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Showing 1 to 20 of 35 for “"hyporheic zone"”.
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Physical, chemical, and microbial dynamics in the hyporheic zone
… where surface water mixes with groundwater (the hyporheic zone), is an important biogeochemical reactor, providing a variety of ecosystem services. In addition to hosting ecologically and economically important microbial processes, it is subject to dynamics in terms of inputs from the surface. In …
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Characterization of hyporheic zone processes of a northern prairie stream
<p> A hyporheic zone occurs beneath and adjacent to streams where surface water and groundwater mix. This zone is known to be a reservoir for solutes and a habitat for interstitial organisms. Hyporheic zone boundaries in the Tongue River, North Dakota, were investigated through examination of the …
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Mixing and Attenuation of Upwelling Groundwater Contaminants in the Hyporheic Zone
The hyporheic zone is the reactive interface between surface water and groundwater found beneath streams and rivers, where chemical gradients and an abundant biological presence allow beneficial attenuation of contaminants. Such attenuation often requires reactants from surface water and …
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Effect of Urbanization on the Hyporheic Zone: Lessons from the Virginia Piedmont
… are a cause of increasing concern. The hyporheic zone is an important part of stream ecosystems, and here we focus on the effect of urbanization on the hyporheic zone from ten first-to-second-order streams within the Virginia Piedmont. We use sediment hydraulic conductivity and stream …
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Using temperature profiles to investigate the hyporheic zone in an agricultural drainage ditch
… on ground water/surface water interaction and hyporheic zone processes in natural rivers and streams. Research into natural systems has revealed significant ground water/surface water interaction and a complex variability that depends primarily on surface conditions, subsurface composition, and …
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Investigation Of Pressure Fluctuations In The Hyporheic Zone In Response To Flow Around A Hydraulic Structure
… the water-riverbed interface. This study maps hyporheic pressure fluctuations as they are related to surface water velocity. The pressure map is used to evaluate lift enhancement and destabilization forces on the riverbed. High pressure events in the subsurface help generate a destabilizing …
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Arsenic transport in groundwater, surface water, and the hyporheic zone of a mine-influenced stream-aquifer system
… arsenic in groundwater, surface water and the hyporheic zone in a stream-aquifer system influenced by an abandoned arsenopyrite mine. Mine tailing piles consisting of a host of arsenic-bearing minerals including arsenopyrite and scorodite remain adjacent to the stream and represent a continuous …
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Preferential and Non-Darcy Flows in the Hyporheic Zone: Surface Water-Groundwater Hydraulics and Effects on Stream Functions
… the dominance of hydraulic conductivity (K) on hyporheic hydraulics and implications to hyporheic zone functions through a series of modeling studies and field experiments. Computational Fluid Dynamics (CFD) software was used to model the effect of varying K on weir-induced hyporheic exchange …
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Effect of Unsteady Surface Water Hydraulics on Mixing-Dependent Hyporheic Denitrification in Riverbed Dunes
… affects surface water (SW) quality. The hyporheic zone, where SW and groundwater interact, possesses unique biogeochemical conditions that can attenuate contaminants (e.g., denitrification), including mixing-dependent reactions that require components from both water sources. Previous …
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Complementary Effects of In-Stream Structures and Inset Floodplains on Solute Retention
… �Solute retention in off channel storage zones such as hyporheic zones and floodplains is typically necessary for significant reaction to occur. �Yet the effects of two common restoration techniques, in stream structures and inset floodplains, on solute retention have not been rigorously …
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Controls on Mixing and Non-Mixing Dependent Denitrification in River Hyporheic Zones
… processes in aquatic systems. The hyporheic zone has unique biogeochemical conditions, and is known to attenuate contaminants originating from SW and traveling through the hyporheic zone, together with necessary reactants. However, the ability of the hyporheic zone to attenuate …
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The hydroecology of groundwater-fed streams in a glacierised catchment
… of groundwater flow dynamics upon benthic and hyporheic macroinvertebrate assemblages. During periods of resource depletion benthic macroinvertebrate abundance was dependent upon contributions from specific flow pathways (DFSdeep), which supplied fine particulate organic matter. Dynamics of …
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Processes and community structure in microbial biofilms of the River Elbe: relation to nutrient dynamics and particulate organic matter
… the effects of microbial biofilms of the hyporheic zone of the river Elbe on nutrient dynamics and elimination. This resulted in four aspects, which were carried out separately. One aspect was the investigation of the dynamics of inorganic nitrogen compounds in the upper sediment layers, …
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HYPORHEIC FLOW, RESIDENCE TIMES AND NITROGEN REACTIONS IN A RIFFLE-POOL SEQUENCE, TRUCKEE RIVER, NV.
… that stimulates nitrogen transformations. In the hyporheic zone, physical and biogeochemical processes controlling nitrification and denitrification processes are directly linked. Thus, this dissertation investigates hyporheic flow, residence times, oxygen dynamics and nitrogen transformations of …
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Experimental Evaluation of Three Backward Transit Time Distributions (bTTD) for Solute Storage and Release During Hyporheic Exchange
Hyporheic exchange in streams supports many important ecosystem services but can also contribute to legacy pollution, by trapping less reactive contaminants in streambed sediments that are then slowly released back to the stream over time. In this study we evaluated three different analytical …
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Comparing Reach Scale Hyporheic Exchange and Denitrification Induced by Instream Restoration Structures and Natural Streambed Morphology
… may be attempted. One strategy is increasing hyporheic zone flow at baseflow by addition of instream structures. The hyporheic zone can be an area of increased biogeochemical activity, with potential enhancement of reactions such as denitrification. However, the comparative effects of various …
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A three dimension hyporheic model of the River Bure: Understanding the nutrient dynamics and the role of streambed heterogeneity
The hyporheic zone is often defined as the zone where mixing of surface water and groundwater occurs in shallow sediments beneath and adjacent to rivers. This mixing contributes to create unique biogeochemical conditions that may attenuate contaminants from either upstream surface water or …
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Flow and reactive transport modeling at the stream-groundwater interface
… water and the subsurface water is an important zone for retention, transformation and attenuation of these solutes. Streambed structures enhance these processes by increased water and solute exchange across this interface, denoted as hyporheic exchange. This thesis investigates the influence of …
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Physical and Deep-Learning-Based Explorations of Microbe-Mediated Reactive Transport Processes in Porous Media Across Scales
… of biomass growth and chromium reduction in the hyporheic zone. Furthermore, this dissertation details the development and performance-testing of deep-learning-based tools for the extraction of motion statistics from videos of particles and the upscaling of RT simulations. Overall, new tools and …
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Ecology and biogeochemistry of fluvial microphytobenthic communities on soft sediments
… biofilm communities exist on a transitional zone (the hyporheic zone) between surface water and underground water. This thesis explores the ecology and biogeochemistry of microphytobenthic communities over multiple spatial scales within the Hampshire Avon river catchment, south England. …
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