Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 13 of 13 for “"Hyporheic Flow"”.
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Hyporheic flow in a mountainous riverine system
Investigation into the effects of beaver dams on hyporheic exchange in peat dominated mountainous streams is needed to better understand stream-floodplain connections and improve our overall conceptual model of water storage and flow through riverine valleys. The objective of this study was to …
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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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Assessment of Hyporheic Exchange at In-stream Restoration Structures on Savage River, Garrett County, Maryland
… that in-stream restoration structures alter hyporheic exchange dynamics in restored channels; this study assessed hyporheic exchange at a recently constructed stream reach, including the effects of in-stream restoration structures. Hydrometric and thermal data were collected in the streambed …
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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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Quantification of Trapped Diluted Bitumen Droplets in Gravel: an Experimental Study
… sediment in rivers is more difficult. Hyporheic flow, where surface water flows through the streambed, is one of the contributing factors for sediment contamination, which has received little research attention. Therefore, a series of laboratory experiments were conducted in this study: …
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Water flow and heat transport modelling at the interface between river and aquifer
… by the advection of water. Characterizing the flow conditions in the streambed is challenging as flow patterns are often complex and multidimensional, driven by surface hydraulic gradients and groundwater discharge. This thesis presents the results of an integrated approach of studies, ranging …
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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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Quantifying groundwater-surface water interactions to improve the outcomes of human activities
… surface water in streams and groundwater in hyporheic zones and shallow fluvial aquifers, and how human beings influence these interactions and are influenced by them. The three chapters of this dissertation span scales from cm to km and locations from Upstate New York to the Peruvian Andes, …
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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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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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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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Investigating nitrate attenuation in an urban stream using stable isotope geochemistry and continuous monitoring
… in an urban stream during high and low flow periods. A wastewater treatment plant (WTP) on Pennypack Creek, an urban stream near Philadelphia, PA, increases nitrate concentrations to a mean of 8.5 mg-l-1 (as N). Concentrations decrease to 5.5 mg-l-1 about 7.5 km downstream. Reaches along …
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Experimental investigation of the impact of the permeable layer thickness on the surface flow above and the threshold for incipient motion of submerged objects
Previous work regarding flows over a permeable bed has confirmed that the flow characteristics deviate from those observed in impermeable rough boundary layers. However, the effect of the permeable bed thickness is not fully understood. Current models for threshold of incipient motion implicitly …