ickes, B.S.

    2008-01-01

    Along >4000 km of the Mississippi River system, we document that climate, land-use change, and river engineering have contributed to statistically significant increases in flooding over the past 100-150 years. Trends were tested using a database of >8 million hydrological measurements. A geospatial database of historical engineering construction was used to quantify the response of flood levels to each unit of engineering infrastructure. Significant climate- and/or land use-driven increases in flow were detected, but the largest and most pervasive contributors to increased flooding on the Mississippi River system were wing dikes and related navigational structures, followed by progressive levee construction. In the area of the 2008 Upper Mississippi flood, for example, about 2 m of the flood crest is linked to navigational and flood-control engineering. Systemwide, large increases in flood levels were documented at locations and at times of wing-dike and levee construction. Copyright 2008 by the American Geophysical Union.

  16. Construction dynamics of a lava channel

    NASA Astrophysics Data System (ADS)

    Harris, Andrew J. L.; Favalli, Massimiliano; Mazzarini, Francesco; Hamilton, Christopher W.

    2009-05-01

    We use a kinematic GPS and laser range finder survey of a 200 m-long section of the Muliwai a Pele lava channel (Mauna Ulu, Kilauea) to examine the construction processes and flow dynamics responsible for the channel-levee structure. The levees comprise three packages. The basal package comprises an 80-150 m wide 'a'a flow in which a ˜2 m deep and ˜11 m wide channel became centred. This is capped by a second package of thin (<45 cm thick) sheets of pahoehoe extending no more than 50 m from the channel. The upper-most package comprises localised 'a'a overflows. The channel itself contains two blockages located 130 m apart and composed of levee chunks veneered with overflow lava. The channel was emplaced over 50 h, spanning 30 May-2 June, 1974, with the flow front arriving at our section (4.4 km from the vent) 8 h after the eruption began. The basal 'a'a flow thickness yields effusion rates of 35 m3 s-1 for the opening phase, with the initial flow advancing across the mapped section at ˜10 m/min. Short-lived overflows of fluid pahoehoe then built the levee cap, increasing the apparent channel depth to 4.8 m. There were at least six pulses at 90-420 m3 s-1, causing overflow of limited extent lasting no more than 5 min. Brim-full flow conditions were thus extremely short-lived. During a dominant period of below-bank flow, flow depth was ˜2 m with an effusion rate of ˜35 m3 s-1, consistent with the mean output rate (obtained from the total flow bulk volume) of 23-54 m3 s-1. During pulses, levee chunks were plucked and floated down channel to form blockages. In a final low effusion rate phase, lava ponded behind the lower blockage to form a syn-channel pond that fed 'a'a overflow. After the end of the eruption the roofed-over pond continued to drain through the lower blockage, causing the roof to founder. Drainage emplaced inflated flows on the channel floor below the lower blockage for a further ˜10 h. The complex processes involved in levee-channel construction

  17. Morphodynamics of submarine channel inception revealed by new experimental approach

    NASA Astrophysics Data System (ADS)

    de Leeuw, Jan; Eggenhuisen, Joris T.; Cartigny, Matthieu J. B.

    2016-03-01

    Submarine channels are ubiquitous on the seafloor and their inception and evolution is a result of dynamic interaction between turbidity currents and the evolving seafloor. However, the morphodynamic links between channel inception and flow dynamics have not yet been monitored in experiments and only in one instance on the modern seafloor. Previous experimental flows did not show channel inception, because flow conditions were not appropriately scaled to sustain suspended sediment transport. Here we introduce and apply new scaling constraints for similarity between natural and experimental turbidity currents. The scaled currents initiate a leveed channel from an initially featureless slope. Channelization commences with deposition of levees in some slope segments and erosion of a conduit in other segments. Channel relief and flow confinement increase progressively during subsequent flows. This morphodynamic evolution determines the architecture of submarine channel deposits in the stratigraphic record and efficiency of sediment bypass to the basin floor.

  18. Morphodynamics of submarine channel inception revealed by new experimental approach.

    PubMed

    de Leeuw, Jan; Eggenhuisen, Joris T; Cartigny, Matthieu J B

    2016-01-01

    Submarine channels are ubiquitous on the seafloor and their inception and evolution is a result of dynamic interaction between turbidity currents and the evolving seafloor. However, the morphodynamic links between channel inception and flow dynamics have not yet been monitored in experiments and only in one instance on the modern seafloor. Previous experimental flows did not show channel inception, because flow conditions were not appropriately scaled to sustain suspended sediment transport. Here we introduce and apply new scaling constraints for similarity between natural and experimental turbidity currents. The scaled currents initiate a leveed channel from an initially featureless slope. Channelization commences with deposition of levees in some slope segments and erosion of a conduit in other segments. Channel relief and flow confinement increase progressively during subsequent flows. This morphodynamic evolution determines the architecture of submarine channel deposits in the stratigraphic record and efficiency of sediment bypass to the basin floor. PMID:26996440

  19. Flood risk changes emerging from the feedbacks between physical and social processes

    NASA Astrophysics Data System (ADS)

    Viglione, Alberto; Di Baldassarre, Giuliano; Carr, Gemma; Kuil, Linda; Yan, Kun; Brandimarte, Luigia; Blöschl, Günter

    2015-04-01

    To explore changes in flood risk, we propose a novel approach whereby the mutual interactions and continuous feedbacks between floods and societies are explicitly accounted for. We apply this approach by using a socio-hydrological model and simulate the behavior of societies that cope with flooding by either building levees or dikes or resettling out of flood-prone areas. We show that this novel approach is able to capture (and explain) spontaneous dynamics, such as adaptation and levee effects, which often emerge from the interplay between physical and social processes. Moreover, the implementation of this approach provides fascinating insights for flood risk management. For instance, when coupled dynamics are accounted for, flood-poor periods can be more dangerous for societies than flood-rich periods because they lower the collective memory of flooding and therefore reduce societal resilience to flooding.

  20. Field Measurements of the 1983 Royal Gardens Lava Flows, Kilauea Volcano, and 1984 Mauna Loa Lava Flow, Hawaii

    NASA Technical Reports Server (NTRS)

    Fink, J.; Zimbelman, J.

    1985-01-01

    Theoretical models used in the remote determination of lava flow rheology and compositions rely on estimates of such geometric and flow parameters as volume flow rates, levee heights, and channel dimensions, as well as morphologic and structural patterns on the flow surfaces. Quantitative measures of these variables are difficult to obtain, even under optimum conditions. Detailed topographic profiles across several Hawaiian lava flows that were carefully monitored by the U.S. Geological Survey during their emplacement in 1983 were surveyed in order to test various flow emplacement models. Twenty two accurate channel cross sections were constructed by combining these profiles with digitized pre-flow topographic measurements. Levee heights, shear zone widths, and flow depths could then be read directly from the cross sections and input into the models. The profiles were also compared with ones constructed for some Martian lava flows.

  1. Field measurements of the 1983 Royal Gardens lava flows, Kilauea Volcano, and 1984 Mauna Loa lava flows, Hawaii

    NASA Astrophysics Data System (ADS)

    Fink, J.; Zimbelman, J.

    1985-04-01

    Theoretical models used in the remote determination of lava flow rheology and compositions rely on estimates of such geometric and flow parameters as volume flow rates, levee heights, and channel dimensions, as well as morphologic and structural patterns on the flow surfaces. Quantitative measures of these variables are difficult to obtain, even under optimum conditions. Detailed topographic profiles across several Hawaiian lava flows that were carefully monitored by the U.S. Geological Survey during their emplacement in 1983 were surveyed in order to test various flow emplacement models. Twenty two accurate channel cross sections were constructed by combining these profiles with digitized pre-flow topographic measurements. Levee heights, shear zone widths, and flow depths could then be read directly from the cross sections and input into the models. The profiles were also compared with ones constructed for some Martian lava flows.

  2. Morphodynamics of submarine channel inception revealed by new experimental approach

    PubMed Central

    de Leeuw, Jan; Eggenhuisen, Joris T.; Cartigny, Matthieu J. B.

    2016-01-01

    Submarine channels are ubiquitous on the seafloor and their inception and evolution is a result of dynamic interaction between turbidity currents and the evolving seafloor. However, the morphodynamic links between channel inception and flow dynamics have not yet been monitored in experiments and only in one instance on the modern seafloor. Previous experimental flows did not show channel inception, because flow conditions were not appropriately scaled to sustain suspended sediment transport. Here we introduce and apply new scaling constraints for similarity between natural and experimental turbidity currents. The scaled currents initiate a leveed channel from an initially featureless slope. Channelization commences with deposition of levees in some slope segments and erosion of a conduit in other segments. Channel relief and flow confinement increase progressively during subsequent flows. This morphodynamic evolution determines the architecture of submarine channel deposits in the stratigraphic record and efficiency of sediment bypass to the basin floor. PMID:26996440

  3. Environments for fostering effective critical thinking in geotechnical engineering education (Geo-EFFECTs)

    NASA Astrophysics Data System (ADS)

    Pierce, Charles E.; Gassman, Sarah L.; Huffman, Jeffrey T.

    2013-06-01

    This paper describes the development, implementation, and assessment of instructional materials for geotechnical engineering concepts using the Environments for Fostering Effective Critical Thinking (EFFECTs) pedagogical framework. The central learning goals of engineering EFFECTs are to (i) improve the understanding and retention of a specific set of concepts that provide core knowledge and (ii) encourage students to recognise and develop critical thinking skills that lead to growth in engineering judgement. The practice of geotechnical engineering deals with complex and uncertain soil conditions, where critical thought and judgement are imperative. Three geo-EFFECTs were created in the context of levee reconstruction, levee permeability, and settlement of a tower structure. Students often provided inaccurate estimates to driving questions set in those contexts; when given opportunities for self-exploration and self-correction in the EFFECT structure, students often achieved more accurate final solutions. Overall, results suggest that EFFECTs have a measurable, positive impact on student learning.

  4. Analyses of water, core material, and elutriate samples collected near New Orleans, Louisiana (Lake Pontchartrain, Louisiana, and vicinity hurricane protection project)

    USGS Publications Warehouse

    Leone, Harold L.

    1976-01-01

    When a hurricane approaches the New Orleans, Louisiana area, the accompanying tides and heavy rainfall increase the level of water in Lake Borgne, Mississippi Sound, and Lake Pontchartrain and pose a major threat of water damage to the populated areas. During Hurricane Betsy (1965), for example, the level of Lake Pontchartrain rose as much as 13 feet. Nineteen core-material-sampling sites were chosen by the U.S. Army Corps of Engineers as possible borrow areas for fill material to be used in levee construction for flood protection around Lake Pontchartrain. Twenty-three receiving-water sites were also selected to represent the water that will contact the proposed levees. Selected nutrients, metals, pesticides, and other organic constituents were analyzed from bed-material and native-water samples as well as upon elutriate samples of specific core material-receiving water systems. The results of these analyses are presented without interpretation. (Woodard-USGS)

  5. Physiography and deposition on a distal deep-sea system: The Valencia Fan (Northwestern Mediterranean)

    USGS Publications Warehouse

    Maldonado, A.; Palanques, A.; Alonso, B.; Kastens, K.A.; Nelson, C.H.; O'Connell, S.; Ryan, William B. F.

    1985-01-01

    The Valencia Fan developed as the distal fill of a deep-sea valley, detached from the continental slope and the main sedimentary source. A survey of side-scan sonar, Sea Beam and reflection seismics shows that the sediment is largely fed through the Valencia Valley. The upper fan comprises large channels with low-relief levees, and the middle fan has sinuous distributary channels. Depositional bedforms predominate on the valley floor and levees, and erosional bedforms are common in the valley walls. A change to slope on the fan apex and the presence of volcanoes on the upper fan are the main factors influencing fan-growth pattern. ?? 1985 Springer-Verlag New York Inc.

  6. Evaluating Effects of Floodplain Constriction Along a High Energy Gravel-Bed River: Snake River, WY

    NASA Astrophysics Data System (ADS)

    Leonard, Christina M.

    This study examined approximately 66 km of the Snake River, WY, USA, spanning a natural reach within Grand Teton National Park and a reach immediately downstream that is confined by artificial levees. We linked the channel adjustments observed within these two reaches between 2007 and 2012 to sediment transport processes by developing a morphological sediment budget. A pair of digital elevation models (DEMs) was generated by fusing LiDAR topography with depth estimates derived from optical image data within wetted channels. Errors for both components of the DEMs (LiDAR and optical bathymetry) were propagated through the DEM of difference and sediment budget calculations. Our results indicated that even with the best available methods for acquiring high resolution topographic data over large areas, the uncertainty associated with bed elevation estimates implied that net volumetric changes were not statistically significant. In addition to the terrain analysis, we performed a tracer study to assess the mobility of different grain size classes in different morphological units. Grain sizes, hydraulic conditions, and flow resistance characteristics along cross-sections were used to calculate critical discharges for entrainment, but this bulk characterization of fluid driving forces failed to predict bed mobility. Our results indicated that over seasonal timescales specific grain classes were not preferentially entrained. Surface and subsurface grain size data were used to calculate armoring and dimensionless sediment transport ratios for both reaches; sediment supply exceeded transport capacity in the natural reach and vice versa in the confined reach. We used a conceptual model to describe channel adjustments to lateral constriction by levees. Initially we suggest levees focused flow energy and incised the bed, resulting in bed armoring. Bed armoring promoted channel widening, but levees prevented this and instead the channel migrated more rapidly within the

  7. The formation and maintenance of single-thread tie channels entering floodplain lakes: observations from three diverse river systems

    SciTech Connect

    Rowland, Joel C; Dietrich, William E; Day, Geoff; Parker, Gary

    2009-01-01

    Tie channels connect rivers to floodplain lakes on many lowland rivers and thereby play a central role in floodplain sedimentology and ecology, yet they are generally unrecognized and little studied. here we report the results of field studies focused on tie channel origin and morphodynamics in three contrasting systems: the Middle Fly River, Papua New Guinea, the Lower Mississippi River, and Birch Creek in Alaska. Across these river systems, tie channels vary by an order of magnitude in size but exhibit the same characteristic morphology and appear to develop and evolve by a similar set of processes. In all three systems, the channels are characterized by a narrow, leveed single-thread morphology with maximum width approximately one tenth the width of the mainstem river. The channels typically have a V shaped cross-section, unlike most fluvial channels. These channels develop as lakes become isolated from the river by sedimentation. Narrowing of the connection between river and lake causes a sediment-laden jet to develop. Levees develop along the margins of the jet leading to channel emergence and eventual levee aggradation to the height of the mainstem levees. Bi-directional flow in these channels is common. Outflows from the lake scour sediment and prevent channel blockage. We propose that channel geometry and size are then controlled by a dynamic balance between channel narrowing by suspended sediment deposition and incision and widening by mass failure of banks during outflows. Tie channels are laterally stable and may convey flow for hundreds to a few thousand of years.

  8. Formation and maintenance of single-thread tie channels entering floodplain lakes: Observations from three diverse river systems

    NASA Astrophysics Data System (ADS)

    Rowland, J. C.; Dietrich, W. E.; Day, G.; Parker, G.

    2009-06-01

    Tie channels connect rivers to floodplain lakes on many lowland rivers and thereby play a central role in floodplain sedimentology and ecology; yet they are generally unrecognized and little studied. Here we report the results of field studies focused on tie channel origin and morphodynamics in the following three contrasting systems: the Middle Fly River (Papua New Guinea), the Lower Mississippi River, and Birch Creek in Alaska. Across these river systems, tie channels vary by an order of magnitude in size but exhibit the same characteristic morphology and appear to develop and evolve by a similar set of processes. In all three systems, the channels are characterized by a narrow, leveed, single-thread morphology with maximum width approximately one tenth the width of the mainstem river. The channels typically have a V-shaped cross section, unlike most fluvial channels. These channels develop as lakes become isolated from the river by sedimentation. Narrowing of the connection between river and lake causes a sediment-laden jet to develop. Levees develop along the margins of the jet leading to channel emergence and eventual levee aggradation to the height of the mainstem levees. Bidirectional flow in these channels is common. Outflows from the lake scour sediment and prevent channel blockage. We propose that channel geometry and size are then controlled by a dynamic balance between channel narrowing by suspended sediment deposition and incision and widening by mass failure of banks during outflows. Tie channels are laterally stable and may convey flow for hundreds to a few thousand of years.

  9. Influence of the Coriolis force on the velocity structure of gravity currents in straight submarine channel systems

    NASA Astrophysics Data System (ADS)

    Cossu, R.; Wells, M. G.; WâHlin, A. K.

    2010-11-01

    Large-scale turbidity currents in submarine channels often show a significant asymmetry in the heights of their levee banks. In the Northern Hemisphere, there are many observations of the right-hand channel levee being noticeably higher than the left-hand levee, a phenomenon that is usually attributed to the effect of Coriolis forces upon turbidity currents. This article presents results from an analog model that documents the influence of Coriolis forces on the dynamics of gravity currents flowing in straight submarine channels. The observations of the transverse velocity structure, downstream velocity, and interface slope show good agreement with a theory that incorporates Ekman boundary layer dynamics. Coriolis forces will be important for most large-scale turbidity currents and need to be explicitly modeled when the Rossby number of these flows (defined as Ro = ∣U/Wf∣, where U is the mean downstream velocity, W is the channel width, and f is the Coriolis parameter defined as f = 2Ω sin(θ), with Ω being the Earth's rotation rate and θ being the latitude) is less than order 1. When Ro ≪ 1, the flow is substantially slower than a nonrotating flow with the same density contrast. The secondary flow field consists of frictionally induced Ekman transports across the channel in the benthic and interfacial boundary layers and a return flow in the interior. The cross-channel velocities are of the order of 10% of the along-channel velocities. The sediment transport associated with such transverse flow patterns should influence the evolution of submarine channel levee systems.

  10. Sedimentology and facies of a Mississippi River meander belt: a fluvial model based on a significant fluvial system

    SciTech Connect

    Pryor, W.A.; Jordan, D.W.

    1988-02-01

    The meander belt of the Mississippi River, in southeastern Missouri, consists of four distinct facies groups: (1) river channel/point bar, (2) chute, (3) crevasse splay/levee, and (4) abandoned channel fill. A depositional model and vertical sequences have been developed from drill cores, vibra-cores, trenches, fathometer surveys, and mapping of these principal facies. This model and he vertical sequences compare very well to ancient sequences because the Mississippi River is a large, significant river with ancient analogs.

  11. Changes in benthic nutrient sources within a wetland after hydrologic reconnection.

    PubMed

    Kuwabara, James S; Topping, Brent R; Carter, James L; Wood, Tamara M; Cameron, Jason M; Asbill-Case, Jessica R; Carlson, Rick A

    2012-09-01

    Removing dams and levees to restore hydrologic connectivity and enhance ecosystem services such as nutrient removal has been an increasingly common management practice. In the present study, the authors assessed geochemical and biological changes following engineered levee breaches that reconnected eutrophic Upper Klamath Lake and Agency Lake, Oregon, USA, to an adjacent, historic wetland that had been under agricultural use for the last seven decades. Over the three-year study, the reconnected wetland served as a benthic source for both macronutrients (dissolved organic carbon [DOC], soluble reactive phosphorus [SRP], and ammonia) and micronutrients (dissolved iron and manganese). The magnitude of those benthic sources was similar to or greater than that of allochthonous sources. The highest DOC benthic flux to the water column occurred immediately after rewetting occurred. It then decreased during the present study to levels more similar to the adjacent lake. Dissolved ammonia fluxes, initially negative after the levee breaches, became consistently positive through the remainder of the study. Nitrate fluxes, also initially negative, became negligible two years after the levee breaches. In contrast to previous laboratory studies, SRP fluxes remained positive, as did fluxes of dissolved iron and manganese. Our results indicate that the timescales of chemical changes following hydrologic reconnection of wetlands are solute-specific and in some cases extend for multiple years beyond the reconnection event. During the present study, colonization of the reconnected wetlands by aquatic benthic invertebrates gradually generated assemblages similar to those in a nearby wetland refuge and provided further evidence of the multiyear transition of this area to permanent aquatic habitat. Such timescales should be considered when developing water-quality management strategies to achieve wetland-restoration goals. PMID:22707141

  12. Morphology, internal structure, seismic stratigraphy, and sedimentation of Indus Fan

    SciTech Connect

    Kolla, V.; Coumes, F.

    1987-06-01

    The upper Indus Fan (1600-3600 m) is characterized by up to several hundred meters relief that resulted from the aggradation of large channel-levee complexes; gradients greater than 1:500; a distinct 3.5 kHz echo character with several continuous subbottom reflectors; and by fine-grained sediments, except within the channels where coarse-grained materials are inferred. The lower fan has a smooth relief with channels and levees of relatively small dimensions; overall gradients of less than 1:1000; prolonged 3.5 kHz echo character with few or no subbottom reflectors; and a dominantly sandy lithology. The characteristics of the middle fan are intermediate between those of the upper and lower fans. Seismic records reveal at least three canyon complexes on the shelf, each of which gave rise to several leveed channels on the fan. The canyons and channels migrated extensively in time and space across the fan, and channel abandonment and avulsion were very common. Seismically, the canyon fill consists of several reflection-free zones overlain by inclined reflections of moderate amplitudes which are inferred to indicate fine-grained sediments. The channel fills consist of high-amplitude, random reflections overlain successively by reflection-free zones and weak to moderate-amplitude continuous reflections. These characteristics suggest coarse-grained deposits at the base fining upward to the top of the channel fill. The channels, especially on the upper and middle fan, are flanked by wedge-shaped, concave-upward reflection packages characteristic of levee-overbank deposits. Sea level changes and the Himalayan orogenies have profoundly affected the Indus Fan sedimentation since the Oligocene-early Miocene. Sedimentation was by channelized turbidity currents with overbank deposition on the upper fan, and by both unchannelized and channelized turbidity currents on the lower fan during the lowstands of sea level.

  13. Factors controlling depositional patterns of Ebro turbidite systems, Mediterranean Sea

    SciTech Connect

    Nelson, C.H.; Maldonado, A.

    1988-06-01

    Tectonic control by subsiding grabens parallel to the Ebro continental margin created a steep narrow slope and rise that resulted in development of coexisting aprons, channel-levee complexes, and a fan, all fed by the same Ebro River source. In unstable steep-slope terrain, mass movement of material caused wide gullied canyons and deposition of nonchannelized base-of-slope aprons that extend 50 km across the rise. Within stable continental-margin areas, channelized turbidity currents formed individual narrow canyons and channel-levee complexes from north to south, successively, at different low sea level stands. Tectonically induced steep gradients (1:25-1:130) across the continental rise and northeastward in Valencia Trough caused sediment to bypass 200 km down Valencia Valley and deposit on Valencia Fan at its end, thus preventing direct development of Ebro channel-levee complexes into fans. When a single source fed channel B for a relatively long period, however, (1) fan-valley sinuosity increased, (2) channel walls were modified through undercutting, slumping, and crevasse splays, and (3) channel bifurcation occurred, although lower fan lobes and a complete fan never developed. The dominance of local tectonic control thus aborted fan development in proximal regions on the continental margin near the Ebro River source and displaced fan formation to a distal site in the Valencia Trough basin. During low sea level stands, continued different local tectonic and sediment-source controls resulted in aprons, channel-levee complexes, and fans forming simultaneously from the same source and without evolving from one type of turbidite system to another. Complex ancient turbidite systems similar to those along the Ebro margin may be anticipated in the stratigraphic record of tectonically active settings like the alpine basins of Europe. 11 figures, 3 tables.

  14. Sedimentology and facies of a Mississippi River meander belt

    SciTech Connect

    Pryor, W.A.; Jordan, D.W.

    1988-01-01

    The meander belt of the Mississippi River in Southeastern Missouri, consists of four facies: river channel, chute, levee, and abandoned channel fill. A depositional model and vertical sequences have been developed from drill cores, vibracores, fathometer surveys, and mapping of these facies. This model and the vertical sequences compare very well to ancient sequences. The vertical sequences observed in cores through the various facies systems have systematic variations and associations that serve as models for meander belt fluvial systems.

  15. High-resolution seismic imaging of the gas and gas hydrate system at Green Canyon 955 in the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Haines, S. S.; Hart, P. E.; Collett, T. S.; Shedd, W. W.; Frye, M.

    2015-12-01

    High-resolution 2D seismic data acquired by the USGS in 2013 enable detailed characterization of the gas and gas hydrate system at lease block Green Canyon 955 (GC955) in the Gulf of Mexico, USA. Earlier studies, based on conventional industry 3D seismic data and logging-while-drilling (LWD) borehole data acquired in 2009, identified general aspects of the regional and local depositional setting along with two gas hydrate-bearing sand reservoirs and one layer containing fracture-filling gas hydrate within fine-grained sediments. These studies also highlighted a number of critical remaining questions. The 2013 high-resolution 2D data fill a significant gap in our previous understanding of the site by enabling interpretation of the complex system of faults and gas chimneys that provide conduits for gas flow and thus control the gas hydrate distribution observed in the LWD data. In addition, we have improved our understanding of the main channel/levee sand reservoir body, mapping in fine detail the levee sequences and the fault system that segments them into individual reservoirs. The 2013 data provide a rarely available high-resolution view of a levee reservoir package, with sequential levee deposits clearly imaged. Further, we can calculate the total gas hydrate resource present in the main reservoir body, refining earlier estimates. Based on the 2013 seismic data and assumptions derived from the LWD data, we estimate an in-place volume of 840 million cubic meters or 29 billion cubic feet of gas in the form of gas hydrate. Together, these interpretations provide a significantly improved understanding of the gas hydrate reservoirs and the gas migration system at GC955.

  16. Holocene sedimentation history of the major fan valleys of Monterey fan

    USGS Publications Warehouse

    Hess, G.R.; Normark, W.R.

    1976-01-01

    There are three major fan valleys on upper Monterey fan. Deep-tow geophysical profiles and 40 sediment cores provide the basis for evaluation of the sedimentation histories of these valleys. Monterey fan valley leads from Monterey canyon to a major suprafan and is bounded by levees that crest more than 400 m above the valley floor. The valley passes through a large z-bend or meander. Monterey East fan valley joins Monterey fan valley at the meander at about 150 m above the valley floor, and marks an earlier position of the lower Monterey fan valley. Ascension valley, a hanging contributary to the Monterey fan valley, appears to have once been the shoreward head of the lower part of the present Monterey fan valley. The relief of Monterey fan valley appears from deep-tow profiles to be erosional. The valley is floored with sand. Holocene turbidity currents do not overtop the levees 400 m above the valley floor, but do at times overflow and transport sand into Monterey East valley, producing a sandy floor. An 1100 m by 300 m dune field was observed on side scan sonar in Monterey East valley. Ascension fan valley was floored with sand during glacial intervals of lowered sea level, then was cut off from its sand source as sea level rose. A narrow (500 m), erosional, meandering channel was incised into the flat valley floor; the relief features otherwise appear depositional, with a hummocky topography perhaps produced in the manner of a braided riverbed. The sand is mantled by about 6 m of probable Holocene mud. Hummocky relief on the back side of the northwestern levees of both Ascension and Monterey valleys is characteristic of many turbidite valleys in the northeast Pacific. The hummocky topography is produced by dune-like features that migrate toward levee crests during growth. ?? 1976.

  17. Gravity deposits in deep sea fans and on Continental Slopes, Black Sea

    SciTech Connect

    Ivanov, M.K.; Konyukhov, A.I.

    1988-08-01

    The Danube fan has a classical structure. It is clearly expressed in the bottom relief and traced by reflection profiles for more than 200 km. The fan body is levee valley, which splits in a mid-fan area into numerous meandering distributaries. The fan consists of gravity and hemipelagic deposits. These are mainly turbidites of various compositions. Channels are filled with grain-flow deposits (sand), debris-flow deposits (sandy clay with shells), and slides from valley walls (mud, sapropelic mud). Levees in upper and mid-fan areas are formed by specific turbidite sequences: mudstone crumbs in the base, thinly laminated silt and clays in the middle, blue mud on the top. Hemipelagic sediments increase noticeably on outer slopes of the levees. In the Pleistocene sequences these are mud; in the Holocene, sapropelic mud and coccolith-diatom ooze. Distal turbidites are widespread in the lower fan areas. In the base of each cycle is a thin sand-silt layer with unclear graded bedding; the upper part is represented by mud. Reflection profiles demonstrate an ancient fan system with buried channels and levees. Configurations of these bodies are very similar to those of the modern fans. The sedimentary lens on the sea floor opposite the mouths of submarine canyons of the Rioni, Inguri, Kodori, Supsa, and Chorokh Rivers was formed by overlapped modern and ancient fans. The Inguri and Rioni produced a practically single submarine fan, the largest in this area. It is rather well expressed morphologically and traced by reflection profiles for more than 100 km. In its lower part it overlays a number of small fans. The Rioni-Inguri fan is smaller than the Danube, but the whole system of overlapped fans occupies an area of about 17,000 km/sup 2/, being more than 3 km thick. The composition and structure of sediments in this deep-sea system change sharply, depending on the geomorphological position.

  18. Holocene Flows of the Cima Volcanic Field, Mojave Desert, Part 2: Flow Rheology from Laboratory Measurements

    NASA Astrophysics Data System (ADS)

    Robertson, T.; Whittington, A. G.; Soldati, A.; Sehlke, A.; Beem, J. R.; Gomez, F. G.

    2014-12-01

    Lava flow morphology is often utilized as an indicator of rheological behavior during flow emplacement. Rheological behavior can be characterized by the viscosity and yield strength of lava, which in turn are dependent on physical and chemical properties including crystallinity, vesicularity, and bulk composition. We are studying the rheology of a basaltic lava flow from a monogenetic Holocene cinder cone in the Cima lava field (Mojave Desert, California). The flow is roughly 2.5 km long and up to 700m wide, with a well-developed central channel along much of its length. Samples were collected along seven different traverses across the flow, along with real-time kinematic (RTK) GPS profiles to allow levee heights and slopes to be measured. Surface textures change from pahoehoe ropes near the vent to predominantly jagged `a`a blocks over the majority of the flow, including all levees and the toe. Chemically the lava shows little variation, plotting on the trachybasalt-basanite boundary on the total alkali-silica diagram. Mineralogically the lava is dominated by plagioclase, clinopyroxene and olivine phenocrysts, with abundant flow-aligned plagioclase microcrystals. The total crystal fraction is ~50% near the vent, with higher percentages in the distal portion of the flow. Vesicularity varies between ~10 and more than ~60%. Levees are ~10-15m high with slopes typically ~25-35˚, suggesting a yield strength at final emplacement of ~150,000 Pa. The effective emplacement temperature and yield strength of lava samples will be determined using the parallel-plate technique. We will test the hypothesis that these physical and rheological properties of the lava during final emplacement correlate with spatial patterns in flow morphology, such as average slope and levee width, which have been determined using remote sensing observations (Beem et al. 2014).

  19. Changes in benthic nutrient sources within a wetland after hydrologic reconnection.

    PubMed

    Kuwabara, James S; Topping, Brent R; Carter, James L; Wood, Tamara M; Cameron, Jason M; Asbill-Case, Jessica R; Carlson, Rick A

    2012-09-01

    Removing dams and levees to restore hydrologic connectivity and enhance ecosystem services such as nutrient removal has been an increasingly common management practice. In the present study, the authors assessed geochemical and biological changes following engineered levee breaches that reconnected eutrophic Upper Klamath Lake and Agency Lake, Oregon, USA, to an adjacent, historic wetland that had been under agricultural use for the last seven decades. Over the three-year study, the reconnected wetland served as a benthic source for both macronutrients (dissolved organic carbon [DOC], soluble reactive phosphorus [SRP], and ammonia) and micronutrients (dissolved iron and manganese). The magnitude of those benthic sources was similar to or greater than that of allochthonous sources. The highest DOC benthic flux to the water column occurred immediately after rewetting occurred. It then decreased during the present study to levels more similar to the adjacent lake. Dissolved ammonia fluxes, initially negative after the levee breaches, became consistently positive through the remainder of the study. Nitrate fluxes, also initially negative, became negligible two years after the levee breaches. In contrast to previous laboratory studies, SRP fluxes remained positive, as did fluxes of dissolved iron and manganese. Our results indicate that the timescales of chemical changes following hydrologic reconnection of wetlands are solute-specific and in some cases extend for multiple years beyond the reconnection event. During the present study, colonization of the reconnected wetlands by aquatic benthic invertebrates gradually generated assemblages similar to those in a nearby wetland refuge and provided further evidence of the multiyear transition of this area to permanent aquatic habitat. Such timescales should be considered when developing water-quality management strategies to achieve wetland-restoration goals.

  20. An inventory of wetland impoundments in the coastal zone of Louisiana, USA: Historical trends

    NASA Astrophysics Data System (ADS)

    Day, Richard H.; Holz, Robert K.; Day, John W.

    1990-03-01

    We inventoried wetland impoundments in the Louisiana, USA, coastal zone from the late 1900s to 1985. Historically, impoundment of wetlands for reclamation resulted in direct wetland loss after levees (dikes) failed and the impounded area was permanently flooded, reverting not to wetland, but to open-water habitat. A current management approach is to surround wetlands by levees and water control structures, a practice termed semi-impoundment marsh management. The purpose of this semi-impoundment is to retard saltwater intrusion and reduce water level fluctuations in an attempt to reduce wetland loss, which is a serious problem in coastal Louisiana. In order to quantify the total impounded area, we used historic data and high-altitude infrared photography to map coastal impoundments. Our goal was to produce a documented inventory of wetlands intentionally impounded by levees in the coastal zone of Louisiana in order to provide a benchmark for further research. We inventoried 370,658 ha within the coastal zone that had been intentionally impounded before 1985. This area is equal to about 30% of the total wetland area in the coastal zone. Of that total area, approximately 12% (43,000 ha) is no longer impounded (i.e., failed impoundments; levees no longer exist or only remnants remain). Of the 328,000 ha still impounded, about 65% (214,000 ha) is developed (agriculture, aquaculture, urban and industrial development, and contained spoil). The remaining 35% (114,000 ha) of impoundments are in an undeveloped state (wetland or openwater habitat). In December 1985, approximately 50% (78,000 ha) of the undeveloped and failed impoundments were open-water habitat. This inventory will allow researchers to monitor future change in land-water ratios that occur within impounded wetlands and thus to assess the utility of coastal wetland management using impoundments.

  1. New generation of integrated geological-geomorphological reconstruction maps in the Rhine-Meuse delta, The Netherlands

    NASA Astrophysics Data System (ADS)

    Pierik, Harm Jan; Cohen, Kim; Stouthamer, Esther

    2016-04-01

    Geological-geomorphological reconstructions are important for integrating diverse types of data and improving understanding of landscape formation processes. This works especially well in densely populated Holocene landscapes, where large quantities of raw data are produced by geotechnical, archaeological, soil science and hydrological communities as well as in academic research. The Rhine-Meuse delta, The Netherlands, has a long tradition of integrated digital reconstruction maps and databases. This contributed to improve understanding of delta evolution, especially regarding the channel belt network evolution. In this contribution, we present a new generation of digital map products for the Holocene Rhine-Meuse delta. Our reconstructions expand existing channel belt network maps, with new map layers containing natural levee extent and relative elevation. The maps we present have been based on hundreds of thousands of lithological borehole descriptions, >1000 radiocarbon dates, and further integrate LIDAR data, soil maps and archaeological information. For selected time slices through the Late Holocene, the map products describe the patterns of levee distribution. Additionally, we mapped the palaeo-topography of the levees through the delta, aiming to resolve what parts of the overbank river landscape were the relatively low and high positioned areas in the past landscape. The resulting palaeogeographical maps are integrative products created for a very data-rich research area. They will allow for delta-wide analysis in studying changes in the Late Holocene landscape and the interaction with past habitation.

  2. Factors controlling navigation-channel Shoaling in Laguna Madre, Texas

    USGS Publications Warehouse

    Morton, R.A.; Nava, R.C.; Arhelger, M.

    2001-01-01

    Shoaling in the Gulf Intracoastal Waterway of Laguna Madre, Tex., is caused primarily by recycling of dredged sediments. Sediment recycling, which is controlled by water depth and location with respect to the predominant wind-driven currents, is minimal where dredged material is placed on tidal flats that are either flooded infrequently or where the water is extremely shallow. In contrast, nearly all of the dredged material placed in open water >1.5 m deep is reworked and either transported back into the channel or dispersed into the surrounding lagoon. A sediment flux analysis incorporating geotechnical properties demonstrated that erosion and not postemplacement compaction caused most sediment losses from the placement areas. Comparing sediment properties in the placement areas and natural lagoon indicated that the remaining dredged material is mostly a residual of initial channel construction. Experimental containment designs (shallow subaqueous mound, submerged levee, and emergent levee) constructed in high-maintenance areas to reduce reworking did not retain large volumes of dredged material. The emergent levee provided the greatest retention potential approximately 2 years after construction.

  3. Habitat-specific foraging of prothonotary warblers: Deducing habitat quality

    USGS Publications Warehouse

    Lyons, J.E.

    2005-01-01

    Foraging behavior often reflects food availability in predictable ways. For example, in habitats where food availability is high, predators should attack prey more often and move more slowly than in habitats where food availability is low. To assess relative food availability and habitat quality, I studied the foraging behavior of breeding Prothonotary Warblers (Protonotaria citrea) in two forest habitat types, cypress-gum swamp forest and coastal-plain levee forest. I quantified foraging behavior with focal animal sampling and continuous recording during foraging bouts. I measured two aspects of foraging behavior: 1) prey attack rate (attacks per minute), using four attack maneuvers (glean, sally, hover, strike), and 2) foraging speed (movements per minute), using three types of movement (hop, short flight [???1 m], long flight [>1 m]). Warblers attacked prey more often in cypress-gum swamp forest than in coastal-plain levee forest. Foraging speed, however, was not different between habitats. I also measured foraging effort (% time spent foraging) and relative frequency of attack maneuvers employed in each habitat; neither of these variables was influenced by forest type. I conclude that Prothonotary Warblers encounter more prey when foraging in cypress-gum swamps than in coastal-plain levee forest, and that greater food availability results in higher density and greater reproductive success for birds breeding in cypress-gum swamp.

  4. Interactive interpretation of morphology of upper Tertiary contourites, Porcupine basin, offshore Ireland

    SciTech Connect

    Macurda, D.B.; Nelson, R.

    1989-03-01

    A workstation-based, seismic-stratigraphic study of a series of Miocene-Pliocene sequences in the eastern portion of Porcupine basin, offshore Ireland, reveals the stratigraphic complexities and evolution of a contourite dune. Five seismic facies are present: parallel reflectors, which onlap the continental slope; a mound, with internal prograding oblique reflectors that dip to the southwest; a channel axis, oriented northwest-southeast; a natural levee, on the southwest side of the channel; and parallel or hummocky reflectors, downdip toward the basin center. Morphologically the mound, comprised of prograding clinoforms and channel and levee facies, resembles the point bar, channel, and levee of a terrestrial river meander system. The length of the mound exceeds 50 km; channel widths are as great as 8 km. Internally the mound is comprised of at least six sequences that were deposited episodically. Current flow was southeast, parallel to contours. Interactive mapping and contouring of seismic sequences, using paper and a seismic workstation, allow the shifts of directions of progradation and main depocenters to be detailed through the Miocene-Pliocene interval. Mapping of seismic facies suggests possible variations in environments and lithofacies. Ongoing investigations of contourites suggest that possible end members are morphologically complex and variable. By understanding their variability, the role of contour currents in modifying submarine fans or possibly forming sand facies capable of reservoiring hydrocarbons can be determined.

  5. Island characteristics within wetlands influence waterbird nest success and abundance

    USGS Publications Warehouse

    Hartman, Christopher; Ackerman, Josh; Herzog, Mark

    2016-01-01

    Coastal waterbird populations are threatened by habitat loss and degradation from urban and agricultural development and forecasted sea level rise associated with climate change. Remaining wetlands often must be managed to ensure that waterbird habitat needs, and other ecosystem functions, are met. For many waterbirds, the availability of island nesting habitat is important for conserving breeding populations. We used linear mixed models to investigate the influence of pond and island landscape characteristics on nest abundance and nest success of American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), and Forster's terns (Sterna forsteri) in San Francisco Bay, California, USA, based on a 9-year dataset that included >9,000 nests. Nest abundance and nest success were greatest within ponds and on individual islands located either <1 km or >4 km from San Francisco Bay. Further, nest abundance was greater within ponds with relatively few islands, and on linear-shaped, highly elongated islands compared to more rounded islands. Nest success was greater on islands located away from the nearest surrounding pond levee. Compared to more rounded islands, linear islands contained more near-water habitat preferred by many nesting waterbirds. Islands located away from pond levees may provide greater protection from terrestrial egg and chick predators. Our results indicate that creating and maintaining a few, relatively small, highly elongated and narrow islands away from mainland levees, in as many wetland ponds as possible would be effective at providing waterbirds with preferred nesting habitat.

  6. InSAR Remote Sensing of Localized Surface Layer Subsidence in New Orleans, LA

    NASA Astrophysics Data System (ADS)

    An, K.; Jones, C. E.; Blom, R. G.; Kent, J. D.; Ivins, E. R.

    2015-12-01

    More than half of Louisiana's drinking water is dependent on groundwater, and extraction of these resources along with high oil and gas production has contributed to localized subsidence in many parts of New Orleans. This increases the vulnerability of levee failure during intense storms such as Hurricane Katrina in 2005, before which rapid subsidence had already been identified and contributed to the failing levees and catastrophic flooding. An interferogram containing airborne radar data from NASA's UAVSAR was combined with local geographic information systems (GIS) data for 2009-12 to help identify the sources of subsidence and mask out unrelated features such as surface water. We have observed the highest vertical velocity rates at the NASA Michoud Assembly Facility (high water use) and Norco (high oil/gas production). Many other notable features such as the: Bonnet-Carre Spillway, MRGO canal, levee lines along the Lower 9th Ward and power plants, are also showing concerning rates of subsidence. Even new housing loads, soil type differences, and buried beach sands seem to have modest correlations with patterns seen in UAVSAR. Current hurricane protection and coastal restoration efforts still have not incorporated late 20th century water level and geodetic data into their projections. Using SAR interferometry and local GIS datasets, areas of subsidence can be identified in a more efficient and economical manner, especially for emergency response.

  7. Sedimentary evolution of the fan systems of the northern Mediterranean margin (Gulf of Lions and western Provence) since the Pliocene

    SciTech Connect

    Droz, L.; Bellaiche, G.; Coutellier, V.

    1988-08-01

    The continental rise of the northern Mediterranean margin is dominated by a coalescing fan-type sedimentation characterized by the complex stacking of interbedded sedimentary bodies, including symmetrical channel-levee complexes organized off the mouth of major canyons, curved ridges probably representing underdeveloped levees of asymmetrical systems, and widespread mass-movement deposits. Fan-type sedimentation in the Mediterranean basin began during the Pliocene. It first appeared ubiquitous on the deep margin and related to the Messinian paleodrainage system. Later, possibly in the early Quaternary, the sedimentation became more focused and organized off major canyons of the margin. The construction of the channel-levee complexes is inferred to have been active mainly during the drops of sea level linked with the Quaternary glaciations. In contrast, mass-movement processes are thought to have been favored during the rise of sea level characterizing the interglacial periods. On the grounds of the relative chronology of the construction of the different types of sedimentary bodies, we tentatively correlate the major active periods of the fan systems with the paleohydrographic network draining, at those times, the southern part of France. These correlations indicate that various successive regions of the Alps provided detritus to the basin through shifting feeding paths (rivers and canyons).

  8. Ground-water and surface-water-level data at Rindge Tract on the Stockton Deep Water Ship Channel, San Joaquin County, California, 1983-84

    USGS Publications Warehouse

    Pierce, Michael J.; Johnson, Karen L.

    1986-01-01

    The Sacramento-San Joaquin Delta is formed at the confluence of the two major rivers that drain the Central Valley of California. The Sacramento and San Joaquin Rivers and many interconnecting sloughs meandered back and forth across the tidelands, frequently overflowing their banks. Approximately 1 ,100 miles of levees were constructed to form about 60 tracts or islands that protect these lands from periodic flooding. The levees were constructed of sand, silt, and peat dredged from the channel bottom and are subject to erosion and failure. Owing to compaction, oxidation of the peat, and other related conditions, the islands are subsiding at rates of up to 0.25 ft/yr. The altitude of the land surface of the islands is often below sea level and below the surface water level in the channel. This condition causes stresses that may contribute to high groundwater levels and levee failure. The U.S. Army Corps of Engineers requested that the U.S. Geological Survey install and maintain continuous recorders to monitor water levels in each of four wells. Monitoring which began in July 1983 also provided data to show the relation between surface water levels in the channel and groundwater levels in the wells. Dredging began in the area of the Rindge Tract site during the latter part of July 1983. Water levels in all four wells dropped 1.5 to 2 ft between September 1983 and September 1984 and continued to drop thorough December 1984. (Lantz-PTT)

  9. Detecting Disaster Damage from 2015 Typhoon Etau by the Combined Use of Different SAR Satellites

    NASA Astrophysics Data System (ADS)

    Honda, Kenichi; Fujihira, Kei; Asada, Norichika; Fukushima, Ayumi; Mushiake, Naruo

    2016-06-01

    In this study, focusing on the flood damages in Joso City in Ibaraki Prefecture, we estimated the extent of inundation using multiple SAR satellites and examined their varied results depending on observational bands. We further examined the potential utilization of combined different SAR data for initial responses to disasters. For classification of the inundated areas, a binary classification was used with a threshold of backscatter coefficient and the difference in backscatter coefficient between the usual condition and the situation after the breach. In the extraction of inundation after the breach of the levee, COSMO-SkyMed showed the accuracy of 72.6%, while ALOS-2 PALSAR-2 indicated the accuracy of 66.1%. The extent of inundation were extracted by difference of backscatter coefficient using the data taken by Sentinel-1 and ALOS-2 PALSAR-2 before the breach of the levee, and the comparison analysis results showed that the extent of inundation expanded after the breach of the levee. From the above results, we graded the characteristics of the satellites by their observational bands and spatial resolution.

  10. The ecology of Barataria Basin, Louisiana: An estuarine profile

    SciTech Connect

    Conner, W.H.; Day, J.W. Jr.

    1987-07-01

    The Barataria Basin lies entirely in Louisiana between the natural levees of the active Mississippi River and the abandoned Bayou Lafourche distributary. It is characterized by a network of interconnecting water bodies which allows transport of water, materials, and migrating organisms throughout the basin. Natural and artificial levees and barrier islands are the only high, well-drained ground in the basin, which is otherwise characterized by extensive swamp forests and fresh, brackish, and salt marshes. These wetlands and water bodies are extremely productive biologically and provide valuable nursery habitat for a number of commercial and recreational fish and shellfish, as well as habitat for wintering waterfowl and furbearers. The basin is a dynamic system undergoing constant change because of geologic and human processes. The network of bays, lakes, and bayous has gradually enlarged over time due to natural subsidence and erosion. Superimposed on these natural processes has been the construction of levees for flood control and network of canals constructed for oil and gas exploration and extraction. These human activities have altered natural hydrologic patterns in the basin and may directly or indirectly contribute to wetland losses. Controlling wetland deterioration in the basin is a major management concern.

  11. Flood Bypass Capacity Optimization

    NASA Astrophysics Data System (ADS)

    Siclari, A.; Hui, R.; Lund, J. R.

    2015-12-01

    Large river flows can damage adjacent flood-prone areas, by exceeding river channel and levee capacities. Particularly large floods are difficult to contain in leveed river banks alone. Flood bypasses often can efficiently reduce flood risks, where excess river flow is diverted over a weir to bypasses, that incur much less damage and cost. Additional benefits of bypasses include ecosystem protection, agriculture, groundwater recharge and recreation. Constructing or expanding an existing bypass costs in land purchase easements, and levee setbacks. Accounting for such benefits and costs, this study develops a simple mathematical model for optimizing flood bypass capacity using benefit-cost and risk analysis. Application to the Yolo Bypass, an existing bypass along the Sacramento River in California, estimates optimal capacity that economically reduces flood damage and increases various benefits, especially for agriculture. Land availability is likely to limit bypass expansion. Compensation for landowners could relax such limitations. Other economic values could affect the optimal results, which are shown by sensitivity analysis on major parameters. By including land geography into the model, location of promising capacity expansions can be identified.

  12. Flood management on the lower Yellow River: hydrological and geomorphological perspectives

    NASA Astrophysics Data System (ADS)

    Shu, Li; Finlayson, Brian

    1993-05-01

    The Yellow River, known also as "China's Sorrow", has a long history of channel changes and disastrous floods in its lower reaches. Past channel positions can be identified from historical documentary records and geomorphological and sedimentological evidence. Since 1947, government policy has been aimed at containing the floods within artificial levees and preventing the river from changing its course. Flood control is based on flood-retarding dams and off-stream retention basins as well as artificial levees lining the channel. The design flood for the system has a recurrence interval of only around 60 years and floods of this and larger magnitudes can be generated downstream of the main flood control dams at Sanmenxia and Xiaolangdi. Rapid sedimentation along the river causes problems for storage and has raised the bed of the river some 10 m above the surrounding floodplain. The present management strategy is probably not viable in the long term and to avoid a major disaster a new management approach is required. The most viable option would appear to be to breach the levees at predetermined points coupled with advanced warning and evacuation of the population thus put at risk.

  13. Insights from a distance - Perspectives on Delta Science and solutions (Invited)

    NASA Astrophysics Data System (ADS)

    Lund, J. R.; Medellin, J.

    2013-12-01

    The Sacramento-San Joaquin Delta is a big and surprisingly diverse place. It also can be seen from a surprisingly diverse range of perspectives, technically, socially, environmentally, and politically. Changing perspective a few feet, from the water, to the levee crest, to inside a polder, all tell different stories. Remote sensed data is proving to be vital in forming both localized and overall understandings of the Delta. Local sensing provides important local perspective and information, while the consistent collection of such data across the landscape puts each place into a bigger picture. This talk summarizes the use of remote sensing data for economic analysis of the Delta as well as for the hydrodynamic and levee analysis. For economic modeling, we are now able to model agricultural production on each island, useful for considering alternative levee policies. These localized agricultural models include effects of water quality on agricultural production and profitability, which should be useful for Delta flow and management policies as well. The development and application of remote sensing data is an important aspect of the scientific and technical program needed for long-term management of a changing Delta.

  14. Risk dynamics: unraveling the role of socio-techno-nature interactions

    NASA Astrophysics Data System (ADS)

    Di Baldassarre, G.; Viglione, A.; Carr, G.; Kuil, L., Jr.; Brandimarte, L.; Yan, K.; Bloeschl, G.

    2015-12-01

    In disaster risk reduction, there is still a lack of methods capturing the dynamics of risk emerging from the complex interplay between physical and social processes. Two examples of these dynamics are the learning and levee effects. The learning effect is about the empirical evidence that more frequent hazardous events are often associated with decreasing societal vulnerability, e.g. human adaptation. The levee effect is about the stylized fact (discussed already by White in the 1940s) that less frequent hazardous events (sometimes paradoxically due to the implementation of risk prevention structures, such as levees) often lead to increasing societal vulnerability. We posit that current projections of future flood risk are not realistic because most analytical frameworks do not capture the aforementioned dynamics. Then, we propose an interdisciplinary approach whereby two-way interactions and feedbacks between social and physical processes are explicitly accounted for (Di Baldassarre et al., 2014; 2015). Here we show an application of this approach with a focus on flood risk changes, and demonstrate its capability to capture and explain the dynamics emerging from socio-techno-nature interactions. Lastly, the potentials and limitations of the proposed approach to assess risk dynamics in a rapidly changing environment are critically discussed.

  15. Channel fill characteristics in submarine fans and deltas

    SciTech Connect

    Bouma, A.H.; Goddard, D. )

    1993-02-01

    Excellent data sources may not answer all pertinent questions and multifold seismic data usually cannot resolve internal characteristics of channel fills, even when it can detect the channel. Well log correlations can be wrong, especially when dealing with thin channel fills and outcrops are seldom sufficiently large to reveal a complete channel fill. In the final analysis, integration of all these types of data is necessary. Although not well understood, a lot of similarities exist between the channel fills from submarine fans and those from deltas. It is definitely beneficial to compare data from both environments. Channels and their fills can be: (1) primarily the result of major erosion forming an incisement that becomes gradually filled; (2) primarily the result of deposition, maintaining a channel, gradually filling it and simultaneously building its levees; (3) massive fill; (4) a bedded fill with or without an upward and/or lateral thinning or fining; or (5) a combination of thick bedded and thin bedded. Many channels alternate between erosional and depositional activities. Often an erosional cut is lined with shale, reducing fluid flow between channel sandstones and those of the levees. Also, a thorough knowledge of all of these varied processes is essential for the understanding of why [open quotes]massive[close quotes] channel fills can be wet and [open quotes]thin-bedded levees[close quotes] deposits oil prone.

  16. Soil properties and pre-Columbian settlement patterns in the Monumental Mounds Region of the Llanos de Moxos, Bolivian Amazon

    NASA Astrophysics Data System (ADS)

    Lombardo, U.; Denier, S.; Veit, H.

    2015-01-01

    In the present paper we explore to what degree soil properties might have influenced pre-Columbian settlement patterns in the Monumental Mounds Region (MMR) of the Llanos de Moxos (LM), Bolivian Amazon. Monumental mounds are pre-Hispanic earth buildings and were preferentially built on mid- to late Holocene palaeolevees of the Grande River (here denominated PR1), while levees of older palaeorivers (PR0) were only sparsely occupied. We dug two transects across PR0 and PR1 levee-backswamp catenas and analysed them for grain size, pH, cation exchange capacity (CEC) and Corg. Our data show that PR1 soils, where the density of mounds is higher, have far greater agricultural potential than PR0 soils, which are affected by aluminium toxicity in the backswamps and by high levels of exchangeable sodium in the levees. This study provides new data on the soil properties of the south-eastern Bolivian Amazon and reinforces the hypothesis that environmental constraints and opportunities exerted an important role on pre-Columbian occupation patterns and the population density reached in the Bolivian Amazon.

  17. Development of hierarchical magnesium composites using hybrid microwave sintering.

    PubMed

    Habibi, Meisam Kouhi; Joshi, Shailendra P; Gupta, Manoj

    2011-01-01

    In this work, hierarchical magnesium based composites with a micro-architecture comprising reinforcing constituent that is a composite in itself were fabricated using powder metallurgy route including microwave assisted rapid sintering technique and hot extrusion. Different level-I composite particles comprises sub-micron pure aluminum (Al) matrix containing Al2O3 particles of different length scale (from micrometer to nanometer size). Microstructural characterization of the hierarchical composites revealed reasonably uniform distribution of level-I composite particles and significant grain refinement compared to monolithic Mg. Hierarchical composite configurations exhibited different mechanical performance as a function of Al2O3 length scale. Among the different hierarchical formulations synthesized, the hierarchical configuration with level-I composition comprising Al and nano-Al2O3 (0.05 microm) exhibited the highest improvement in tensile yield strength (0.2% YS), ultimate tensile strength (UTS), tensile failure strain (FS), compressive yield strength (0.2% CYS) and ultimate compressive strength (UCS) (+96%, +80%, +42%, +80%, and +83%) as compared to monolithic Mg. An attempt has been made in the present study to correlate the effect of different length scales of Al2O3 particulates on the microstructural and mechanical response of magnesium. PMID:24427874

  18. Environmental and human impact on the sedimentary dynamic in the Rhone Delta subaquatic canyons (France-Switzerland)

    NASA Astrophysics Data System (ADS)

    Arantegui, A.; Corella, J. P.; Loizeau, J. L.; Anselmetti, F. S.; Girardclos, S.

    2012-04-01

    Deltas are very sensitive environments and highly vulnerable to variations in water discharge and the amount of suspended sediment load provided by the delta-forming currents. Human activities in the watershed, such as building of dams and irrigation ditches, or river bed deviations, may affect the discharge regime and sediment input, thus affecting delta growth. Underwater currents create deeply incised canyons cutting into the delta lobes. Understanding the sedimentary processes in these subaquatic canyons is crucial to reconstruct the fluvial evolution and human impact on deltaic environments and to carry out a geological risk assessment related to mass movements, which may affect underwater structures and civil infractructure. Recently acquired high-resolution multibeam bathymetry on the Rhone Delta in Lake Geneva (Sastre et al. 2010) revealed the complexity of the underwater morphology formed by active and inactive canyons first described by Forel (1892). In order to unravel the sedimentary processes and sedimentary evolution in these canyons, 27 sediment cores were retrieved in the distal part of each canyon and in the canyon floor/levee complex of the active canyon. Geophysical, sedimentological, geochemical and radiometric dating techniques were applied to analyse these cores. Preliminary data show that only the canyon originating at the current river mouth is active nowadays, while the others remain inactive since engineering works in the watershed occurred, confirming Sastre et al. (2010). However, alternating hemipelagic and turbiditic deposits on the easternmost canyons, evidence underflow processes during the last decades as well. Two canyons, which are located close to the Rhone river mouth, correspond to particularly interesting deeply incised crevasse channels formed when the underwater current broke through the outer bend of a meander in the proximal northern levee. In these canyons, turbidites occur in the sediment record indicating ongoing

  19. Anatomy and dynamics of a floodplain, Powder River, Montana, U.S.A.

    USGS Publications Warehouse

    Pizzuto, J.E.; Moody, J.A.; Meade, R.H.

    2008-01-01

    Centimeter-scale measurements on several Powder River floodplains provide insights into the nature of overbank depositional processes that created the floodplains; during a 20-year period after a major flood in 1978. Rising stages initially entered across a sill at the downriver end of the floodplains. Later, as stages continued to rise, water entered the floodplains through distinct low saddles along natural levees. The annual maximum depth of water over the levee crest averaged 0.19 in from 1983 through 1996, and the estimated flow velocities were approximately 0.15 m s-1. Water ponded in the floodplain trough, a topographic low between the natural levee and the pre-flood riverbank, and mud settled as thin layers of nearly constant thickness. Mud layers alternated with sand layers, which were relatively thick near the channel. Together, these beds created a distinctive natural levee. In some locations, individual flood deposits began as a thin mud layer that gradually coarsened upwards to medium-grained sand. Coarsening-upwards sequences form initially as mud because only the uppermost layers of water in the channel supply the first overbank flows, which are rich in mud but starved of sand. At successively higher stages, fine sands and then medium sands increase in concentration in the floodwater and are deposited as fine- and medium-sand layers overlying the initial mud layer. Theoretical predictions from mathematical models of sediment transport by advection and diffusion indicate that these processes acting alone are unlikely to create the observed sand layers of nearly uniform thickness that extend across much of the floodplain. We infer that other transport processes, notably bedload transport, must be important along Powder River. Even with the centimeter-scale measurements of floodplain deposits, daily hydraulic data, and precise annual surface topographic surveys, we were unable to determine any clear correspondence between the gauged flow record of

  20. Dike Strength Analysis on a Regional Scale Based On a Stochastic Subsoil Model

    NASA Astrophysics Data System (ADS)

    Koelewijn, A. R.; Vastenburg, E. W.

    2013-12-01

    About two-third of the Netherlands is protected against flooding by dikes and levees. The subsoil can be characterized by fluvial and marine sediments. Maintaining the safety of these dikes and levees is of vital importance. Insufficient safety is not permissible, but excessive safety would imply a waste of money and other resources. Therefore safety assessments are carried out on a regular basis. Over the past decades, a practice has grown to calculate a limited number of cross-sections, roughly one every 500 to 1000 meters. For this purpose, a representative cross-section is selected as an estimate of the most vulnerable surface geometry and the subsoil conditions determined from boreholes and cone penetration tests, for which slope stability and piping analyses are carried out. This is a time-consuming procedure which is not only expensive, but also neglects geological knowledge. A method to incorporate geological knowledge of an area, including updating on the basis of additional investigations, has been described in Koelewijn et al. [2011]. In addition, various groups have worked to incorporate geotechnical stability models and detailed Lidar-measurements of the surface into a more efficient and rational calculation process [Knoeff et al. 2011, Lam et al. 2013, van den Ham & Mastbergen, 2013]. Combining this experience with the 3D subsoil model opens possibilities for cost-effective additional soil investigations for those locations where ruling out unfavorable conditions really influences the decisions to be made regarding rejection and improvement, see the figure for examples of different subsoil profiles along a dike. The resulting system has been applied for semi-automated calculations of dikes in various parts of the Netherlands, totalling over 4000 km by now, and a part of the Mississippi levee system. [van den Ham & Mastbergen, 2013] G.A. van den Ham & D.R. Mastbergen, A semi-probabilistic assessment method for flow slides. AGU Fall meeting, 2013

  1. Hydrodynamic Modeling of Flood Dynamics and Restoration Potential of Lower Missouri River Floodplains

    NASA Astrophysics Data System (ADS)

    Lindner, G. A.

    2012-12-01

    Lower Missouri River floodplains have the potential to provide multiple ecosystem services including agricultural production, floodwater storage, nutrient processing, and provision of habitats. In this research, a 2-dimensional hydrodynamic model of a representative looped floodplain bottom of approximately 20 km is utilized to explore how floodplain inundation contributes to ecosystem benefits and costs. High resolution 2-dimensional hydrodynamic modeling provides insights into the way velocities, flood stages, residence times, and transported constituents (sediment, nutrients, and fish larvae, for example) are affected by levee geometry, floodplain vegetation patterns, and flood magnitude and duration. The utility of 2-dimensional numerical hydraulic models to represent the channel and floodplain are demonstrated at a scale relevant to understanding processes that control channel/floodplain dynamics. The sensitivity of model response to alternative land use scenarios, including levee setbacks and variable overbank roughness, is quantified using hydraulic parameters such as velocity, water level, conveyance, and residence time. The 2-dimensional models are calibrated to existing 1-dimensional modeling solutions and field measurements of water surface from 1993 and 2007 for the 2-year, 5-year, and 10-year recurrence intervals. Calibration runs with current levee configurations are matched to approximately ±0.1 meters. Simulations of alternative land use scenarios demonstrate the tradeoffs between ecological restoration and flood risk reductions. Levee setbacks with low hydraulic roughness associated with traditional row crop agriculture on the floodplains have the greatest potential for flood stage reductions, while native plant communities with higher roughness can negate the effects of the setbacks by increasing water levels due to enhanced frictional resistance. Residence times, which are presumed to be related to ecosystem services, demonstrate increasingly

  2. New Views of the Gulf of Alaska Margin Mapped for UNCLOS Applications

    NASA Astrophysics Data System (ADS)

    Mayer, L. A.; Gardner, J. V.; Armstrong, A.; Calder, B. R.; Malik, M.; Angwenyi, C.; Karlpata, S.; Montoro-Dantes, H.; Morishita, T.; Mustapha, A.; van Waes, M.; Wood, D.; Withers, A.

    2005-12-01

    Article 76 of the UN Convention on the Law of the Sea (UNCLOS) outlines a series of criteria that may allow a coastal state to extend its legal jurisdiction beyond the EEZ. The mapping required to support an UNCLOS submission generates datasets useful to a wide spectrum of disciplines; the new maps will provide a new framework for the next generation of continental-margin studies. As part of an ongoing U.S. UNCLOS effort, >162,000 km2 of the Gulf of Alaska (GOA) margin between the 1 and 4.5 km isobaths was mapped in 2005 with a 12-kHz multibeam echosounder (MBES) that provides bathymetry and co-registered backscatter. The data have a spatial resolution of 100 m. The north and east GOA shelf is truncated by the strike-slip Queen Charlotte-Fairweather and Transition Faults. The margin is draped by overlapping submarine-fans e modified by incised channel-levee systems. The Baranof Fan is composed of several fans. The southern-most mapped fan is a small feature from which springs the upper reaches of Mukluk Channel. Horizon channel-levee complex traverses SW across the margin. The two channels meet ~80 km down slope at a 90? junction where Mukluk Channel is captured by Horizon Channel. Chatham Fan covers more than 3000 km2 and is incised by an unnamed meandering channel and built by an associated levee complex. The levee is incised by a meandering channel-levee complex. The sediments of this fan have high backscatter. Vast zones of rotational sliding occupy the northern flanks of the levees. The slides typically are retrogressive and shear-dominated with limited down slope movement. The next fan complex to the north, Kruzofi fan, buries more than 7500 km2 of the margin. This fan developed between the levee of Chatham fan and a curving depositional ridge. Gravity data implies that this ridge may be structurally controlled. The growth of Kruzofi fan to the east appears to have been so rapid that the channels have been deflected to the NW so that they trend sub

  3. Surface-Water and Ground-Water Interactions in the Central Everglades, Florida

    USGS Publications Warehouse

    Harvey, Judson W.; Newlin, Jessica T.; Krest, James M.; Choi, Jungyill; Nemeth, Eric A.; Krupa, Steven L.

    2004-01-01

    Everglades restoration. A century of water management for flood control and water storage in the Everglades resulted in the creation of the Water Conservation Areas (WCAs). Construction of the major canals began in the 1910s and the systems of levees that enclose the basins and structures that move water between basins were largely completed by the 1950s. The abandoned wetlands that remained outside of the Water Conservation areas tended to dry out and subside by 10 feet or more, which created abrupt transitions in land-surface elevations and water levels across the levees. The increases in topographic and hydraulic gradients near the margins of the WCAs, along with rapid pumping of water between basins to achieve management objectives, have together altered the patterns of recharge and discharge in the Everglades. The most evident change is the increase in the magnitude of recharge (on the upgradient side) and discharge (on the downgradient side) of levees separating WCA-2A from other basins or areas outside. Recharge and discharge in the vast interior of WCA-2A also likely have increased, but fluxes in the interior wetlands are more subtle and more difficult to quantify compared with areas close to the levees. Surface-water and ground-water interactions differ in fundamental ways between wetlands near WCA-2A's boundaries and wetlands in the basin's interior. The levees that form the WCA's boundaries have introduced step functions in the topographic and hydraulic gradients that are important as a force to drive water flow across the wetland ground surface. The resulting recharge and discharge fluxes tend to be unidirectional (connecting points of recharge on the upgradient side of the levee with points of discharge on the downgradient side), and fluxes are also relatively steady in magnitude compared with fluxes in the interior. Recharge flow paths are also relatively deep in their extent near levees, with fluxes passing entirely through the 1-m peat layer and inte

  4. [Neuronal communication and synaptic metabolism in childhood epilepsy].

    PubMed

    García-Cazorla, Àngels; Cortès-Saladelafont, Elisenda; Duarte, Sofia

    2015-03-01

    Introduccion. Los conocimientos que la neurociencia basica y el neurometabolismo estan aportando en epilepsia pediatrica, y en concreto en mecanismos de comunicacion sinaptica, crecen rapidamente. Existe, no obstante, una desconexion entre estos avances y una vision que los integre de manera global y en la practica clinica y terapeutica. Objetivos. Ofrecer una vision integradora de los diferentes mecanismos moleculares y metabolicos que se conocen y postulan en epilepsia pediatrica, y sugerir conceptos como el de 'metabolismo sinaptico' y 'fenotipos sinapticos' como herramientas utiles para desarrollar este enfoque. Desarrollo. Se revisan los estudios mas destacados que intentan explicar las caracteristicas esenciales de la comunicacion sinaptica en el cerebro en desarrollo, a traves de diferentes moleculas, basicamente proteinas sinapticas, canales ionicos (cotransportadores de cloro, sodio y potasio), la compartimentalizacion pre y postsinaptica, y los principales actores metabolicos (neurotransmisores, metabolismo energetico, factores de crecimiento y lipidos). A partir de esta combinacion de mecanismos biologicos se sugieren ejemplos de 'fenotipos sinapticos' en dos casos concretos de epilepsia genetica (SCN1A) y metabolica (epilepsia con respuesta a la piridoxina). Conclusiones. Una perspectiva holistica, entendiendo la diversidad de elementos relacionados y que suceden en determinados momentos del neurodesarrollo, puede ayudar a delinear fenotipos, vias de metabolismo sinaptico y conectividad cerebral, que faciliten no solo la comprension de la fisiopatologia, sino nuevas aproximaciones terapeuticas en epilepsia pediatrica.

  5. Effects of large pressure amplitude low frequency noise in the parotid gland perivasculo-ductal connective tissue.

    PubMed

    Oliveira, Pedro; Brito, José; Mendes, João; da Fonseca, Jorge; Águas, Artur; Martins dos Santos, José

    2013-01-01

    Introdução: Em tecidos e órgãos expostos a ruído de baixa frequência de alta amplitude ocorre fibrose na ausência de sinais inflamatórios, que se pensa ser uma resposta protetora. No tecido conjuntivo perivasculo-ductal da glândula parótida seguem artérias, veias e a árvore ductal. Crê-se que o tecido conjuntivo perivasculo-ductal funcione como um estabilizador mecânico do tecido glandular.Material e Métodos: Para quantificar a proliferação de tecido conjuntivo perivasculo-ductal em ratos expostos a ruído de baixafrequência de alta amplitude foram utilizados 60 ratos Wistar igualmente divididos em seis grupos. Um grupo mantido em silêncio, e os restantes 5 expostos a ruído de baixa frequência de alta amplitude continuamente: g1-168h (1 semana); g2-504h (3 semanas); g3-840h (5semanas); g4-1512h (9 semanas) e g5-2184h (13 semanas). Após a exposição, as parótidas foram removidas e o tecido conjuntivo perivasculo-ductal foi medido em todos os grupos. Foi efectuada análise estatística com ANOVA por SPSS 13.0.Resultados: A tendência é um aumento global das áreas do tecido conjuntivo perivasculo-ductal, que se desenvolve de forma linear e significativa com o tempo de exposição (p < 0,001).Discussão: Tem sido sugerido que a resposta biológica à exposição ao ruído de baixa frequência de alta amplitude está associada à necessidade de manter a integridade estrutural. O reforço estrutural seria conseguido através do aumento do tecido conjuntivo perivasculo-ductal.Conclusões: Assim, estes resultados mostram que o tecido conjuntivo perivasculo-ductal aumenta em resposta à exposição ao ruído de baixa frequência de alta amplitude.

  6. The Himalaya-Bengal Fan source to sink system - new insights by correlation of re-processed seismic data and IODP Expedition 354 results

    NASA Astrophysics Data System (ADS)

    Bergmann, Fenna; Schwenk, Tilmann; Spiess, Volkard; France-Lanord, Christian

    2016-04-01

    The Bengal Fan, hosted in the northern Indian Ocean, is the largest submarine fan on Earth. Fan evolution started in the Early Eocene as a direct response to the collision of India with the Asian continent in Middle Paleocene times. Subsequently the Himalayan plateau uplift was initiated. Thereby generated interactions with the regional climate caused the evolution of the Indian monsoonal system. Drained by the rivers Ganges and Brahmaputra, ~ 80% of eroded Himalayan sediments are deposited in the Bengal Fan. Hence, the Fan provides the most complete record of the Himalayan history and is well suited to investigate the direct link between the tectonic uplift and the climate evolution of the region. Sediments are transported onto the deep sea fan by turbidity currents building up chan-nel-levee systems. These channel-levee systems are the main architectural elements of the Bengal Fan and are suspected to have their onset in Late Miocene times. Frequent channel avulsion on the upper fan led to the abandonment of old channels and formation of new channel-levee systems or even channel-reoccupation. This complex erosional/depositional system involves lateral depocenter migration, probably on millennial timescales. Conse-quently, investigations of the Himalaya as sediment source begins with a comprehensive understanding of transport, deposition and modification within the Bengal Fan sediment sink. In February/March 2015 the IODP Expedition 354 drilled at 7 sites along a ~320 km long E-W transect at 8° N. Aiming at the recovery of pre-fan deposits and deposits of the Pliocene and Upper Miocene Fan evolution, three deep sites (900 - 1200 mbsf) were realized. These where complemented by four shallow sites (200-300 mbsf) for a detailed study of the depos-its of the last 1-2 million years, including the latest known channel activities (Holocene times). Several channel-levee systems and inter-channel deposits were drilled, active at different times of Fan evolution. To

  7. Geologically recent small-scale surface features in Meridiani Planum and Gale Crater, Mars

    NASA Astrophysics Data System (ADS)

    Horne, David

    2014-05-01

    Enigmatic small scale (<1m) depositional and erosional features have been imaged at several locations in the equatorial Meridiani Planum region by the rover Opportunity. They occur in loose, dark basaltic sands partly covering exposures of light-toned bedrock. Leveed fissures are narrow, elongate, steep-sided depressions flanked by raised levees or half-cones of soil, typically 2-10 cm wide and up to 50 cm long in most cases. Some cross-cut and are therefore younger than eolian ripples thought to have last been active c. 50,000 years ago. Gutters are elongate, straight or sinuous surface depressions, typically 2-10cm wide and 1-5 cm deep, sometimes internally terraced or with a hollow near one end, and in one case seem to give way to small depositional fans downslope; they have the appearance of having been formed by liquid flow rather than by wind erosion. Leveed fissures were imaged at more than 25 locations by Opportunity between 2004 and 2013, particularly near the rims of Endurance, Erebus and Endeavour craters, but also on the plains between Santa Maria and Endeavour craters; sharply-defined gutters are less common but examples were imaged close to the rim of Endurance and on the approach to Endeavour, whereas subdued, possibly wind-softened examples are more widespread. Scrutiny of images obtained by the rover Spirit in Gusev Crater between 2004 and 2010 has so far failed to find any leveed fissures or gutters, but examples of both types of features, as well as numerous small holes suggestive of surface sediment falling into underlying voids, were imaged by the rover Curiosity in the Yellowknife Bay region of Gale Crater during 2013. Leveed fissures appear to have been formed by venting from beneath. Ground disturbance by the rover can be ruled out in many cases by the appearance of features in images taken before close approach. Blowholes seem plausible close to crater rims (where wind might enter a connected void system through a crater wall) but less so

  8. Floodflow characteristics at proposed bridge site for State Highway 99, Kansas River at Wamego, Kansas

    USGS Publications Warehouse

    Medina, K.D.

    1987-01-01

    The Kansas Department of Transportation has proposed replacing a bridge over the Kansas River on State Highway 99, at Wamego, Kansas. The ability of the main channel along with the existing agricultural levee to contain the flow of the Kansas River, the effect of overflow structures under the highway south of the bridge, and the effect of an island upstream from the proposed bridge are discussed. The design of the proposed new bridge is adequate for passage of a 100-yr flood of 155,000 cu ft/sec; however, the existing levee along the right bank of the river upstream of the proposed bridge will not confine the flow to the main channel because parts of the levee have been broken or removed. The present overflow structures would allow a discharge of 26,000 cu ft/sec to occur in the bypass reach with a maximum depth of flow over the highway of 1.3 ft. If the structures were removed but the highway grade maintained, the discharge would increase to about 30,000 cu ft/sec with a depth of flow over the highway of 1.5 ft. If the overflow structures were removed and the elevated sections of the highway grade leveled, the discharge would increase to about 31,500 cu ft/sec, with a maximum depth of flow over the highway of 1.3 ft. The velocity of flow through four 30-in diameter concrete culverts located at overflow structure sites would be 8.6 ft/sec. Foreseeable changes in the island upstream from the proposed bridge would not interfere with the flow capacity of the new bridge. (Author 's abstract)

  9. Hydraulic analyses of water-surface profiles in the vicinity of the Coamo Dam and Highway 52 Bridge, southern Puerto Rico; flood analyses as related to the flood of October 7, 1985

    USGS Publications Warehouse

    Johnson, K.G.; Quinones-Marquez, Ferdinand; Gonzalez, Ralph

    1987-01-01

    The magnitude, frequency and extent of the flood of October 7, 1985 at the Rio Coamo in the vicinity of the Coamo Dam and Highway 52 bridge in southern Puerto Rico, were investigated. The observed flood profiles were used to calibrate a step-backwater model. The calibrated model was then used to investigate several alternative flow conditions in the vicinity of the bridge. The peak discharge of the flood at the Highway 52 bridge was 72,000 cu ft/sec. This peak discharge was determined from the peak computed at a reach in the vicinity of the Banos de Coamo, about 1.2 mi upstream from the bridge. The computed discharge at the Banos de Coamo of 66,000 cu ft/sec was adjusted to the dam and bridge location by multiplying it by the ratio of the drainage areas raised to the 0.83 power. The flood had a recurrence interval of about 100 yr, exceeding all previously known floods at the site. The flood overtopped the spillway and levee of the Coamo Dam just upstream of Highway 52. The flow over the spillway was 54,000 cu ft/sec. Flow over the levee was about 18,000 cu ft/sec. About 10,000 cu ft/sec of the flow over the levee returned to the main channel at the base of the embankment at the northeast approach to the bridge. The remaining 8,000 cu ft/sec flowed south through the underpass on Highway 153. The embankment and shoulder on the northern span of the bridge were eroded with the eventual collapse of the approach slab. (Author 's abstract)

  10. [How far reaches earliness of optical coherence tomography in cognitive impairment].

    PubMed

    Gimenez-Castejon, D; Gomez-Gallego, M; Martinez-Martinez, M L; Dudekova, M; Lajara-Blesa, J

    2016-07-01

    Introduccion. La enfermedad de Alzheimer (EA) es la primera causa de demencia mundial. Cada vez son mas los esfuerzos para lograr una deteccion temprana del deterioro cognitivo y surgen en el panorama cientifico entidades diagnosticas como el deterioro cognitivo leve (DCL) y las quejas subjetivas de memoria (QSM). Debido a ello, aparecen numerosos biomarcadores estudiados para conseguir dicho objetivo, entre ellos la tomografia de coherencia optica. Sujetos y metodos. Se ha realizado un estudio que utiliza la tomografia de coherencia optica para medir el grosor macular y la capa de fibras nerviosas de la retina en pacientes diagnosticados de EA (n = 36), pacientes con DCL (n = 33), en individuos con QSM (n = 24) y en sujetos control (n = 45). Resultados. Se han encontrado diferencias estadisticamente significativas en cuanto al grosor macular entre todos los grupos estudiados (QSM: 261,8 ± 25,88 µm; DCL: 259,19 ± 22,582 µm; EA leve: 258,53 ± 14,804 µm; EA moderada: 249,32 ± 18,467 µm) y sujetos control (271,96 ± 15,57 µm). Respecto a la capa de fibras nerviosas de la retina, ocurre de igual manera, y la diferencia es estadisticamente significativa frente al grupo control (94,51 ± 9,203 µm) de todos los grupos (QSM: 90,44 ± 9,059 µm; DCL: 89,4 ± 10,421 µm; EA leve: 87,12 ± 10,279 µm; EA moderada: 82,25 ± 10,636 µm). Conclusion. La tomografia de coherencia optica podria situarse como un futuro biomarcador y una herramienta de apoyo para facilitar el diagnostico precoz del deterioro cognitivo y de la EA.

  11. Processes of late Quaternary turbidity current flow and deposition on the Var deep sea fan, northwest Mediterranean sea

    SciTech Connect

    Piper, D. ); Savoye, B. )

    1993-09-01

    Late Quaternary sedimentation patterns on the Var deep-sea fan are known from high-resolution seismic boomer profiles (vertical resolution < 1 m), piston cores, SAR side-scan sonargraphs, and submersible dives. Foram biostratigraphy and radiocarbon dating provide chronologic control that is seismically correlated across the fan. Regional erosional events correspond to the isotopic state 2 and 6 glacial maxima. A widespread surface sand layer was deposited from the 1979 turbidity current, which broke two submarine cables. Numerical modeling constrains its character. A small slide on the upper prodelta developed into an accelerating turbidity current, which eroded sand from the Var canyon. The current was 30 m thick in the upper valley, expanding downflow to >120 m, where it spilled over the eastern Var sedimentary ridge at a velocity of 2.5 ms[sup [minus]1]. Other Holocene turbidity currents (with a 103-yr recurrence interval) were muddier and thicker, but also deposited sand on middle fan-valley levees and are inferred to have had a similar slide-related origin. Late Pleistocene turbidity currents deposited on the high Var sedimentary ridge. The presence of sediment waves and the cross-flow slope inferred from levee asymmetry indicate that some flow were hundreds of meters thick, with velocities of 0.35 ms[sup [minus]1]. Estimated times for deposition of thick levee mud beds are many days or weeks. Late Pleistocene flows therefore are interpreted to result from hyperpycnal flow of glacial outwash in the Var River. Variation in late Pleistocene-Holocene turbidite sedimentation thus is controlled more by changes in sediment supply than by sea level.

  12. Quaternary conception fan, Santa Barbara, California: two distinct canyon(s)-fan systems

    SciTech Connect

    Kraemer, S.M.C.

    1987-05-01

    The Quaternary Conception fan forms the gentle northwestern slope of the Santa Barbara basin, California. Two distinct canyon(s)-fan systems which show conspicuous differences in growth pattern coalesced to form this sediment wedge. The older Cojo canyon-fan system fed a typical radial fan characterized by (1) a single persistent conduit, (2) rhythmic interbedded levees in the upper and mid-fan built by frequent episodic turbidity flows, (3) an apparently well-developed distributary system, and (4) distal sand deposition on the lower fan and basin plain. Subsequently, the Gaviota canyons formed a radial fan/slope apron system. Two subparallel canyons were incised along fault zones where headward erosion was enhanced by slumping and increased fluvial sediment supply during the Pleistocene due to the capture of the Santa Ynez River near Gaviota Creek. Tectonism produced channel aggradation, which resulted in a series of en echelon channels. The eastern channel is associated with slumping and numerous coalescing slope gullies. These features resulted from oversteepening of the fan slope. Due to the absence of distinct gradient breaks, recent channel morphology was used to define fan divisions: (1) upper fan, broad channel with levees, gradient range from 1:25 to 1:40, (2) middle fan, levee heights decrease and channels narrow, gradients range from 1:40 to 1:100, and (3) lower fan, relatively smooth surface morphology, gradients less than 1:100. These higher gradients on the present Conception fan are unlike radial fan systems and have resulted in (1) relatively straight incised channels, (2) no distinct distributary system with evidence of channel braiding or avulsion, and (3) no suprafan bulge despite high sand supply. Morphology of the Cojo canyon-fan system suggests gradients were lower during deposition than presently observed on the fan.

  13. Sediment dynamics within the intertidal floodplain of the lower Amazon River

    NASA Astrophysics Data System (ADS)

    Fricke, A. T.; Nittrouer, C. A.; Ogston, A. S.; Nowacki, D. J.; Asp, N. E.; Souza Filho, P. W.

    2014-12-01

    Tidal influence extends ~800 kilometers upstream of the Amazon River mouth, producing semidiurnal oscillations in water elevation and slowing or reversing the flow of the world's largest river. This tidally influenced reach, known as the tidal river, is flanked by an expansive intertidal floodplain, and includes confluences with two large tributaries, the Xingu and Tapajós. The relative magnitude of the seasonal and tidal signals changes along the length of the tidal river, yielding diverse floodplain environments that span a range of seasonal and tidal influence. Near the upstream limit of tides, natural levees isolate the river from the floodplain during low to moderate flows, while in the lower tidal river, natural levees are absent and river-floodplain exchange is dominated by the tides rather than seasonal variation in river stage. This difference between fluvial and tidal systems strongly affects the nature of sediment exchange between the channel and floodplain, including frequency, duration, and depth of inundation. Here we present data on the impact of this fluvial-tidal continuum on sedimentary processes in the floodplain and resultant depositional signatures. Changes in levee prominence, grain size, and sediment accumulation combine to produce the distinct morphologies of floodplain lakes, intertidal backswamps, and intertidal flats. In addition to sediment accumulation on the periodically exposed floodplain, Amazon River sediment accumulates within the drowned tributary confluences of the Xingu and Tapajós Rivers. Here seasonal and tidal changes in water temperature, discharge, and suspended-sediment concentration drive barotropic and baroclinic flows that transport Amazon River sediment into tributary basins. These findings help to constrain the fate of sediment within the ungauged Amazon tidal river, and will help in understanding the response of the lower Amazon River to changes in accommodation space associated with rising sea level, and changes

  14. Soil-atmosphere exchange of methane in adjacent cultivated and floodplain forest soils

    NASA Astrophysics Data System (ADS)

    Burke, Roger A.; Meyer, Judith L.; Cruse, Jennifer M.; Birkhead, Karen M.; Paul, Michael J.

    1999-04-01

    The soil-atmosphere exchange of methane was measured in adjacent cultivated (corn) and forest (upper floodplain, mixed hardwood) habitats of the southeastern U.S. piedmont for a period of 3 years using closed chambers. We have evaluated the effect of the following factors on soil-atmosphere methane exchange: (1) interannual variability of climatic conditions, (2) landscape position (i.e., river levee versus terrace), and (3) disturbance ranging from intense (cultivation) through moderate (approximately annual flooding events that last from weeks to months) to subtle (approximately annual flooding of a few days duration). We found that mean methane consumption in the cultivated and forested terrace sites was <0.3 mg CH4 m-2 d-1, whereas the mean consumption rate in forested levee sites was about 1.4 mg CH4 m-2 d-1 over the course of the 3 years. Moisture levels in the upper soil (0-5 cm) appear to exert little control of methane exchange in any of the habitats. We observed little seasonal variation in methane flux in the levee sites, in contrast to results observed by others in higher-latitude and tropical forests. Our results suggest that very subtle differences in landscape position and disturbance impact the strength of the soil methane sink. We cannot conclude that agricultural development destroyed the methane sink capacity of these floodplain terrace soils because it was probably already quite low due to periodic disturbance by flooding. Limited measurements of nitrogen cycling suggest that methane flux differences observed among the different habitats are not obviously related to differences in N mineralization or nitrification as in other ecosystems.

  15. Channel formation by flow stripping: large-scale scour features along the Monterey East Channel and their relation to sediment waves

    USGS Publications Warehouse

    Fildani, A.; Normark, W.R.; Kostic, S.; Parker, G.

    2006-01-01

    The Monterey East system is formed by large-scale sediment waves deposited as a result of flows stripped from the deeply incised Monterey fan valley (Monterey Channel) at the apex of the Shepard Meander. The system is dissected by a linear series of steps that take the form of scour-shaped depressions ranging from 3·5 to 4·5 km in width, 3 to 6 km in length and from 80 to 200 m in depth. These giant scours are aligned downstream from a breech in the levee on the southern side of the Shepard Meander. The floor of the breech is only 150 m above the floor of the Monterey fan valley but more than 100 m below the levee crests resulting in significant flow stripping. Numerical modeling suggests that the steps in the Monterey East system were created by Froude-supercritical turbidity currents stripped from the main flow in the Monterey channel itself. Froude-supercritical flow over an erodible bed can be subject to an instability that gives rise to the formation of cyclic steps, i.e. trains of upstream-migrating steps bounded upstream and downstream by hydraulic jumps in the flow above them. The flow that creates these steps may be net-erosional or net-depositional. In the former case it gives rise to trains of scours such as those in the Monterey East system, and in the latter case it gives rise to the familiar trains of upstream-migrating sediment waves commonly seen on submarine levees. The Monterey East system provides a unique opportunity to introduce the concept of cyclic steps in the submarine environment to study processes that might result in channel initiation on modern submarine fans.

  16. Influence of the vegetation management of the leeves in irrigated rice organic in diversity of Hymenoptera parasitoids.

    PubMed

    Simões-Pires, P R; Jahnke, S M; Redaelli, L R

    2016-04-19

    Among the natural enemies of insect pests in rice fields, parasitoids are especially notable. To better understand the space-time dynamics of these insects, the objectives of this study were to describe and compare groups of parasitoids in organic irrigated rice fields using two management approaches for levee vegetation, and to relate them to the phenological stages of rice cultivation (the seedling, vegetative, and reproductive stages). The samples were taken in a plantation located in Viamão, RS, Brazil. The total area of 18 ha was divided into two parts: a no-cut (NC) subarea in which the wild vegetation of the levees was maintained, and a cut (C) subarea in which the levee vegetation was cut monthly. In each subarea, four Malaise traps considered as pseudo-replicas were installed and remained in the field for 24 hours at each sampling location. Collections occurred twice a month from the beginning of cultivation (October 2012) until harvest (March 2013). A total of 3,184 Hymenoptera parasitoids were collected: 2,038 individuals in the NC subarea and 1,146 in the C subarea. We identified 458 morphospecies distributed in 24 families. Mymaridae was the most abundant and Eulophidae was the richest in both subareas. A total of 198 morphospecies was shared between the subareas, including Platygastridae, Eulophidae, and Mymaridae, which were the families with the highest number of shared species. The richness and abundance of parasitoids varied according to their phenological developmental stages, with peak abundance registering during the vegetative period. The Morisita index identified three groupings, indicating a similarity that was related to the three phases of rice growth and development: seedling, vegetative and post-harvest. PMID:27097090

  17. Seismic responses and controlling factors of Miocene deepwater gravity-flow deposits in Block A, Lower Congo Basin

    NASA Astrophysics Data System (ADS)

    Wang, Linlin; Wang, Zhenqi; Yu, Shui; Ngia, Ngong Roger

    2016-08-01

    The Miocene deepwater gravity-flow sedimentary system in Block A of the southwestern part of the Lower Congo Basin was identified and interpreted using high-resolution 3-D seismic, drilling and logging data to reveal development characteristics and main controlling factors. Five types of deepwater gravity-flow sedimentary units have been identified in the Miocene section of Block A, including mass transport, deepwater channel, levee, abandoned channel and sedimentary lobe deposits. Each type of sedimentary unit has distinct external features, internal structures and lateral characteristics in seismic profiles. Mass transport deposits (MTDs) in particular correspond to chaotic low-amplitude reflections in contact with mutants on both sides. The cross section of deepwater channel deposits in the seismic profile is in U- or V-shape. The channel deposits change in ascending order from low-amplitude, poor-continuity, chaotic filling reflections at the bottom, to high-amplitude, moderate to poor continuity, chaotic or sub-parallel reflections in the middle section and to moderate-weak amplitude, good continuity, parallel or sub-parallel reflections in the upper section. The sedimentary lobes are laterally lobate, which corresponds to high-amplitude, good-continuity, moundy reflection signatures in the seismic profile. Due to sediment flux, faults, and inherited terrain, few mass transport deposits occur in the northeastern part of the study area. The front of MTDs is mainly composed of channel-levee complex deposits, while abandoned-channel and lobe-deposits are usually developed in high-curvature channel sections and the channel terminals, respectively. The distribution of deepwater channel, levee, abandoned channel and sedimentary lobe deposits is predominantly controlled by relative sea level fluctuations and to a lesser extent by tectonism and inherited terrain.

  18. Contribution of Clay mineralogy of Bengal Fan deposits at 8°N for understanding of Himalayan provenance and environmental conditions

    NASA Astrophysics Data System (ADS)

    Huyghe, Pascale; France-Lanord, Christian; IODP Expedition 354 Scientists

    2016-04-01

    The IODP 354 expedition (February-March 2015) focused on the middle part of the Bengal Fan (8°N). Seven sites were drilled along a 320 km- long transect and provided good recovery and excellent data to study both provenance of the material from the Himalayan orogeny and palaeoceanography linked to the Asian monsoon. Neogene sediments consist of an alternation of rapidly deposited, silty to muddy turbidites (10-100 cm/kyr) forming levees of channels intercalated with minor slowly deposited hemipelagic clays (1-2 cm/kyr), which may be found over the whole investigated area. Thick interlevee sand sheet units also occur between channel levees. The turbiditic sand, silt and clay have mineralogical signatures very similar to those of the modern Ganges and Brahmaputra rivers and are therefore relevant for reconstructing time series of erosion, weathering, and changes in Himalayan sources regions. Hemipelagic calcareous clays may provide additional information on environmental conditions throughout the Himalayan basin. Preliminar shipboard XRD analysis revealed that the clayey assemblages of sediments are relatively constant through the Neogene. Turbidite clay assemblages are dominated by detrital illite and chlorite as observed in the modern Himalayan rivers, suggesting that erosion conditions were relatively steady over the last 25 Ma. Hemipelagic clay assemblages vary from 1) identical to the illite-chlorite rich clays of turbidites, characteristic for Himalayan rivers, to 2) smectite rich assemblages enriched in iron and depleted in potassium, representing either more extreme sorting of the same material or input from another source. Further detailed investigation using decomposition of X-Ray diffraction (XRD) patterns reveals much more complex clay assemblages, especially great quantities of mixed-layers, the quantity and mineralogy of which varies and differs in the three depositional units as determined by turbidites levees, hemipelagic clayey beds and interlevees

  19. Dam failure analysis for the Lago de Matrullas Dam, Orocovis, Puerto Rico

    USGS Publications Warehouse

    Torres-Sierra, Heriberto; Gómez-Fragoso, Julieta

    2015-01-01

    Results from the simulated dam failure of the Lago de Matrullas Dam using the HEC–RAS model for the 6- and 24-hour PMP events showed peak discharges at the dam of 3,149.33 and 3,604.70 m3/s, respectively. Dam failure during the 100-year-recurrence, 24-hour rainfall event resulted in a peak discharge of 2,103.12 m3/s directly downstream from the dam. Dam failure under sunny day conditions produced a peak discharge of 1,695.91 m3/s at the dam assuming the antecedent lake level was at the morning-glory spillway invert elevation. Flood-inundation maps prepared as part of the study depict the flood extent and provide valuable information for preparing an Emergency Action Plan. Results of the failure analysis indicate that a failure of the Lago de Matrullas Dam could cause flooding to many of the inhabited areas along stream banks from the Lago de Matrullas Dam to the mouth of the Río Grande de Manatí. Among the areas most affected are the low-lying regions in the vicinity of the towns of Ciales, Manatí, and Barceloneta. The delineation of the flood boundaries near the town of Barceloneta considered the effects of a levee constructed during 2000 at Barceloneta in the flood plain of the Río Grande de Manatí to provide protection against flooding to the near-by low-lying populated areas. The results showed overtopping can be expected in the aforementioned levee during 6- and 24-hour probable-maximum-precipitation dam failure scenarios. No overtopping of the levee was simulated, however, during dam failure scenarios under the 100-year recurrence, 24-hour rainfall event or sunny day conditions.

  20. Pleistocene Through Oligocene Record of Himalayan Orogeny and Climate. The Iodp Expedition 354 Drilling Transect across the Middle Bengal Fan at 8°N

    NASA Astrophysics Data System (ADS)

    Spiess, V.; France-Lanord, C.; Schwenk, T.; Klaus, A.

    2015-12-01

    IODP Expedition 354 in the Bay of Bengal February-March 2015 drilled a seven site, 320 km-long transect across the Bengal Fan at 8°N. Three deep penetration and additional four shallow holes provided a spatial overview of the primarily turbiditic depositional system, comprising the Bengal deep sea fan. Sediments originate from Himalayan rivers, documenting terrestrial changes of the monsoon evolution and Himalayan erosion and weathering, and are transported through a delta and shelf canyon, supplying turbidity currents loaded with a full spectrum of grain sizes. Mostly following transport channels, sediments deposit on and between levees, while depocenters are laterally shifting over hundreds of kilometers on millennial time scales. Expedition 354 documented these deposits in space and time by identifying, coring and dating numerous stratigraphic marker horizons across the transect, allowing a detailed reconstruction of channel-levee migration, abandonment, reoccupation and overall uniform growth in the late Pleistocene. High resolution records of these growth patterns were acquired in several levee, interlevee and hemipelagic successions. Miocene through Pliocene fan development was studied at three deeper sites, which document and recovered sand rich facies throughout most of the cores acquired by the half-APC coring technology, intercalated by longer periods of hemipelagic deposition and absence of turbiditic input as the results of major depocenter shifts. Recovered sediments have Himalayan mineralogical and geochemical signatures suitable to reconstruct time series of erosion, weathering and changes in source regions as well as impacts on the global carbon cycle. Miocene shifts in terrestrial vegetation, in sediment budget and in style of sediment transport have been tracked. Expedition 354 has extended the record of early fan deposition by 10 Ma into the Late Oligocene.

  1. Large Fluvial Fans: Aspects of the Attribute Array

    NASA Technical Reports Server (NTRS)

    Wilkinson, Justin M.

    2015-01-01

    In arguing for a strict definition of the alluvial fan (coarse-grained with radii less than10 km, in mountain-front settings), Blair and McPherson (1994) proposed that there is no meaningful difference between large fluvial fans (LFF) and floodplains, because the building blocks of both are channel-levee-overbank deposits. Sediment bodies at the LFF scale (greater than 100 km long, fan-shaped in planform), are relatively unstudied although greater than 160 are now identified globally. The following perspectives suggest that the significance of LFF needs to be reconsidered.

  2. Bottomland Hardwood Forests along the Upper Mississippi River

    USGS Publications Warehouse

    Yin, Y.; Nelson, J.C.; Lubinski, S.J.

    1997-01-01

    Bottomland hardwood forests along the United States' Upper Mississippi River have been drastically reduced in acreage and repeatedly logged during the nineteenth and twentieth centuries. Conversion to agricultural land, timber harvesting, and river modifications for flood prevention and for navigation were the primary factors that caused the changes. Navigation structures and flood-prevention levees have altered the fluvial geomorphic dynamics of the river and floodplain system. Restoration and maintenance of the diversity, productivity, and natural regeneration dynamics of the bottomland hardwood forests under the modified river environment represent a major management challenge.

  3. Wetland physical and biotic studies using multispectral data

    NASA Technical Reports Server (NTRS)

    Ormsby, J. P.; Gervin, J. C.; Nickeson, J. E.; Willey, G.

    1986-01-01

    A November 1982 Landsat-4 TM scene and March and September 1984 airborne L-band radar data for a brackish-wetland area of the Blackwater National Wildlife Refuge (near Chesapeake Bay) are analyzed to monitor changes in vegetation and water area. The accuracy of level-I classification of the TM image is found to be 81 percent, but that of the few level-II/III classes for which ground truth was available is only 53 percent. The value of radar images for discriminating water areas obscured by vegetation and estimating plant heights is indicated.

  4. Space geodesy: subsidence and flooding in New Orleans.

    PubMed

    Dixon, Timothy H; Amelung, Falk; Ferretti, Alessandro; Novali, Fabrizio; Rocca, Fabio; Dokka, Roy; Sella, Giovanni; Kim, Sang-Wan; Wdowinski, Shimon; Whitman, Dean

    2006-06-01

    It has long been recognized that New Orleans is subsiding and is therefore susceptible to catastrophic flooding. Here we present a new subsidence map for the city, generated from space-based synthetic-aperture radar measurements, which reveals that parts of New Orleans underwent rapid subsidence in the three years before Hurricane Katrina struck in August 2005. One such area is next to the Mississippi River-Gulf Outlet (MRGO) canal, where levees failed during the peak storm surge: the map indicates that this weakness could be explained by subsidence of a metre or more since their construction.

  5. Distribution and seismic facies of Mississippi fan channels

    SciTech Connect

    Weimer, P.; Buffler, R.T. )

    1988-10-01

    Analysis of a closely spaced grid of multifold seismic data across the upper Pliocene-Pleistocene Mississippi fan in the deep Gulf of Mexico allows for the first time a detailed description of a large part of the fan. Mapping of the 17 channel-levee systems show considerable variability in parameters such as size, location, geometry, lateral migration, aggradation, sinuosity, and downfan bifurcation, which suggests that multiple factors control channel evolution. The youngest channel, cored during Deep Sea Drilling Project Leg 96, refects only style in channel evolution. Such complexity in large, mud-dominated, submarine fan systems must be considered in evaluating fan models and interpreting ancient fan systems.

  6. Joint Tomographic Inversion of Body-Wave Arrivals and Gravity Data at the Sacramento-San Joaquin River Delta

    NASA Astrophysics Data System (ADS)

    Teel, A.; Thurber, C. H.; Bennington, N. L.; Zhang, H.

    2011-12-01

    The Sacramento-San Joaquin River Delta (SSJRD) occurs at the confluence of the Sacramento and San Joaquin rivers in the Central Valley of California. The Central Valley is a sedimentary basin that divides the granitic Sierra Nevada range on the east from the heterogeneous Franciscan formation to the west. It is home to a series of levees that control about half of California's annual stream flow, and more than half of Californians get their drinking water from the SSJRD area. Previous studies show that ground motion from magnitude 6.0 earthquakes, which have recurrence intervals of about 100 years in the area, are capable of causing levee failure. While the highest risk for levee failure is in the western SSJRD, since it is near at least five major faults, a medium to high risk of catastrophic levee failure also exists for most of the central SSJRD. These assessments incorporate qualitative estimates of parameters such as basin amplification based on individual knowledge and experience, since geotechnical information is limited in the area. Likewise, two fault models are used in the study, which differ primarily in the assumed presence or absence of a blind thrust fault under the northwest corner of the SSJRD. To improve hazard assessment, particularly in regards to basin amplification of strong ground motion, local tomographic imaging is necessary to determine the shape of the Central Valley at depth and to help evaluate the presence of faults. We will present a new local P-wave velocity model for the SSJRD, determined from joint inversion of seismic arrival times and gravity measurements. For the purposes of this study, gravity data primarily complement body-wave data by providing information on shallow density structure and are more effective at delineating lateral density variations. Seismic waves provide better depth resolution but are limited by the spatial distribution of earthquake and receiver locations. Our datasets comprise over 213,000 (regional and

  7. Near Surface Shear Wave Velocity Model of the Sacramento-San Joaquin Delta

    NASA Astrophysics Data System (ADS)

    Shuler, S.; Craig, M. S.; Hayashi, K.; Galvin, J. L.; Deqiang, C.; Jones, M. G.

    2015-12-01

    Multichannel analysis of surface wave measurements (MASW) and microtremor array measurements (MAM) were performed at twelve sites across the Sacramento-San Joaquin Delta to obtain high resolution shear wave velocity (VS) models. Deeper surveys were performed at four of the sites using the two station spatial autocorrelation (SPAC) method. For the MASW and MAM surveys, a 48-channel seismic system with 4.5 Hz geophones was used with a 10-lb sledgehammer and a metal plate as a source. Surveys were conducted at various locations on the crest of levees, the toe of the levees, and off of the levees. For MASW surveys, we used a record length of 2.048 s, a sample interval of 1 ms, and 1 m geophone spacing. For MAM, ambient noise was recorded for 65.536 s with a sampling interval of 4 ms and 1 m geophone spacing. VS was determined to depths of ~ 20 m using the MASW method and ~ 40 m using the MAM method. Maximum separation between stations in the two-station SPAC surveys was typically 1600 m to 1800 m, providing coherent signal with wavelengths in excess of 5 km and depth penetration of as much as 2000 m. Measured values of VS30 in the study area ranged from 97 m/s to 257 m/s, corresponding to NEHRP site classifications D and E. Comparison of our measured velocity profiles with available geotechnical logs, including soil type, SPT, and CPT, reveals the existence of a small number of characteristic horizons within the upper 40m in the Delta: levee fill material, peat, transitional silty sand, and eolian sand at depth. Sites with a peat layer at the surface exhibited extremely low values of VS. Based on soil borings, the thickness of peat layers were approximately 0 m to 8 m. The VS for the peat layers ranged from 42 m/s to 150 m/s while the eolian sand layer exhibited VS ranging from of 220 m/s to 370 m/s. Soft near surface soils present in the region pose an increased earthquake hazard risk due to the potential for high ground accelerations.

  8. Thematic mapper studies of Andean volcanoes

    NASA Technical Reports Server (NTRS)

    Francis, P. W.

    1986-01-01

    The primary objective was to identify all the active volcanoes in the Andean region of Bolivia. Morphological features of the Tata Sabaya volcano, Bolivia, were studied with the thematic mapper. Details include marginal levees on lava and pyroclastic flows, and summit crater structure. Valley glacier moraine deposits, not easily identified on the multispectral band scanner, were also unambiguous, and provide useful marker horizons on large volcanic edifices which were built up in preglacial times but which were active subsequently. With such high resolution imagery, it is not only possible to identify potentially active volcanoes, but also to use standard photogeological interpretation to outline the history of individual volcanoes.

  9. [Intragenic deletions of NRXN1: three new case reports and a review of the phenotype].

    PubMed

    Galán-Sánchez, Francisco; Esteban-Cantó, Vanessa; Blaya-Fernández, Pedro; Jadraque-Rodríguez, Rocío; Manchón-Trives, Irene; Alcaraz-Más, Luis

    2015-03-01

    Objetivo. Aportar datos sobre el fenotipo determinado por las microdeleciones de los exones alfa del gen NRXN1. Casos clinicos. Se estudian tres casos neuropediatricos con microdeleciones intragenicas NRXN1 alfa. El fenotipo en estos tres casos es inespecifico, con retraso mental leve-moderado, trastornos de comportamiento y escasos rasgos dismorficos o malformaciones. Conclusion. El fenotipo encontrado en las microdeleciones de los exones alfa del gen NRXN1 es claramente distinguible del fenotipo encontrado en las microdeleciones de los exones beta, con macrocefalia, epilepsia y retraso mental.

  10. The rheology and composition of cryovolcanic flows on icy satellites

    NASA Technical Reports Server (NTRS)

    Kargel, Jeffrey S.

    1993-01-01

    The rheologic properties of terrestrial lavas have been related to morphologic features of their flows, such as levees, banked surfaces, multilobate structures, and compressible folds. These features also have been used to determine rheologies and constrain the compositions of extraterrestrial flows. However, with rare exceptions, such features are not resolvable in Voyager images of the satellites of outer planets. Often only flow length and edge thickness of cryovolcanic flows can be measured reasonably accurately from Voyager images. The semiempirical lava-flow model presented here is a renewed effort to extract useful information from such measurements.

  11. Economics of sunflower oil as an extender or substitute for diesel fuel

    SciTech Connect

    Helgeson, D.L.; Schaffner, L.W.

    1982-05-01

    The economics of sunflower oil as an extender or substitute for diesel fuel in US agriculture, with particular emphasis on North Dakota, is examined. A study of the spot market prices indicates that crude sunflower oil has moved closer competitively with bulk diesel prices. On the question of energy efficiency, it is estimated, that using current production and processing estimates, there is a positive net energy ratio of 5.78 to 1. Processing can take place at the commercial leveL, in intermediate sized plants or on-farm. Costs were analyzed for three sizes of farm presses. (Refs. 6).

  12. Distribution of Sea Level Muons at Zenith Angles below 10 TeV Energy

    NASA Astrophysics Data System (ADS)

    Mitra, M.

    The moderate energy primary cosmic ray nucleon spectrum has been constructed fro the direct measurements of Webber et al., Seo et al., Menn et al. along with the other results surveyed by Swordy. The sea leve muon energy spectra at different zenith angles have been derived from the decay of non-prompt mesons by adopting standard diffusion equation of hadronic cascades. The contribution of charmed mesons to muon spectrum has also been accounted following standard procedure. Our estimated tota muon energy spectra have been found comparable with the global spectrograph muon flux results of MARS, DEIS, MSU and other groups.

  13. Residual flood-risk: assessing the effectiveness of alternative large-scale mitigation strategies

    NASA Astrophysics Data System (ADS)

    Carisi, Francesca; Domeneghetti, Alessio; Castellarin, Attilio

    2016-04-01

    The EU Flood Directive (2007/60/CE) requires institutions and public bodies, in order to formulate robust flood-risk management strategies for large European rivers, to address several fundamental tasks. For instance, they have to address the problem of flood-risk mitigation from a global perspective (i.e., entire middle-lower river reaches) by identifying critical reaches, inundation areas and corresponding overflow volumes. To this aim, we focus on the identification of large-scale flood risk mitigation strategies for the middle-lower reach of the Po river, the longest Italian river and the largest in terms of streamflow. We refer to the so-called residual flood-risk and in particular to its portion referring to the possibility to experience events associated with larger return periods than the reference one (e.g. ~200 years in our case). In particular, being a further levee heightening not technically viable nor economically conceivable for the case study, the study develops and tests the applicability of a quasi-2D hydraulic model for the identification of large-scale flood-risk mitigation strategies relative to a 500-year flood event. In particular, we consider and model in the study different geometrical configurations of the main embankment system for a ~400km reach stretching from Isola S.Antonio to the Po river delta in the Adriatic Sea: overtopping without levee breaching, overtopping and natural levee breaching, overtopping and forced levee breaching. The simulations enable the assessment of the overflowed volumes and water depths on flooded areas. Expected damages are estimated using simplified graphical tools, which we termed "Vulnerability Hypsometric Curves" (HVCs) and report the extent of the area for a given land use category that is located below a certain elevation. The analysis aims at finding the optimal configuration that minimizes the expected damages in the areas prone to flood. The outcomes of our study indicate that coupling a large

  14. Operational flood forecasting: further lessons learned form a recent inundation in Tuscany, Italy

    NASA Astrophysics Data System (ADS)

    Caparrini, F.; Castelli, F.; di Carlo, E.

    2010-09-01

    After a few years of experimental setup, model refinement and parameters calibration, a distributed flood forecasting system for the Tuscany region was promoted to operational use in early 2008. The hydrologic core of the system, MOBIDIC, is a fully distributed soil moisture accounting model, with sequential assimilation of hydrometric data. The model is forced by the real-time dense hydrometeorological network of the Regional Hydrologic Service as well from the QPF products of a number of different limited area meteorological models (LAMI, WRF+ECMWF, WRF+GFS). Given the relatively short response time of the Tuscany basins, the river flow forecasts based on ground measured precipitation are operationally used mainly as a monitoring tool, while the true usable predictions are necessarily based on the QPF input. The first severe flooding event the system had to face occurred in late December 2009, when a failure of the right levee of the Serchio river caused an extensive inundation (on December 25th). In the days following the levee breaking, intensive monitoring and forecast was needed (another flood peak occurred on the night between December 29th and January 1st 2010) as a support for decisions regarding the management of the increased vulnerability of the area and the planning of emergency reparation works at the river banks. The operational use of the system during such a complex event, when both the meteorological and the hydrological components may be said to have performed well form a strict modeling point of view, brought to attention a number of additional issues about the system as a whole. The main of these issues may be phrased in terms of additional system requirements, namely: the ranking of different QPF products in terms of some likelihood measure; the rapid redefinition of alarm thresholds due to sudden changes in the river flow capacity; the supervised prediction for evaluating the consequences of different management scenarios for reservoirs

  15. Photographic copy of circa 1935, black and white, 10” x ...

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

    Photographic copy of circa 1935, black and white, 10” x 14” photograph. Loose in Huey P. Long folder in oversized box located at the National Museum of American History, Smithsonian Institution, Archives Center, Work and Industry Division, Washington, D.C. Photographer, Lionel T. Berryhill, Apple Valley, California. CIRCA 1935 PHOTOGRAPH OF BRIDGE TAKEN FROM WEST BANK LOOKING NORTH AT PIER “A” NEAR LEVEE. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  16. Strategic Floodplain Reconnection Along the Lower Tisza and Lower Illinois Rivers: Identifying Opportunities, Tradeoffs, and Limitations

    NASA Astrophysics Data System (ADS)

    Guida, R.; Remo, J. W.; Secchi, S.; Swanson, T.; Kiss, T.

    2015-12-01

    During the late 19th and into the 20th Centuries, the Tisza and Illinois Rivers were highly altered through the construction of levees and dams to reclaim their floodplain-wetland systems for agriculture and to facilitate navigation. In recent decades, flood levels have continued to rise due to aggradation on the confined floodplains reducing flood-conveyance capacity. As a result, "Room for the River" proposals have gained more prominence. Our overarching hypothesis is that strategically reconnecting these rivers to their floodplains will reduce flood levels and increase ecological habitat while limiting socioeconomic impacts. In this study, we assessed several reconnection scenarios, including levee setbacks and removals, for the Lower Tisza River (LTR; Hungary) and the Lower Illinois River (LIR; Illinois, USA). To model water-surface elevations (WSELs) for the 5- through 500-year flood events, we employed HEC-RAS (1D) and SOBEK (1D/2D) hydraulic models. To determine socioeconomic tradeoffs using these modeled WSELs, we developed a corresponding suite of expected annual damages (EADs) using FEMA's Hazus-MH flood-loss modeling software for buildings and integrated geospatial and soil productivity indices to estimate agricultural losses. To assess ecosystem benefits of reconnection along the LTR, we used historic wetland extent as a proxy for increasing needed floodplain habitats. For the LIR, we performed habitat screening using Land Capability Potential Index and other assessment tools to estimate potential ecosystem benefits. Results indicate that levee removal and/or setbacks may reduce flood heights up to 1.6 m along the LTR and over 1.0 m along the LIR. While urban areas have the highest EADs, several lower-production agricultural areas show potential for reducing flood heights while minimizing damages. Strategic-floodplain reconnection benefits along the LTR and LIR include over half of historically-significant wetlands being reconnected and the creation of

  17. Erosional and depositional patterns associated with the 1993 Missouri River floods inferred from SIR-C and TOPSAR radar data

    USGS Publications Warehouse

    Izenberg, N.R.; Arvidson, R. E.; Brackett, R.A.; Saatchi, S.S.; Osburn, G.R.; Dohrenwend, J.

    1996-01-01

    The Missouri River floods of 1993 caused significant and widespread damage to the floodplains between Kansas City and St. Louis. Immediately downstream of levee breaks, flood waters scoured the bottoms. As the floodwaters continued, they spread laterally and deposited massive amounts of sand as crevasse splays on top of agricultural fields. We explore the use of radar interferometry and backscatter data for quantitative estimation of scour and deposition for Jameson Island/Arrow Rock Bottoms and Lisbon Bottoms, two bottoms that were heavily damaged during the floods and subsequently abandoned. Shuttle imaging radar C (SIR-C) L band (24 cm) HH (horizontally transmitted and horizontally received) radar backscatter data acquired in October 1994 were used together with a distorted Born approximation canopy scattering model to determine that the abundance of natural leafy forbs controlled the magnitude of backscatter for former agricultural fields. Forb areal density was found to be inversely correlated with thickness of sand deposited during the floods, presumably because thick sands prevented roots from reaching nutrient rich, moist bottoms soils. Using the inverse relationship, a lower bound for the mass of sand added was found to be 6.3 million metric tons over the 17 km2 study area. Digital elevation data from topographic synthetic aperture radar (TOPSAR) C band (5.6 cm) interferometric observations acquired in August 1994 were compared to a series of elevation profiles collected on the ground. Vertical errors in TOPSAR were estimated to range from 1 to 2 m, providing enough accuracy to generate an estimate of total mass (4.7 million metric tons) removed during erosion of levees and scour of the bottoms terrains. Net accretion of material to the study areas is consistent with the geologic record of major floods where sediment-laden floodwaters crested over natural levees, initially scoured into the bottoms, and then deposited sands as crevasse splays as the flows

  18. Documenting channel features associated with gas hydrates in the Krishna-Godavari Basin, offshore India

    USGS Publications Warehouse

    Riedel, M.; Collett, T.S.; Shankar, U.

    2011-01-01

    During the India National Gas Hydrate Program (NGHP) Expedition 01 in 2006 significant sand and gas hydrate were recovered at Site NGHP-01-15 within the Krishna-Godavari Basin, East Coast off India. At the drill site NGHP-01-15, a 5-8m thick interval was found that is characterized by higher sand content than anywhere else at the site and within the KG Basin. Gas hydrate concentrations were determined to be 20-40% of the pore volume using wire-line electrical resistivity data as well as core-derived pore-fluid freshening trends. The gas hydrate-bearing interval was linked to a prominent seismic reflection observed in the 3D seismic data. This reflection event, mapped for about 1km2 south of the drill site, is bound by a fault at its northern limit that may act as migration conduit for free gas to enter the gas hydrate stability zone (GHSZ) and subsequently charge the sand-rich layer. On 3D and additional regional 2D seismic data a prominent channel system was imaged mainly by using the seismic instantaneous amplitude attribute. The channel can be clearly identified by changes in the seismic character of the channel fill (sand-rich) and pronounced levees (less sand content than in the fill, but higher than in surrounding mud-dominated sediments). The entire channel sequence (channel fill and levees) has been subsequently covered and back-filled with a more mud-prone sediment sequence. Where the levees intersect the base of the GHSZ, their reflection strengths are significantly increased to 5- to 6-times the surrounding reflection amplitudes. Using the 3D seismic data these high-amplitude reflection edges where linked to the gas hydrate-bearing layer at Site NGHP-01-15. Further south along the channel the same reflection elements representing the levees do not show similarly large reflection amplitudes. However, the channel system is still characterized by several high-amplitude reflection events (a few hundred meters wide and up to ~1km in extent) interpreted as gas

  19. Is It Feasible to Build New Land in the Mississippi River Delta?

    NASA Astrophysics Data System (ADS)

    Kim, Wonsuck; Mohrig, David; Twilley, Robert; Paola, Chris; Parker, Gary

    2009-10-01

    What if the Mississippi River levees were cut below New Orleans? What if much of the water and sediment were allowed to flow out and build new deltas? Could deltaic land loss be reversed, and indeed restored? Using a conservative sediment supply rate and a range of rates of sea level rise and subsidence, a physically based model of deltaic river sedimentation [Kim et al., 2009] predicts that approximately 700-1200 square kilometers of new land (exposed surface and in-channel freshwater habitat) could be built over a century (Figure 1).

  20. Attributes and origins of ancient submarine slides and filled embayments: examples from the Gulf Coast basin

    USGS Publications Warehouse

    Morton, Robert

    1993-01-01

    Submarine slides exhibit landward-dipping, wavy, mounded, and chaotic seismic reflections that are manifestations of slump blocks and other mass transport material. Composition of these internally derived slide deposits depends on the composition of the preexisting shelf margin. Embayment fill above the slide consists mostly of externally derived mudstones and sandstones deposited by various disorganized slope processes, as well as more organized submarine channel-levee systems. Thickest slope sandstones, which are potential hydrocarbon reservoirs, commonly occur above the basal slide mudstones where seismic reflections change from chaotic patterns to overlying wavy or subhorizontal reflections.

  1. Wetland sedimentation from hurricanes Katrina and Rita.

    PubMed

    Turner, R Eugene; Baustian, Joseph J; Swenson, Erick M; Spicer, Jennifer S

    2006-10-20

    More than 131 x 10(6) metric tons (MT) of inorganic sediments accumulated in coastal wetlands when Hurricanes Katrina and Rita crossed the Louisiana coast in 2005, plus another 281 x 10(6) MT when accumulation was prorated for open water area. The annualized combined amount of inorganic sediments per hurricane equals (i) 12% of the Mississippi River's suspended load, (ii) 5.5 times the inorganic load delivered by overbank flooding before flood protection levees were constructed, and (iii) 227 times the amount introduced by a river diversion built for wetland restoration. The accumulation from hurricanes is sufficient to account for all the inorganic sediments in healthy saltmarsh wetlands.

  2. Volcanic features of Hawaii. A basis for comparison with Mars

    NASA Technical Reports Server (NTRS)

    Carr, M. H.; Greeley, R.

    1980-01-01

    Despite the difference in size Martian and Hawaiian volcanoes have numerous characteristics in common. Specific features such as lava channels, collapsed lava tubes, levees and flow fronts, all very common in Hawaii, are also abundant on the flanks of some of the Martian volcanoes. Striking differences also exist, such as the apparent lack of radial rift zones on some Martian volcanoes and the paucity of cinder and spatter cones. Some of the best photographs of Martian and Hawaiian volcanic features are presented. Descriptive legends are provided for each picture. An overview of the geological processes and structures depicted is included.

  3. Mechanisms of sandstone deposition in a late Proterozoic submarine canyon, Adelaide geosyncline, South Australia

    SciTech Connect

    von der Borch, C.C.; Grady, A.E.

    1984-06-01

    Late Proterozoic submarine canyon fills the Adelaide Supergroup (Flinders Range, South Australia) are asymmetrical in terms of their facies. Coarse breccia units, commonly associated with coarse-grained channelized turbidite sandstone units, generally occur adjacent to north walls of all the east-west-trending canyon incisions. In contrast, fine-grained sandstones and mudstones within the canyon fill are generally associated with south walls. In one canyon (Patsy-Springs canyon), an additional element of asymmetry is associated with the prevalence of northward-climbing sets of climbing ripples (southward-dipping stoss sides) within channelized turbidites, in what are interpreted to be major thalweg channels and their associated levees. Flute casts at the bases of individual turbidite sandstones invariably indicate initial turbidity current flow to the west throughout the vertical sequences of the channel fills. Parallel laminations above the flute casts in each flow pass upward into climbing ripples with south-dipping stoss sides, implying southward lateral accretion across the channel of a levee or bar as each turbidity current decelerated. The asymmetries outlined could be explained by: Coriolis force acting on the turbidity currents, or the existence on a steep slope of a meandering canyon gorge, confining a thalweg channel developed within subsequent canyon fill. In such a situation, roller-coastering turbidity currents would seek outer bends of the meandering primary gorge.

  4. More than 100 Years of Background-Level Sedimentary Metals, Nisqually River Delta, South Puget Sound, Washington

    USGS Publications Warehouse

    Takesue, Renee K.; Swarzenski, Peter W.

    2011-01-01

    The Nisqually River Delta is located about 25 km south of the Tacoma Narrows in the southern reach of Puget Sound. Delta evolution is controlled by sedimentation from the Nisqually River and erosion by strong tidal currents that may reach 0.95 m/s in the Nisqually Reach. The Nisqually River flows 116 km from the Cascade Range, including the slopes of Mount Rainier, through glacially carved valleys to Puget Sound. Extensive tidal flats on the delta consist of late-Holocene silty and sandy strata from normal river streamflow and seasonal floods and possibly from distal sediment-rich debris flows associated with volcanic and seismic events. In the early 1900s, dikes and levees were constructed around Nisqually Delta salt marshes, and the reclaimed land was used for agriculture and pasture. In 1974, U.S. Fish and Wildlife Service established the Nisqually National Wildlife Refuge on the reclaimed land to protect migratory birds; its creation has prevented further human alteration of the Delta and estuary. In October 2009, original dikes and levees were removed to restore tidal exchange to almost 3 km2 of man-made freshwater marsh on the Nisqually Delta.

  5. Napa Earthquake impact on water systems

    NASA Astrophysics Data System (ADS)

    Wang, J.

    2014-12-01

    South Napa earthquake occurred in Napa, California on August 24 at 3am, local time, and the magnitude is 6.0. The earthquake was the largest in SF Bay Area since the 1989 Loma Prieta earthquake. Economic loss topped $ 1 billion. Wine makers cleaning up and estimated the damage on tourism. Around 15,000 cases of lovely cabernet were pouring into the garden at the Hess Collection. Earthquake potentially raise water pollution risks, could cause water crisis. CA suffered water shortage recent years, and it could be helpful on how to prevent underground/surface water pollution from earthquake. This research gives a clear view on drinking water system in CA, pollution on river systems, as well as estimation on earthquake impact on water supply. The Sacramento-San Joaquin River delta (close to Napa), is the center of the state's water distribution system, delivering fresh water to more than 25 million residents and 3 million acres of farmland. Delta water conveyed through a network of levees is crucial to Southern California. The drought has significantly curtailed water export, and salt water intrusion reduced fresh water outflows. Strong shaking from a nearby earthquake can cause saturated, loose, sandy soils liquefaction, and could potentially damage major delta levee systems near Napa. Napa earthquake is a wake-up call for Southern California. It could potentially damage freshwater supply system.

  6. [CONSISTENCY OF MINI NUTRITIONAL ASSESSMENT TO IDENTIFY SARCOPENIA IN OLDER ADULTS IN NURSING HOMES IN BOGOTA, COLOMBIA].

    PubMed

    Díaz Muñoz, Gustavo Alfonso; Cárdenas Zuluaga, Diana María; Mesa Jimenez, Alfonso

    2015-07-01

    Introducción: la desnutrición y la sarcopenia son de alta prevalencia en el adulto mayor, compartiendo mecanismos fisiológicos y desenlaces adversos para la salud. Objetivos: cuantificar la consistencia del MNA con el diagnóstico de sarcopenia en el adulto mayor institucionalizado. Métodos: estudio transversal de consistencia, en 4 residencias geriátricas de Bogotá. El tamizaje y la valoración nutricional se hicieron con la forma larga Mini Nutritional Assessment; el diagnóstico de sarcopenia se hizo con el algoritmo y puntos de corte del Consenso Europeo (EWGSOP). Análisis estadístico: Ji2 de Pearson, U de Mann-Whitney y coeficiente kappa de Cohen. Resultados y discusión: participaron 108 personas, 62% mujeres, con una edad promedio de 80,4 años (DE 7,7). La prevalencia de sarcopenia, riesgo de desnutrición y desnutrición fueron del 38,9%, 33,3% y 2,8%, respectivamente. La concordancia del MNA con el diagnóstico de sarcopenia fue leve (kappa 0,1908 IC95% 0,0025 a 0,3791; p < 0.05) Conclusión: la leve concordancia del MNA para identificar la sarcopenia sugiere que no es una herramienta adecuada para el diagnóstico de sarcopenia en los adultos mayores institucionalizados.

  7. Inventory and Comparison of Floodplain Embankment along Large Rivers

    NASA Astrophysics Data System (ADS)

    Hudson, Paul

    2016-04-01

    Flood control is a fundamental human response to flood risk, and floodplain embankment by dike (levee) construction is among the oldest forms of societal impacts to natural systems. Large lowland alluvial valleys are some of Earth's most distinctive environments and represent high levels of geodiversity and biodiversity. Embankment of large lowland alluvial river valleys alters fundamental processes related to floodplain hydrology, sedimentation, and ecology and eventually results in a transformation of the embanked floodplain environment. Since embankment, many large lowland floodplains have been heaviliy modified for floodplain agriculture and include high population densities, increasing flood risk. While there is much discussion about the pros and cons of dike construction and the impact to floodplain environments there is no systematic inventory which documents the magnitude and intensity of floodplain embankment to lowland rivers. In this study we characterize and inventory floodplain embankment along large lowland alluvial valleys. The review includes some of Earth's largest embanked fluvial systems, and primarilly focuses on northern hemisphere rivers in the United States, Europe and Asia. Data sources includes the U.S. National Levee Database, SRTM DEM, recently obtained high resolution satellite imagery, various national topographic map series, and hydrologic data from the published literature. These data are integrated into a GIS framework to facilitate the measurement and characterisation of floodplain embankment. Spatial indices of floodplain embankment are constructed, including the intensity of embankment and how it relates to the natural floodplain and constriction of flooding.

  8. A new dry hypothesis for the formation of Martian linear gullies

    USGS Publications Warehouse

    Diniega, Serina; Hansen, Candice J.; McElwaine, Jim N.; Hugenholtz, C.H.; Dundas, Colin M.; McEwen, Alfred S.; Bourke, Mary C.

    2013-01-01

    Long, narrow grooves found on the slopes of martian sand dunes have been cited as evidence of liquid water via the hypothesis that melt-water initiated debris flows eroded channels and deposited lateral levées. However, this theory has several short-comings for explaining the observed morphology and activity of these linear gullies. We present an alternative hypothesis that is consistent with the observed morphology, location, and current activity: that blocks of CO2 ice break from over-steepened cornices as sublimation processes destabilize the surface in the spring, and these blocks move downslope, carving out levéed grooves of relatively uniform width and forming terminal pits. To test this hypothesis, we describe experiments involving water and CO2 blocks on terrestrial dunes and then compare results with the martian features. Furthermore, we present a theoretical model of the initiation of block motion due to sublimation and use this to quantitatively compare the expected behavior of blocks on the Earth and Mars. The model demonstrates that CO2 blocks can be expected to move via our proposed mechanism on the Earth and Mars, and the experiments show that the motion of these blocks will naturally create the main morphological features of linear gullies seen on Mars.

  9. Dispersal of larval suckers at the Williamson River Delta, Upper Klamath Lake, Oregon, 2006-09

    USGS Publications Warehouse

    Wood, Tamara M.; Hendrixson, Heather A.; Markle, Douglas F.; Erdman, Charles S.; Burdick, Summer M.; Ellsworth, Craig M.; Buccola, Norman L.

    2012-01-01

    An advection/diffusion modeling approach was used to simulate the transport of larval suckers from spawning areas in the Williamson River, through the newly restored Williamson River Delta, to Upper Klamath Lake. The density simulations spanned the years of phased restoration, from 2006/2007 prior to any levee breaching, to 2008 when the northern part of the delta was reconnected to the lake, and 2009 when levees on both sides of the delta had been breached. Model simulation results from all four years were compared to field data using rank correlation. Spearman ρ correlation coefficients were usually significant and in the range 0.30 to 0.60, providing moderately strong validation of the model. The correlation coefficients varied with fish size class in a way that suggested that the model best described the distribution of smaller fish near the Williamson River channel, and larger fish away from the channel. When Lost River and shortnose/Klamath largescale suckers were simulated independently, the correlation results suggested that the model better described the transport and dispersal of the latter species. The incorporation of night-time-only drift behavior in the Williamson River channel neither improved nor degraded correlations with field data. The model showed that advection by currents is an important factor in larval dispersal.

  10. Drainage systems associated with mid-ocean channels and submarine Yazoos: Alternative to submarine fan depositional systems

    SciTech Connect

    Hesse, R. )

    1989-12-01

    Submarine drainage systems associated with mid-ocean channels and Yazoo River-type tributaries in small ocean basins represent a contrast to deep-sea fan depositional systems. Deep-sea fans are diverging sediment-dispersal systems of distributary fan valleys. Deep-sea channel-submarine-yazoo systems, on the other hand, form centripetally converging patterns of tributaries and yazoo-type satellite channels that join a major basin-draining (mid-ocean) channel. The facies model for such systems is characterized by randomly stacked fining-upward, gravelly, and sandy channel-fill and submarine point-bar sequences of the main channel encased in fine-grained overbank deposits. Second-order channels contain sandy proximal overbank deposits, whereas the levees of the main channel are predominantly composed of silt and clay. Second-order channels may be braided and may broaden into braid plains. Morphology and surficial sediment distribution have been studied within the Northwest Atlantic Mid-Ocean Channel of the Labrador Sea and its associated levees and yazoo-type (and other) tributaries.

  11. The BP oil spill and the bounty of Plaquemines Parish.

    PubMed

    Fertel, Randy

    2011-01-01

    The source of 25 to 30 percent of America's seafood, the Mississippi River Delta's cornucopian world is now uncertain. And yet, even if shrimp, oysters, and finfish are unaffected by the BP Oil Spill - a big if - one can already reflect on the passing of the culture once built upon gathering them. For almost three centuries, levees made life possible along the riverbanks and in the wetlands beyond. Those same levees also ensured the wetlands would eventually melt away into the Gulf. Cutting off the silt left behind during annual river inundations subjected the fragile land to erosion. Sulfur, natural gas, and oil production companies dug twenty thousand miles of canals to gain more direct routes to their fields and to pump out their mineral wealth. This caused salt-water intrusion that killed off plant life and caused more erosion. The world that sustained my Plaquemines ancestors was less subject to collapse following disasters not only because the ecosystem before the wetlands' ongoing loss was then more vibrant, complex, and robust; but also because their lives, especially their culinary lives, were more vibrant, complex, and robust. Life was hard, but when it came to putting food on the table, life followed the seasons. PMID:21591308

  12. Control of soil acidification by fluvial sedimentation in an estuarine floodplain, eastern Australia

    NASA Astrophysics Data System (ADS)

    Lin, C.; Melville, M. D.

    1993-05-01

    A shallow stratigraphic sequence with associated pyrite-induced soil acidification was investigated along a transect from the levee to the backswamp in an estuarine floodplain of eastern Australia. Three sedimentary layers were identified and interpreted to correspond with three depositional stages. Firstly, a layer of humic, pyrite-rich, silty mud was deposited under a saline, mangrove-inhabited, intertidal environment during the present high sea level episode. This pyritic layer is buried by the second sedimentary layer of grey brown mud with limited pyrite content, that was deposited in a brackish lagoonal environment. This material now represents much of the contemporary backswamp surface. The third sedimentary layer is a sandy mud without pyrite, that has been deposited by freshwater overbank floods. It is concluded that fluvial sedimentation has been increasingly important in the development of the stratigraphic sequence, controlling the pyrite content, thickness and occurrence depth of the pyritic layer. The present drainage conditions have allowed oxidation of pyrite in the soils of the backswamp and the resulting acidification has caused elevated concentrations of toxic aluminium that threaten the local environment. However, in the levee, the pyritic layer is covered by thick non-pyritic freshwater sediments and low-pyritic lagoonal sediments, and the soil profiles are unlikely to contribute to any acidification hazard.

  13. Vegetation of natural and artificial shorelines in Upper Klamath Basin’s fringe wetlands

    USGS Publications Warehouse

    Ray, Andrew M.; Irvine, Kathryn M.; Hamilton, Andy S.

    2013-01-01

    The Upper Klamath Basin (UKB) in northern California and southern Oregon supports large hypereutrophic lakes surrounded by natural and artificial shorelines. Lake shorelines contain fringe wetlands that provide key ecological services to the people of this region. These wetlands also provide a context for drawing inferences about how differing wetland types and wave exposure contribute to the vegetative assemblages in lake-fringe wetlands. Here, we summarize how elevation profiles and vegetation richness vary as a function of wave exposure and wetland type. Our results show that levee wetland shorelines are 4X steeper and support fewer species than other wetland types. We also summarize the occurrence probability of the five common wetland plant species that represent the overwhelming majority of the diversity of these wetlands. In brief, the occurrence probability of the culturally significant Nuphar lutea spp. polysepala and the invasive Phalaris arundinacea in wave exposed and sheltered sites varies based on wetland type. The occurrence probability for P. arundinacea was greatest in exposed portions of deltaic shorelines, but these trends were reversed on levees where the occurrence probability was greater in sheltered sites. The widespread Schoenoplectus acutus var. acutus occurred throughout all wetland and exposure type combinations but had a higher probability of occurrence in wave exposed sites. Results from this work will add to our current understanding of how wetland shoreline profiles interact with wave exposure to influence the occurrence probability of the dominant vegetative species in UKB’s shoreline wetlands.

  14. Surface-water hydrologic data for the Houston metropolitan area, Texas, water years 1990?95

    USGS Publications Warehouse

    Sneck-Fahrer, Debra A.; Liscum, Fred; East, Jeffrey W.

    2003-01-01

    Most of the Sacramento-San Joaquin Delta was leveed, drained, and converted to agricultural use by the 1930s. Land-surface elevations have since subsided by more than 20 feet in some areas. Subsidence increases the likelihood of levee failure and flooding, which, in turn, jeopardizes water delivery and water quality in the Delta. This is of major concern because the Delta supplies water to two-thirds of California. Previous research has shown that oxidation of peat soils is the primary cause of subsidence in the Delta. Therefore, a possible strategy for remedying this situation is to convert drained agricultural fields back to wetlands, which are flooded at least part of the year. Rehabilitation of wetlands would promote the growth of peat, thereby mitigating and possibly reversing subsidence. This report describes a study that evaluated this strategy. In three experimental enclosures or ponds, carbon inputs were measured in the form of plant biomass and outputs in the form of carbon dioxide (CO2) and methane (CH4) fluxes. Each of the ponds received one of the following water treatments: seasonally flooded, seasonally flooded and irrigated, or permanently flooded. Land-surface elevation, ground-water levels, and soil and air temperature also were measured. This report presents the data collected during the initial phase of the study, which ran from November 1992 through September 1995.

  15. NASA Ames DEVELOP Interns Collaborate with the South Bay Salt Pond Restoration Project to Monitor and Study Restoration Efforts using NASA's Satellites

    NASA Technical Reports Server (NTRS)

    Newcomer, Michelle E.; Kuss, Amber Jean; Nguyen, Andrew; Schmidt, Cynthia L.

    2012-01-01

    In the past, natural tidal marshes in the south bay were segmented by levees and converted into ponds for use in salt production. In an effort to provide habitat for migratory birds and other native plants and animals, as well as to rebuild natural capital, the South Bay Salt Pond Restoration Project (SBSPRP) is focused on restoring a portion of the over 15,000 acres of wetlands in California's South San Francisco Bay. The process of restoration begins when a levee is breached; the bay water and sediment flow into the ponds and eventually restore natural tidal marshes. Since the spring of 2010 the NASA Ames Research Center (ARC) DEVELOP student internship program has collaborated with the South Bay Salt Pond Restoration Project (SBSPRP) to study the effects of these restoration efforts and to provide valuable information to assist in habitat management and ecological forecasting. All of the studies were based on remote sensing techniques -- NASA's area of expertise in the field of Earth Science, and used various analytical techniques such as predictive modeling, flora and fauna classification, and spectral detection, to name a few. Each study was conducted by a team of aspiring scientists as a part of the DEVELOP program at Ames.

  16. Characterization of subsurface stratigraphy along the lower American River floodplain using electrical resistivity, Sacramento, California, 2011

    USGS Publications Warehouse

    Burton, Bethany L.; Powers, Michael H.; Ball, Lyndsay B.

    2014-01-01

    In July 2011, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, completed a geophysical survey using electrical resistivity along an approximately 6-mile reach of the lower American River in Sacramento, California, to map near-surface lithological variations. This survey is a part of a manifold and comprehensive study of river-flow dynamics and geologic boundary-property knowledge necessary to estimate scour potential and levee erosion risk. Data were acquired on the left (south or west) bank between river mile 5 and 10.7 as well as a short section on the right bank from river mile 5.4 to 6. Thirteen direct-current resistivity profiles and approximately 8.3 miles of capacitively coupled resisistivity data were acquired along accessible areas of the floodplain between the levee and river bank. Capacitively coupled resistivity was used as a reconnaissance tool, because it allowed for greater spatial coverage of data but with lower resolution and depth of investigation than the DC resistivity method. The study area contains Pleistocene-age alluvial deposits, dominated by gravels, sands, silts, and clays, that vary in both lateral extent and depth. Several generations of lithologic logs were used to help interpret resistivity variations observed in the resistivity models.

  17. Decreasing flood risk perception in Porto Alegre - Brazil and its influence on water resource management decisions

    NASA Astrophysics Data System (ADS)

    Allasia, D. G.; Tassi, R.; Bemfica, D.; Goldenfum, J. A.

    2015-06-01

    Porto Alegre is the capital and largest city in the Brazilian state of Rio Grande do Sul in Southern Brazil with approximately 1.5 million inhabitants. The city lies on the eastern bank of the Guaiba Lake, formed by the convergence of five rivers and leading to the Lagoa dos Patos, a giant freshwater lagoon navigable by even the largest of ships. This river junction has become an important alluvial port as well as a chief industrial and commercial centre. However, this strategic location resulted in severe damage because of its exposure to flooding from the river system, affecting the city in the years 1873, 1928, 1936, 1941 and 1967. In order to reduce flood risk, a complex system of levees and pump stations was implemented during 1960s and 1970s. Since its construction, not a single large flood event occurred. However, in recent years, the levees in the downtown region of Porto Alegre were severally criticized by city planners and population. Several projects have been proposed to demolish the Mauá Wall due to the false perception of lack of flood risk. Similar opinions and reactions against flood infrastructure have been observed in other cities in Brazil, such as Itajaí and Blumenau, with disastrous consequences. This paper illustrates how the perception of flood risk in Porto Alegre has changed over recent years as a result of flood infrastructure, and how such changes in perceptions can influence water management decisions.

  18. Erosion and sedimentation during the September 2015 flooding of the Kinu River, central Japan

    NASA Astrophysics Data System (ADS)

    Dan Matsumoto; Sawai, Yuki; Yamada, Masaki; Namegaya, Yuichi; Shinozaki, Tetsuya; Takeda, Daisuke; Fujino, Shigehiro; Tanigawa, Koichiro; Nakamura, Atsunori; Pilarczyk, Jessica E.

    2016-09-01

    Erosional and sedimentary features associated with flooding have been documented in both modern and past cases. However, only a few studies have demonstrated the relationship between these features and the corresponding hydraulic conditions that produced them, making it difficult to evaluate the magnitude of paleo-flooding. This study describes the characteristics associated with inundation depth and flow direction, as well as the erosional and sedimentary features resulting from the disastrous flooding of the Kinu River, central Japan, in September 2015. Water levels rose rapidly due to heavy rainfall that eventually overtopped, and subsequently breached, a levee in Joso City, causing destructive flooding on the surrounding floodplain. Distinctive erosional features are found next to the breached levee, while depositional features, such as a sandy crevasse-splay deposit are found further away from the breach. The deposit can be divided into three units based on sedimentary facies. The vertical and lateral changes of these sedimentary facies may be the result of temporal and spatial changes associated with flow during the single flooding event. These observations and quantitative data provide information that can be used to reveal the paleohydrology of flood deposits in the stratigraphic record, leading to improved mitigation of future flooding disasters.

  19. Sand boils induced by the 1993 Mississippi River flood: Could they one day be misinterpreted as earthquake-induced liquefaction?

    USGS Publications Warehouse

    Li, Y.; Craven, J.; Schweig, E.S.; Obermeier, S.F.

    1996-01-01

    In areas that are seismically active but lacking clear surficial faulting, many paleoearthquake studies depend on the interpretation of ancient liquefaction features (sand blows) as indicators of prehistoric seismicity. Sand blows, however, can be mimicked by nonseismic sand boils formed by water seeping beneath levees during floods. We examined sand boils induced by the Mississippi River flood of 1993 in order to compare their characteristics with sand blows of the New Madrid earthquakes of 1811-1812. We found a number of criteria that allow a distinction between the two types of deposits. (1) Earthquake-induced liquefaction deposits are broadly distributed about an epicentral area, whereas flood-induced sand boils are limited to a narrow band along a river's levee. (2) The conduits of most earthquake-induced sand blows are planar dikes, whereas the conduits of flood-induced sand boils are most commonly tubular. (3) Depression of the preearthquake ground surface is usual for sand blows, not for sand boils. (4) Flood-induced sand boils tend to be better sorted and much finer than sand-blow deposits. (5) Source beds for earthquake-induced deposits occur at a wide range of depths, whereas the source bed for sand boils is always near surface. (6) Materials removed from the walls surrounding the vent of a sand blow are seen inside sand blows, but are rarely seen inside sand boils. In general, flood-induced sand boils examined are interpreted to represent a less-energetic genesis than earthquake-induced liquefaction.

  20. Assessment of floodplain vulnerability during extreme Mississippi River flood 2011.

    PubMed

    Goodwell, Allison E; Zhu, Zhenduo; Dutta, Debsunder; Greenberg, Jonathan A; Kumar, Praveen; Garcia, Marcelo H; Rhoads, Bruce L; Holmes, Robert R; Parker, Gary; Berretta, David P; Jacobson, Robert B

    2014-01-01

    Regional change in the variability and magnitude of flooding could be a major consequence of future global climate change. Extreme floods have the capacity to rapidly transform landscapes and expose landscape vulnerabilities through highly variable spatial patterns of inundation, erosion, and deposition. We use the historic activation of the Birds Point-New Madrid Floodway during the Mississippi and Ohio River Flooding of 2011 as a scientifically unique stress experiment to analyze indicators of floodplain vulnerability. We use pre- and postflood airborne Light Detection and Ranging data sets to locate erosional and depositional hotspots over the 540 km(2) agricultural Floodway. While riparian vegetation between the river and the main levee breach likely prevented widespread deposition, localized scour and deposition occurred near the levee breaches. Eroded gullies nearly 1 km in length were observed at a low ridge of a relict meander scar of the Mississippi River. Our flow modeling and spatial mapping analysis attributes this vulnerability to a combination of erodible soils, flow acceleration associated with legacy fluvial landforms, and a lack of woody vegetation to anchor soil and enhance flow resistance. Results from this study could guide future mitigation and adaptation measures in cases of extreme flooding.

  1. A Self-Replication Model for Long Channelized Lava Flows on the Mars Plains

    NASA Technical Reports Server (NTRS)

    Baloga, S. M.; Glaze, L. S.

    2008-01-01

    A model is presented for channelized lava flows emplaced by a self-replicating, levee-building process over long distances on the plains of Mars. Such flows may exhibit morphologic evidence of stagnation, overspills, and upstream breakouts. However, these processes do not inhibit the formation and persistence of a prominent central channel that can often be traced for more than 100 km. The two central assumptions of the self-replication model are (1) the flow advances at the average upstream velocity of the molten core and (2) the fraction of the lava that travels faster than the average upstream velocity forms stationary margins in the advancing distal zone to preserve the self-replication process. For an exemplary 300 km long flow north of Pavonis Mons, the model indicates that 8 m of crust must have formed during emplacement, as determined from the channel and levee dimensions. When combined with independent thermal dynamic estimates for the crustal growth rate, relatively narrow constraints are obtained for the flow rate (2250 m3 s 1), emplacement duration (600 d), and the lava viscosity of the molten interior (106 Pa s). Minor, transient overspills and breakouts increase the emplacement time by only a factor of 2. The primary difference between the prodigious channelized Martian flows and their smaller terrestrial counterparts is that high volumetric flow rates must have persisted for many hundreds of days on Mars, in contrast to a few hours or days on Earth.

  2. [Variability in the clinical presentation of Pompe disease: development following enzyme replacement therapy].

    PubMed

    Ley-Martos, Myriam; Salado-Reyes, María J; Espinosa-Rosso, Raúl; Solera-García, Jesús; Jiménez-Jiménez, Luis

    2015-11-01

    Introduccion. La enfermedad de Pompe es un trastorno generalizado progresivo producido por el deficit de la enzima alfa-glucosidasa acida (AGA) de los lisosomas. Se presentan tres casos manifestados de forma muy diferente y tratados con terapia enzimatica sustitutiva (TES), con evolucion favorable. Casos clinicos. Caso 1: varon de 3 meses, con debilidad y rechazo de la alimentacion, hepatomegalia leve, ligera macroglosia e hipotonia, y aumento de las enzimas musculares. Caso 2: varon de 5 meses, con retraso del desarrollo motor, sordera neurosensorial grave, trastornos respiratorios de repeticion de evolucion torpida, hipotonia y leve elevacion de la creatincinasa. Caso 3: varon de 22 años con disnea progresiva, con antecedentes de elevacion de la creatincinasa y las transaminasas, e hipercolesterolemia. Sufrio insuficiencia respiratoria grave que preciso intubacion endotraqueal. La biopsia muscular presento depositos de glucogeno sugestivos de la enfermedad. En los tres casos, el estudio electromiografico dio un patron caracteristico, con descargas pseudomiotonicas, y se confirmo el deficit de AGA en los linfocitos. Se encontro una mutacion en un caso y dos mutaciones en los otros dos. Todos recibieron TES con evolucion favorable: desaparicion de las alteraciones cardiacas en el caso 1, mejoria en los hitos motores en los dos casos infantiles y retirada del respirador en el caso 3. Conclusion. La enfermedad de Pompe tiene una amplia variabilidad en la expresion clinica. La TES consigue una buena respuesta, especialmente en las formas infantiles. La supervivencia a largo plazo de las formas infantiles tratadas permitira conocer mas aspectos del curso de la enfermedad.

  3. Wetland loss and the subdelta life cycle

    NASA Astrophysics Data System (ADS)

    Wells, John T.; Coleman, James M.

    1987-07-01

    The rapid deterioration of marsh habitat observed during recent years in the modern Mississippi River Delta is a consequence, at least in part, of the natural life cycle of subdeltas. With life spans typically less than 200 years, subdeltas or bay-fill deposits are scaled-down versions of major delta lobes, yet provide, through pulses of sediment, nearly all the subaerial land in an active delta. Using maps, charts, and aerial photographs, curves were constructed for rates of change in land area, sediment volume, and linear progradation in the four subdeltas that have formed on the modern Mississippi River Delta since the first accurate survey in 1838. Results indicate that each subdelta (1) lasted for approximately 115-175 years, (2) included both periods of growth and deterioration, (3) was initiated by a crevasse or break in the natural levee system, (4) showed linear advancement and volumetric growth during subaerial deterioration, and (5) displayed a new pulse of subaerial growth during the high discharge decade of the 1970s. Contrary to popular accounts, demise of the Mississippi River Delta through deterioration of its subdeltas is not a result of the construction of artificial levees upstream or discharge of sediment off the continental shelf edge. Rather, it is attributable to a substantial decrease and fining of sediments being transported downstream to depositional sites within a delta that has developed, through natural processes, a complex and inefficient channel network for delivering these sediments.

  4. Time-Lapse Seismic Tomography and Electrical Resistivity Mapping of a Small Embankment Dam with Possible Zones of Weakness

    NASA Astrophysics Data System (ADS)

    Wodajo, L. T.; Hickey, C. J.; Song, C. R.

    2013-12-01

    Earthen dam or levee failure can occur with little to no warning. Internal problems such as seepage and piping are among the major causes of failure in earthen embankment dams and levees. Identifying and mitigating these problems requires a cost effective and non-invasive method of investigating these critical structures. This study focuses on the early detection of internal problems such as seepage and piping using time lapse seismic refraction tomography (SRT) and electrical resistivity tomography (ERT). For this study, two quarter scale model dams were built at the USDA-ARS Hydraulic Engineering Research Unit in Stillwater, OK. These dams were constructed with two internal compromised zones that would be susceptible to seepage and piping. The zones consist of a sandy region and a region compacted at lower moisture content. Time lapse seismic refraction and electrical resistivity measurements were conducted over a course of two years to monitor changes in the internal structure of the model dams due to seasonal changes, cyclic loadings and internal erosion failure. The results will provide an insight on how compromised zones due to seepage and piping can be identified at an early stage using both SRT and ERT time-lapse measurements and how joint interpretation of these two methods helps in closely identifying what attributed to the compromised zone. [This research was funded by the department of Homeland Security- sponsored Southeast Region Research Initiative (SERRI) at the Department of Energy's Oak Ridge National Laboratory.

  5. Sedimentary evolution of the Pliocene and Pleistocene Ebro margin, northeastern Spain

    USGS Publications Warehouse

    Alonso, B.; Field, M.E.; Gardner, J.V.; Maldonado, A.

    1990-01-01

    The Pliocene and Pleistocene deposits of the Spanish Ebro margin overlie a regional unconformity and contain a major disconformity. These unconformities, named Reflector M and Reflector G, mark the bases of two seismic sequences. Except for close to the upper boundary where a few small channel deposits are recognized, the lower sequence lacks channels. The upper sequence contains nine channel-levee complexes as well as base-of-slope aprons that represent the proximal part of the Valencia turbidite system. Diverse geometries and variations in seismic units distinguish shelf, slope, base-of-slope and basin-floor facies. Four events characterize the late Miocene to Pleistocene evolution of the Ebro margin: (a) formation of a paleodrainage system and an extensive erosion-to-depositional surface during the latest Miocene (Messinian), (b) deposition of hemipelagic units during the early Pliocene, (c) development of canyons during the late Pliocene to early Pleistocene, and (d) deposition of slope wedges, channel-levee complexes, and base-of-slope aprons alternating with hemipelagic deposition during the Pleistocene. Sea-level fluctuations influenced the evolution of the sedimentary sequences of the Ebro margin, but the major control was the sediment supply from the Ebro River. ?? 1990.

  6. Development history of deep water Plio-Pleistocene sands in the East Breaks 165 field, Gulf of Mexico

    SciTech Connect

    Bernaski, G.; Guderjahn, C.G. )

    1991-03-01

    The stratigraphic complexity of the Plio-Pleistocene reservoir sands in the East Breaks 165 field (offshore Texas) is readily demonstrated after the completion of exploration and development involved: (1) prediction of turbidite sand facies distributions and thickness, and (2) identification of fault offsets in the high variable reservoir sands. The well control and a 3D seismic data set provide the basis for reservoir description and a deepwater sand depositional model in the East Breaks 165 area. Four main productive sand intervals are present in the Plio-Pleistocene section. All are characterized by rapid lateral thickness and facies and fining-upward channel levee/overbank facies. The channel systems developed within an intraslope basin. The main reservoir structure is a highly faulted anticline located downthrown to northeast-trending extensional faults with up to 2,500 feet of displacement. The faulting is result of structural collapse owing to salt withdrawal from a salt-cored anticlinal ridge. Numerous small-scale faults that juxtapose permeable and impermeable units have added further complexity to the field development. The refined turbidite channel and channel levee/overbank model has been important in delineating future recompletion and development targets in the East Breaks 165 field. This model should also prove to be a useful analog for future Gulf of Mexico deepwater exploration and development programs.

  7. Wetland hydrology and tree distribution of the Apalachicola River flood plain, Florida

    USGS Publications Warehouse

    Leitman, H.M.; Sohm, J.E.; Franklin, M.A.

    1982-01-01

    The Apalachicola River is part of a 50,800-square-kilometer drainage basin in northwest Florida, Alabama, and Georgia. The river is formed by the confluence of the Chattahoochee and Flint Rivers at Jim Woodruff Dam and flows 171 kilometers to Apalachicola Bay in the Gulf of Mexico. Its flood plain supports 450 square kilometers of bottom-land hardwood and tupelco-cypress forests. The most common trees, constituting 62 percent of the total basal area, were five wet-site species; water tupelo, Ogeeche tupelo, baldcypress, Carolina ash, and swamp tupelo. Other common species were sweetgum, overcup oak, planertree, green ash, water hickory, sugarberry, and diamond-leaf oak. Five forest types were defined based on species predominance by basal area. Biomass increased downstream and was greatest in forests growing on permanently saturated soils. Water and tree relations varied with river location because range in water-level fluctuation and topographic relief in the flood plain diminished downstream. Heights of natural riverbank levees and size and distribution of breaks in levees had a major controlling effect on flood-plain hydrology. Depth of water, duration of inundation and saturation, and river location, but not water velocity, were very highly correlated with forest types. (USGS)

  8. A remote sensing approach for connecting the historic 2011 Mississippi River flood to wetland sedimentation on the Delta

    NASA Astrophysics Data System (ADS)

    Falcini, Federico; Colella, Simone; Volpe, Gianluca; Khan, Nicole; Macelloni, Leonardo; Santoleri, Rosalia; Horton, Benjamin; Jerolmack, Douglas

    2013-04-01

    Wetlands in the Mississippi River deltaic plain are deteriorating in part because levees and control structures starve them of sediment. In Spring of 2011 a record breaking flood brought discharge on the lower Mississippi River to dangerous levels, forcing managers to divert additional water to the adjacent Atchafalaya River Basin. Here we quantify differences between the Mississippi and Atchafalaya River inundation and sediment-plume patterns using field-calibrated satellite data, and assess the impact these outflows had on wetland sedimentation. Since standard products available from MyOcean were not suitable for this purpose an ad hoc processing was developed to establish a relationship between field suspended sediment concentration (SSC) data and the corrected MODIS reflectance at 645 nm. We show that the focused, high-momentum jet from the leveed Mississippi delivered sediment far offshore. In contrast, the plume from the Atchafalaya was more diffuse; diverted water inundated a large area, and sediment was trapped within the coastal current. Maximum sedimentation (up to several centimetres) occurred in the Atchafalaya Basin despite the larger sediment load carried by the Mississippi. Little accumulation occurred along the shoreline between these river sources. The correspondence between zones of high shoreline deposition, and coastal SSC patterns indentified from satellite data, is strongly suggestive of plume-derived deposition on marshes. Our findings allow us to set an hydrodynamic theory that provides a mechanistic link between river-mouth dynamics and wetland sedimentation patterns, which is relevant for plans to restore deltaic wetlands.

  9. Geologic map of Late Cenozoic deposits, Santa Clara County, California

    USGS Publications Warehouse

    Helley, E.J.; Brabb, E.E.

    1971-01-01

    This map is the first of several in the San Francisco Bay region showing the distribution and differentiation of the late Cenozoic alluvial, estuarine, and volcanic deposits. The sedimentary deposits of gravel, sand, silt, and clay were separated into geologic map units on the basis of their post-depositional soil development, texture, and geomorphology. Some of the geologic units are associated with different landforms having recognizable topographic expression such as alluvial fans, natural stream terraces, levees, and interfluvial basins. The relative ages of these unites were established on the basis of intensity of soil profile development, stratigraphic position, and geomorphic expression. The older deposits exhibit strongly developed soil profiles with strong horizon differentiation whereas younger deposits display minimal soil profile development, consisting primarily of organic matter accumulations near the land surface. Geomorphic expression and degree of erosion and dissection were additional criteria used to aid in the age determinations. For example, younger deposits form well-defined morphologic features such as levees, terraces, and broad, undissected alluvial fans along the margin of the bay basin and are related to present drainage patterns. The oldest deposits shown on this map (QTs) are structurally deformed by folding and faulting and therefore exhibit no original depositional geomorphic features. These deposits are not related to present drainage patterns but suggest earlier patterns much different from those existing today.

  10. Red mud product development

    SciTech Connect

    Kirkpatrick, D.B.

    1996-10-01

    Kaiser Alumina and Chemical Co. impounds red mud, the byproduct of alumina production, behind levees. Kaiser recognizes that this action cannot be maintained indefinitely. Therefore, a project is in progress to produce useful products from red mud that increase the profitability of the Gramercy facility. Before products could be developed, an obstacle had to be overcome. The annual rainfall in South Louisiana prevents evaporative drying of the mud lakes. Innovative methods were applied to dry the lake mud. Two products have been developed. A daily landfill cover and an absorbant, which are marketed under the Cajunite{trademark} banner. Both products are currently being tested by potential customers at their sites. Environmental concerns were addressed during development. Extensive TCLP results show no metal leachate problems. All pilot tests and plant trials received LADEQ approval. Products that are under development include levee core, road base, fertilizer fillers and synthetic soils. State and Federal agencies are interested in using red mud to remediate coastal erosion. Kaiser is also pursuing the recovery of metals from red mud.

  11. Pictorial account and landscape evolution of the crevasses near Fort St. Philip, Louisiana

    USGS Publications Warehouse

    Suir, Glenn M.; Jones, William R.; Garber, Adrienne L.; Barras, John A.

    2014-01-01

    Quantifying the effects of active natural and constructed crevasses is critical to the planning and success of future ecosystem restoration activities. This document provides a historical overview of landscape changes within the vicinity of the natural crevasses near Fort St. Philip, Louisiana. A significant event influencing landscape change within the Fort St. Philip study area was the breaching of the eastern levee of the Mississippi River. Initially, the river water that was diverted through these crevasse channels physically removed significant marsh areas within the study area. These initial direct impacts were succeeded by several decades of larger regional loss patterns driven by subsidence and other episodic events (e.g, hurricanes and floods), and recent localized land gains. These increases in land area are potentially the long-term results of the Fort St. Philip crevasses, and the short-term impacts of delta management activities. However, for the majority of the 1956-2008 period of analysis, the crevassing of the eastern bank of the Mississippi River levee was a loss accelerant in the Fort St. Philip area.

  12. Varying depositional environments across the Oligocene-Miocene boundary and their relevance for East Antarctic ice sheet history: IODP Site U1356, Wilkes Land margin

    NASA Astrophysics Data System (ADS)

    Salabarnada, Ariadna; Escutia, Carlota; Nelson, Hans; Damuth, John E.; Brinkhuis, Henk

    2014-05-01

    IODP Expedition 318 drilled seven sites in two transects across the Wilkes Land (WL) margin of Antarctica. The objective was to obtain a long-term record of the Cenozoic Antarctic glaciation in response to climatic changes, including major transitions. Our work focuses on the study of nearly 300 meters of Oligocene-early Miocene sediments from Site 1356 (cores 42R to 72R) located on a channel levee in the lower continental rise. Shipboard core descriptions reported these sediments to consist of strongly bioturbated claystone and calcareous claystone with Zoophycos or Nereites ichnofacies. Subordinate lithofacies include: 1) laminated silty claystones, 2) convoluted claystones, sandstones and conglomerates; 3) mudstones and sandstones, with a few dispersed to common clasts; and 4) graded or cross-laminated siltstones and sandstones. Based on our study of facies associations in the cores, we differentiate 3 major sedimentary phases, representing important changes in the depositional environments off the WL margin. During the early-late Oligocene, sediments record deposition in a deep-water setting, with bottom currents reworking hemipelagic sediments. Late Oligocene sedimentary processes are dominated by successive fine- to coarse-grained debris-flow mass transport deposits. In the early Miocene, turbidites and hemipelagic sedimentation, characteristic of levee deposition, dominate. With this interpretation of sedimentary environments, plus the correlation between Site U1356 and seismic reflection profiles at the site and vicinity, we can begin to link the relation between along-slope and down-slope processes to the evolution of the East Antarctic Ice Sheet.

  13. The BP oil spill and the bounty of Plaquemines Parish.

    PubMed

    Fertel, Randy

    2011-01-01

    The source of 25 to 30 percent of America's seafood, the Mississippi River Delta's cornucopian world is now uncertain. And yet, even if shrimp, oysters, and finfish are unaffected by the BP Oil Spill - a big if - one can already reflect on the passing of the culture once built upon gathering them. For almost three centuries, levees made life possible along the riverbanks and in the wetlands beyond. Those same levees also ensured the wetlands would eventually melt away into the Gulf. Cutting off the silt left behind during annual river inundations subjected the fragile land to erosion. Sulfur, natural gas, and oil production companies dug twenty thousand miles of canals to gain more direct routes to their fields and to pump out their mineral wealth. This caused salt-water intrusion that killed off plant life and caused more erosion. The world that sustained my Plaquemines ancestors was less subject to collapse following disasters not only because the ecosystem before the wetlands' ongoing loss was then more vibrant, complex, and robust; but also because their lives, especially their culinary lives, were more vibrant, complex, and robust. Life was hard, but when it came to putting food on the table, life followed the seasons.

  14. Assessment of floodplain vulnerability during extreme Mississippi River flood 2011.

    PubMed

    Goodwell, Allison E; Zhu, Zhenduo; Dutta, Debsunder; Greenberg, Jonathan A; Kumar, Praveen; Garcia, Marcelo H; Rhoads, Bruce L; Holmes, Robert R; Parker, Gary; Berretta, David P; Jacobson, Robert B

    2014-01-01

    Regional change in the variability and magnitude of flooding could be a major consequence of future global climate change. Extreme floods have the capacity to rapidly transform landscapes and expose landscape vulnerabilities through highly variable spatial patterns of inundation, erosion, and deposition. We use the historic activation of the Birds Point-New Madrid Floodway during the Mississippi and Ohio River Flooding of 2011 as a scientifically unique stress experiment to analyze indicators of floodplain vulnerability. We use pre- and postflood airborne Light Detection and Ranging data sets to locate erosional and depositional hotspots over the 540 km(2) agricultural Floodway. While riparian vegetation between the river and the main levee breach likely prevented widespread deposition, localized scour and deposition occurred near the levee breaches. Eroded gullies nearly 1 km in length were observed at a low ridge of a relict meander scar of the Mississippi River. Our flow modeling and spatial mapping analysis attributes this vulnerability to a combination of erodible soils, flow acceleration associated with legacy fluvial landforms, and a lack of woody vegetation to anchor soil and enhance flow resistance. Results from this study could guide future mitigation and adaptation measures in cases of extreme flooding. PMID:24512322

  15. Water quality of a coastal Louisiana swamp and how dredging is undermining restoration efforts

    NASA Astrophysics Data System (ADS)

    Lane, Robert R.; Huang, Haosheng; Day, John W.; Justic, Dubravko; DeLaune, Ronald D.

    2015-01-01

    The Bayou Boeuf Basin (BBB), a sub-basin of the Barataria Basin estuary in coastal Louisiana, consists of forested and floating wetlands receiving drainage from surrounding agricultural fields and urban watersheds. We characterized surface water quality in the BBB, and determined through hydrologic modeling if a series of levee breaks along major drainage channels would significantly improve water quality by allowing flow into surrounding wetlands. Surface water monitoring found surrounding sugarcane farm fields to be major sources of nutrient and sediment loading. Hydrological modeling indicated that levee breaks would increase N reduction from the current 21.4% to only 29.2%, which is much lower than the anticipated 90-100% removal rate. This was due to several factors, one them being dredging of main drainage channels to such a degree that water levels do not rise much above the surrounding wetland elevation even during severe storms, so only a very small fraction of the stormwater carried in the channel is exposed to wetlands. These unexpected results provide insight into an undoubtedly pervasive problem in human dominated wetland systems; that of decreased flooding during storm events due to channel deepening by dredging activities. Additional water quality management practices should be implemented at the farm field level, prior to water entering major drainage canals.

  16. Hurricane-dominated carbonate tidal flats, Caicos Platform, British West Indies

    SciTech Connect

    Wanless, H.R.; Tyrrell, K.M.; Tedesco, L.P.

    1987-05-01

    Hurricane-generated, thinly bedded grainstones are the dominant style of stratification throughout the carbonate tidal flat complex on Caicos Platform, BWI. This is in dramatic contrast to the winter storm-generated, millimeter laminae which dominate stratification on the Andros tidal flats and have become the general criteria for recognizing ancient carbonate tidal flat sequences. Hurricane Kate, which passed directly across the Caicos tidal flats on November 18, 1985, provided an opportunity both to document the character and distribution of a specific storm sediment layer and to evaluate the role of hurricanes in molding the geometry of the tidal flat system. Though moderate in strength and producing only incomplete flooding, Hurricane Kate deposited a 0.5-2-cm thick layer of fine peloidal grainstone across significant portions of the extremely broad low-relief shore and channel levees and minor sections of the sequence beneath both the channel levees and the inland algal marsh. These storm layers are interbedded with organic-rich layers which represent prolonged periods of Scytonema algal mat growth between hurricanes. Recognition that centimeter-thick grainstone layers dominate entire tidal flat complexes necessitates both a thorough modification of criteria for defining ancient tidal flat deposits and a reevaluation of supposedly subtidal thinly bedded limestones.

  17. Erosion and sedimentation during the September 2015 flooding of the Kinu River, central Japan

    PubMed Central

    Dan Matsumoto; Sawai, Yuki; Yamada, Masaki; Namegaya, Yuichi; Shinozaki, Tetsuya; Takeda, Daisuke; Fujino, Shigehiro; Tanigawa, Koichiro; Nakamura, Atsunori; Pilarczyk, Jessica E.

    2016-01-01

    Erosional and sedimentary features associated with flooding have been documented in both modern and past cases. However, only a few studies have demonstrated the relationship between these features and the corresponding hydraulic conditions that produced them, making it difficult to evaluate the magnitude of paleo-flooding. This study describes the characteristics associated with inundation depth and flow direction, as well as the erosional and sedimentary features resulting from the disastrous flooding of the Kinu River, central Japan, in September 2015. Water levels rose rapidly due to heavy rainfall that eventually overtopped, and subsequently breached, a levee in Joso City, causing destructive flooding on the surrounding floodplain. Distinctive erosional features are found next to the breached levee, while depositional features, such as a sandy crevasse-splay deposit are found further away from the breach. The deposit can be divided into three units based on sedimentary facies. The vertical and lateral changes of these sedimentary facies may be the result of temporal and spatial changes associated with flow during the single flooding event. These observations and quantitative data provide information that can be used to reveal the paleohydrology of flood deposits in the stratigraphic record, leading to improved mitigation of future flooding disasters. PMID:27677769

  18. Assessing tidal marsh vulnerability to sea-level rise in the Skagit Delta

    USGS Publications Warehouse

    Hood, W. Gregory; Grossman, Eric; Curt Veldhuisen,

    2016-01-01

    Historical aerial photographs, from 1937 to the present, show Skagit Delta tidal marshes prograding into Skagit Bay for most of the record, but the progradation rates have been steadily declining and the marshes have begun to erode in recent decades despite the large suspended sediment load provided by the Skagit River. In an area of the delta isolated from direct riverine sediment supply by anthropogenic blockage of historical distributaries, 0.5-m tall marsh cliffs along with concave marsh profiles indicate wave erosion is contributing to marsh retreat. This is further supported by a “natural experiment” provided by rocky outcrops that shelter high marsh in their lee, while being bounded by 0.5-m lower eroded marsh to windward and on either side. Coastal wetlands with high sediment supply are thought to be resilient to sea level rise, but the case of the Skagit Delta shows this is not necessarily true. A combination of sea level rise and wave-generated erosion may overwhelm sediment supply. Additionally, anthropogenic obstruction of historical distributaries and levee construction along the remaining distributaries likely increase the jet momentum of river discharge, forcing much suspended sediment to bypass the tidal marshes and be exported from Skagit Bay. Adaptive response to the threat of climate change related sea level rise and increased wave frequency or intensity should consider the efficacy of restoring historical distributaries and managed retreat of constrictive river levees to maximize sediment delivery to delta marshes.

  19. Assessment of floodplain vulnerability during extreme Mississippi River flood 2011

    USGS Publications Warehouse

    Goodwell, Allison E.; Zhu, Zhenduo; Dutta, Debsunder; Greenberg, Jonathan A.; Kumar, Praveen; Garcia, Marcelo H.; Rhoads, Bruce L.; Holmes, Jr., Robert R.; Parker, Gary; Berretta, David P.; Jacobson, Robert B.

    2014-01-01

    Regional change in the variability and magnitude of flooding could be a major consequence of future global climate change. Extreme floods have the capacity to rapidly transform landscapes and expose landscape vulnerabilities through highly variable spatial patterns of inundation, erosion, and deposition. We use the historic activation of the Birds Point-New Madrid Floodway during the Mississippi and Ohio River Flooding of 2011 as a scientifically unique stress experiment to analyze indicators of floodplain vulnerability. We use pre- and postflood airborne Light Detection and Ranging data sets to locate erosional and depositional hotspots over the 540 km2 agricultural Floodway. While riparian vegetation between the river and the main levee breach likely prevented widespread deposition, localized scour and deposition occurred near the levee breaches. Eroded gullies nearly 1 km in length were observed at a low ridge of a relict meander scar of the Mississippi River. Our flow modeling and spatial mapping analysis attributes this vulnerability to a combination of erodible soils, flow acceleration associated with legacy fluvial landforms, and a lack of woody vegetation to anchor soil and enhance flow resistance. Results from this study could guide future mitigation and adaptation measures in cases of extreme flooding.

  20. Linking the historic 2011 Mississippi River flood to coastal wetland sedimentation

    USGS Publications Warehouse

    Falcini, Federico; Khan, Nicole S.; Macelloni, Leonardo; Horton, Benjamin P.; Lutken, Carol B.; McKee, Karen L.; Santoleri, Rosalia; Colella, Simone; Li, Chunyan; Volpe, Gianluca; D’Emidio, Marco; Salusti, Alessandro; Jerolmack, Douglas J.

    2012-01-01

    Wetlands in the Mississippi River deltaic plain are deteriorating in part because levees and control structures starve them of sediment. In Spring of 2011 a record-breaking flood brought discharge on the lower Mississippi River to dangerous levels, forcing managers to divert up to 3500 m3/s-1 of water to the Atchafalaya River Basin. Here we quantify differences between the Mississippi and Atchafalaya River inundation and sediment-plume patterns using field-calibrated satellite data, and assess the impact these outflows had on wetland sedimentation. We characterize hydrodynamics and suspended sediment patterns of the Mississippi River plume using in-situ data collected during the historic flood. We show that the focused, high-momentum jet from the leveed Mississippi delivered sediment far offshore. In contrast, the plume from the Atchafalaya was more diffuse; diverted water inundated a large area; and sediment was trapped within the coastal current. Maximum sedimentation (up to several centimetres) occurred in the Atchafalaya Basin despite the larger sediment load carried by the Mississippi. Minimum accumulation occurred along the shoreline between these river sources. Our findings provide a mechanistic link between river-mouth dynamics and wetland sedimentation patterns that is relevant for plans to restore deltaic wetlands using artificial diversions.

  1. Seismic stratigraphy and sedimentation of Magdalena Fan, Southern Colombian Basin, Caribbean Sea

    SciTech Connect

    Kolla, V.; Buffler, R.T.; Ladd, J.W.

    1984-03-01

    Analysis of all available seismic data from the Magdalena Fan in the southern Colombian basin, Caribbean Sea, allows subdivision of the sedimentary section into six seismic sequences (units). Although sediments were deposited in the present-day Magdalena Fan region since about Late Cretaceous, terrigenous sedimentation became significant only in the late Cenozoic during deposition of the upper three sequences associated with the uplifts of the Andes. These upper three sequences comprise the Magdalena Fan proper. The uppermost sequence probably represents the last main phase of sedimentation subsequent to the major uplift of the Andes in the Pliocene. The morphologic and shallow acoustic (3.5 kHz) characteristics of this fan unit are: upper fan, 1:60-1:110 gradients, channels having well-developed levees, and several subbottom reflectors in all areas except in channels; middle fan, 1:110-1:200 gradients, numerous channels with very subdued levees, and several to few subbottom reflectors; lower fan, < 1:250 gradients, small channels, relatively smooth sea floor, and few or no subbottom reflectors.

  2. Acrostichum, a Pioneering Fern of Floodplain Areas from the Late Oligocene Sariñena Formation of the Iberian Peninsula.

    PubMed

    Moreno-Domínguez, Rafael; Cascales-Miñana, Borja; Ferrer, Javier; Diez, José B

    2016-01-01

    Acrostichum is considered today an opportunistic fern in disturbed areas, which indicates the first stages of colonisation of such zones. However, in the fossil record, Acrostichum appears related to fluvio-lacustrine environments, freshwater marshes and mangrove deposits. We report here for first time fossil evidence of Acrostichum that reveals a pioneering behaviour of this fern in the colonisation of perturbed communities in Europe, which corroborates previous assumptions about the paleobiology of Acrostichum. Plant remains were collected from the Chattian (late Oligocene) La Val fossil site (Estadilla, Huesca, northeastern Spain) belonging to the Sariñena Formation, which mainly embraces crevasse splays, levees and floodplain deposits. Evidence shows that Acrostichum grew within the levee's vegetal community or close to/on the river banks as well as on floodplain areas and closer to/on the shores of ephemeral ponds. But most importantly, the observed co-existence of Equisetum and Acrostichum remains in the same beds indicates that such strata represent short-lived inundated terrains, e.g., floodplains where the water table was temporarily stagnant. Evidence shows wetland environments dominated by pioneering taxa, implying a pioneering role for Acrostichum during the late Oligocene in the Iberian Peninsula. PMID:27631099

  3. Probably maximum flood of the Sava River

    NASA Astrophysics Data System (ADS)

    Brilly, Mitja; Vidmar, Andrej; Raj, Mojca Å.

    2010-05-01

    The Nuclear Power Plant Krško (NEK) situated on the left bank of the Save River close to the border of Croatia. Probably Maximum Flood, on the location of the NEK could result in combination of probably maximum precipitation, sequential storm before PMP or snowmelt on the Sava River watershed. Mediterranean climate characterises very high precipitation and temporary high snow pack. The HBV-96 model as Integrated Hydrological Modelling System (IHMS) used for modelling. Model was calibrated and verification for daily time step at first for time period 1190-2006. Calibration and verification for hourly time step was done for period 1998-1999. The stream routing parameters were calibrated for flood event in years 1998 and 2007 and than verification for flood event in 1990. Discharge routing data analysis shown that possible inundation of Ljubljana and Savinja valley was not properly estimated. The flood areas are protected with levees and water does not spread over flooded areas in events used for calibration. Inundated areas in Ljubljana valley and Savinja valley are protected by levees and model could not simulate properly inundation of PMF. We recalibrate parameters controlled inundation on those areas for the worst scenario. Calculated PMF values drop down tramendosly after recalibration.

  4. Lessons from Katrina: Flood Management Technology Strategies for the US.

    NASA Astrophysics Data System (ADS)

    Galloway, Gerald

    2006-04-01

    Coastal and riverine flooding and hurricane-driven storms have long plagued those in the United States who live or work on or near the shoreline or the rivers edge. The devastation wrought by Hurricane Katrina brought the challenge of protecting against such events to the political and technical forefront. The predicted impacts of global warming strongly suggest that our floodplains and coastlines could be at greatly increased risk. This presentation will review the development of the U.S. program for providing structural protection, discuss the effectiveness of employing levees, dams, floodways, beach nourishment and storm barriers in this struggle, highlight the changes over the last two decades that have gradually shifted the focus from a structural-only approach to one that includes the non-structural approaches such as wise land use, wetland restoration, relocations, insurance, floodproofing, and emergency warning and evacuation. Using post-Katrina planning as an example, it will explore what new approaches can be taken. Should New Orleans take a 'levees only' approach to its protection? or should attention to New Orleans be part of a coastal Louisiana integrated flood damage reduction and coastal restoration strategy. The nation needs to make changes in its water resources policies and investment strategy to deal with the new threat that it now faces.

  5. Dendrogeomorphic estimate of changes in sedimentation rate along the Kankakee River near Momence, Illinois

    USGS Publications Warehouse

    Phipps, R.L.; Johnson, G.P.; Terrio, P.J.

    1995-01-01

    Changes in sedimentation rates wee estimated using root-burial depth and tree-age data at six selected data-collection sites along the Kankakee River near Momence in Kankakee County, Illinois. Five sites were in backwater areas away from the river channel, and one site was on a natural levee near the channel. A summary of the dendrogeomorphic data at the six sites indicates that sedimentation rates were greater after 1950 than before 1950. Greater sedimentation rates after 1950 were observed at four of the five backwater sites, whereas no change in sedimentation rate after 1950 was observed at the fifth backwater site. The observed rates could have been affected by any combination of soil erosion, soil compaction, or increased streamflow. A greater sedimentation rate after 1950 was observed at the levee site, which appeared to have been affected by erosion from a flood in 1950. Effects of erosion were not observed at any of th other sites. No erosional effects and soil not susceptible to compaction at the five backwater sites indicate that neither erosion nor compaction affected observed sedimentation rates. The effect of increased stream- flow in the Kankakee River Basin since the early 1900's on the observed sedimentation rates is not known.

  6. Hydrologic inferences from tree-ring studies on the Hawkesbury River, Sydney, Australia

    NASA Astrophysics Data System (ADS)

    Martens, Daniel M.

    1993-11-01

    Introduced Salix trees in Australian alluvial environments can be used to make a number of hydrologic inferences. Dendrochronological studies along the Hawkesbury River near Windsor suggest that the Salix growth form and annual growth-ring variability are closely associated with the local hydrologic regime. Detailed analyses of 33 trees showed that tree growth is suppressed close to water and increases with height above mean low stage levels because of the decreasing influence of flooding. Alluvial levels contain discrete vegetation patterns and growth characteristics that are not explained by variations in soil and climate. Growth of Salix in thickets on low in-channel benches is flood limited with fitted exponential growth curves having positive or zero slopes. The high in-channel bench contains vegetation influenced by flooding but growing according to classical exponential decay functions. Trees on floodplain levees show full canopy development and the most rapid growth because of fertile soils, the high availability of water, and limited influence of floods overtopping levee tops. Elevation and tree-growth relations are used to develop a relation between growth and flood frequency. This is applicable to catchments of similar size, soil type, and climate. Analyses of tree form and root distribution indicated that dendrochronological techniques may be used to determine the minimum land surface age and rates of accretion around the tree bole in alluvial areas of southeastern Australia.

  7. Floodplain geomorphic processes and environmental impacts of human alteration along coastal plain rivers, USA

    USGS Publications Warehouse

    Hupp, C.R.; Pierce, A.R.; Noe, G.B.

    2009-01-01

    Human alterations along stream channels and within catchments have affected fluvial geomorphic processes worldwide. Typically these alterations reduce the ecosystem services that functioning floodplains provide; in this paper we are concerned with the sediment and associated material trapping service. Similarly, these alterations may negatively impact the natural ecology of floodplains through reductions in suitable habitats, biodiversity, and nutrient cycling. Dams, stream channelization, and levee/canal construction are common human alterations along Coastal Plain fluvial systems. We use three case studies to illustrate these alterations and their impacts on floodplain geomorphic and ecological processes. They include: 1) dams along the lower Roanoke River, North Carolina, 2) stream channelization in west Tennessee, and 3) multiple impacts including canal and artificial levee construction in the central Atchafalaya Basin, Louisiana. Human alterations typically shift affected streams away from natural dynamic equilibrium where net sediment deposition is, approximately, in balance with net erosion. Identification and understanding of critical fluvial parameters (e.g., stream gradient, grain-size, and hydrography) and spatial and temporal sediment deposition/erosion process trajectories should facilitate management efforts to retain and/or regain important ecosystem services. ?? 2009, The Society of Wetland Scientists.

  8. The value of coastal wetlands for hurricane protection.

    PubMed

    Costanza, Robert; Pérez-Maqueo, Octavio; Martinez, M Luisa; Sutton, Paul; Anderson, Sharolyn J; Mulder, Kenneth

    2008-06-01

    Coastal wetlands reduce the damaging effects of hurricanes on coastal communities. A regression model using 34 major US hurricanes since 1980 with the natural log of damage per unit gross domestic product in the hurricane swath as the dependent variable and the natural logs of wind speed and wetland area in the swath as the independent variables was highly significant and explained 60% of the variation in relative damages. A loss of 1 ha of wetland in the model corresponded to an average USD 33,000 (median = USD 5000) increase in storm damage from specific storms. Using this relationship, and taking into account the annual probability of hits by hurricanes of varying intensities, we mapped the annual value of coastal wetlands by 1 km x 1 km pixel and by state. The annual value ranged from USD 250 to USD 51,000 ha(-1) yr(-1), with a mean of USD 8240 ha(-1) yr(-1) (median = USD 3230 ha(-1) yr(-1)) significantly larger than previous estimates. Coastal wetlands in the US were estimated to currently provide USD 23.2 billion yr(-1) in storm protection services. Coastal wetlands function as valuable, selfmaintaining "horizontal levees" for storm protection, and also provide a host of other ecosystem services that vertical levees do not. Their restoration and preservation is an extremely cost-effective strategy for society.

  9. Investigating extent of dissolved organic carbon stabilization by metal based coagulant in a wetland environment

    NASA Astrophysics Data System (ADS)

    Henneberry, Y.; Mourad, D.; Kraus, T.; Bachand, P.; Fujii, R.; Horwath, W.

    2008-12-01

    This study is part of a larger project designed to investigate the feasibility of using metal-based coagulants to remove dissolved organic carbon (DOC) from island drainage water in the San Joaquin Delta and subsequently retaining the metal-DOC precipitate (floc) in wetlands constructed at the foot of levees to promote levee stability. Dissolved organic carbon is a constituent of concern as some forms of DOC can be converted to carcinogenic compounds during drinking water treatment. The focus of this work is to assess floc stability over time and to determine whether floc can be permanently sequestered as part of wetland sediment. Drainage water collected seasonally from Twitchell Island was coagulated with ferric sulfate and polyaluminum chloride at optimal and 50%-optimal dosage levels. Floc was incubated in the laboratory under anaerobic conditions for six weeks under various conditions including different DOC concentrations, microbial inoculants, and addition of nutrients. Preliminary results indicate the floc is a stable system; little to no DOC was released from the floc into the water column under incubations with native microbial inoculate. In addition, floc incubated with previously coagulated water appeared to remove additional DOC from the water column. Future work will involve field and laboratory studies using 13C labeled plant material to examine the effects of fresh plant matter and the effects of peat soil DOC on floc stability, in order to elucidate mechanisms behind carbon stabilization by metal-based floc.

  10. Creating Flood Inundation Maps Using 1D Hydrologic Model and GIS for Lower Meric River Basin, Turkey

    NASA Astrophysics Data System (ADS)

    Sonmez, O.; Dogan, E.; Demir, I.

    2012-12-01

    In Turkey, one of the areas facing the danger of flooding is Lower Meric River basin, the part between Edirne and Enos, Turkey. Despite being in the flood zone, the region is used widely as an agricultural and settlement land. The State Hydraulic Works (DSI) has built levees to prevent flood damages on the Lower Evros River Basin. However, having floods in the region reaching areas behind levees, clearly showed the need for reviewing and updating the cross-sections of the critical areas in the river bed. In this study, determination of floodplains for various stream-flow values in any cross sections of the river is aimed. The study area is divided into two sections (Study Area 1 & Study Area 2). Available stream flow gauging station data, which is located in study areas, are used in model. Model created using HEC-RAS, is calibrated with 2006 flood which occurred in the study area. After calibration, floodplain maps are created for 1000 m3/s flows from 1000 to6000 m3/s flows for Study Area1. For Study Area 2, floodplain maps are created for 2, 5, 10, 50, 100 years return periods. The models can illustrate the extent of flooding under different conditions allowing residents in the area to see how predicted flood levels could affect their property, and help them make informed decisions.

  11. [Prefrontal clinical symptoms in daily living: screening assessment by means of the short Prefrontal Symptoms Inventory (PSI-20)].

    PubMed

    Pedrero-Pérez, Eduardo J; Ruiz-Sánchez de León, José M; Morales-Alonso, Sara; Pedrero-Aguilar, Jara; Fernández-Méndez, Laura M

    2015-05-01

    Introduccion. La estimacion de sintomas cotidianos de disfuncion frontal se considera imprescindible para aportar validez ecologica a las evaluaciones neuropsicologicas. Los cuestionarios disponibles se construyeron para estimar problemas ejecutivos en la vida diaria en poblaciones con daño neurologico. Se requieren instrumentos enfocados a medir estos comportamientos en la poblacion general o en poblaciones clinicas con fallos leves o moderados. Objetivo. Estudiar la validez factorial y encontrar indicios de validez concurrente de la version abreviada del inventario de sintomas prefrontales. Sujetos y metodos. Se obtuvieron tres muestras: la primera, a traves de Internet (n = 504); la segunda, en poblacion no clinica mediante lapiz y papel (n = 1.257), y la tercera, de pacientes en tratamiento por adiccion a sustancias (n = 602). Se utilizo un metodo de analisis factorial sin restricciones sobre la primera muestra y los resultados se sometieron a analisis factorial confirmatorio sobre las otras dos muestras. Resultados. La estructura de tres factores encontrada se confirmo con excelentes indicadores de ajuste en las otras dos muestras. Se hallaron indicios de validez concurrente con pruebas de calidad de vida y salud mental. Conclusiones. Se propone un cuestionario breve para la deteccion de fallos de origen prefrontal en la vida diaria, que mejora las cualidades psicometricas de tests similares, pero orientados a patologias neurologicas graves. La estabilidad estructural de la prueba garantiza la utilidad en la poblacion general, para la deteccion precoz del deterioro cognitivo, y en poblaciones clinicas con deterioro leve o moderado. Se proponen baremos para la interpretacion de resultados.

  12. Eustatic and structural control of submarine-fan sedimentation, Conception fan, Santa Barbara basin, California

    SciTech Connect

    Thor, D.R.

    1984-04-01

    Eustatic sea level lows provide an opportunity for submarine-fan development; topography and structure, however, can control depositional-sequence geometry. Analysis of high-resolution seismic data provides a basis to evaluate to the evolution and geometry of the Pleistocene-Holocene Conception fan. The fan formed in the restricted, tectonically active Santo Barbara basin. It consists of 4 vertically stacked depositional sequences, each bounded by nondepositional unconformities. The unconformities are defined by seismic-sequence boundaries and were formed during sea-level falls that are related to Pleistocene glacioeustatic changes. Each depositional sequence consists of lowstand, sandrich facies (fan channel, levee, and lobe) topped by highstand, mud-rich facies. The geometry of the depositional sequences tends to be rectilinear, not arcuate, because lateral progradation is restricted by topographically high structures. The modern fan surface and the Holocene depositional sequence provide a good analog for the older, underlying depositional sequences. The fan surface is characterized by 4 main channels, 2 of which head into submarine canyons incised into the shelf. Submarine canyons that fed the other 2 channels are now filled and have no topographic expression. In addition, numerous partially buried channel segments occur in the interchannel areas. The Holocene depositional sequence consists of lenticular and sheet-drape deposits interpreted to be channel, levee, and lobe facies. The facies geometry suggests that Mutti's topographic compensation, channel migration, and avulsion were typical processes on Conception fan.

  13. [Relationship between dyslipidemia and severity in preeclampsia].

    PubMed

    Duarte-Mote, Jesús; Perez-Torres, Carolina; Espinosa-López, Rogelio; Eng-Castro, Víctor Lee; Calvo-Colindres, Jesús; Sánchez-Rojas, Graciela; Romero-Figueroa, Maria del Socorro

    2014-01-01

    Introducción: se ha identificado que los valores del colesterol y los triglicéridos (TG) son más altos en la preeclampsia que en el embarazo normal; sin embargo, aún no está claro si estos niveles tienen relación con la gravedad del proceso. El objetivo del estudio fue determinar si existe relación entre la dislipidemia y la gravedad en la preeclampsia. Métodos: estudio transversal comparativo en 200 pacientes, 100 con embarazo normal y 100 con preeclampsia. Se identificó edad, antecedentes ginecoobstétricos, colesterol total y TG. Se utilizó estadística descriptiva: t de Student para comparar el grupo de pacientes con preeclampsia y embarazos normales, y ANOVA y razón de momios para el subanálisis de preeclampsia leve y severa. Resultados: no se encontraron diferencias estadísticamente significativas en edad, ni en colesterol. Los TG presentaron una diferencia estadísticamente significativa: fueron más altos en relación con la gravedad de la preeclampsia (embarazo normal 245 mg, preeclampsia leve 308 mg y preeclampsia severa 349 mg). Conclusión: los niveles elevados de colesterol y TG en pacientes con preeclampsia no demostraron consistencia en relación con la gravedad de la preeclampsia.

  14. Minimizing contamination hazards to waterbirds using agricultural drainage evaporation ponds

    NASA Astrophysics Data System (ADS)

    Bradford, David F.; Smith, Lynda A.; Drezner, Deborah S.; Shoemaker, J. David

    1991-11-01

    In much of the San Joaquin Valley, California, USA, inadequate drainage of applied irrigation water and accumulating salts in the soil have necessitated the installation of subsurface tile drainage systems to preserve crop productivity. At present, these subsurface drainage waters are disposed of by means of evaporation ponds or discharges into the San Joaquin River. Unfortunately, most of these agricultural drainage waters contain high concentrations of salts and naturally occurring trace elements, such as selenium, and recent evidence indicates that substantial numbers of waterbirds are exposed to contamination by selenium in the evaporation ponds. In order to avoid, minimize, or mitigate the adverse impacts on wildlife using the ponds, alternative pond management methods must be identified and evaluated for implementation. A number of methods have the potential to be cost-effective in significantly reducing the contamination hazard to birds using agricultural evaporation ponds. Twenty general methods were evaluated in this study, and four methods are recommended for implementation: remove levee vegetation, remove windbreaks, deepen the ponds, and haze birds. A number of other methods are recommended for further consideration because they appear to have good prospects for reducing the contamination hazard: steepen interior levee slopes, apply herbicides and insecticides, place netting on pond shorelines, and provide freshwater habitat adjacent to evaporation ponds. It may be necessary to use a combination of methods to effectively control selenium contamination of aquatic birds because it is unlikely that a single affordable pond management method will be able to entirely eliminate the contamination hazard.

  15. Prevalence of lead exposure among age and sex cohorts of Canada geese

    USGS Publications Warehouse

    DeStefano, S.; Brand, C.J.; Rusch, D.H.

    1992-01-01

    moins de 1% des adultes et aucun oison n'en portait. Cependant, les concentrations sanguines m??dianes de base (??chantillons de sang contenant moins de 0,18 ppm de plomb) ??taient plus ??lev??es chez les adultes que chez les oisons, ce qui signifie probablement que les adultes avaient ??t?? expos??s au plomb au cours de saisons pr??c??dentes. Les plombs perdus ??taient abondants dans les territoires de migration et les territoires d'hiver et la proportion d'??chantillons de sang contenant des concentrations a?Y 0,18 ppm ??tait plus ??lev??e chez les oiseaux immatures (< 1 an) que chez les oiseaux adultes (> 1 an). Les concentrations m??dianes de base sont demeur??es plus ??lev??es chez les adultes que chez les immatures durant tout l'automne et tout l'hiver. Nous avons ??galement constat?? que plus de m??les immatures que de femelles immatures avaient des concentrations ??lev??es de plomb. Les taux plus ??lev??s d'ingestion de nourriture et de mati??res min??rales (y compris des plombs de chasse) expliquent probablement en partie la pr??sence de concentrations ??lev??es de plomb chez les Bernaches du Canada immatures.

  16. Sedimentation History of Halfway Creek Marsh, Upper Mississippi River National Wildlife and Fish Refuge, Wisconsin, 1846-2006

    USGS Publications Warehouse

    Fitzpatrick, Faith A.; Knox, James C.; Schubauer-Berigan, Joseph P.

    2007-01-01

    The history of overbank sedimentation in the vicinity of Halfway Creek Marsh near La Crosse, Wis., was examined during 2005?06 by the U.S. Geological Survey and University of Wisconsin?Madison as part of a broader study of sediment and nutrient loadings to the Upper Mississippi River bottomlands by the U.S. Environmental Protection Agency, U.S. Fish and Wildlife Service, and U.S. Geological Survey. Historical sedimentation patterns and rates were interpreted from field-scale topographic surveys and sediment cores collected from the marsh and upstream flood plains. Historical maps and aerial photographs were used to establish the timing of disturbances and to document changes in channel patterns after Euro-American settlement (post 1846). Episodic overbank sedimentation patterns and rates were linked to watershed agricultural activity, large floods, artificial levee construction, channel alterations, and dam failures over the past 160 years. These forces affected sedimentation on and between levees, the development of alluvial fans and flood-plain splays, and the general pattern of flood-plain sedimentation through the upper and lower marsh. Historical overbank deposits, episodically deposited after about 1860, are as much as 6 feet thick in the upper marsh and as much as 4 feet thick in the lower marsh, representing a total volume of approximately 1.8 million cubic yards. These stratified deposits consist of multiple layers of silt and clay, very fine to fine sand, and some medium to very coarse sand. Coarse-grained deposits are associated with flood-plain splays caused by breaches in artificial levees during large floods. Estimated sedimentation rates were highest from 1919 to 1936 [26,890 cubic yards per year (yd3/yr)] and exceeded by about 30 times the 1846?85 rate of 920 yd3/yr and exceeded by 7 times the 1994?2006 rate of 3,740 yd3/yr. The 1994?2006 sedimentation rate was the lowest since Euro-American settlement, but natural levees along the 1994?2006 channel

  17. Field-wide Pressure Response of Three Mid-Cenozoic Sandstone Reservoirs to Fluid Production: a Reverse Analog to Carbon Storage

    NASA Astrophysics Data System (ADS)

    Gillespie, J.; Jordan, P. D.; Chehal, S.; Gonzales, G.; goodell, J. A.; Wilson, J.

    2013-12-01

    Potential carbon storage reservoirs exist in mature oilfields of the southern San Joaquin Valley, California. Data regarding fluid extraction and injection and reservoir pressure exist for the three main oil reservoirs with carbon storage potential: the Monterey (Stevens sandstone member), Vedder and Temblor formations. The pressure response of these reservoirs to fluid volume changes over time provides information regarding how carbon storage may affect the pressure gradients in the adjacent saline aquifers outside the fields where less data exist. This project may provide a template for analysis of other potential carbon storage reservoirs that are contiguous with oilfields. A field-scale version of the productivity index (PI, defined as the average net fluid production rate divided by the average pressure drop over the time period) was calculated for fields with substantial production from depths suitable for carbon storage. The PI determines the reservoir's pressure response to fluid production and is related to the effective CO2 storage capacity. The variance of the 2005 pressure values within each reservoir provides a measure of reservoir continuity. The highest PI values (113,000 and 88,410 m3/yr/MPa) are in the Vedder Formation. The lowest PI values occur in the Temblor Formation and range from 3734 to 16,460 m3/yr/MPa. This indicates the Vedder reservoirs have more pressure support from the aquifer beyond the field than do the Temblor reservoirs. The pressure variance of 3.2 MPa within the Vedder Formation in the Greeley Field is the lowest. The greatest variance (8.5 MPa) occurs within the Temblor Formation in the Carneros unit of the Railroad Gap field. This indicates greater uniformity in the Vedder and more compartmentalization of the Temblor. Pressure response in the Stevens is more varied within the two fields examined in this study: North and South Coles Levee. In North Coles Levee, water injection was employed throughout the field resulting in a

  18. Simulations of Flooding on Pea River and Whitewater Creek in the Vicinity of the Proposed Elba Bypass at Elba, Alabama

    USGS Publications Warehouse

    Hedgecock, T. Scott

    2003-01-01

    A two-dimensional finite-element surface-water model was used to study the effects of proposed modifications to the State Highway 203 corridor (proposed Elba Bypass/relocated U.S. Highway 84) on water-surface elevations and flow distributions during flooding in the Pea River and Whitewater Creek Basins at Elba, Coffee County, Alabama. Flooding was first simulated for the March 17, 1990, flood, using the 1990 flood-plain conditions to calibrate the model to match measured data collected by the U.S. Geological Survey and the U.S. Army Corps of Engineers after the flood. After model calibration, the effects of flooding were simulated for four scenarios: (1) floods having the 50- and 100-year recurrence intervals for the existing flood-plain, bridge, highway, and levee conditions; (2) floods having the 50- and 100-year recurrence intervals for the existing flood-plain and levee conditions with the State Highway 203 embankment and bridge removed; (3) floods having the 50- and 100-year recurrence intervals for the existing flood-plain, bridge, and highway conditions with proposed modifications (elevating) to the levee; and (4) floods having the 50- and 100-year recurrence intervals for the proposed conditions reflecting the Elba Bypass and modified levee. The simulation of floodflow for the Pea River and Whitewater Creek flood of March 17, 1990, in the study reach compared closely to flood profile data obtained after the flood. The flood of March 17, 1990, had an estimated peak discharge of 58,000 cubic feet per second at the gage (just below the confluence) and was estimated to be between a 50-year and 100-year flood event. The estimated peak discharge for Pea River and Whitewater Creek was 40,000 and 42,000 cubic feet per second, respectively. Simulation of floodflows for the 50-year flood (51,400 cubic feet per second) at the gage for existing flood-plain, bridge, highway, and levee conditions indicated that about 31 percent of the peak flow was conveyed by the State

  19. Hydrogeology and effects of landfills on ground-water quality, southern Franklin County, Ohio

    USGS Publications Warehouse

    De Roche, J.T.

    1985-01-01

    Hydrogeology and water quality were evaluated near five land-fills along a 5-mile segment of the Scioto River valley south of Columbus, Ohio. Heterogenous surficial deposits o sand, gravel, and till up to 160 feet thick are hydraulically connected to the underlying Devonian limestone, the landfills and Scioto River, which has been leveed with 12 to 35 feet of refuse. Ground-water withdrawals caused a maximum 21-foot decline in ground-water levels from 1979 to 1982. The study reach of Scioto River within the influence of ground-water pumping is a losing stream, except for s small segment adjacent to one landfill. Analysis of variance indicated significant difference in ground-water quality between wells upgradient of landfills, down-gradient of landfills, and wells penetrating refuse. Elevated specific conductance and concentrations of total dissolved solids, ammonia, carbon dioxide, and dissolved organic carbon in water from wells downgradient from and penetrating landfills indicate leachate production and migration is occurring. Analysis of bed-material samples from Scioto River and Scioto Big Run revealed concentrations of polynuclear aromatic hydrocarbons ranging from 220 to 9,440 micograms per kilogram of sediment (?g/kg) and concentrations of toxic metals ranging from 1 to 720 ?g/kg. Samples from an upstream control station on Scioto River contained no organic compounds and lower concentrations of metals (ranging from 1 to 260 ?g/kg). Because of multiple land uses within the study area, organic compounds recovered from the streamed sediments cannot be attributed to any single source. The generation of hydrogen sulfide and methane gases, presence of a zone of increased hardness, elevated concentrations of common ionic species, and dominance of ammonia over other nitrogen species indicate that leachate is being produced and its migrating from four landfills and the river levee. Based on hydraulic relationships between ground water and surface water, it is highly

  20. Production and decomposition of forest litter fall on the Apalachicola River flood plain, Florida: Chapter B, Apalachicola River quality assessment

    USGS Publications Warehouse

    Elder, John F.; Cairns, Duncan J.

    1982-01-01

    Measurements of litter fall (leaves and other particulate organic material) and leaf decomposition were made on the bottom-land hardwood swamp of the Apalachicola River flood plain in 1979-80. Litter fall was collected monthly from nets located in 16 study plots. The plots represented five forest types in the swamp and levee areas of the Apalachicola River flood plain. Forty-three species of trees, vines, and other plants contributed to the total litter fall, but more than 90 percent of the leaf material originated from 12 species. Nonleaf material made up 42 percent of the total litter fall. Average litter fall was determined to be 800 grams per square meter per year, resulting in an annual deposition of 3.6 ? 105 metric tons of organic material in the 454-square-kilometer flood plain. The levee communities have less tree biomass but greater tree diversity than do swamp communities. The levee vegetation, containing less tree biomass, produces slightly more litter fall per unit of ground surface area than does the swamp vegetation. The swamps are dominated by three genera: tupelo (Nyssa), cypress (Taxodium) and ash (Fraxinus). These genera account for more than 50 percent of the total leaf fall in the flood plain, but they are the least productive, on a weight-perbiomass basis, of any of the 12 major leaf producers. Decomposition rates of leaves from five common floodplain tree species were measured using a standard leaf-bag technique. Leaf decomposition was highly species dependent. Tupelo (Nyssa spp.) and sweetgum (Liquidambar styraciflua) leaves decomposed completely in 6 months when flooded by river water. Leaves of baldcypress (Taxodium distichum) and diamond-leaf oak (Quercus laurifolia) were much more resistant. Water hickory (Carya aquatica) leaves showed intermediate decomposition rates. Decomposition of all species was greatly reduced in dry environments. Carbon and biomass loss rates from the leaves were nearly linear over a 6-month period, but nitrogen

  1. Vegetation and its relationship with geomorphologic units in the Parana River floodplain, Argentina

    NASA Astrophysics Data System (ADS)

    Marchetti, Z. Y.; Latrubesse, E. M.; Pereira, M. S.; Ramonell, C. G.

    2013-10-01

    The Parana River is one of the most important fluvial systems of South America and its floodplain includes the most diverse subtropical ecosystem on the continent. However, the relationship between basic aspects, such as the vegetation and geomorphology of the river floodplain, has scarcely been investigated. In this paper, the annual dynamics of vegetation in relation to the geomorphologic and hydrological characteristics of a river floodplain around 31° 30' S, are analyzed. The annual dynamics of vegetation was investigated using values of the Normalized Difference Vegetation Index (NDVI) obtained from satellite images at two scales of spatial analysis: the first, at the geomorphologic unit level, through several transects crossing the total width of each unit and, the second, through some transects selected from each unit. Our analysis considered variables of different temporal stability (such as geomorphology, hydrology, vegetation, precipitation, and ground temperature), using scenes corresponding to two hydrological cycles of the system (2009 and 2010), which represented relatively "dry" and "humid" years. Five main geomorphologic units were identified in the floodplain of this anabranching system, which were named considering the predominant landforms and the most important (or typical) water course of each area: Bars and Islands of the Main Channel of the Parana River (BI-MCH), Scroll Bars of the Colastine Branch (SB-C), Scroll Bars of the San Javier River Channel (SB-SJ), Crevasse Splays and Levees of the Malo-Mendieta minor channels (CSL-MM), and Crevasse Splays and Levees of the Santa Fe-Coronda river channels (CSL-SFC). These major units are assembled at different general levels and with variable slopes, which partially control the permanence and other characteristics of the flood flow. The crevasse splays and river levees units were predominantly characterized by herbaceous-bushy marshy vegetation, with low mean NDVI values, while SB-C and BI

  2. Floodplains and Sedimentation Processes in a Changing Basin: Case Study Sacramento Valley

    NASA Astrophysics Data System (ADS)

    Singer, M. B.; Aalto, R.

    2006-12-01

    The diverse floodplains of the Sacramento Valley in California have undergone dramatic post-glaciation changes. The natural reduction in sediment supply following glacial melting appears to have altered channel pattern of the in the Middle Sacramento River from braided to meandering. This trend has been exacerbated by recent dam construction, gravel and sand mining, and bank protection, which have apparently increased the frequency of chute cutoff and decreased channel sinuosity. The sum of factors controlling sediment supply and channel pattern are evidently converting the Sacramento from an aggraded river with frequent access to its natural floodplain to a degrading river with limited connectivity. We have documented via 210Pb dating low volumes of recent sediment transfer to: inset floodplains in Upper Sacramento River canyons; meander belt deposits, low-lying sinks bounding natural levees, and oxbow lakes along the Middle Sacramento River; and crevasses splay deposits and lowland floodways in the Lower Sacramento Valley. These observations are contrasted with historical maps and preserved deposits from the previous era of floodplain creation, which suggest higher rates of sediment accumulation. The presence of high sand content in recent deposits along channel margins determined via granulometry and its rapid decline with depth and distance from the channel attests to recent erosion of channel sediments throughout the Sacramento River. Most of the natural crevasses splays that once dominated sediment transfer into floodplains along the Sacramento's lower course have been cut off from the channel by flood control levees built upon channel banks. However, several splay fans were retrofitted for use in the valley's flood control system (c. 1920's) as lateral spill weirs that shunt flood flow out of the mainstem Sacramento River. These weirs focus flow and sediment transport into engineered floodways (i.e., leveed portions of natural low gradient flood basins

  3. Adjustment of Submarine Channel Architecture to Changes in Sediment Supply, Western Niger Delta Slope

    NASA Astrophysics Data System (ADS)

    Jobe, Z. R.; Sylvester, Z.; Parker, A. O.; Pirmez, C.; Slowey, N. C.

    2013-12-01

    Three-dimensional seismic, piston cores, and autonomous underwater vehicle data (chirp sub-bottom profiles, multibeam bathymetry, and sidescan sonar) provide a multi-scale dataset used to examine the evolution of a submarine channel system on the western Niger Delta continental slope. Four phases of channel evolution are documented that are interpreted to relate to changes in the sediment routing system. The first phase is incisional and creates a large valley within which the subsequent phases evolve. The second phase records the development of sinuosity through lateral accretion of the meander bends. Meander cutoffs and channel-bank mass wasting result in terraced and scalloped channel margins. This phase is volumetrically most significant in terms of channel fill. The third phase is characterized by thalweg aggradation with slight channel narrowing; preferential deposition towards the outer banks results in a reduction of sinuosity. This phase likely reflects the updip abandonment of the channel system. The fourth phase is characterized by inner levee deposition that occurs primarily on outer banks, causing a reduction in channel width and sinuosity. These changes are caused by the capture of a small slope channel that is the source for underfit flows that attempt to adjust the channel cross section and thalweg gradient through inner levee deposition. Chirp sub-bottom profiles and piston core data reveal that these sigmoidal inner levees consist of thin-bedded, ripple-laminated turbidites interbedded with mudstones. The channel thalweg consists of amalgamated, sand-rich turbidites with dune-scale bedforms and occasional mass transport deposits. Core transects taken across the channel demonstrate that sand bed thickness decreases with height above the channel thalweg. Laser particle size analyzer data indicate a progressive decrease in grain size with height above the channel thalweg. These vertical trends in grain size and bed thickness distribution are used to

  4. Detecting fluid leakage of a reservoir dam based on streaming self-potential measurements

    NASA Astrophysics Data System (ADS)

    Song, Seo Young; Kim, Bitnarae; Nam, Myung Jin; Lim, Sung Keun

    2015-04-01

    Between many reservoir dams for agriculture in suburban area of South Korea, water leakage has been reported several times. The dam under consideration in this study, which is located in Gyeong-buk, in the south-east of the Korean Peninsula, was reported to have a large leakage at the right foot of downstream side of the reservoir dam. For the detection of the leakage, not only geological survey but also geophysical explorations have been made for precision safety diagnosis, since the leakage can lead to dam failure. Geophysical exploration includes both electrical-resistivity and self-potential surveys, while geological surveys water permeability test, standard penetration test, and sampling for undisturbed sample during the course of the drilling investigation. The geophysical explorations were made not only along the top of dam but also transverse the heel of dam. The leakage of water installations can change the known-heterogeneous structure of the dam body but also cause streaming spontaneous (self) potential (SP) anomaly, which can be detected by electrical resistivity and SP measurements, respectively. For the interpretation of streaming SP, we used trial-and-error method by comparing synthetic SP data with field SP data for model update. For the computation, we first invert the resistivity data to obtain the distorted resistivity structure of the dam levee then make three-dimensional electrical-resistivity modeling for the streaming potential distribution of the dam levee. Our simulation algorithm of streaming SP distribution based on the integrated finite difference scheme computes two-dimensional (2D) SP distribution based on the distribution of calculated flow velocities of fluid for a given permeability structure together with physical properties. This permeability is repeatedly updated based on error between synthetic and field SP data, until the synthetic data match the field data. Through this trial-and-error-based SP interpretation, we locate the

  5. Alluvial Morphology In Cohesive Sediment: The Mahakam Lowland Area

    NASA Astrophysics Data System (ADS)

    Vermeulen, B.; van Berkum, S.; Hoitink, A.; Sassi, M.; Hidayat, H.

    2011-12-01

    In the lower part of its course, the Mahakam River (Indonesia) flows through the subsiding Kutai Basin, through its own cohesive alluvium. The river is surrounded by a large number of floodplain lakes and peat domes. Its planform geometry and bed morphology reveal the presence of very sharp bends and associated deep scours. The lakes are connected to the river by small-sized tie-channels, which play a crucial role the discharge regime of the Mahakam downstream of the lake district. This study aims to establish the morphology of the sharp river bends and tie-channels, and to evaluate the contribution of sediment cohesion, riparian vegetation and the presence of peat in the area to river banks stability. Based on a detailed reconnaissance survey of the river banks, patterns of sedimentation and erosion in highly curved bends are found to be mirrored relative to those in mildly curved river stretches. Bars develop at the concave banks of sharp bends. On the convex sides, reattachment bars are often found, indicating flow separation at the inner bank. These sharp bends are thought to develop due to failure of the river to cutoff meanders due to erosion resistance of the banks. The top of the levees are located high in the landscape, forming a barrier between the surrounding swampy floodplains and the river. These levees form a buffer between the river corridor and peat domes, suggesting peat domes to be formed in areas outside the river corridor, rather than vice versa. Tie-channels are characterized by a very stable morphology and exhibit levees with decreasing height away from the river. The bed of these channels is armored with gravel and concretions of iron, organic matter and clay, suggesting that very high flow velocity can occur when the water level in the river changes abruptly. Both in the tie-channels and in the meandering part of the river, we found no apparent effect of vegetation on morphometric properties. We conclude the morphological characteristics of

  6. Debris flows from small catchments of the Ma Ha Tuak Range, metropolitan Phoenix, Arizona

    NASA Astrophysics Data System (ADS)

    Dorn, Ronald I.

    2010-08-01

    Debris flows debauch from tiny but steep mountain catchments throughout metropolitan Phoenix, Arizona, USA. Urban growth in the past half-decade has led to home construction directly underneath hundreds of debris-flow channels, but debris flows are not recognized as a potential hazard at present. One of the first steps in a hazard assessment is to determine occurrence rates. The north flank of the Ma Ha Tuak Range, just 10 km from downtown Phoenix, was selected to determine the feasibility of using the varnish microlaminations (VML) method to date every debris-flow levee from 127 catchment areas. Only 152 of the 780 debris-flow levees yielded VML ages in a first round of sampling; this high failure rate is due to erosion of VML by microcolonial fungi. The temporal pattern of preserved debris-flow levees indicates anomalously high production of debris flows at about 8.1 ka and about 2.8 ka, corresponding to Northern Hemisphere climatic anomalies. Because many prior debris flows are obliterated by newer events, the minimum overall occurrence rates of 1.3 debris flows per century for the last 60 ka, 2.2 flows/century for the latest Pleistocene, and 5 flows/century for the last 8.1 ka has little meaning in assessment of a contemporary hazard. This is because newer debris flows have obliterated an unknown number of past deposits. More meaningful to a hazards analysis is the estimate that 56 flows have occurred in the last 100 years on the north side of the range, an estimate that is consistent with direct observations of three small debris flows resulting events from a January 18-22, 2010 storm producing 70 mm of precipitation in the Ma Ha Tuak Range, and a 500 m long debris flow in a northern metropolitan Phoenix location that received over 150 mm of precipitation in this same storm. These findings support the need for a more extensive hazard assessment of debris flows in metropolitan Phoenix.

  7. Using 10Be erosion rates and fluvial channel morphology to constrain fault throw rates in the southwestern Sacramento River Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Cyr, A. J.

    2013-12-01

    The Sacramento - San Joaquin River Delta, California, USA, is a critical region for California water resources, agriculture, and threatened or endangered species. This landscape is affected by an extensive set of levees that enclose artificial islands created for agricultural use. In addition to their importance for sustaining agriculture, this levee system also supports extensive transport and power transmission infrastructure and urban/suburban development. These levees are susceptible to damage from even moderate ground shaking by either a large earthquake on one of the high-activity faults in the nearby San Francisco Bay region, or even a moderate earthquake on one of the low-activity faults in the Delta region itself. However, despite this danger the earthquake hazards in this region are poorly constrained due to our lack of understanding of faults in and near the Delta region. As part of an effort to better constrain the seismic hazard associated with known, but poorly constrained, faults in the region, a geomorphic analysis of the Dunnigan Hills, northwest of Woodland, CA, is being combined with cosmogenic 10Be catchment-averaged erosion rates. The Dunnigan Hills are a low-relief (maximum elevation 87 m) landscape generated by fault-bend folding above the west-vergent Sweitzer reverse fault that soles into a blind east-vergent reverse fault. These faults have been imaged by seismic reflection data, and local microseismicity indicates that this system is actively propagating to the east. However, the throw rates on the faults in this system remain unconstrained, despite the potential for significant shaking such as that experienced in the nearby April, 1892 earthquake sequence between Winters and Vacaville, Ca, ~25 km to the south, which has been estimated at magnitude 6.0 or greater. Geomorphic and cosmogenic 10Be analyses from 12 catchments draining the eastern flank of the Dunnigan Hills will be used to infer vertical rock uplift rates to better constrain

  8. Estimating the Response of Physical Processes in the South San Francisco Bay for Flood Stage Frequency Analysis

    NASA Astrophysics Data System (ADS)

    Andes, L.; Wu, F.; MacWilliams, M.; Lu, C.; Lo, J.

    2012-12-01

    Coastal flooding in the far south San Francisco Bay (SSFB) can be a function of astronomical tide, residual tide, in-bay wind speed and direction and fluvial discharge. These physical processes and coastal levee failure were considered as input parameters into a Monte Carlo Simulation (MCS) to estimate coastal flood stage frequency in the SSFB. Limited data is available in the SSFB to estimate the contribution of these physical processes to coastal flood statistics. Over 100 years of measured water surface elevation (WSE) is available at the San Francisco tide station which can be used as input to hydrodynamic model simulations to estimate the WSE response in the SSFB. Data sampling criteria have been developed to select significant events at the San Francisco tide station for data transfer to the project site and statistical analysis. The coincidently sampled astronomical and residual tides at the San Francisco tide station were analyzed to cover the full range of the combinations of astronomical and residual tides that contribute to coastal flood statistics at the project site. A look-up table of astronomical and residual tide in the form of WSE responses at the project site from the hydrodynamic simulations was established for the interpolation in the MCS. The hydrodynamic model simulations indicated that the higher-high astronomical tides between 5.15 and 7.25 feet MLLW amplifies with a factor of 1.40 to 1.90 as a function of tidal frequency and water depth, including tidal range. The residual tide varies minimally as it propagates into the SSFB. In-Bay wind set-up from a significant event was found to contribute on the order of one foot to the total WSE in the SSFB; however, wind events with strong magnitudes along the primary axis of the bay occur infrequently making an insignificant contribution to the overall flood statistics. The fluvial discharges of Guadalupe River and Coyote Creek were considered in the hydrodynamic simulations as they are located

  9. Structural controls on the development of submarine channel/fan systems since the Pleistocene in the accretionary wedge off SW Taiwan

    NASA Astrophysics Data System (ADS)

    Shen, Kang-Nien; Tien-Shun Lin, Andrew; Lin, Che-Chuan; Liu, Char-Shine; Wang, Yunshuen

    2016-04-01

    The accretionary wedge off SW Taiwan is the result of incipient arc-continent collision between the Luzon volcanic arc and the northern rifted margin of the South China Sea (SCS). Dynamic interactions of thrusting, folding and a rigorous sediment supply from the Taiwan mountain belts have resulted in two arrays of canyons/channels and slope-fan systems in the accretionary wedge. The Penghu canyon/fan system lies in the lower wedge and near the northern rifted margin of the SCS. The Penghu canyon is a river-fed canyon and receives sediments from southern Taiwan and SE China during eustatic lowstands. It becomes detached from river inputs during eustatic highstands as it is in the present-day. The Gaoping canyon/fan system in the south traverses both the upper slope and lower slope domains of the accretionary wedge. This system is a river-fed system during a full eustatic cycle and it drains sediments from the onshore Gaoping River. We interpreted multiple grids of multichannel seismic reflection data of MCS994, MCS1000-6, MCS1014, MCS1046 collected onboard Ocean Research I during 2012 April to 2013 August to map out thrust/fold structures and channel/fan systems in the study area. Seismic facies analyses were performed on seismic sections and key stratal surfaces of base of Pliocene and base of Pleistocene are correlated from boreholes drilled in the shelf of the northern SCS margin. Our results show that the upper Gaoping Canyon has been confined by structural ridges with limited switching of canyon courses, whereas the lower Gaoping canyon/fan system has been developed on lower slope with channel/levee deposition in multiple slope fans since early Pleistocene. Pleistocene lateral aggrading channel-and-levee systems are especially evident near the modern canyon course in the lower slope. The Penghu can/fan system in the lower accretionary wedge is also evident by seismic facies showing channel cut-and-fill, channel abandonment and channel-and-levee systems. This

  10. Factors Controlling Tidal Flat Morphology in South San Francisco Bay

    NASA Astrophysics Data System (ADS)

    Bearman, J. A.; Foxgrover, A.; Friedrichs, C.; Jaffe, B.

    2006-12-01

    Since the 1850's, the San Francisco Bay has been subjected to a wide array of human-induced change. From the time of the first US Coast and Geodetic Survey bathymetric surveys in 1858, the saltmarshes and mudflats of South San Francisco Bay (SSFB) have decreased in area by 80% and 40%, respectively. Much of the saltmarsh loss was due to salt pond leveeing, while mudflat loss can be related to lack of sediment input, wind-wave erosion, and sea level rise. Plans for marsh restoration include breaching of salt pond levees with the goal of restoring the 15,100 acres of acquired ponds to tidal marsh the largest such restoration in the western US. The effect this would have upon the adjacent mudflats is unclear. In this analysis, the tidal flats of SSFB are broken into geographically similar regions and multiple cross-sections are drawn from mean high water to below mean lower low water at close intervals, allowing for a mean tidal flat bathymetric profile to be determined for each segment and for each time period 1858, 1898, 1931, 1956, 1983, 2005. Eigenfunction analysis is used to separate the spatial and temporal changes in profile shape into the dominant components of variability, allowing evaluation of the behavior of mudflats relative to spatially and temporally-varying forcings. The components of bathymetric variability derived from objective statistical analysis are compared to theoretical models for tidal flat profiles as a function of waves, tides and sediment supply. Theoretical models predict that wave-dominated or sediment-starved flats tend to have concave-upwards bathymetric profiles, whereas tide-dominated or accretionary flats tend to have convex-upwards bathymetric profiles. Initial results from an analysis of the 1980's bathymetry data suggest the South Bay mudflats can be broken into three morphologically distinct sections: 1) concave-up, erosional mudflats in the Eastern zone, which is most subject to wind waves; 2) convex-up, accretionary flats in

  11. Alterações Induzidas Pelo Exercício no Número, Função e Morfologia de Monócitos de Ratos

    PubMed Central

    GUERESCHI, MARCIA G.; PRESTES, JONATO; DONATTO, FELIPE F.; DIAS, RODRIGO; FROLLINI, ANELENA B.; FERREIRA, CLÍLTON KO.; CAVAGLIERI, CLAUDIA R.; PALANCH, ADRIANNE C.

    2008-01-01

    O propósito desse estudo foi verificar as alterações histofisiológicas em monócitos e macrófagos induzidas por curtos períodos de exercícios. Ratos Wistar (idade = 2 meses, peso corporal = 200g) foram divididos em sete grupos (n=6 cada): controle sedentário (C), grupos exercitados (natação) na intensidade leve por 5 (5L), 10 (10L) e 15 minutos (15L), e grupos exercitados em intensidade moderada por 5 (5M), 10 (10M) e 15 minutes (15M). Na intensidade moderada os animais carregaram uma carga de 5% do peso corporal dos mesmos em seus respectivos dorsos. Os monócitos sangüíneos foram avaliados quanto à quantidade e morfologia e os macrófagos peritoneais foram analisados quanto à quantidade e atividade fagocitária. Os dados foram analisados usando ANOVA e Tukey’s post hoc test (p ≤ 0,05). Os grupos de intensidade leve e 5M apresentaram aumento nos níveis dos monócitos quando comparados com o controle. Foi observado aumento na área celular dos monócitos para os grupos 5L, 10L, 5M e 10M; a área nuclear aumentou para os grupos 10L, 5M e 10M em comparação com o controle. Houve aumento nos macrófagos peritoneais para os grupos 15L, 10M, 15M e diminuição no grupo 5M. A capacidade fagocitária dos macrófagos aumentou nos grupos de intensidade leve e para o grupo 10M. O exercício realizado por curtos períodos modulou o número e função dos macrófagos, assim como o número e morfologia dos monócitos, sendo tais alterações dependentes da intensidade. A soma das respostas agudas observadas nesse estudo pode exercer um efeito protetor contra doenças, podendo ser utilizada para a melhora da saúde e qualidade de vida.

  12. Importance of biogeomorphic and spatial properties in assessing a tidal salt marsh vulnerability to sea-level rise

    USGS Publications Warehouse

    Thorne, Karen M.; Elliott-Fisk, Deborah L.; Wylie, Glenn D.; Perry, William M.; Takekawa, John Y.

    2014-01-01

    We evaluated the biogeomorphic processes of a large (309 ha) tidal salt marsh and examined factors that influence its ability to keep pace with relative sea-level rise (SLR). Detailed elevation data from 1995 and 2008 were compared with digital elevation models (DEMs) to assess marsh surface elevation change during this time. Overall, 37 % (113 ha) of the marsh increased in elevation at a rate that exceeded SLR, whereas 63 % (196 ha) of the area did not keep pace with SLR. Of the total area, 55 % (169 ha) subsided during the study period, but subsidence varied spatially across the marsh surface. To determine which biogeomorphic and spatial factors contributed to measured elevation change, we collected soil cores and determined percent and origin of organic matter (OM), particle size, bulk density (BD), and distance to nearest bay edge, levee, and channel. We then used Akaike Information Criterion (AICc) model selection to assess those variables most important to determine measured elevation change. Soil stable isotope compositions were evaluated to assess the source of the OM. The samples had limited percent OM by weight (-3, indicating that the soils had high mineral content with a relatively low proportion of pore space. The most parsimonious model with the highest AICc weight (0.53) included distance from bay's edge (i.e., lower intertidal) and distance from levee (i.e., upper intertidal). Close proximity to sediment source was the greatest factor in determining whether an area increased in elevation, whereas areas near landward levees experienced subsidence. Our study indicated that the ability of a marsh to keep pace with SLR varied across the surface, and assessing changes in elevation over time provides an alternative method to long-term accretion monitoring. SLR models that do not consider spatial variability of biogeomorphic and accretion processes may not correctly forecast marsh drowning rates, which may be especially true in modified and urbanized

  13. Severe Storms and California's Fragile Delta--Historical Impacts and New Monitoring Approaches

    NASA Astrophysics Data System (ADS)

    Dettinger, M. D.; Ralph, F.; White, A. B.; Anderson, M.; Florsheim, J.; Cayan, D. R.; Hinojosa, A.

    2013-12-01

    California's Sacramento-San Joaquin Delta is a broad inland delta, 100 km east of San Francisco, that has experienced severe ecosystem losses and transformations over the past 100+ years, as it has been engineered to be an ever more important center for the State's water, utilities and transportation, and agriculture systems. As important and engineered as the Delta is, it is also an increasingly fragile system with aging levees, subsiding land surfaces, and a multitude of invading species. Severe storms and the floods that they engender pose great risks to the levees and other infrastructures in the Delta, while also playing necessary roles in key biogeomorphological processes that will need to be maintained (or expanded) if Delta ecosystems are to be restored. Of particular concern are the severe storms associated with landfalling atmospheric rivers (ARs) that, since 1950, have caused 80% of major floods, 76% of inundations of the ecologically important floodplains like the broad Yolo Bypass immediately above the Delta, and 81% of levee breaks in the Central Valley and Delta. Because of the critical role of severe storms and especially ARs in many of the environmental and infrastructural problems facing the Delta (and California, more generally), a new severe-storm monitoring network using several new remote atmospheric-observing technologies is being implemented across the broad catchment of the Delta and much of California by the California Department of Water Resources, NOAA, and Scripps Institution of Oceanography with increasing participation from local agencies. The network is intended to provide much more precise now-casting of critical but previously under-monitored storm characteristics, like rapidly evolving snowlines, barrier jets, and patterns of AR vapor transport into the State, characteristics that will enable a new era of storm-forecast improvements. The network relies on new radar, sounder, and GPS technologies installed strategically and for the

  14. The Bulgheria canyon-fan: a small-scale proximal system in the eastern Tyrrhenian Sea (Italy)

    NASA Astrophysics Data System (ADS)

    Budillon, Francesca; Conforti, Alessandro; Tonielli, Renato; de Falco, Giovanni; di Martino, Gabriella; Innangi, Sara; Marsella, Ennio

    2011-03-01

    The Bulgheria canyon-fan system in the eastern Tyrrhenian Sea displays well-developed, small-scale, fluvial-like features and has formed alongside the northern slope of the Sapri peri-Tyrrhenian basin. This study reveals, for the first time, the morphology and course of the present-day system as well as the buried elements based on a Digital Terrain Model and high-resolution seismic profiles interpretation. Two adjacent canyons (Infreschi and Luna) originate in the Cilento outer shelf at a short distance from each other and feed an intraslope basin fan through two main sub-parallel channels that run about 12 and 8 km, respectively. Channel and levee development seems to be controlled primarily by the local slope gradient and by Coriolis forces that induce a faster vertical growth of the right-side features, as is often observed in the Northern Hemisphere. Centrifugal forces, on the other hand, have induced episodic flow-stripping at the meander loops and bends, causing local destruction of the main channel levees rather than new levee growth at the outer bends. Overbank deposits are associated with overspill turbidite deposition in the mid fan where a topographic constraint occurs, whereas large-sediment, low-angle wave fields are mainly developed on the outer fan. Buried features and relict morphologies suggest that the Infreschi channel experienced at least two phases of re-incision since the final stages of the middle Pleistocene. Local re-adjustment of outer lobe growth due to channel avulsion and meander abandonment is possibly a consequence of relative base-level fluctuations. The sedimentary record of the mid and outer fan includes outrun mass wasting deposits from extensive failures of the Sapri slope. Indeed, a marked scar is present on the eastern side of the modern outer lobe that indicates the persistency of mass flow passages up to recent times. In addition to the environmental factors that are currently considered to cause canyon formation on the

  15. Sources of debris flow material in burned areas

    USGS Publications Warehouse

    Santi, P.M.; deWolfe, V.G.; Higgins, J.D.; Cannon, S.H.; Gartner, J.E.

    2008-01-01

    The vulnerability of recently burned areas to debris flows has been well established. Likewise, it has been shown that many, if not most, post-fire debris flows are initiated by runoff and erosion and grow in size through erosion and scour by the moving debris flow, as opposed to landslide-initiated flows with little growth. To better understand the development and character of these flows, a study has been completed encompassing 46 debris flows in California, Utah, and Colorado, in nine different recently burned areas. For each debris flow, progressive debris production was measured at intervals along the length of the channel, and from these measurements graphs were developed showing cumulative volume of debris as a function of channel length. All 46 debris flows showed significant bulking by scour and erosion, with average yield rates for each channel ranging from 0.3 to 9.9??m3 of debris produced for every meter of channel length, with an overall average value of 2.5??m3/m. Significant increases in yield rate partway down the channel were identified in 87% of the channels, with an average of a three-fold increase in yield rate. Yield rates for short reaches of channels (up to several hundred meters) ranged as high as 22.3??m3/m. Debris was contributed from side channels into the main channels for 54% of the flows, with an average of 23% of the total debris coming from those side channels. Rill erosion was identified for 30% of the flows, with rills contributing between 0.1 and 10.5% of the total debris, with an average of 3%. Debris was deposited as levees in 87% of the flows, with most of the deposition occurring in the lower part of the basin. A median value of 10% of the total debris flow was deposited as levees for these cases, with a range from near zero to nearly 100%. These results show that channel erosion and scour are the dominant sources of debris in burned areas, with yield rates increasing significantly partway down the channel. Side channels are

  16. Yazoo River Basin (Lower Mississippi River) Hydrologic Observatory

    NASA Astrophysics Data System (ADS)

    Cheng, A.; Davidson, G.; Altinakar, M.; Holt, R.

    2004-12-01

    The proposed Yazoo River Basin Hydrologic Observatory consists of the 34,000 square km Yazoo River watershed in northwestern Mississippi and a 320 km segment of the Mississippi River separated from the watershed by a manmade levee. Discharge from the basin flows from the Yazoo River into the Mississippi River north of Vicksburg, MS. Major streams within the basin include the Yazoo, Tallahatchie, Yalobusha, Coldwater, Yocona, and Big Sunflower Rivers. Four large flood control reservoirs (Arkabutla, Enid, Sardis, and Grenada) and two national forests (Delta and Holly Springs) are also located within the basin. The watershed is divided between upland forested hills and intensively cultivated lowlands. The lowland area, locally known as the "Delta", lies on the ancestral floodplain of the Mississippi River. Flooding by the Mississippi River was once a common event, but is now limited by the levee system. Abundant wetlands occupy abandoned stream channels throughout the Delta. The Yazoo River Basin has many unique features that make it an attractive site for an Hydrologic Observatory. Example features and issues of scientific interest include: 1) Extensive system of levees which have altered recharge to the regional aquifer, shifted population centers, and created backwater flooding areas. 2) Abundant wetlands with a century-long history of response to agricultural sediment and chemical fluxes. 3) Erosion of upland streams, and stream sediment loads that are the highest in the nation. 4) Groundwater mining in spite of abundant precipitation due to a regional surface clay layer that limits infiltration. 5) A history of agricultural Best Management Practices enabling evaluation of the effectiveness of such measures. 6) Large scale catfish farming with heavy reliance on groundwater. 7) Near enough to the Gulf coast to be impacted by hurricane events. 8) Already existing network of monitoring stations for stream flow, sediment-load, and weather, including complete coverage

  17. Sea level controls on the textural characteristics and depositional architecture of the Hueneme and associated submarine fan systems, Santa Monica Basin, California

    USGS Publications Warehouse

    Normark, W.R.; Piper, D.J.W.; Hiscott, R.N.

    1998-01-01

    Hueneme and Dume submarine fans in Santa Monica Basin consist of sandy channel and muddy levee facies on the upper fan. lenticular sand sheets on the middle fan. and thinly bedded turbidite and hemipelagic facies elsewhere. Fifteen widely correlatable key seismic reflections in high-resolution airgun and deep-towed boomer profiles subdivide the fan and basin deposits into time-slices that show different thickness and seismic-facies distributions, inferred to result from changes in Quaternary sea level and sediment supply. At times of low sea level, highly efficient turbidity currents generated by hyperpycnal flows or sediment failures at river deltas carry sand well out onto the middle-fan area. Thick, muddy flows formed rapidly prograding high levees mainly on the western (right-hand) side of three valleys that fed Hueneme fan at different times: the most recently active of the lowstand fan valleys. Hueneme fan valley, now heads in Hueneme Canyon. At times of high sea level, fans receive sand from submarine canyons that intercept littoral-drift cells and mixed sediment from earthquake-triggered slumps. Turbidity currents are confined to 'underfit' talweg channels in fan valleys and to steep, small, basin-margin fans like Dume fan. Mud is effectively separated from sand at high sea level and moves basinward across the shelf in plumes and in storm-generated lutite flows, contributing to a basin-floor blanket that is locally thicker than contemporary fan deposits and that onlaps older fans at the basin margin. The infilling of Santa Monica Basin has involved both fan and basin-floor aggradation accompanied by landward and basinward facies shifts. Progradation was restricted to the downslope growth of high muddy levees and the periodic basinward advance of the toe of the steeper and sandier Dume fan. Although the region is tectonically active, major sedimentation changes can be related to eustatic sea-level changes. The primary controls on facies shifts and fan growth

  18. Fifty-year flood-inundation maps for La Lima, Honduras

    USGS Publications Warehouse

    Mastin, Mark C.; Olsen, T.D.

    2002-01-01

    After the devastating floods caused by Hurricane Mitch in 1998, maps of the areas and depths of the 50-year-flood inundation at 15 municipalities in Honduras were prepared as a tool for agencies involved in reconstruction and planning. This report, which is one in a series of 15, presents maps of areas in the municipality of La Lima that would be inundated by Rio Chamelecon with a discharge of 500 cubic meters per second, the approximate capacity of the river channel through the city of La Lima. The 50-year flood (2,400 cubic meters per second), the original design flow to be mapped, would inundate the entire area surveyed for this municipality. Because water-surface elevations of the 50-year flood could not be mapped properly without substantially expanding the area of the survey, the available data were used instead to estimate the channel capacity of Rio Chamelecon in La Lima by trial-and-error runs of different flows in a numerical model and to estimate the increase in height of levees needed to contain flows of 1,000 and 2,400 cubic meters per second. Geographic Information System (GIS) coverages of the flood inundation are available on a computer in the municipality of La Lima as part of the Municipal GIS project and on the Internet at the Flood Hazard Mapping Web page (http://mitchnts1.cr.usgs.gov/projects/floodhazard.html). These coverages allow users to view the flood inundation in much more detail than is possible using the maps in this report. Water-surface elevations for various discharges on Rio Chamelecon at La Lima were determined using HEC-RAS, a one-dimensional, steady-flow, step-backwater computer program. The channel and floodplain cross sections used in HEC-RAS were developed from an airborne light-detection-and-ranging (LIDAR) topographic survey of the area and ground surveys at three bridges. Top-of-levee or top-of-channel-bank elevations and locations at the cross sections were critical to estimating the channel capacity of Rio Chamelecon

  19. River Maintenance Management System Using Three-Dimensional UAV Data in Japan

    NASA Astrophysics Data System (ADS)

    Kubota, S.; Kawai, Y.

    2016-10-01

    River administration facilities such as levees and river walls play a major role in preventing flooding due to heavy rain. The forms of such facilities must be constantly monitored for alteration due to rain and running water, and limited human resources and budgets make it necessary to efficiently maintain river administration facilities. During maintenance, inspection results are commonly recorded on paper documents. Continuous inspection and repair using information systems are an on-going challenge. This study proposes a maintenance management system for river facilities that uses three-dimensional data to solve these problems and make operation and maintenance more efficient. The system uses three-dimensional data to visualize river facility deformation and its process, and it has functions that visualize information about river management at any point in the three-dimensional data. The threedimensional data is generated by photogrammetry using a camera on an Unmanned Aerial Vehicle.

  20. Space Radar Image of Glascow, Missouri

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a false-color L-band image of an area near Glasgow, Missouri, centered at about 39.2 degrees north latitude and 92.8 degrees west longitude. The image was acquired using the L-band radar channel (horizontally transmitted and received and horizontally transmitted/vertically received) polarizations combined. The data were acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on orbit 50 on October 3,1994. The area shown is approximately 37 kilometers by 25 kilometers (23 miles by 16 miles). The radar data, coupled with pre-flood aerial photography and satellite data and post-flood topographic and field data, are being used to evaluate changes associated with levee breaks in landforms, where deposits formed during the widespread flooding in 1993 along the Missouri and Mississippi Rivers. The distinct radar scattering properties of farmland, sand fields and scoured areas will be used to inventory floodplains along the Missouri River and determine the processes by which these areas return to preflood conditions. The image shows one such levee break near Glasgow, Missouri. In the upper center of the radar image, below the bend of the river, is a region covered by several meters of sand, shown as dark regions. West (left) of the dark areas, a gap in the levee tree canopy shows the area where the levee failed. Radar data such as these can help scientists more accurately assess the potential for future flooding in this region and how that might impact surrounding communities. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific

  1. Space Radar Image of Missouri River, Glasgow, Missouri

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a false-color L-band image of an area near Glasgow, Missouri, centered at about 39.2 degrees north latitude and 92.8 degrees west longitude. The image was acquired by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space shuttle Endeavour on its 50th orbit on October 3, 1994. The false-color composite was made by displaying the L-band (horizontally transmitted and received) return in red; the L-band (horizontally transmitted and vertically received) return in green; and the sum of the two channels in blue. The area shown is approximately 37 kilometers by 25 kilometers (23 miles by 16 miles). The radar data, coupled with pre-flood aerial photography and satellite data and post-flood topographic and field data, are being used to evaluate changes associated with levee breaks in landforms, where deposits formed during the widespread flooding in 1993 along the Missouri and Mississippi Rivers. The distinct radar scattering properties of farmland, sand fields and scoured areas will be used to inventory floodplains along the Missouri River and determine the processes by which these areas return to preflood conditions. The image shows one such levee break near Glasgow, Missouri. In the upper center of the radar image is a region covered by several meters of sand, shown as blue regions below the bend in the river. West (left) of this dark area, a blue gap in the levee tree canopy can be seen, showing the area where the levee failed. Radar data such as these can help scientists more accurately assess the potential for future flooding in this region and how that might impact surrounding communities. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar(SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm

  2. Characterization and categorization of higher-dimensional presentation techniques

    NASA Astrophysics Data System (ADS)

    Cluff, Elizabeth; Burton, Robert P.; Barrett, William A.

    1990-09-01

    Existing, documented techniques for the presentation of higher dimensionaL information are characterized. Techniques include: Symbolic Star PLots, Chernoff Faces, Gtyphs, Boxes, Profile PLots, SymboLic Scatter PLots, KLeiner-Hartigan Tree SymboLs, GeneraLized Draftsman DispLays, Andrew's PLots, ParaLLeL Axes Graphics, and Cartesian Hyperspace Graphics. Each technique is evaLuated based on accuracy, simpLicity, clarity, appearance, well-designed structure, information leveL, dimansonaL capacity, flexibility, interpretability, visual impact, mastery time, and computational tractability. Strengths, weaknesses and applicabilities of each technique are determined. Techniques are categorized as symbolic and non-symbolic. Characteristics of each category are identified.

  3. Canali-type channels on Venus - Some genetic constraints

    NASA Technical Reports Server (NTRS)

    Komatsu, Goro; Kargel, Jeffrey S.; Baker, Victor R.

    1992-01-01

    Canali-type channels on Venus are unique because of their great lengths (up to 6800 km) and nearly constant channel cross sectional shapes along their paths. A simple model incorporating channel flow and radiative cooling suggests that common terrestrial-type tholeiite lava cannot sustain a superheated and turbulent state for the long distances required for thermal erosion of canali within allowable discharge rates. If canali formed mainly by constructional processes, laminar tholeiitic flow of relatively high, sustained discharge rates might travel the observed distances, but the absence of levees would need to be explained. An exotic low temperature, low viscosity lava like carbonatite or sulfur seems to be required for the erosional genesis of canali.

  4. Floodflow characteristics of Honcut Creek at State Highway 70 bridges near Live Oak, California

    USGS Publications Warehouse

    Blodgett, J.C.

    1982-01-01

    The present arrangement of the bridges and approach embankments occupies about 66 percent of the channel (between the levee and high ground). Measurements of the average velocity of flow at a bridge range from l to 3.2 feet per second, depending on the flood stages of the Feather River. The maximum point velocity of flow measured during the 1979-80 flood season was 5. 6 feet per second. In general, flow velocities will be less than about 6 feet per second because flooding and high stages on the Feather River create ponded conditions at the bridge site. For present channel and bridge conditions, overbank flows are distributed among the three bridges in a proportion of about 10, 40, and 50 percent for flows from 2,850 to 8,480 cubic feet per second.

  5. Closing the loop of the soil water retention curve

    USGS Publications Warehouse

    Lu, Ning; Alsherif, N; Wayllace, Alexandra; Godt, Jonathan W.

    2015-01-01

    The authors, to their knowledge for the first time, produced two complete principal soil water retention curves (SWRCs) under both positive and negative matric suction regimes. An innovative testing technique combining the transient water release and imbibition method (TRIM) and constant flow method (CFM) was used to identify the principal paths of SWRC in the positive pore-water pressure regime under unsaturated conditions. A negative matric suction of 9.8 kPa is needed to reach full saturation or close the loop of the SWRC for a silty soil. This work pushes the understanding of the interaction of soil and water into new territory by quantifying the boundaries of the SWRC over the entire suction domain, including both wetting and drying conditions that are relevant to field conditions such as slope wetting under heavy rainfall or rapid groundwater table rise in earthen dams or levees.

  6. A New Approach to Monitoring Coastal Marshes for Persistent Flooding

    NASA Astrophysics Data System (ADS)

    Kalcic, M. T.; Underwood, L. W.; Fletcher, R. M.

    2012-12-01

    Many areas in coastal Louisiana are below sea level and protected from flooding by a system of natural and man-made levees. Flooding is common when the levees are overtopped by storm surge or rising rivers. Many levees in this region are further stressed by erosion and subsidence. The floodwaters can become constricted by levees and trapped, causing prolonged inundation. Vegetative communities in coastal regions, from fresh swamp forest to saline marsh, can be negatively affected by inundation and changes in salinity. As saltwater persists, it can have a toxic effect upon marsh vegetation causing die off and conversion to open water types, destroying valuable species habitats. The length of time the water persists and the average annual salinity are important variables in modeling habitat switching (cover type change). Marsh type habitat switching affects fish, shellfish, and wildlife inhabitants, and can affect the regional ecosystem and economy. There are numerous restoration and revitalization projects underway in the coastal region, and their effects on the entire ecosystem need to be understood. For these reasons, monitoring persistent saltwater intrusion and inundation is important. For this study, persistent flooding in Louisiana coastal marshes was mapped using MODIS (Moderate Resolution Imaging Spectroradiometer) time series of a Normalized Difference Water Index (NDWI). The time series data were derived for 2000 through 2009, including flooding due to Hurricane Rita in 2005 and Hurricane Ike in 2008. Using the NDWI, duration and extent of flooding can be inferred. The Time Series Product Tool (TSPT), developed at NASA SSC, is a suite of software developed in MATLAB® that enables improved-quality time series images to be computed using advanced temporal processing techniques. This software has been used to compute time series for monitoring temporal changes in environmental phenomena, (e.g. NDVI times series from MODIS), and was modified and used to

  7. A New Approach to Monitoring Coastal Marshes for Persistent Flooding

    NASA Technical Reports Server (NTRS)

    Kalcic, M. T.; Undersood, Lauren W.; Fletcher, Rose

    2012-01-01

    Many areas in coastal Louisiana are below sea level and protected from flooding by a system of natural and man-made levees. Flooding is common when the levees are overtopped by storm surge or rising rivers. Many levees in this region are further stressed by erosion and subsidence. The floodwaters can become constricted by levees and trapped, causing prolonged inundation. Vegetative communities in coastal regions, from fresh swamp forest to saline marsh, can be negatively affected by inundation and changes in salinity. As saltwater persists, it can have a toxic effect upon marsh vegetation causing die off and conversion to open water types, destroying valuable species habitats. The length of time the water persists and the average annual salinity are important variables in modeling habitat switching (cover type change). Marsh type habitat switching affects fish, shellfish, and wildlife inhabitants, and can affect the regional ecosystem and economy. There are numerous restoration and revitalization projects underway in the coastal region, and their effects on the entire ecosystem need to be understood. For these reasons, monitoring persistent saltwater intrusion and inundation is important. For this study, persistent flooding in Louisiana coastal marshes was mapped using MODIS (Moderate Resolution Imaging Spectroradiometer) time series of a Normalized Difference Water Index (NDWI). The time series data were derived for 2000 through 2009, including flooding due to Hurricane Rita in 2005 and Hurricane Ike in 2008. Using the NDWI, duration and extent of flooding can be inferred. The Time Series Product Tool (TSPT), developed at NASA SSC, is a suite of software developed in MATLAB(R) that enables improved-quality time series images to be computed using advanced temporal processing techniques. This software has been used to compute time series for monitoring temporal changes in environmental phenomena, (e.g. NDVI times series from MODIS), and was modified and used to

  8. Volcanoes

    USGS Publications Warehouse

    Tilling, Robert I.; ,

    1998-01-01

    Volcanoes destroy and volcanoes create. The catastrophic eruption of Mount St. Helens on May 18, 1980, made clear the awesome destructive power of a volcano. Yet, over a time span longer than human memory and record, volcanoes have played a key role in forming and modifying the planet upon which we live. More than 80 percent of the Earth's surface--above and below sea level--is of volcanic origin. Gaseous emissions from volcanic vents over hundreds of millions of years formed the Earth's earliest oceans and atmosphere, which supplied the ingredients vital to evolve and sustain life. Over geologic eons, countless volcanic eruptions have produced mountains, plateaus, and plains, which subsequent erosion and weathering have sculpted into majestic landscapes and formed fertile soils.

  9. Geomorphology and stratigraphy of Alba Patera, Mars

    NASA Astrophysics Data System (ADS)

    Schneeberger, D. M.; Pieri, D. C.

    1991-02-01

    Geomorphic and stratigraphic analysis of Alba Patera suggests a volcanic construct built by lavas with rheologic properties similar to basalts. A series of evolving eruptive styles is suggested by changes in morphology and inferred progressive reductions in flow volume with higher stratigraphic position. Alba Patera's volcanic history has been summarized into four main phases. The first is characterized by extensive flood like flows presumably erupted from fissures associated with the initial intrusion of magma into the region. The second phase is associated with the emplacement of pyroclastic rock, a more speculative interpretation. The third phase produced the voluminous tabular, crested, and undifferentiated flows, probably from a more centralized vent source. The fourth and last phase is marked the effusion of levee like flows and the collapse of the summit calderas and final graben formation.

  10. Floods and Societies: Dynamic Modeling

    NASA Astrophysics Data System (ADS)

    Di Baldassarre, G.; Viglione, A.; Carr, G.; Kuil, L., Jr.; Brandimarte, L.; Bloeschl, G.

    2014-12-01

    There is growing concern that future flood losses and fatalities might increase significantly in many regions of the world because of rapid urbanization in deltas and floodplains, in addition to sea level rise and climate change. To better anticipate long-term trajectories of future flood risk, there is a need to treat floodplains and deltas as fully coupled human-physical systems. Here we propose a novel approach to explore the long-term behavior emerging from the mutual interactions and feedbacks between physical and social systems. The implementation of our modeling framework shows that green societies, which cope with flooding by resettling out of floodplains, are more resilient to increasing flood frequency than technological societies, which deal with flooding by building levees. Also, we show that when coupled dynamics are accounted for, flood-poor periods could (paradoxically) be more dangerous than flood-rich periods.

  11. An alligator basks in the sun at KSC.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    On the bank of a levee near Schwartz Rd. at Kennedy Space Center, an alligator suns itself with a wary eye out for trespassers. Nearly 5,000 alligators can be found in canals, ponds, and waterways throughout the Center and the Merritt Island National Wildlife Refuge, which shares a boundary with the Center. American alligators feed and rest in the water, and lay their eggs in dens they dig into the banks. The young alligators spend their first several weeks in these dens. The Wildlife Refuge encompasses 92,000 acres that are a habitat for more than 331 species of birds, 31 mammals, 117 fishes, and 65 amphibians and reptiles. The marshes and open water of the refuge provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds, as well as a variety of insects.

  12. Habitat conservation and creation: Invoking the flood-pulse concept to enhance fisheries in the lower Mississippi River

    USGS Publications Warehouse

    Schramm, H.L.; Eggleton, M.A.; Mayo, R.M.

    2000-01-01

    Analysis of four years of growth data failed to identify a single temperature or hydrologic variable that consistently accounted for variation in annual growth of catfishes (Ictaluridae). Instead, a composite variable that measured duration of floodplain inundation when water temperature exceeded minima for active feeding was directly related to growth. Results indicated that floodplain inundation have provided little direct energetic benefit to fishes when water temperatures were sub-optimal for active feeding, but floodplain resources were exploited when thermal conditions were sufficient for active feeding and growth. Thus, the flood-pulse concept applies to the lower Mississippi River (LMR) when modified to consider temperature. Managing the existing leveed floodplain to prolong inundation, increase water temperatures during spring flooding, and maintain connectivity of floodplain habitats with the main river channel should benefit fish production in the LMR.

  13. Rheological analyses of lava flows on Mars

    NASA Technical Reports Server (NTRS)

    Moore, H. J.; Davis, P. A.

    1991-01-01

    Researchers obtained 183 profiles of lava flows on Mars using photoclinometry. These photoclinometric profiles were leveled by adjusting them until the levee crests or bases had the same elevations (depending on the situation). Here, researchers report some of the results of their analysis of 27 flows on the flanks of Alba Patera (3 flows), near the summit of Ascraeus Mons (6 flows), the flanks of Arsia Mons (3 flows), and the flanks of Olympus Mons (15 flows). Results suggest that the flows examined to date are not felsic or ultramafic; rather, they probably range from basalts to basaltic andesites. Thus, the suggestion that flows on Olympus Mons and elsewhere may be more silicic than Hawaiian basalts is supported by the researchers' results. These suggestions are testable with suitable measurements of silica contents of the flows.

  14. Flood Hazards - A National Threat

    USGS Publications Warehouse

    ,

    2006-01-01

    In the late summer of 2005, the remarkable flooding brought by Hurricane Katrina, which caused more than $200 billion in losses, constituted the costliest natural disaster in U.S. history. However, even in typical years, flooding causes billions of dollars in damage and threatens lives and property in every State. Natural processes, such as hurricanes, weather systems, and snowmelt, can cause floods. Failure of levees and dams and inadequate drainage in urban areas can also result in flooding. On average, floods kill about 140 people each year and cause $6 billion in property damage. Although loss of life to floods during the past half-century has declined, mostly because of improved warning systems, economic losses have continued to rise due to increased urbanization and coastal development.

  15. Speciation of Heavy Metals in Katrina Sediments from New Orleans, Louisiana

    NASA Astrophysics Data System (ADS)

    Roy, Amitava; Bianchetti, Christopher; Tittsworth, Roland; Pardue, John

    2007-02-01

    Hurricane Katrina, a Category 4 storm on the Saffir-Simpson scale, struck the Gulf Coast of Louisiana on August 29th, 2005. The storm surge resulted in breaches of the levee system in New Orleans at least at two locations, flooding up to 80% of the city. The floodwater also brought sediment which was left behind once the water receded after a few days. The dry sediment covered large parts of the city. Much of it was made airborne by vehicular traffic and was potentially inhaled. The sediments from the Lakeview area contained an appreciable amount of clay minerals which were absent in samples from Mid City. The speciation of these metals was quantitatively different in two neighborhoods. In one location metallic copper and zinc were present. A small amount of hexavalent chromium was detected at two sites.

  16. Environmental assessment and finding of no significant impact for completion of flood protection works, Bannister Road Federal Complex, Kansas City, Missouri

    SciTech Connect

    Not Available

    1991-09-18

    The Department of Energy (DOE) proposes to provide partial funding to the Corps of Engineers (COE) for the completion of the flood protection works at the Bannister Road Federal Complex in Kansas City, Missouri. The DOE Kansas City Plant is a major tenant of the Complex. COE has prepared an environmental assessment (EA) for the project which includes the construction of levees, floodwalls, and drainage ditches. DOE has adopted the EA prepared by COE (DOE/EA-0509), this report. Based on the analyses in this EA, DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969, 42 USC 4321 et seq. Therefore, the preparation of an environmental impact statement is not required, and DOE is issuing this Finding of No Significant Impact (FONSI).

  17. Documenting the stages and streamflows associated with the 2011 activation of the New Madrid Floodway, Missouri: Chapter E in 2011 floods of the central United States

    USGS Publications Warehouse

    Koenig, Todd A.; Holmes, Jr., Robert R.

    2013-01-01

    The U.S. Geological Survey initiated a substantial effort in the summer of 2011 to measure and document the record-setting floods of the Mississippi and Ohio Rivers, including the reach in and near the New Madrid Floodway. The activation of the floodway, which had not occurred since 1937, provided a rare opportunity to collect a unique dataset describing a flood wave downstream from a levee breach as well as the flow through a large floodway. A total of 42 submersible pressure transducers collected time series of water levels while crews collected hundreds of depth, velocity, and streamflow measurements at selected locations in and near the floodway throughout the period from late April to late June. These data are presented in this chapter.

  18. Digital geospatial presentation of geoelectrical and geotechnical data for the lower American River and flood plain, east Sacramento, California

    USGS Publications Warehouse

    Ball, Lyndsay B.; Burton, Bethany L.; Powers, Michael H.; Asch, Theodore H.

    2015-01-01

    To characterize the extent and thickness of lithologic units that may have differing scour potential, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, has performed several geoelectrical surveys of the lower American River channel and flood plain between Cal Expo and the Rio Americano High School in east Sacramento, California. Additional geotechnical data have been collected by the U.S. Army Corps of Engineers and its contractors. Data resulting from these surveys have been compiled into similar database formats and converted to uniform geospatial datums and projections. These data have been visualized in a digital three-dimensional framework project that can be viewed using freely available software. These data facilitate a comprehensive analysis of the resistivity structure underlying the lower American River corridor and assist in levee system management.

  19. Mapping Supports Potential Submission to U.N. Law of the Sea

    NASA Astrophysics Data System (ADS)

    Gardner, James V.; Mayer, Larry A.; Armstrong, Andrew

    2006-04-01

    Multibeam bathymetric data from selected U.S. continental margins are being collected for use in the future development of potential submissions that the United States may make to the United Nations Commission on the Law of the Sea (UNCLOS) to extend the nation's sovereign rights over the resources of the seafloor and the subsurface. However, the new data also represent a valuable resource for the next generation of marine geologists to study the complexity of surficial processes of several U.S. continental margins. For example, the details of the morphology of large sediment slides on the U.S. Atlantic continental slope and rise have been mapped, and enigmatic features such as a meandering channel on a channel levee on the U.S. Alaskan Pacific margin have been discovered.

  20. The elite code grey team: a new model for residency preparedness and training in advance of a disaster.

    PubMed

    Bagatell, Stuart; Wiese, Jeff

    2008-08-01

    Hurricane Katrina and the resulting levee failures decimated the New Orleans landscape, trapping physicians inside hospital facilities for up to 5 days. With over 2000 people trapped in the 3 primary teaching hospitals, there were only 3 fatalities. Yet despite the lack of adverse events, the experience revealed that graduate medical education is woefully underprepared to deal with disaster. As call schedules obviously did not anticipate the disaster, the assignment of physicians to these shifts was random, without regard to the ability to withstand that stress and the conditions. The group of physicians that was assigned was a heterogeneous mix of personalities, experience levels, and psychological fortitude. None of the physicians had been formally trained in the core principles of disaster management. This article reviews an innovative approach to disaster management, drawing upon the expertise of law enforcement, the airline industry, and on-going physician development programs in disaster medicine. PMID:18703918

  1. Sea Level Rise in Santa Clara County

    NASA Technical Reports Server (NTRS)

    Milesi, Cristina

    2005-01-01

    Presentation by Cristina Milesi, First Author, NASA Ames Research Center, Moffett Field, CA at the "Meeting the Challenge of Sea Level Rise in Santa Clara County" on June 19, 2005 Santa Clara County, bordering with the southern portion of the San Francisco Bay, is highly vulnerable to flooding and to sea level rise (SLR). In this presentation, the latest sea level rise projections for the San Francisco Bay will be discussed in the context of extreme water height frequency and extent of flooding vulnerability. I will also present preliminary estimations of levee requirements and possible mitigation through tidal restoration of existing salt ponds. The examples will draw mainly from the work done by the NASA Climate Adaptation Science Investigators at NASA Ames.

  2. Floods of December 1961 in Mississippi and adjoining states

    USGS Publications Warehouse

    Shell, James D.

    1962-01-01

    Widespread floods occurred over parts of Mississippi, Louisiana, and Alabama after heavy rains during December 18, 1961. A series of low-pressure systems produced as much as 19 inches of rainfall in some areas. Heavy rainfall, 7 to 11 inches, on December 10 resulted in outstanding floods on small streams in southern Mississippi and southwestern Alabama. Subsequent rains produced multiple floods on small streams and outstanding floods of prolonged duration along the Big Black, upper Pearl, and lower Tombigbee Rivers in Mississippi. At Jackson, Miss., the Pearl River reached the highest stage known. Along the east bank, flood waters topped or breached some of the levee system protecting the Flowood industrial area, but other parts were saved by extensive reinforcement and by emergency operation of the partially completed dam 10 miles upstream. Additional heavy damage to commercial and industrial property was prevented as a result of these measures. Elsewhere, damage was restricted primarily to secondary highways and bridges. Two lives were lost.

  3. Magnitude and Distribution of Flows into Northeastern Florida Bay

    USGS Publications Warehouse

    Patino, Eduardo; Hittle, Clinton D.

    2000-01-01

    Changes in water-management practices have been made to accommodate a large and rapidly growing urban population along the Atlantic Coast and to meet the demand for intensive agricultural activities. These changes have resulted in a highly managed hydrologic system consisting of numerous canals, levees, control structures, and pumping stations that have altered the hydrology of the Everglades and Florida Bay ecosystems. Over the past decade, Florida Bay has experienced sea-grass die-off and algal blooms, which are indicators of ecological change attributed primarily to the increase in salinity and nutrient content of bay waters. Because plans are to restore sheetflow in the Everglades wetlands to its natural state, water managers anticipate a change in the magnitude and timing of freshwater exiting the mainland through the creeks that cut through the embankment or as sheetflow into Florida Bay.

  4. A river-dominated delta in Naples harbour (Southern Tyrrhenian Sea margin, Italy)

    NASA Astrophysics Data System (ADS)

    Milia, A.; Marsella, E.; Sammartino, S.

    2003-04-01

    Naples Harbour is located on the Southern Tyrrhenian Sea margin between the volcanic areas of the Campi Flegrei and Vesuvius. Volcanic products are consequently interlayered within the sedimentary succession of Naples Harbour. The interpreation of high resolution seismic reflection profiles and cores permitted to investigate the depositional systems that characterized the highstand systems tract between 10-50 m of water depth. In addition, a multibeam survey permitted to image the morphology of the sea floor. The harbour results characterized by a regressive/progradational coast river dominated. We recognize two depositional systems younger than 4 ka: the oldest one is elongated toward northwest and dominated by shoreface processes; the youngest one instead located in front of the river dominated by submarine channel-levees processes. This change in the depositional system distribution with time was probably induced by a change in the hydrodinamic regimes.

  5. Hydrologic effects of area B flood control plan on urbanization of Dade County, Florida

    USGS Publications Warehouse

    Kohout, F.A.; Hartwell, J.H.

    1967-01-01

    Swampy low land (Area B) that fringes the Everglades west of Metropolitan Miami, Florida (Area A) probably will be urbanized in the future. Area B will be protected from flooding by huge pumps that will pump water westward from Area B over a levee system into Conservation Area 3B. The total capacity of the pumps will be about 13,400 cubic feet per second which is sufficient to lower water levels 2 inches per day in the 203 square miles of Area B. As this capacity is about equal to the highest gravity-flow discharge to the ocean through existing canals of the Miami area, a great potential. will exist, not only for control of floods, but also for beneficial control and management of a major segment of the water resources in southeastern Florida.

  6. Estimating the Response and Uncertainty Limits of Physical Processes in the South San Francisco Bay for Extreme Water Elevation Frequency Analysis

    NASA Astrophysics Data System (ADS)

    Andes, L.; Wu, F.; Lo, J.; MacWilliams, M.; Lu, C.; Dean, R.; Hanes, D. M.

    2013-12-01

    Coastal flooding in the far south San Francisco Bay (SSFB) can be a function of astronomical tide, residual tide (i.e. water elevation deviation from computed astronomical tide that is associated with many possible physical processes), in-bay wind speed and direction and fluvial discharge. These physical processes and coastal levee failure were considered as input parameters into a Monte Carlo Simulation (MCS) to estimate extreme water elevation frequency in the SSFB. Limited data is available in the SSFB to estimate the contribution of these physical processes to extreme water elevation statistics. Over 100 years of measured water surface elevation (WSE) data is available at the San Francisco (SF) tide station. A sensitivity analysis of storm event sampling criteria was conducted to select significant events at the SF tide station for data transfer to the project site and statistical analysis. The coincidently sampled astronomical and residual tides at the San Francisco tide station were analyzed and used to develop the storm event databases. Sampling methods employed were compared with annual maximum and partial duration approaches. Additional statistical testing was performed to justify the assumption of coincident sampling. The selected database was found to be most representative of the full range of the combinations of astronomical and residual tides that contribute to extreme water elevation statistics at the project site. A look-up table of astronomical and residual tide, wind speed and direction, and levee failure in the form of WSE responses at the project site from the hydrodynamic simulations was established for the interpolation in the MCS. The hydrodynamic model simulations indicated that the astronomical tides in the SSFB amplify inversely as a function of tidal range at the SF tide station. The residual tide varies minimally as it propagates into the SSFB. In-Bay wind set-up from a significant event was found to contribute on the order of one foot

  7. Initial Biotic Survey of Lisbon Bottom, Big Muddy National Fish and Wildlife Refuge

    USGS Publications Warehouse

    Humburg, Dale D.; Burke, Vincent J.

    1999-01-01

    The 2,300-acre Lisbon Bottom Unit, located in central Missouri, became part of the Big Muddy National Fish and Wildlife Refuge (NFWR) after the Great Flood of 1993 devastated the Unit?s farmland and network of levees. As a result, interdisciplinary studies were initiated through collaboration among various researches, universities, and State and Federal conservation agencies to investigate the short-term effects of the flood and to expand information about the Missouri River and flood-plain systems. The studies included in these chapters investigate diverse aspects of Lisbon Bottom Unit?s physical setting and biota and provide baseline information that managers can use to assess restoration efforts on Lisbon Bottom and other units of the Big Muddy NFWR.

  8. Numerical Study on Tsunami Hazard Mitigation Using a Submerged Breakwater

    PubMed Central

    Yoo, Jeseon; Han, Sejong; Cho, Yong-Sik

    2014-01-01

    Most coastal structures have been built in surf zones to protect coastal areas. In general, the transformation of waves in the surf zone is quite complicated and numerous hazards to coastal communities may be associated with such phenomena. Therefore, the behavior of waves in the surf zone should be carefully analyzed and predicted. Furthermore, an accurate analysis of deformed waves around coastal structures is directly related to the construction of economically sound and safe coastal structures because wave height plays an important role in determining the weight and shape of a levee body or armoring material. In this study, a numerical model using a large eddy simulation is employed to predict the runup heights of nonlinear waves that passed a submerged structure in the surf zone. Reduced runup heights are also predicted, and their characteristics in terms of wave reflection, transmission, and dissipation coefficients are investigated. PMID:25215334

  9. Contraction scour at a bridge over the Iowa River

    USGS Publications Warehouse

    Fischer, Edward E.

    1994-01-01

    Flooding of the Iowa River during July and August 1993 caused extensive contraction scour at the State Highway 99 bridge over the Iowa River at Wapello, Iowa. At least 3.3 m of piling under the footing of the second pier from the right (west) abutment were exposed. The scoured streambed did not fill in again after the flood receded, and a bathymetric survey in November 1993 showed that the streambed had been scoured for a distance of about 500 m upstream from the bridge. The bridge was closed to traffic, first because of water over the roadway when a levee failed, and then remained closed because of the exposed piling. The bridge subsequently was reopened to traffic with a weight limit of 13.6 tons.

  10. Annual peak streamflow and ancillary data for small watersheds in central and western Texas

    USGS Publications Warehouse

    Harwell, Glenn R.; Asquith, William H.

    2011-01-01

    Estimates of annual peak-streamflow frequency are needed for flood-plain management, assessment of flood risk, and design of structures, such as roads, bridges, culverts, dams, and levees. Regional regression equations have been developed and are used extensively to estimate annual peak-streamflow frequency for ungaged sites in natural (unregulated and rural or nonurbanized) watersheds in Texas (Asquith and Slade, 1997; Asquith and Thompson, 2008; Asquith and Roussel, 2009). The most recent regional regression equations were developed by using data from 638 Texas streamflow-gaging stations throughout the State with eight or more years of data by using drainage area, channel slope, and mean annual precipitation as predictor variables (Asquith and Roussel, 2009). However, because of a lack of sufficient historical streamflow data from small, rural watersheds in certain parts of the State (central and western), substantial uncertainity exists when using the regional regression equations for the purpose of estimating annual peak-streamflow frequency.

  11. Large public display boards: a case study of an OR board and design implications.

    PubMed Central

    Lasome, C. E.; Xiao, Y.

    2001-01-01

    A compelling reason for studying artifacts in collaborative work is to inform design. We present a case study of a public display board (12 ft by 4 ft) in a Level-I trauma center operating room (OR) unit. The board has evolved into a sophisticated coordination tool for clinicians and supporting personnel. This paper draws on study findings about how the OR board is used and organizes the findings into three areas: (1) visual and physical properties of the board that are exploited for collaboration, (2) purposes the board was configured to serve, and (3) types of physical and perceptual interaction with the board. Findings and implications related to layout, size, flexibility, task management, problem-solving, resourcing, shared awareness, and communication are discussed in an effort to propose guidelines to facilitate the design of electronic, computer driven display boards in the OR environment. PMID:11825209

  12. Testing for possible cyclicity in carbonate sediments of Middle Ordovician of east Tennessee

    SciTech Connect

    Ghazizadeh, M.; Walker, K.R.

    1986-05-01

    Middle Ordovician carbonate sediments (Chickamauga Group) near Decatur, Tennessee, consist of 450 m of complex tidal-flat and subtidal sediments. Fourteen facies are recognized: (1) cherty dolostone (supratidal environment); (2) green and red silty mudstone (supratidal mud flat); (3) greenish-gray micrite-biomicrite (supratidal mud flat); (4) red silty, intrapelbiosparite-biosparite (intertidal channel); (5) green and red, loosely packed, ostracod-rich pelbiomicrite (intertidal pond); (6) stromatolitic mudstone (intertidal levee); (7) bryozoan-ostracod-brachiopod-rich pelbiomicrite (subtidal lagoon type I); (8) silty, packed pelbiomicrite-pelbiosparite (subtidal lagoon type II); (9) ostracod-gastropod-rich, bioturbated pelbiomicrite (subtidal lagoon type III); (10) bioturbated brachiopod-molluscan-rich biomicrite (subtidal lagoon type IV); (11) bioturbated green and red silty mudstone to silty sparse biomicrite (lagoon); (12) gray-tan mudstone to sparse biomicrite (quiet water, deeper subtidal lagoon); (13) intrapelbiosparite-pelbiosparite (subtidal channel); and (14) Tetradium-rich packstone (subtidal wave baffle).

  13. Speedy repair returns Basin Pipeline to service

    SciTech Connect

    Not Available

    1987-08-24

    This article reports that a ruptured section of the Basin Pipeline, a 24-in., crude-oil line 25 miles northeast of Wichita Falls, Tex., was quickly replaced after the Red River cut a new channel and damaged the pipeline during May 30-31 flooding. Until that time, the pipeline, operated by Texaco Pipeline Inc., had safely delivered more than 400,000 b/d of crude oil from Jal, N.M., to Cushing, Okla. Because of flooding caused by heavy rains, the river broke through a levee, traversed a flood plain, then cut a new channel about 1,000 ft wide and 16 ft deep, approximately 1,000 ft north of its original shore. It was under the new channel that the pipeline rupture occurred. There was no damage at the original spanned crossing of the river. Also described are the welding progress and the procedures involved in removal of the damaged pipe.

  14. Mozambique upper fan: origin of depositional units

    SciTech Connect

    Droz, L.; Mougenot, D.

    1987-11-01

    The upper Mozambique Fan includes a stable down-stream region, with a north-south channel flanked by thick (1.5 sec two-way traveltime) asymmetric levees, and a migrating upstream region where at least two main feeding paths have been successively dominant. From the Oligocene to early Miocene, the north-south Serpa Pinto Valley acted as the main conduit for the north Mozambique terrigenous sediments. From the middle Miocene, the west-east Zambezi Valley became the dominant path and supplied the fan with sediments transported by the Zambezi River from the central part of Mozanbique. The transfer from one sediment-feeding system to the other is related to the abandonment of the Serpa Pinto Valley because of graben formation along the Davie Ridge, which trapped the sediments, and the increase of the Zambezi River sediment supply because of the creation and erosion of the East African Rift. 13 figures.

  15. Controlling disasters: recognising latent goals after Hurricane Katrina.

    PubMed

    Miller, Lee M

    2012-01-01

    Classic sociological theory can be used to interpret the aftermath of Hurricane Katrina, which made landfall in the United States on 29 August 2005. The delayed and ineffective response to the storm and the subsequent failure of the levees become more understandable when one considers the latent goals of social control in disaster recovery. Constructing the survivors as suspect or criminal and conceptualising the impacts of the disaster as individual problems occurred in order to justify the emphasis on controlling the survivors of Katrina rather than on assisting them. Parallels are drawn here between the disaster response featuring social control efforts and a recent paradigmatic shift in criminal justice from justice to 'risk management'. Recognition of the implicit aims of the inadequate disaster response provides a more complete explanation of why post-Katrina efforts failed to achieve the manifest goals of response and recovery. The conclusion suggests ways to ensure more equitable and just disaster responses.

  16. Latest Subsidence Pattern At Lusi And Implications For Mitigation

    NASA Astrophysics Data System (ADS)

    Williams, V. S.; Wibowo, H. T.

    2009-12-01

    Since beginning of the LUSI eruption, extrusion of mud has been accompanied by deformation of the land beneath the mud extending out as much as two km from the main vent. Deformation generally consists of subsidence, but includes uplift in certain areas and minor surface faulting and cracking as surface blocks of sediment move. Monthly leveling since 12/2007 by laser surveying gives the most reliable measure of vertical movement around the perimeter of the mud ponds. This has been augmented by differential GPS measurements that extend farther out. Subsidence beneath the mud within the levees is difficult to measure accurately. Rapid subsidence, rising mud, and continuous addition of dirt to maintain the internal dikes made it impossible to maintain a system of benchmarks in the inner area. Shape of the surface beneath the mud can be estimated by indicators such as early GPS measurements, tilting of partially buried buildings, and the rate at which tiers of sandbags have disappeared beneath the mud. We have synthesized all available data to produce a map of total deformation for the first 35 months of eruption despite limitations of the data such as variable quality, contradictions, poor point distribution, and observations over variable time intervals. Pre-eruption land surface near LUSI was a level plain 4 m above MSL sloping about 45 cm/km NE toward the sea and away from the artificially high channel and levees of the Porong River. Land around the vent has subsided in the form of an asymmetrical shallow funnel where the gentle tilt of about 10 m/km around the margins increases dramatically near the vent. Early continuous differential GPS measurements of horizontal movement indicate a point of maximum subsidence about 250 m northwest of the main vent. About 200 m south of the vent is a flexure zone trending generally east-west that separates fast subsidence from slower subsidence to the south. This flexure has caused difficulty in mitigation by blocking flow of

  17. The ecology of the Sacramento-San Joaquin Delta

    SciTech Connect

    Herbold, B.; Moyle, P.B. . Dept. of Wildlife and Fisheries Biology)

    1989-09-01

    This report describes an ecosystem significantly different from other delta ecosystems in North America. The Sacramento-San Joaquin Delta is one of the 60 largest river deltas in the world and is the largest river delta on the west coast. As the hub of California's water system, the delta is of immense municipal, agricultural, and industrial importance. The amount of freshwater that flows through the delta controls the delta's productivity and regulates the life cycles of many of its organisms. The vast estuary of the Sacramento and San Joaquin Rivers is one of the most highly modified and intensively managed estuaries in the world. Biological processes in the delta are obscured by the temporal dynamics of the system. Many of the most significant alterations, such as leveeing, diking, and agricultural practices, are not now recognized as such by most citizens, making conservation and protection of the delta difficult. 308 refs., 43 figs., 11 tabs.

  18. Women & smoking: becoming part of the solution.

    PubMed

    Suárez, Nery

    2011-10-01

    El hecho de que tantas enfermedades, ya sean graves o leves, estén relacionadas con el tabaquismo es una de las conclusiones más asombrosas de la investigación médica de este siglo; si bien es posible que no sea tan sorprendente como el hecho de que tantas personas lo hayan ignorado. —Sir Richard Doll, 1912–2005 Las empresas transnacionales del tabaco minimizan los peligros de fumar en poderosas campañas de publicidad desplegadas alrededor del mundo, al mismo tiempo que los organismos internacionales e instituciones sanitarias se esfuerzan por contrarrestar estos mensajes mediáticos con presupuestos ínfimos: una asimetría asombrosa que pone en peligro la salud de millones de personas.

  19. Numerical study on tsunami hazard mitigation using a submerged breakwater.

    PubMed

    Ha, Taemin; Yoo, Jeseon; Han, Sejong; Cho, Yong-Sik

    2014-01-01

    Most coastal structures have been built in surf zones to protect coastal areas. In general, the transformation of waves in the surf zone is quite complicated and numerous hazards to coastal communities may be associated with such phenomena. Therefore, the behavior of waves in the surf zone should be carefully analyzed and predicted. Furthermore, an accurate analysis of deformed waves around coastal structures is directly related to the construction of economically sound and safe coastal structures because wave height plays an important role in determining the weight and shape of a levee body or armoring material. In this study, a numerical model using a large eddy simulation is employed to predict the runup heights of nonlinear waves that passed a submerged structure in the surf zone. Reduced runup heights are also predicted, and their characteristics in terms of wave reflection, transmission, and dissipation coefficients are investigated. PMID:25215334

  20. Geomorphology and stratigraphy of Alba Patera, Mars

    NASA Technical Reports Server (NTRS)

    Schneeberger, Dale M.; Pieri, David C.

    1991-01-01

    Geomorphic and stratigraphic analysis of Alba Patera suggests a volcanic construct built by lavas with rheologic properties similar to basalts. A series of evolving eruptive styles is suggested by changes in morphology and inferred progressive reductions in flow volume with higher stratigraphic position. Alba Patera's volcanic history has been summarized into four main phases. The first is characterized by extensive flood like flows presumably erupted from fissures associated with the initial intrusion of magma into the region. The second phase is associated with the emplacement of pyroclastic rock, a more speculative interpretation. The third phase produced the voluminous tabular, crested, and undifferentiated flows, probably from a more centralized vent source. The fourth and last phase is marked the effusion of levee like flows and the collapse of the summit calderas and final graben formation.

  1. Channel, floodplain, and wetland responses to floods and overbank sedimentation, 1846-2006, Halfway Creek Marsh, Upper Mississippi Valley, Wisconsin

    USGS Publications Warehouse

    Fitzpatrick, F.A.; Knox, J.C.; Schubauer-Berigan, J. P.

    2009-01-01

    Conversion of upland forest and prairie vegetation to agricultural land uses, following Euro-American settlement in the Upper Mississippi River System, led to accelerated runoff and soil erosion that subsequently transformed channels, floodplains, and wetlands on bottomlands. Halfway Creek Marsh, at the junction of Halfway Creek and the Mississippi River on Wisconsin's western border, is representative of such historical transformation. This marsh became the focus of a 2005-2006 investigation by scientists from the U.S. Geological Survey, the University of Wisconsin- Madison, and the U.S. Environmental Protection Agency, who used an understanding of the historical transformation to help managers identify possible restoration alternatives for Halfway Creek Marsh. Field-scale topographic surveys and sediment cores provided data for reconstructing patterns and rates of historical overbank sedimentation in the marsh. Information culled from historical maps, aerial photographs, General Land Offi ce Survey notes, and other historical documents helped establish the timing of anthropogenic disturbances and document changes in channel patterns. Major human disturbances, in addition to agricultural land uses, included railroad and road building, construction of artifi cial levees, drainage alterations, and repeated dam failures associated with large floods. A volume of approximately 1,400,000 m3, involving up to 2 m of sandy historical overbank deposition, is stored through the upper and lower marshes and along the adjacent margins of Halfway Creek and its principal tributary, Sand Lake Coulee. The estimated overbank sedimentation rate for the entire marsh is ??3,000 m3 yr-1 for the recent period 1994-2006. In spite of reduced surface runoff and soil erosion in recent years, this recent sedimentation rate still exceeds by ??4 times the early settlement (1846-1885) rate of 700 m3 yr-1, when anthropogenic acceleration of upland surface runoff and soil erosion was beginning

  2. The BIG'95 debris flow and adjacent unfailed sediments in the NW Mediterranean Sea: geotechnical-sedimentological properties, and dating

    NASA Astrophysics Data System (ADS)

    Urgeles, R.; Lastras, G.; Canals, M.; Willmott, V.; Moreno, A.; Casas, D.; Baraza, J.; Berné, S.

    2003-04-01

    In this study sedimentological, geotechnical, and age data from 7 piston cores of the continental slope and rise off the Ebro margin, North-western Mediterranean, are presented. The cores were obtained within and nearby an area that has undergone a major instability event occurred about 10 ka, known as the BIG'95. They show, at least, three distinct units, which are identified in relation to such event, namely a post-landslide, landslide and pre-landslide unit. Each one of these units shows distinct sedimentological and geotechnical characteristics interpreted in terms of depositional processes and consolidation history. The sedimentological and geotechnical data allows to infer that the BIG'95 is the result of a retrogressive slide and that the location of the channel levee complexes probably had a fundamental role in triggering the landslide, as well as controlling the location of the failure surface.

  3. Ecological dynamics of wetlands at Lisbon Bottom, Big Muddy National Fish and Wildlife Refuge, Missouri

    USGS Publications Warehouse

    Chapman, Duane C.; Ehrhardt, Ellen A.; Fairchild, James F.; Jacobson, Robert B.; Poulton, Barry C.; Sappington, Linda C.; Kelly, Brian P.; Mabee, William R.

    2002-01-01

    The study documented the interaction between hydrology and the biological dynamics within a single spring season at Lisbon Bottom in 1999. The study goal was to provide information necessary for resource managers to develop management strategies for this and other units of the Big Muddy National Fish and Wildlife Refuge. Researchers studied the hydrology, limnology, and biological dynamics of zooplankton, macroinvertebrates, fish and waterbird communities. Lisbon Bottom is one of several parcels of 1993 flood-damaged land that was purchased from willing sellers by the U.S. Fish and Wildlife Service as part of the Big Muddy National Fish and Wildlife Refuge. Lisbon Bottom is a loop bend in the river near Glasgow in Howard County, Missouri between approximately river mile (RM) 213 to RM 219. Flooding at Lisbon in 1993 and 1995 breeched local levees and created a diverse wetland complex.

  4. Age of Palos Verdes submarine debris avalanche, southern California

    USGS Publications Warehouse

    Normark, W.R.; McGann, M.; Sliter, R.

    2004-01-01

    The Palos Verdes debris avalanche is the largest, by volume, late Quaternary mass-wasted deposit recognized from the inner California Borderland basins. Early workers speculated that the sediment failure giving rise to the deposit is young, taking place well after sea level reached its present position. A newly acquired, closely-spaced grid of high-resolution, deep-tow boomer profiles of the debris avalanche shows that the Palos Verdes debris avalanche fills a turbidite leveed channel that extends seaward from San Pedro Sea Valley, with the bulk of the avalanche deposit appearing to result from a single failure on the adjacent slope. Radiocarbon dates from piston-cored sediment samples acquired near the distal edge of the avalanche deposit indicate that the main failure took place about 7500 yr BP. ?? 2003 Elsevier B.V. All rights reserved.

  5. Physical properties of lava flows on the southwest flank of Tyrrhena Patera, Mars

    NASA Technical Reports Server (NTRS)

    Crown, David A.; Porter, Tracy K.; Greeley, Ronald

    1991-01-01

    Tyrrhena Patera (TP) (22 degrees S, 253.5 degrees W), a large, low-relief volcano located in the ancient southern highlands of Mars, is one of four highland paterae thought to be structurally associated with the Hellas basin. The highland paterae are Hesperian in age and among the oldest central vent volcanoes on Mars. The morphology and distribution of units in the eroded shield of TP are consistent with the emplacement of pyroclastic flows. A large flank unit extending from TP to the SW contains well-defined lava flow lobes and leveed channels. This flank unit is the first definitive evidence of effusive volcanic activity associated with the highland paterae and may include the best preserved lava flows observed in the Southern Hemisphere of Mars. Flank flow unit averages, channelized flow, flow thickness, and yield strength estimates are discussed. Analysis suggests the temporal evolution of Martian magmas.

  6. Centrifugal trapping in the magnetotail

    NASA Technical Reports Server (NTRS)

    Delcourt, D. C.; Martin, R. F., Jr.; Sauvaud, J. A.; Moore, T. E.

    1995-01-01

    Particles leving the neutral sheet in the distant magnetotail at times display adiabatic trajectory sequences characterized by an inflection toward the equator and subsequent mirroring in its vicinity. We demonstrate that this low-latitude mirroring results primarily from a centrifugal deceleration due to the fast direction-changing E x B drift. This effect which we refer to as 'centrifugal trapping' appears both in guiding centre and full particle treatments. It thus does not directly relate to nonadiabatic motion. However, pitch angle scattering due to nonadiabatic neutral sheet interaction does play a role in reducing the parallel speed of the particles. We show that centrifugal trapping is an important mechanism for the confinement of the slowest (typically below the equatorial E x B drift speed) plasma sheet populations to the midplane vicinity.

  7. Maternal reading skills and child mortality in Nigeria: a reassessment of why education matters.

    PubMed

    Smith-Greenaway, Emily

    2013-10-01

    Mother's formal schooling-even at the primary level-is associated with lower risk of child mortality, although the reasons why remain unclear. This study examines whether mother's reading skills help to explain the association in Nigeria. Using data from the Demographic and Health Survey, the analysis demonstrates that women's reading skills increase linearly with years of primary school; however, many women with several years of formal school are unable to read at all. The results further show that mother's reading skills help to explain the relationship between mother's formal schooling and child mortality, and that mother's reading skills are highly associated with child mortality. The study highlights the need for more data on literacy and for more research on whether and how mother's reading skills lower child mortality in other contexts.

  8. Recent functional insights into the role of (p)ppGpp in bacterial physiology

    PubMed Central

    Hauryliuk, Vasili; Atkinson, Gemma C.; Murakami, Katsuhiko S.; Tenson, Tanel; Gerdes, Kenn

    2015-01-01

    The alarmone (p)ppGpp is involved in regulating growth and several different stress responses in bacteria. In recent years, substantial progress has been made in our understanding of the molecular mechanisms of (p)ppGpp metabolism and (p)ppGpp-mediated regulation. In this Review, we summarize these recent insights, with a focus on the molecular mechanisms governing the activity of the RelA/SpoT Homologue (RSH) proteins, which are key players that regulate the cellular leves of (p)ppGpp, the structural basis of transcriptional regulation by (p)ppGpp and the role of (p)ppGpp in GTP metabolism and in the emergence of bacterial persisters. PMID:25853779

  9. Hurricane Public Health Research Center at Louisiana State University a Case of Academia Being Prepared

    NASA Astrophysics Data System (ADS)

    van Heerden, I. L.

    2006-12-01

    Recent floods along the Atlantic and Gulf seaboards and elsewhere in the world before Katrina had demonstrated the complexity of public health impacts including trauma; fires; chemical, sewerage, and corpse contamination of air and water; and diseases. We realized that Louisiana's vulnerability was exacerbated because forty percent of the state is coastal zone in which 70% of the population resides. Ninety percent of this zone is near or below sea level and protected by man-made hurricane-protection levees. New Orleans ranked among the highest in the nation with respect to potential societal, mortality, and economic impacts. Recognizing that emergency responders had in the past been unprepared for the extent of the public health impacts of these complex flooding disasters, we created a multi-disciplinary, multi-campus research center to address these issues for New Orleans. The Louisiana Board of Regents, through its millennium Health Excellence Fund, awarded a 5-year contract to the Center in 2001. The research team combined the resources of natural scientists, social scientists, engineers, and the mental health and medical communities. We met annually with a Board of Advisors, made up of federal, state, local government, and non-governmental agency officials, first responders and emergency managers. Their advice was invaluable in acquiring various datasets and directing aspects of the various research efforts. Our center developed detailed models for assessment and amelioration of public health impacts due to hurricanes and major floods. Initial research had showed that a Category 3 storm would cause levee overtopping, and that most levee systems were unprotected from the impacts of storm-induced wave erosion. Sections of levees with distinct sags suggested the beginnings of foundation and subsidence problems. We recognized that a slow moving Cat 3 could flood up to the eaves of houses and would have residence times of weeks. The resultant mix of sewage, corpses

  10. Parental focus of attention in a videotape feedback task as a function of hypothesized risk for offspring schizophrenia.

    PubMed

    Lieber, D J

    1977-12-01

    The families of 29 disturbed but nonpsychotic adolescents were observed in a structured task in which they discussed their reactions to viewing themselves interacting on videotape. Measures derived from the Singer-Wynne concenpt of transactional style deviance were applied to the parental behaviors and related to prior assessments of parental communication disorder based on individual parental TAT protocols. The results confirm the Singer-Wynne hypothesis of the cross-situational stability of transactional style deviance. The most striking finding, however, is that an index of positive focusing behavior differentiates more strongly parents of adolescents hypothesized to be at varying leves of risk for schizophrenia than does the measure of transactional style deviance.

  11. Influence of auditory fatigue on masked speech intelligibility

    NASA Technical Reports Server (NTRS)

    Parker, D. E.; Martens, W. L.; Johnston, P. A.

    1980-01-01

    Intelligibility of PB word lists embedded in simultaneous masking noise was evaluated before and after fatiguing-noise exposure, which was determined by observing the number of words correctly repeated during a shadowing task. Both the speech signal and the masking noise were filtered to a 2825-3185-Hz band. Masking-noise leves were varied from 0- to 90-dB SL. Fatigue was produced by a 1500-3000-Hz octave band of noise at 115 dB (re 20 micron-Pa) presented continuously for 5 min. The results of three experiments indicated that speed intelligibility was reduced when the speech was presented against a background of silence but that the fatiguing-noise exposure had no effect on intelligibility when the speech was made more intense and embedded in masking noise of 40-90-dB SL. These observations are interpreted by considering the recruitment produced by fatigue and masking noise.

  12. Methods for Estimating Magnitude and Frequency of Floods in Rural Basins in the Southeastern United States: South Carolina

    USGS Publications Warehouse

    Feaster, Toby D.; Gotvald, Anthony J.; Weaver, J. Curtis

    2009-01-01

    For more than 50 years, the U.S. Geological Survey (USGS) has been developing regional regression equations that can be used to estimate flood magnitude and frequency at ungaged sites. Flood magnitude relates to the volume of flow that occurs over some period of time and usually is presented in cubic feet per second. Flood frequency relates to the probability of occurrence of a flood; that is, on average, what is the likelihood that a flood with a specified magnitude will occur in any given year (1 percent chance, 10 percent chance, 50 percent chance, and so on). Such flood estimates are needed for the efficient design of bridges, highway embankments, levees, and other structures near streams. In addition, these estimates are needed for the effective planning and management of land and water resources, to protect lives and property in flood-prone areas, and to determine flood-insurance rates.

  13. The spatial and temporal variability of residential real estate values in response to flooding.

    PubMed

    Montz, B E; Tobin, G A

    1988-12-01

    A relationship between residential property values and the incidence of flooding is represented, using a case study of two Californian communities that were flooded following a levee break. Analysis of the real estate market before and after the flood shows that the flood was capitalized into housing values, whereby both list and selling prices dropped immediately and have recently begun to recover. However, recovery of the market is not uniform throughout the floodplain. Houses that suffered eighteen inches of water recovered to near pre-flood values in less than one year. In contrast, houses that had approximately ten feet of water in them have not recovered to the same extent, indicating that capitalization and recovery do not occur evenly. These findings suggest that policies and programs should address these spatial and temporal differences in recovery, which are expected to vary with different flood frequencies and magnitudes.

  14. Flooding and forest succession in a modified stretch along the upper Mississippi River

    USGS Publications Warehouse

    Yin, Yao

    1998-01-01

    This research examines the effect of a rare flood on floodplain forest regeneration in a 102-km stretch of the Mississippi River beginning 21 km above the mouth of the Ohio River. The river has been restricted by levees and navigation structures and subjected to sediment dredging to maintain a stable navigation channel. Because the bank erosion-accretion process has been slowed or eliminated, cottonwood (Populus spp.) and willow (Salix spp.) communities regenerate poorly in the modified river environment. An unusually large flood in 1993 destroyed the entire ground vegetation layer, killing 77.2% of the saplings and 32.2% of the trees. The flood created an alternative mechanism for cottonwood and willow to regenerate under canopy openings, enabling the community type composition of the present-day forest to be sustained for the next 50 years. Over time, however, the forest will likely exhibit considerable compositional fluctuation.

  15. Nominations sought for inaugural Gilbert F. White Lecture

    NASA Astrophysics Data System (ADS)

    Williams, Danica

    2012-04-01

    Nominations for the first Gilbert F. White Distinguished Lecture Award, sponsored by AGU's Natural Hazards Focus Group, are due 1 May. The lecture, established last year, will be given during the 2012 AGU Fall Meeting in San Francisco, 3-7 December. The lecture is named for Gilbert F. White (1911-2006), an AGU Fellow who was internationally known for his significant contributions to natural hazards research. Some of White's most notable work involved the identification and classification of adjustment mechanisms for flooding in the United States, perceptions of natural hazards, and the importance of sound water management in contemporary society. White advocated, where feasible, adaptation to or accommodation of food hazards rather than the "structural" solutions (e.g., dams, levees, and foodwalls) that dominated policy in the early twentieth century

  16. Molecular genetic evidence of formosan subterranean termite (Isoptera: Rhinotermitidae) colony survivorship after prolonged inundation.

    PubMed

    Owens, Carrie B; Su, Nan-Yao; Husseneder, Claudia; Riegel, Claudia; Brown, Kenneth S

    2012-04-01

    Levee breaches because of Hurricane Katrina in 2005 inundated 80% of the city of New Orleans, LA. Formosan subterranean termites were observed actively foraging within in-ground monitoring stations within months after this period of flooding. It was unknown if the activity could be attributed to preexisting colonies that survived inundation or to other colonies surviving flooding by being located at higher elevations readily invading these territories. Genotypic profiles of 17 termite colonies collected from eight inundated locations before flooding were compared with termite colonies after flooding from the same locations to determine Formosan subterranean termite survival after sustained flooding. Results indicate that 14 colonies were able to survive inundation for extended periods.

  17. Assessing the Vulnerability of Large Critical Infrastructure Using Fully-Coupled Blast Effects Modeling

    SciTech Connect

    McMichael, L D; Noble, C R; Margraf, J D; Glascoe, L G

    2009-03-26

    Structural failures, such as the MacArthur Maze I-880 overpass in Oakland, California and the I-35 bridge in Minneapolis, Minnesota, are recent examples of our national infrastructure's fragility and serve as an important reminder of such infrastructure in our everyday lives. These two failures, as well as the World Trade Center's collapse and the levee failures in New Orleans, highlight the national importance of protecting our infrastructure as much as possible against acts of terrorism and natural hazards. This paper describes a process for evaluating the vulnerability of critical infrastructure to large blast loads using a fully-coupled finite element approach. A description of the finite element software and modeling technique is discussed along with the experimental validation of the numerical tools. We discuss how such an approach can be used for specific problems such as modeling the progressive collapse of a building.

  18. Channel-conveyance capacity, channel change, and sediment transport in the lower Puyallup, White, and Carbon Rivers, western Washington

    USGS Publications Warehouse

    Czuba, Jonathan A.; Czuba, Christiana R.; Magirl, Chistopher S.; Voss, Frank D.

    2010-01-01

    -conveyance capacity was the White River between R Street Bridge and the Lake Tapps return, a reach affected by recent flooding. Conveyance capacity also decreased in sections of the Puyallup River. Conveyance capacity was mostly unchanged along other study reaches. Bedload transport was simulated throughout the entire river network and consistent with other observations and analyses, the hydraulic model showed that the upper Puyallup and White Rivers tended to accumulate sediment. Accuracy of the bedload-transport modeling, however, was limited due to a scarcity of sediment-transport data sets from the Puyallup system, mantling of sand over cobbles in the lower Puyallup and White Rivers, and overall uncertainty in modeling sediment transport in gravel-bedded rivers. Consequently, the output results from the model were treated as more qualitative in value, useful in comparing geomorphic trends within different river reaches, but not accurate in producing precise predictions of mass of sediment moved or deposited. The hydraulic model and the bedload-transport component were useful for analyzing proposed river-management options, if surveyed cross sections adequately represented the river-management site and proposed management options. The hydraulic model showed that setback levees would provide greater flood protection than gravel-bar scalping after the initial project construction and for some time thereafter, although the model was not accurate enough to quantify the length of time of the flood protection. The greatest hydraulic benefit from setback levees would be a substantial increase in the effective channel-conveyance area. By widening the distance between levees, the new floodplain would accommodate larger increases in discharge with relatively small incremental increases in stage. Model simulation results indicate that the hydraulic benefit from a setback levee also would be long-lived and would effectively compensate for increased deposition within the setback reach

  19. The Long Term Recovery of New Orleans’ Population after Hurricane Katrina

    PubMed Central

    Fussell, Elizabeth

    2015-01-01

    Hurricane Katrina created a catastrophe in the city of New Orleans when the storm surge caused the levee system to fail on August 29, 2005. The destruction of housing displaced hundreds of thousands of residents for varying lengths of time, often permanently. It also revealed gaps in our knowledge of how population is recovered after a disaster causes widespread destruction of urban infrastructure, housing and workplaces, and how mechanisms driving housing recovery often produce unequal social, spatial and temporal population recovery. In this article, I assemble social, spatial and temporal explanatory frameworks for housing and population recovery and then review research on mobility – both evacuation and migration – after Hurricane Katrina. The review reveals a need for a comprehensive social, spatial and temporal framework for explaining inequality in population recovery and displacement. It also shows how little is known about in-migrants and permanent out-migrants after a disaster. PMID:26880853

  20. The ecology of riparian habitats of the southern California coastal region: A community profile

    SciTech Connect

    Faber, P.M.; Keller, E.; Sands, A.; Massey, B.M. , Mill Valley, CA; Keller , Santa Barbara, CA; Sands , Mill Valley, CA; Massey , Long Beach, CA )

    1989-09-01

    In the 200 years since California's settlement by Europeans, almost every river in southern California has been channelized or dammed to allow development on the floodplains, causing the loss of a highly productive ecosystem. The riparian zone occurs along streambanks where soils are fertile and water is abundant; amphibians, reptiles, birds, and mammals all move back and forth across the riparian zone from streams into adjacent wetland and upland areas. Irreversible alterations of the riparian ecosystem result from the diversion or loss of transported water to the system through diking, damming, channelization, levee building, or road construction. Clearing for crops, grazing, or golf courses is potentially reversible as long as the water supply remains unaltered. Successful restoration work requires early agreement on project goals, site-specific restoration design, correct project implementation, enforcement of permit conditions, a maintenance and management program, and long-range monitoring. 288 refs., 54 figs., 13 tabs.