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 18 of 18 for “"Stream chemistry"”.
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The influence of urbanization on runoff generation and stream chemistry in Massachusetts watersheds
… attributes influenced by urbanization on stream nutrient concentrations in headwater catchments in Massachusetts. In addition, I evaluate the importance of surface versus subsurface flow paths during rainfall events in stormflow generation in a small urban catchment. The percentage of …
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Impacts of climate change on stream hydrologic and geochemical fluxes
… stored and transported before it contributes to streams. However, hydrologists don’t currently have the data needed to constrain or model how subsurface flowpaths are changing, thus making it difficult to predict future streamflow and chemistry. Characterizing changing flow and chemistry in …
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Evolution of chemical composition along river drainage networks
<p>Surface water chemistry from a tropical and temperate rivers system was studied in order to understand the controls on longitudinal variation of stream chemistry. In the Rio Icacos-Blanco system in Puerto Rico, I examined changes in stream chemistry associated with a change in bedrock …
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Effects of Acid Deposition and Changing Climate on the Hydrochemistry and Critical Loads of Watersheds in the Adirondack Region of New York
… organic acids from soil. The future recovery of stream chemistry from acidic deposition may be altered by projected increases in temperature and precipitation associated with a changing climate. The goals of this study were to conduct a modeling analysis of the response of soils and streams in …
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Groundwater-surface water exchange within montane and alpine regions of the Front Range and Rocky Mountains, Colorado
… I have examined over 15 years of historical stream chemistry data within a subalpine creek within the Rocky Mountains and examined groundwater-surface exchange characteristics during low streamflow within a montane creek within the Front Range. An end-member mixing model was performed on …
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General reviews of electrochemical and corrosion phenomena under conditions associated with supercritical water oxidation
… toxic organic compounds present in aqueous waste streams. Organic wastes that have been identified as possible targets for destruction by SCWO include EPA-regulated organic wastes, organic components of DOE mixed low-level radioactive wastes, and DOD chemical weapons stockpiles. SCWO capitalizes …
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Quantifying Solute and Water Fluxes in Headwater Streams Using Passive Flux Meters
… to determine time-integrated patterns of water chemistry at one or many locations throughout a stream network while minimizing cost and sampling time. A passive flux meter (PFM) simultaneously estimates time-averaged water and solute mass fluxes in flowing water. PFMs have been used in …
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Seasonal Variation in Whole Stream Metabolism across Varying Land Use Types
Historically, whole stream open channel metabolism has been measured over short periods in conjunction with nutrient injections to assess nutrient dynamics within streams. The purpose of my study was to understand the seasonal changes in metabolism within and among streams as well as the impacts of …
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Causal history analysis of complex system dynamics
… natural systems, such as the fractal dynamics of stream chemistry, the chaotic behavior of atmospheric convection, the entropy production due to the dissipative structure of plants, and so forth. Multivariate interactions of the entire system definitely play a key role in sustaining these emergent …
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NUTRIENT RETENTION BY RIPARIAN FORESTED BUFFERS IN WESTERN MARYLAND: DO THEY WORK AND ARE THEY WORTH IT?
… western Maryland, we conducted two synoptic stream chemistry studies that contained forest buffers planted under CREP and a range of pre-existing natural forested riparian zones. We used a steady-state reach mass balance model to estimate lateral groundwater inputs and tested several nutrient …
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Hydrochemical dynamics on sub-Antarctic Marion Island
… Mg²⁺, K⁺, Na⁺, Cl⁻ , SO4²⁻, NO³⁻). In addition, stream water physicochemistry (pH, water temperature, dissolved oxygen and total dissolved solids) was monitored in situ at a single site in the stream at 5 minute resolution for the duration of the field campaign. Monthly precipitation δ²H and δ¹⁸O …
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Surface Water Impacts from Active Underground Mining
… to assess optimal barrier pillar size for stream protection. Typical analytical and empirical methods used in mine planning were compared against SDPS methods to ensure the validity and advantage to the use of SDPS for this purpose. Finally, underground mining effects on stream chemistry …
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The Effects of Urban Land Use Type on Low Order Stream Geochemistry, Columbus, Ohio
… Some previous studies on urban impacts to streams have primarily examined the bulk chemical contributions to high order rivers and streams, while not focusing so strongly on the tributaries that control their chemistry. Small scale analysis of solute concentrations in urban tributaries is …
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The Effects of Vegetation on Stream Bank Erosion
… quality improvement, habitat restoration, and stream bank stabilization. While considerable research has been conducted on the effects of riparian buffers on water quality and aquatic habitat, little is known about the influence of riparian vegetation on stream bank erosion. The overall goal of …
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Spatial and temporal analysis of pharmaceutical concentrations and chitobiase activity in the Upper Tennessee River
… Composite surface samples were collected upstream and downstream of sewage treatment plants and at the inflow of major tributaries to the Tennessee River to determine the presence and potential sources of pharmaceuticals. Subsurface samples were collected at 7 meters depth to determine …
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Changes in water chemistry and fluvial geomorphology from arsenic contaminated floodplains of Whitewood Creek and Belle Fourche River, South Dakota
… The introduction of mine tailings into these streams has impacted them chemically and geomorphologically for over 100 years. This study is a continuation of the work from Ji (2021) who focused on the long-term behavior of arsenic in the mine tailings. Her work involved sequential extractions …
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Hydrological processes in volcanic ash soils : measuring, modelling and understanding runoff generation in an undisturbed catchment
Streamflow dynamics in mountainous environments are controlled by runoff generation processes in the basin upstream. Runoff generation processes are thus a major control of the terrestrial part of the water cycle, influencing both, water quality and water quantity as well as their dynamics. The …
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Modeling the interactions of forest cutting and climate change on the hydrology, biomass and biogeochemistry of a northeastern forest
… used to simulate forest biomass, and soil and stream chemistry at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA. Previous versions of PnET-BGC could accurately simulate the longer-term biogeochemical response to harvesting, but were unable to reproduce the marked changes in …