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Climate change in combination with land use alterations may lead to significant changes in soil erosion and sediment fluxes in streams. Optical turbidity sensors can monitor with high frequency and can be used as a proxy for suspended sediment concentration (SSC) provided there is an acceptable calibration curve for turbidity measured by sensors and SSC from water samples. This study used such calibration data from 31 streams in 11 different research projects or monitoring programmes in six Northern European countries. The aim was to find patterns in the turbidity-SSC correlations based on stream characteristics such as mean and maximum turbidity and SSC, catchment area, land use, hydrology, soil type, topography, and the number and representativeness of the data that are used for the calibration. There were large variations, but the best correlations between turbidity and SSC were found in streams with a mean and maximum SSC of >30–200 mg/l, and a mean and maximum turbidity above 60–200 NTU/FNU, respectively. Streams draining agricultural areas with fine-grained soils had better correlations than forested streams draining more coarse-grained soils. However, the study also revealed considerable differences in methodological approaches, including analytical methods to determine SSC, water sampling strategies, quality control procedures, and the use of sensors based on different measuring principles. Relatively few national monitoring programmes in the six countries involved in the study included optical turbidity sensors, which may partly explain this lack of methodological harmonisation. Given the risk of future changes in soil erosion and sediment fluxes, increased harmonisation is highly recommended, so that turbidity data from optical sensors can be better evaluated and intercalibrated across streams in comparable geographical regions.

La costa de La Barceloneta està en constant evolució a causa de tempestes, erosions i variacions del nivell del mar. En aquest treball s'ha dut a terme l'estudi d'aquesta platja durant l'episodi de la tempesta Celia, amb l'objectiu d'ampliar els coneixements hidrodinàmics en aquesta zona, que compta amb molta activitat. L'estudi es va realitzar gràcies a la recopilació de dades durant el període de març i abril pel projecte MARLIT. Les dades recopilades es van analitzar i representar per comprendre que tots els paràmetres estudiats experimenten canvis simultanis i correlacionats per poder formar una tempesta d'ones., La costa de La Barceloneta está en constante evolución debido a tormentas, erosiones y variaciones del nivel del mar. En este trabajo se ha llevado a cabo el estudio de esta playa durante el episodio de la tormenta Celia, con el objetivo de ampliar los conocimientos hidrodinámicos en esta zona, que cuenta con mucho flujo de actividad. El estudio se realizó gracias a la recopilación de datos durante el periodo de marzo y abril por el proyecto MARLIT. Los datos recopilados se analizaron y representado para comprender que todos los parámetros estudiados experimentan cambios simultáneos y correlacionados para poder formar una tormenta de olas., The coast of La Barceloneta is in constant evolution due to storms, erosions, and variations in sea level. In this study, the research of this beach was carried out during the episode of the Celia storm, with the aim of expanding the hydrodynamic knowledge in this area, which experiences a high level of activity. The study was performed thanks to the data collection during the period of March and April by the MARLIT project. The collected data were analyzed and represented to understand that all the parameters studied undergo simultaneous and correlated changes in order to form a wave storm.

The potential of the gulf of Urabá to hold a multi-purpose port motivated a sediment dynamics study to describe the seasonal sediment concentration patterns in this tropical region. Challenges addressed in this study include a complex three-dimensional flow pattern in a tropical estuary and the lack of in-situ measurements. To overcome such challenges, this study completed: (i) Measurements of suspended sediment concentrations during two climatic seasons and an extreme event (2010–2011); (ii) Definition of boundary conditions from global databases; (iii) Qualitative analysis of sediment concentrations from satellite imagery; and (iv) integration of the previously mentioned steps to build a process-based 3D sediment transport model. Seasonal patterns of suspended sediment concentrations were identified and corroborated by the agreement between model results, satellite imagery and field measurements. During the calm rainy season, the Atrato River turbid plume extends northward and dominates the sediment dynamics in the gulf. On the other hand, during the dry season and extreme events, bed transport is enhanced and the river's plume and the littoral drift shift southwards. © 2017 Elsevier Ltd

Increasing evidence suggests that coral reefs exposed to elevated turbidity may be more resilient to climate change impacts and serve as an important conservation hotspot. However, logistical difficulties in studying turbid environments have led to poor representation of these reef types within the scientific literature, with studies using different methods and definitions to characterize turbid reefs. Here we review the geological origins and growth histories of turbid reefs from the Holocene (past), their current ecological and environmental states (present), and their potential responses and resilience to increasing local and global pressures (future). We classify turbid reefs using new descriptors based on their turbidity regime (persistent, fluctuating, transitional) and sources of sediment input (natural versus anthropogenic). Further, by comparing the composition, function and resilience of two of the most studied turbid reefs, Paluma Shoals Reef Complex, Australia (natural turbidity) and Singapore reefs (anthropogenic turbidity), we found them to be two distinct types of turbid reefs with different conservation status. As the geographic range of turbid reefs is expected to increase due to local and global stressors, improving our understanding of their responses to environmental change will be central to global coral reef conservation efforts.

© 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0, Sediments from coal mine drainages (CMDs) contain large quantities of suspended pollutants (possibly numerous chemical substances) along with sulfates and hazardous elements (e.g., chromium, zinc, copper, lead) that irreversibly accumulate in the water. As this accumulation can continue for decades after discontinuation of coal extraction, it is necessary to employ multidisciplinary approaches to control the threat in such zones. The quantity of amorphous material in some CMDs was evaluated by X-ray powder diffraction (XRD) using the Rietveld-based SIROQUANT software package. Modern Dual Beam Focused Ion Beam (FIB), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscope (H-TEM), and energy-dispersive X-ray spectrometer (EDS) were used to evaluate the occurrence and transformation of nanophases (NPs). FIB is used to determine the 3D distribution of different species (internal structure) within individual NPs, whereas EDS is used to observe NP features (e.g., shape, constituent, range, assembly, and form of polymerization). The mineralogy of the sediment from the Brazilian CMDs, including the proportions of quartz, clays, Al–Fe-oxides, and amorphous NPs, appears to be related to the nature of the mineral matter in the relevant coal cleaning rejects (CCRs). The sediments of CMDs from the Brazilian coal area derived at a lower-pH range have different amorphous compositions as compared to those derived at a higher pH range. These special amorphous compositions are shown to be related to several other sediment properties such as particle surface area. The information gleaned in this study will be useful for further geochemical evaluation of CMDs in other parts of the world., Peer Reviewed, Postprint (author's final draft)

Optical technology is used to measure and monitor water quality, to date mainly in drinking water treatment, where water is typically much cleaner than in heavily polluted agricultural streams. To characterize suspended sediments (SS) and dissolved organic matter (DOM) in surface water some optical measurements have been used (absorbance and fluorescence spectroscopy). This study aims to use laboratory optical instruments (using turbidimeter and fluorescence and absorbance spectrophotometer) to evaluate how different sediment concentrations measured as turbidity affect fluorescence and absorbance determination of the dissolved organic matter. In the study, ten agricultural catchments located in southern Sweden were analyzed. Clay and sandy soils are most dominant in these catchments with predominant intensive crop production and high livestock in some like F26, E23. Turbidity was measured using a nephelometric turbidimeter to measure the absorption and scatter properties of suspended sediments in the water. Higher turbid waters were found in catchments with clay soil textures (C6, M36, O8, E23, and U8) than sandy soils (E21, F26, I28, M36, and N34). Absorbance and excitation wavelength at 240-600 nm and emission wavelengths at 211-260 nm were used to measure SS and DOC in the water samples. A strong correlation was identified between turbidity and absorbance at 240 and 600 nm range than it was with the fluorescence index vs. turbidity. The result showed a variation in fluorescence index (values range from 1.51 to 1.79) among catchments, these indicate where DOM is coming from. DOM in most catchments is delivered from terrestrial sources, only F26 with a value of FI=1.51 DOM might be derived from a microbial source. The results show a variation among agriculture catchments. UV and FI can be used as a substitute to measure turbidity (SS and DOM) but according to results obtained UV correlates well with turbidity than FI. Implying that UV254 can be a better surrogate p

In the Mediterranean region, floods are expected to increase as a result of climate change and knowledge of soil erosion hot spots during exceptional rainfalls is required to support mitigation measures. This study quantifies the main sediment sources during an exceptional rainfall event in 2012 (235 mm) at the outlet of two catchments located in NE Spain. To this purpose, suspended sediments were collected during the flood event, complemented with entrapped sediments in mat taken one year after the event. We used fingerprinting methodology and applied the FingerPro unmixing model to estimate the contribution from main sources. The selected tracers clearly distinguished agricultural, rangeland, subsoil and channel banks as the four potential sources in both catchments. In the Vandunchil catchment, the 8 time-integrated suspended sediment samples revealed changes in source contribution during the 2-h sampling sequence. There were relatively high contributions from rangeland, agriculture and subsoil at the beginning of the sampling, representing 30, 40 and 35% of the total source contributions, respectively. Our records captured the delivery of pulses of eroded surface soil transported by runoff with direct connectivity to the stream. The sequence was followed by a sharp increase in channel bank contribution (up to 90%) in comparison to the other sources, reflecting streambank erosion and landslide occurrence, which manifested during the flood. In contrast, in the La Reina catchment, agricultural soils contributed the most (65%) and, together with subsoils (32%), were the main sources. These results reflect the effect of the higher connectivity and slope gradient of these cultivated fields of the La Reina catchment in comparison with those of the Vandunchil catchment. We discuss the possibility of using different properties, such as radionuclides, geochemistry and magnetic measurements, as tracers to distinguish between potential sources during an exceptional event in

Transport of hydrophobic pollutants in rivers such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metals is often facilitated by suspended sediment particles, which are typically mobilized during high discharge events. Suspended sediments thus represent a means of transport for particle related pollutants within river reaches and may represent a suitable proxy for average pollutant concentrations estimation in a river reach or catchment. In this study, multiple high discharge/turbidity events were sampled at high temporal resolution in the Globaqua River Basins Sava (Slovenia, Serbia), Adige (Italy), and Evrotas (Greece) and analysed for persistent organic pollutants such as PAHs (polycyclic aromatic hydrocarbons) or PCBs (polychlorinated biphenyls) and heavy metals. For comparison, river bed sediment samples were analysed as well. Further, results are compared to previous studies in contrasting catchments in Germany, Iran, Spain, and beyond. Overall results show that loadings of suspended sediments with pollutants are catchment-specific and relatively stable over time at a given location. For PAHs, loadings on suspended particles mainly correlate to urban pressures (potentially diluted by sediment mass fluxes) in the rivers, whereas metal concentrations mainly display a geogenic origin. By cross-comparison with known urban pressure/sediment yield relationships (e.g. for PAHs) or soil background values (for metals) anthropogenic impact – e.g. caused by industrial activities – may be identified. Sampling of suspended sediments gives much more reliable results compared to sediment grab samples which typically show a more heterogeneous contaminant distribution. Based on mean annual suspended sediment concentrations and distribution coefficients of pollutants the fraction of particle facilitated transport versus dissolved fluxes can be calculated. © 2018 The Authors

A large, open ocean applicable sediment trap has been developed at the Woods Hole Oceanographic Institution in order to assess the fluxes of particles sinking through the deep water column, under the sponsorship of the National Science Foundation. PARFLUX Mark II trap, 1978-79 version for PARFLUX phase 1 program, has been successfully developed and has gathered much meaningful data. A trap opening is 1.5 m2 and consists of 94 hexagonal buffer cells with the nominal form ratio of 2. Sediment particles are concentrated to the receiving cup located at the bottom of the funnel-shaped trap. Two types of receiving cups have been developed; a trap with Type S cup is open at both ends as it sinks to the designated depth. Twenty-four hours after the deployment the receiving cup moves into alignment with the funnel to store the sediment. At the end of deployment a spring mechanism activated by a quartz oscillator based electrical timer-release retracts the receiving cup, seals the collected sample and leave the funnel open at both ends while the trap ascends for recovery. Type C mechanism is installed with a shutter which seals the cup during recovery; this type involves a simple mechanism with less moving parts. Sodium azide/sodium chloride solution is diffused through a series of membrane filters to keep the cup contents in an aseptic condition. Since October 1976 to December 1979, we have deployed and recovered 24 traps successfully along with several moorings as deep as 5,600 m for as long as 112 days. This reports the engineering detail and lists the required parts to assist the construction, operation and maintenance of the PARFLUX Mark II sediment trap., Prepared for the National Science Foundation under Grants OCE 76-82063 and OCE 77-27004.

A large, open ocean applicable sediment trap has been developed at the Woods Hole Oceanographic Institution in order to assess the fluxes of particles sinking through the deep water column, under the sponsorship of the National Science Foundation. PARFLUX Mark II trap, 1978-79 version for PARFLUX phase 1 program, has been successfully developed and has gathered much meaningful data. A trap opening is 1.5 m2 and consists of 94 hexagonal buffer cells with the nominal form ratio of 2. Sediment particles are concentrated to the receiving cup located at the bottom of the funnel-shaped trap. Two types of receiving cups have been developed; a trap with Type S cup is open at both ends as it sinks to the designated depth. Twenty-four hours after the deployment the receiving cup moves into alignment with the funnel to store the sediment. At the end of deployment a spring mechanism activated by a quartz oscillator based electrical timer-release retracts the receiving cup, seals the collected sample and leave the funnel open at both ends while the trap ascends for recovery. Type C mechanism is installed with a shutter which seals the cup during recovery; this type involves a simple mechanism with less moving parts. Sodium azide/sodium chloride solution is diffused through a series of membrane filters to keep the cup contents in an aseptic condition. Since October 1976 to December 1979, we have deployed and recovered 24 traps successfully along with several moorings as deep as 5,600 m for as long as 112 days. This reports the engineering detail and lists the required parts to assist the construction, operation and maintenance of the PARFLUX Mark II sediment trap., Prepared for the National Science Foundation under Grants OCE 76-82063 and OCE 77-27004.

This paper examines the effects of gravel mining on the suspended sediment transport in the Upper River Cinca (Central Pyrenees). Discharge, sediment transport and sediment grain-size distribution were measured, sampled and further determined in five monitoring sections along a 5 km river reach. Samples were taken at a section upstream from the mined area (i.e. reference section) and in four sections downstream (0, 200, 500 and 1500 m). The results show that sediment concentrations downstream from the target site were up to one order of magnitude higher than in the reference section. Average concentrations during the impact were similar to those observed during floods, with maximum values attaining 6 g/l. Total load ranged from 2.2 to 17 Mg/day between sections; these values include the effects of the earth-moving works performed before the mining started. Concentrations at the lowermost section of the study reach were similar to those observed at the upstream reference section, suggesting that most of the suspended material was deposited in the channel. The transported material was coarse than that sampled under reference conditions; nevertheless, largest particles settled quickly, suggesting a selective transport downstream. This study constitutes a first step towards a better understanding of local sediment dynamics in rivers affected by maintenance works and related activities, such as gravel mining, and, overall, supports the comprehensive assessment of the effects of human actions on channel morphodynamics and the ecological functioning of mountain fluvial systems. © Universidad de La Rioja.

Sediment profiles in open channels are usually predicted by advection-diffusion models. Most basic forms consider the terminal settling velocity of a single particle in still clear water. Alternative forms account for hindered settling at higher concentrations. It is not known, however, how these modifications relate to mass and momentum conservation of each phase. For dilute flow, it is known that the original form can be derived from a two-phase analysis, assuming a dilute suspension, neglect of inertial effects in the momentum balance and using a linear drag force formulation. Here we study how and if it is possible to understand the hindered-settling modifications for the non-dilute case, and formulate a relation between advection-diffusion models and parameters involved in the turbulent drag force. This note verifies that the transient two-phase flow solutions converge to steady state, and compares the results to experimental data., Offshore and Dredging Engineering

Sediment profiles in open channels are usually predicted by advection-diffusion models. Most basic forms consider the terminal settling velocity of a single particle in still clear water. Alternative forms account for hindered settling at higher concentrations. It is not known, however, how these modifications relate to mass and momentum conservation of each phase. For dilute flow, it is known that the original form can be derived from a two-phase analysis, assuming a dilute suspension, neglect of inertial effects in the momentum balance and using a linear drag force formulation. Here we study how and if it is possible to understand the hindered-settling modifications for the non-dilute case, and formulate a relation between advection-diffusion models and parameters involved in the turbulent drag force. This note verifies that the transient two-phase flow solutions converge to steady state, and compares the results to experimental data., Offshore and Dredging Engineering

A frequently cited concern for potential detrimental impacts to aquatic orgamsims associated with dredging projects is sediment resuspension resulting from the excavation process, overflow, or open-water placement. However, very few attempts have been made to place dredging-induced resuspension into perspective with other natural (e.g., tidal flows, high riverine discharges, storm wind and wave forces) or anthropogenic (e.g., commercial or recreational vessel traffic passage and maneuvering) sources of resuspension. The present study examines suspended sediment plumes created by various types of vessels within Newark Bay, New Jersey. Spatial scales, total suspended solids (TSS) concentration gradients, and dispersion patterns were measured by a combination of acoustic Doppler current profiler (ADCP) surveys and collection of water samples for gravimetric analysis. Plumes varied substantially among vessel type and movement patterns. Often very large plumes, initially extending from the surface to the bottom, were associated with turning maneuvers of deep draft vessels. Plumes rapidly dissipated in the upper portion of the water column, but persisted at depth for relatively long periods. TSS concentrations above 90 mg/l occurred over broad areas following vessel maneuvers. Ambient TSS concentrations ranged from 10 mg/l (surface) to 60 mg/l (just above the bottom). Bottom plumes remained detectable against ambient throughout the time intervals between successive arrivals and departures, persisting for at least 50 minutes where tidal currents could disperse plumes. Residual plumes (maximum 40 mg/l) in the lower 2 m of the water column were detectable at the point of deep draft vessel passage up to 65 minutes., The original document contains color images. Prepared in collaboration with HDR, Inc., Pearl River, NY, Bowhead Information Technology Services, Vicksburg, MS, and the U.S. Army Corps of Engineers, New York, NY. Sponsored in part by the Dredging Operations and Environment Research (DOER) Program and Dredging Operations and Technical Support (DOTS) Program, US Army Engineer Research and Development Center, Vicksburg, MS.

The long-term goal is to understand the impact, and relative importance, of different physical processes on very-high-frequency (100 kHz 1 MHz) acoustic propagation in different environments and in support of high-data- rate underwater acoustic communication systems. To develop and test an integrated very-high-frequency acoustic communication system for use on autonomous platforms

A project is being proposed to construct shallow-water habitat (SWH) along Middle Decatur Bend of the Missouri River in Burt County, Nebraska. The U.S. Army Corps of Engineers (USACE) is constructing SWH along the lower Missouri River downstream of Gavins Point Dam to mitigate aquatic habitat lost from past bank stabilization and channelization, and enhance habitat for the endangered pallid sturgeon (Scaphirhynchus albus) population along the lower Missouri River. The Omaha District (District) is referring to the proposed project as the Middle Decatur Revetment project. The District plans to construct SWH by excavating material behind an existing revetment. The removal of deposited sediment will involve hydraulic dredging and it is proposed that the dredge spoil be discharged to the adjacent Missouri River. It is believed that some of the sediment to be dredged was newly deposited during the Missouri River flood of 2011 and will be primarily sand with some silts and clays. An estimated 264,000 cubic yards of sediment/soil would be excavated and discharged to the Missouri River.

The goal of this research was to develop greater understanding of the dynamics of fluid mud and its role in the transport and deposition of sediment in coastal environments. In particular, we sought greater understanding of the processes that influence the formation and maintenance of fluid mud in energetic environments.

This is the second in a series of two technical notes that evaluate the capability of the Lindorm Inc. SediMeter(trademark). The SediMeter utilizes infrared optical backscatter (OBS) detectors to determine the location of the sea/river/lake bottom. The previous technical note (ERDC TN-DOER T11, Perkey and Wadman 2013) presented results of laboratory tests performed to assess the instrument s accuracy. That technical note concluded that the SediMeter was not able to reliably record bed elevation changes on the scale of 1mm. However, that technical note further stated that in areas where dredged material may be impacting bottom elevations on larger scales (such as beneficial use of dredged material to build marsh land), the SediMeter might serve as a useful monitoring instrument. This document will present results from field deployment and testing of the SediMeter performed on the USACE Field Research Facility (FRF) property in Currituck Sound, North Carolina. In addition to the SediMeter, the SeaTek Multiple Transducer Array (MTA) and the Nortek Vectrino II Acoustic Doppler Velocimeter (ADV) were also deployed and tested in Currituck Sound. Both of these instruments utilize high-frequency acoustic signals to determine the location of the bottom with an advertised resolution of 1 mm or less. Results of the tests conducted with these instruments will also be presented to assess their feasibility for monitoring fine-scale sedimentation that might occur as a result of particles settling out of dredge plumes., See also ADA583160, ERDC-TN-DOER-T11, Laboratory Feasibility Study Concerning the Use of the SediMeter (trademark) to Detect Fine-Scale ( or = 1 mm) Sedimentation Resulting from Dredging Operations, Jul 2013. The original document contains color images.

Propeller wash induces disturbances to the bottom sediment in Department of Defense (DoD) harbors in multiple ways. Resuspension of bottom sediment, which is often contaminated, by propeller wash in DoD harbors is a phenomenon constantly observed and occasionally reported. While these resuspension events occur frequently, their effects on potential for erosion, transport, re-deposition, and re-contamination of bottom sediments have not been rigorously studied or quantified. This study aims to demonstrate and validate an innovative quantitative method that integrates information from state-of-science measuring devices/tools with predictive methods, including models. These measuring devices have been used to measure and evaluate critical parameters that govern propeller wash resuspension and subsequent fate and transport of the eroded sediments in DoD harbors. Accurate model results helped to reduce the uncertainty associated with propeller wash hydrodynamics and shear stress and resuspension potential of the sediment bed. Field data were used to support the fate and transport model, CH3D, which was successfully calibrated for San Diego Bay, CA; Pearl Harbor, HI; and Sinclair Inlet, WA. Once validated with the field data, CH3D was used to predict footprints (deposition) of the sediment plume and re-contamination potential from propeller wash. We have further extended the model's simulation and prediction capabilities on both the resuspension potential and fate and transport of the plume far and beyond the scenarios when the data were measured., The original document contains color images. Prepared in collaboration with NAVFAC-Pacific, U.S. Army ERDC, Vicksburg, MS, the University of Wisconsin-Milwaukee, and Germano & Associates, Bellvue, WA.

Mediterranean rivers are characterized by highly variable hydrological regimes that are strongly dependent on the seasonal rainfall. Sediment transport is closely related to the occurrence of flash-floods capable to deliver enough kinetic energy to mobilize the bed and channel sediments. Contaminants accumulated in the sediments are likely to be mobilized as well during such events. However, whereas there are many studies characterizing contaminants in steady sediments, those devoted to the transport dynamics of suspended-sediment borne pollution are lacking. Here we examined the occurrence and transport of persistent organic microcontaminants present in the circulating suspended sediments during a controlled flushing flow in the low part of the River Ebro (NE Spain) 12km downstream of a well-known contaminated hot-spot associated to a nearby chloro-alkali industry. Polycyclic aromatic hydrocarbons (PAHs) and semi-volatile organochlorine pollutants (DDT and related compounds, DDX; polychlorinated byphenils, PCBs; and other organochlorine compound, OCs) were measured in the particulate material by GC-MS and GC-MS/MS, using previously developed analytical methods. The concentration levels observed were compared to previously reported values in steady sediments in the same river and discussed on a regulatory perspective. Hydrographs and sedigraphs recorded showed a peak-flow of 1300m3s-1 and a corresponding peak of suspended sediments of 315mgL-1. Combination of flow discharge, suspended sediments and pollutants' concentrations data allowed for quantifying the mass flows (mass per unit of time) and setting the load budgets (weight amount) of the different pollutants transported by the river during the monitored event. Mean mass-flows and total load values found were 20.2mgs-1 (400g) for PAHs, 38mgs-1 (940g) for DDX, 44mgs-1 (1038g) for PCBs and 8mgs-1 (200g) for OCs. The dynamic pattern behavior of PAHs differs substantially to that of organochlorine pollutants, thus r

The U.S. Army Corps of Engineers (USACE) is proposing a project to construct shallow-water habitat (SWH) along the Little Sioux Bend of the Missouri River between RM666 and RM669. The construction of SWH will enhance the aquatic habitat of the Missouri River and benefit the endangered pallid sturgeon (Scaphirhynchus albus) population. Although on the Nebraska side of the Missouri River, the project area is located in Harrison County, Iowa and Burt County, Nebraska and will basically run down the old river channel that is the legal boundary between the States of Iowa and Nebraska. The USACE is proposing to use hydraulic dredging to excavate sediment/soil from the old river channel and discharge the dredge spoil to the Missouri River adjacent to the proposed project area. Section 404 of the Federal Clean Water Act (CWA) requires that a 404 permit be appropriately obtained prior to the discharge of any dredge or fill material into waters of the United States. Under 401 of the Federal CWA an applicant for a federal license or permit (i.e. 404 permit) must obtain a certification that the discharge and activity is consistent with appropriate State or Tribal water quality regulations. Regarding the Little Sioux project, a 401 water quality certification has been requested from the Iowa Department of Natural Resources (IDNR) and Nebraska Department of Environmental Quality (NDEQ) regarding compliance with State water quality standards and implementation plans. The Water Quality Sampling Report and Factual Determinations, Results of Sediment Sampling and Elutriate Testing at the Proposed Little Sioux Bend Shallow Water Habitat Project Site (USACE, April 2013) was previously prepared to support Section 404 permitting and State 401certification considerations at the proposed Little Sioux project.

A project is being proposed to expand and enhance previously constructed shallow-water habitat (SWH) along the Missouri River at Glovers Point Bend in Thurston County, Nebraska. The U.S. Army Corps of Engineers (USACE) is constructing SWH along the lower Missouri River downstream of Gavins Point Dam to mitigate aquatic habitat lost from past bank stabilization and channelization. Increasing SWH will enhance habitat for the endangered pallid sturgeon (Scaphirhynchus albus) population along the lower Missouri River. The District is referring to the proposed project as the Glovers Point project. Deposited sediment will be excavated from the area to enhance and expand previously constructed SWH at the project site. Sediment excavation will involve hydraulic dredging with the dredge spoil being discharged to the adjacent Missouri River. It is believed the dredge material will be primarily sand with some silts and clays. An estimated 910,000 cubic yards of material would be excavated and discharged to the Missouri River.

A project is being proposed to enhance shallow-water habitat (SWH) along Upper Calhoun Bend of the Missouri River in Pottawattamie County, Iowa. The U.S. Army Corps of Engineers (USACE) is constructing SWH along the lower Missouri River downstream of Gavins Point Dam to mitigate aquatic habitat lost from past bank stabilization and channelization, and enhance habitat for the endangered pallid sturgeon (Scaphirhynchus albus) population along the lower Missouri River. The Omaha District (District) is referring to the proposed project as the Wilson Island project. Deposited sediment will be excavated at the project site to enhance backwater habitat at an existing chute area. Sediment excavation will involve hydraulic dredging with the dredge spoil being discharged to the adjacent Missouri River. It is believed the sediment/soil to be dredged will be primarily alluvial material. An estimated 910,000 cubic yards of sediment/soil could be excavated and discharged to the Missouri River.

A project is being proposed to construct shallow-water habitat (SWH) along the Missouri River at Indian Cave State Park in Richardson County, Nebraska. The U.S. Army Corps of Engineers (USACE) is constructing SWH along the lower Missouri River downstream of Gavins Point Dam to mitigate aquatic habitat lost from past bank stabilization and channelization, and enhance habitat for the endangered pallid sturgeon (Scaphirhynchus albus) population along the lower Missouri River. The Omaha District (District) is referring to the proposed project as the Indian Cave State Park project. Deposited sediment will be excavated at the project site to create a backwater area. Sediment excavation will involve hydraulic dredging with the dredge spoil being discharged to the adjacent Missouri River. It is believed the sediment/soil to be dredged will be primarily alluvial material. An estimated 400,000 cubic yards of sediment/soil would be excavated and discharged to the Missouri River.

A project is being proposed to restore previously constructed shallow-water habitat (SWH) along Middle Decatur Bend of the Missouri River in Burt County, Nebraska. The U.S. Army Corps of Engineers (USACE) is constructing SWH along the lower Missouri River downstream of Gavins Point Dam to mitigate aquatic habitat lost from past bank stabilization and channelization, and enhance habitat for the endangered pallid sturgeon (Scaphirhynchus albus) population along the lower Missouri River. The Omaha District (District) is referring to the proposed project as the Middle Decatur project. The District plans to restore connectivity to previously constructed SWH by cleaning out the original flow path and excavating a new inlet. The removal of newly deposited sediment will involve hydraulic dredging and it is proposed that the dredge spoil be discharged to the adjacent Missouri River. It is believed the sediment to be dredged was largely deposited during the Missouri River flood of 2011 and will be primarily sand with some silts and clays. An estimated 300,000 cubic yards of sediment/soil would be excavated and discharged to the Missouri River.

A project is being proposed to create shallow-water habitat (SWH) along the Missouri River in Harrison County, Iowa and Burt County, Nebraska. The U.S. Army Corps of Engineers (USACE) is constructing SWH along the lower Missouri River downstream of Gavins Point Dam to mitigate aquatic habitat lost from past bank stabilization and channelization. Increasing SWH will enhance the endangered pallid sturgeon (Scaphirhynchus albus) population along the lower Missouri River. The District is referring to the proposed project as the Little Sioux project. Hydraulic dredging would be used to excavate sediment/soil from an old chute area of the Missouri River to create SWH. The material to be dredged is believed to be primarily sands and silts with some clays. It is proposed that the dredge spoil be discharged to the Missouri River adjacent to the proposed project area.

In situ amendments are a promising approach to enhance removal of metal contaminants from diverse environments including soil, groundwater and sediments. Apatite and chitin were selected and tested for copper, chromium, and zinc metal removal in marine sediment samples. Microbiological, molecular biological and chemical analyses were applied to investigate the role of these amendments in metal immobilization processes. Both apatite and chitin promoted microbial growth. These amendments induced corresponding bacterial groups including sulfide producers, iron reducers, and phosphate solubilizers; all that facilitated heavy metal immobilization and removal from marine sediments. Molecular biological approaches showed chitin greatly induced microbial population shifts in sediments and overlying water: chitin only, or chitin with apatite induced growth of bacterial groups such as Acidobacteria, Betaproteobacteria, Epsilonproteobacteria, Firmicutes, Planctomycetes, Rhodospirillaceae, Spirochaetes, and Verrucomicrobia; whereas these bacteria were not present in the control. Community structures were also altered under treatments with increase of relative abundance of Deltaproteobacteria and decrease of Actinobacteria, Alphaproteobacteria, and Nitrospirae. Many of these groups of bacteria have been shown to be involved in metal reduction and immobilization. Chemical analysis of pore- and overlying water also demonstrated metal immobilization primarily under chitin treatments. X-Ray absorption spectroscopy (XAS) spectra showed more sorbed Zn occurred over time in both apatite and chitin treatments (from 9% - 27%). The amendments improved zinc immobilization in marine sediments that led to significant changes in the mineralogy: easily mobile Zn hydroxide phase was converted to an immobile Zn phosphate (hopeite). In-situ amendment of apatite and chitin offers a great bioremediation potential for marine sediments contaminated with heavy metals., Published in the Open Journal of Metal, v3 p51-61, Jul 2013. The original document contains color images. Prepared in collaboration with the Stroud Water Research Center, Avondale, PA, the Department of Earth Sciences, University of Southern California, Los Angeles, and the National Risk Management Research Laboratory, Environmental Protection Agency, Cincinnati, OH.

Prepared in collaboration with Army Engineer District, Jacksonville, FL.

A combined Suspended Solid Concentration (SSC)/flow velocity sensor and a three-tier wireless sensor network (WSN) were demonstrated at three military installations-- Fort Riley, Fort Benning, and Aberdeen Proving Ground from 2010 to 2012. Twelve sensors were deployed to continuously monitored SSC. The SSC measurement range was found to be 0-5,000 mg/L and, in most cases, the SSC measurement error was limited within 10%. Fouling on optical lenses was reduced with an air-blast lens cleaning system embedded in the sensor, although maintenance of the system has presented a challenge. An algorithm for fouling and clogging correction was also developed for data post-processing. Data post-processing applied to a six-month SSC data showed that the sensor can be used in long-term natural water monitoring. While measuring SSC, the sensor also measured flow velocity in the range of 0.125-4.5 m/s. In most cases, the error was limited below 20%. One of the velocity sensors was deployed at a USGS stream-gaging station. Through continuous velocity measurement over a one-year period, the measured point velocities were used to generate an index-rating curve, which was then used to estimate the mean velocity from measured point velocity. This experiment demonstrated the possibility of using both stage and point velocity measurements to provide better discharge estimation., Prepared in collaboration with the BAE Department, Kansas State University, Manhattan, and Oklahoma State Univ, Stillwater.

The long-term goal of this work is to develop a fundamental understanding and predictive capability of the underlying physics of the interaction of nonlinear internal waves (NLIWs) with the continental shelf seafloor over a broad range of environmental conditions. We are particularly interested in how such interactions impact underwater optics and acoustics and shelf energetics and ecology by simulating enhanced bottom boundary layer (BBL) turbulence and particulate resuspension leading to benthic nepheloid layer (BNL) formation. The specific objectives of this project are as follows: using Large Eddy Simulations (LES), we investigate the structural transition to turbulence within the separated BBL layer under a NLIW of depression and quantify the resulting NLIW energy losses; by means of Lagrangian coherent structure (LCS) theory, we identify mechanisms for capturing nearbed particles by the BBL-turbulence and their transport/deposition into BNLs; we analyze field observations from the New Jersey shelf to identify the applicability of hypothesized BBL physics and flesh out the underlying fluid mechanics from the field data.

Geotextile tubes filled with sand are being evaluated for filter treatment of runoff containing lead and other metals stemming from firing small arms on military training ranges. Such filter tubes trap total suspended sediment (TSS) in the runoff, thus removing most of the metals, which are adsorbed to the sediment. Mathematical models were developed within two Excel workbooks to assess sand filter performance for a cascade of filters capturing runoff from the impact area of small arms firing ranges. One of the workbooks assesses filter cascade characteristics for a single design storm, while the other workbook assesses filter characteristics for a continuous, steady rainfall so that the useful life of the filters, as impacted by clogging, could be estimated. Model computations include the approach depth of flow, including filter over-topping, and the flow rate through each filter over time for specific storm events. The time history of effluent TSS concentration and the TSS trapped within each filter are also computed, as well as the TSS removal coefficient and hydraulic conductivity of each filter. The models provide useful general performance information. In order to provide more specific performance information, laboratory experiments with site-specific sand filter material and runoff TSS are required to determine three filter parameters that can be used as part of the model input., The original document contains color images.

The long-term goal is to improve our capabilities for remotely sensing and modeling water column properties in shallow coastal bays, especially suspended sediment concentration and other contributions to water clarity/turbidity, and their spatial and temporal variability.

Our research in the mouth of the Columbia River has four primary objectives: 1. Measure the variability of optical properties in-space in the mouth of the Columbia River on ebbing and flooding tides during a high flow period; 2. Relate this variability to the concentration and dynamics of dissolved and particulate materials, including variability in the particle size distribution; 3. Relate the optical properties to the ocean reflectance, so algorithms to invert surface color to in-water constituents can be tested and improved; 4. Investigate sediment parameters that optimize fit between derived suspended sediment distribution in the Columbia River mouth and the distribution produced by Delft-3D.

A three-dimensional mixture theory model (SedMix3D) was used to simulate the flow and sediment transport over vortex ripples for scaled laboratory conditions. SedMix3D treats the fluid-sediment mixture as a continuum of varying density and viscosity with the concentration of sediment and velocity of the mixture calculated using a sediment flux equation coupled to the Navier-Stokes equations for the mixture. Mixture theory allows the model to simulate the three-dimensional flow and sediment concentration within and above an evolving sediment bed. Grid spacing was on the order of a sediment grain diameter and time steps were O(10-5 s). The simulation was forced with a time series of free-stream velocity measured in a free-surface laboratory flume. Spatial variations in the simulated suspended sediment concentration were primarily associated with the non-uniform generation of vortex structures over the ripple flanks. The suspended sediment was initially picked up in regions of high vorticity, and then caused a damping of the vorticity while being advected through the water column., Presented at Marine and River Dune Dynamics MARID IV held in Bruges, Belgium on 15-16 Apr 2013. Published in Proceedings of MARID IV, p209-213, 2013. Sponsored in part by the DoD High Performance Computing Modernization Program.

Fine-grained sediments constitute a major stressing factor for the aquatic ecosystem in the 15 000 km2 Kharaa River catchment in Northern Mongolia. The objectives of this study were to identify the suspended sediment (SS) sources and quantify the sediment budget of the basin. Sediment sources were identified with the help of sediment tracing methods utilizing Be-7, Cs-137 and Pb-210 radionuclides. High-resolution discharge data were used in combination with daily suspended solid measurements to calculate the SS budget. These calculations were compared with the monthly archive data on SS and discharge to investigate temporal load variations. In addition, the sediment budget model SedNet was used to estimate the SS budget and test its applicability in a cold semi-arid region. Results of the sediment tracing showed that riverbank erosion generates 74.5% of the suspended sediment load, whereas surface erosion contributes 21.7% and gully erosion only 3.8%. In the most intensely used agricultural tributary catchment Zagdelin Gol, upland erosion contributed only 12.7% to the total SS losses. The calculated mean annual sediment load for the years 1990–2002 was 20.3 kt⋅a−1. The SedNet model computed SS export from the catchment in the same order of magnitude as measured data (16.2 kt⋅a−1). The results help to identify effective management measures to reduce sediment loads and mitigate its impact on the aquatic environment.

This Coastal and Hydraulics Engineering Technical Note (CHETN) summarizes estuarine suspended sediment budgets developed for several estuaries of the Chesapeake Bay in Maryland and Virginia (Herman and Friedrichs 2010). These sediment budgets provide better understanding of sediment transport patterns and pathways, and will aid in improving Regional Sediment Management (RSM) practices in the US Army Engineer Districts, Baltimore and Norfolk. Sediment budgets were calculated for the Patuxent River, Maryland; York River, Virginia; and a partial budget was developed for the Potomac River, Maryland.

The long term goal of this work is to develop a fundamental understanding and predictive capability of the underlying physics of the interaction of nonlinear internal waves (NLIWs) with the continental shelf seafloor over a broad range of environmental conditions. We are particularly interested in how such interactions impact underwater optics and acoustics and shelf energetics and ecology by stimulating enhanced bottom boundary layer (BBL) turbulence and particulate resuspension leading to benthic nepheloid layer (BNL) formation., Prepared in collaboration with the Department of Aerospace Engineering and Engineering Mechanics, San Diego State University, San Diego, CA.

The wave-driven dynamics of the coastal ocean, which is important for transport processes, mixing and circulation, is strongly affected by mud deposits on the continental shelf and in the nearshore. However, the mechanics of wave-mud interaction and the impacts on coastal wave dynamics is not well understood. The overall objective of this work is to contribute to the understanding of the macroscale damping effects of mud on waves and to improve modeling and prediction of wave evolution along muddy coastlines. The specific objectives of the proposed effort are to: 1) establish a comprehensive dataset from two new datasets acquired in 2008 (ONR-funded wave-mud MURI) of waves propagating across more than 25 km over a muddy seafloor, and 2) determine the characteristics of mud-induced dissipation of wave energy from intermediate- to shallow-water depths., The original document contains color images.

The ability to predict the sound field in shallow water is constrained by the knowledge of the geoacoustic properties of the bottom. The long term objectives of this research project are related to the investigation of experimental methods and inversion techniques for estimating parameters of geoacoustic models of the ocean bottom and the associated uncertainties in the model parameter values. The specific goals are to evaluate the performance of geoacoustic inversion techniques that have been developed for use in range-dependent shallow water environments, and synthesize the results obtained for characterizing the seabed from the SW06 and other recent experiments. The wider context of this research is to achieve improved sonar system performance through greater understanding of the physics of the interaction of sound with the ocean bottom. There are two objectives in this research report. The first is to compare the performance of geoacoustic inversion methods that have been developed for estimating geoacoustic models from acoustic field data. The inversion performance has been assessed previously in ONR Benchmarking workshops (Tolstoy et al., 1998; Chapman et al., 2003) that used simulated acoustic fields for several candidate shallow water waveguide environments. The hypothesis in this work is that data from the ONR SW06 experiment can serve as an experimental benchmark for assessing inversion performance against real data. This report compares the performance of geoacoustic inversion methods that were used to estimate parameters of geoacoustic profiles in SW06. These include matched field inversion, reflection coefficient and bottom loss inversion, and wavenumber extraction inversion. A critical issue in the many of the inversion methods is the impact of uncertainty in the knowledge of the ocean environment and the experimental geometry on inversion performance. A second objective in this work is to investigate approaches for estimating geoacoustic model paramet, The original document contains color images.

Ocean waves are an important aspect of upper ocean dynamics, in particular on the shallow continental shelves and in coastal areas. The long-term objective of this work is to advance modeling capability in such coastal areas by improving model representations of effects associated with nonlinearity, inhomogeneity, and dissipation. The specific objectives of the present work are 1) to develop and implement an efficient and scalable approximation for the nonlinear quadruplet source term, 2) to develop and implement a generalized nonlinear source term that is accurate in water of arbitrary depth, 3) to develop and implement an improved nonlinear closure for triad nonlinear interactions in shallow water, and 4) improve representations of dissipation by wave breaking and wave-bottom interactions in shoaling waves. This project is a collaboration with Tim Janssen and Gerbrant van Vledder (see also their annual report). My primary responsibility in this joint effort is the dissemination and analysis of field observations., The original document contains color images.

The long-term goal of our research is to improve fundamental understanding and numerical representation of coastal bottom-boundary layer processes, with an emphasis on sediment dynamics. Our aim is to improve quantitative regional-scale models describing the relationships among meteorological and oceanographic forcing, freshwater influx, particle resuspension, and transport and accumulation of sediment in the coastal ocean. We are participating in the Optics Acoustics and Stress In Situ (OASIS) project to focus on the interaction between bed and suspended sediments and the influence of fine sediment and flocs on optical properties in the water column. Quantitative understanding of bottom-boundary layer processes and sediment dynamics is important to the Navy because these processes determine environmental conditions in coastal regions, including current speeds, turbulence, water-column turbidity, and bottom acoustic properties., The original document contains color images.

Our long term goal is to develop a tested model of optical properties in the surf zone and adjacent nearshore ocean, including the influence of suspended sediment, bubble population and surface foam, to assess how optical properties are related to short term events such as individual breaking wave crests, and to determine how wave-driven surf zone circulation influences spatial distribution of optical properties just offshore of breaking through seaward transport of fine sediment, small persistent bubbles and surface foam., The original document contains color images.

LONG-TERM GOALS: *To link the geotechnical properties of sediment substrates to the spatial and hydrodynamic characteristics of tidal channels *To develop new morphological indicators of tidal flat morphodynamics that can be easily derived from remote sensing images. To link these indicators to mechanical properties of tidal flat substrates, The original document contains color images.

LONG-TERM GOALS: To develop a robust coastal/nearshore modeling system for inlet hydrodynamics, sediment deposition/resuspension, river plume processes and the resulting morphodynamics in a highly dynamic environment dominated by strong tidal flows and waves. OBJECTIVES: *To study the interactions of tidal flow, waves and complex bathymetry at New River Inlet, NC using NearCoM-TVD and field data observed during the recent field campaign through close collaboration with other researchers. *To study how a spatially/temporally varying bottom friction parameterization due to wave-current interactions, seabed dynamics (bedforms; sheet flows) can affect the hydrodynamics, sediment transport and the resulting morphodynamics of a tidal inlet. *To investigate the relationship/correlations between the flow variables computed from the numerical model results and remotely-sensed signatures., The original document contains color images.

The main objectives of our FY12 effort were to: 1) measure the intra-tidal three dimensional flow velocity distribution; 2) measure the concurrent suspended sediment concentration (the accompanying sediment transports will be obtained by multiplying the concentration with the simultaneously measured velocity); 3) extract the tidal flow circulation with Delft 3D to retrieve the residual flow circulation associated with the forcing by waves, wind and density differences; 4) verify Delft3D in predicting the complex velocity field and concurrent sediment transports under a range of environmental conditions (i.e. waves, wind and potentially stratification)., The original document contains color images. Prepared in collaboration with Rosenstiel School of Marine and Atmospheric Science, Miami, FL, under grant nos. N00014-10-1-0409, N00014-10-1-0379.

The goal of this research is to quantify through observations and modeling how density fronts in shallow estuarine flows impact the mobilization, redistribution, trapping, and deposition of suspended sediment., The original document contains color images.

The purpose of this technical note is to describe a laboratory system. The laboratory system was developed to expose early life history stages of fish and shellfish to specified concentrations and durations of suspended sediment in a controlled laboratory environment. This allows for the design of experiments that simulate resuspension of sediment as a result of dredging operations or other factors such as vessel traffic, freshets, or storms. The design and construction of the Fish Larvae and Egg Exposure System (FLEES) permits studies to be performed using various aquatic species and life stages (e.g., walleye eggs, salmonid larvae, oysters) that are driving environmental windows on dredging project operations at one or more sites. By using the FLEES, exposure response curves can be developed between aquatic organism health and suspended sediment concentrations, thus generating effects data that are needed to evaluate the effectiveness and necessity of EWs intended to protect the selected species., The original document contains color images.

Channel instability is a serious problem throughout the United States (U.S.). The magnitude of this problem is illustrated in the Corps of Engineers final report to Congress for the Streambank Erosion Control Evaluation and Demonstration Program, which reported that the U.S. contains over one-half million (574,000) miles of eroding bank lines (USACE 1981). Dams, levees, diversion structures, and the straightening, widening, deepening, and clearing of channel systems are common methods used to provide flood control, navigation, water supply, sediment management, irrigation, recreation, and hydropower. The cumulative impacts of these types of activities, combined with watershed changes such as de-forestation and urbanization, have significantly disrupted the dynamic equilibrium of stream systems and the related ecosystems. The sediments generated by these disturbances clog flood-control channels, destroy wetlands and lakes, adversely impact fish and wildlife habitats, degrade the water quality of streams, adversely impact infrastructure, and initiate accelerated stream instabilities. The accelerated sediment yields associated with these watershed instabilities are particularly a problem with respect to sedimentation in reservoirs.

Ocean waves are an important aspect of upper ocean dynamics, in particular on the shallow continental shelves and in coastal areas. The long-term objective of this work is to advance wave modeling capability in such coastal areas by improving model representations of effects associated with nonlinearity, inhomogeneity, and dissipation. The specific objectives of the present work are 1) to develop and implement an efficient and scalable approximation for the nonlinear quadruplet source term, 2) to develop and implement a generalized nonlinear source term that is accurate in water of arbitrary depth, 3) to develop an improved nonlinear closure for triad nonlinear interactions in shallow water, and 4) improve representations of dissipation by wave breaking and wave-bottom interactions in shoaling waves., Prepared in cooperation with Theiss Research, El Granada, CA and the Department of Civil Engineering and Geosciences, Delft University of Technology, The Netherlands.