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DigitalCommons@USU
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The Ayuquila River watershed is important to western Mexico because of its biodiversity, physiography, fisheries resources, and water production. However, human activities are continuingly affecting natural resources within the basin. Soil...
2004-05-01
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The Colorado River in Glen, Marble, and Grand Canyons is subject to a complex regulatory framework, including the Colorado River Compact, the Endangered Species Act, and the Grand Canyon Protection Act of 1992. Physical, biological, and cultural...
2017-08-01
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The sum of benthic autotrophic and bacterial production often exceeds the sum of pelagic autotrophic and bacterial production, and hence may contribute substantially to whole-lake carbon fluxes, especially in shallow lakes. Furthermore, both...
2017-08-09
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Since the late 1990s, the central basin of Lake Erie has reputedly experienced an increase in the frequency and severity of hypoxic events. However, total phosphorus (TP) loading, in-lake TP concentrations, chlorophyll a (Chl a), and sediment...
2017-06-01
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The diel (24-h) oxygen (O2) curves approach has become a popular method for analyzing gross primary production (GPP) and ecosystem respiration (ER) rates in aquatic systems. Despite the simplicity of this approach, there remain aspects of the...
2017-02-01
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Anthropogenic activities can induce major trophic shifts in aquatic systems, yet we have an incomplete understanding of the implication of such shifts on ecosystem function and on primary production (PP) in particular. In recent decades,...
2016-12-01
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Ecosystems are generally linked via fluxes of nutrients and energy across their boundaries. For example, freshwater ecosystems in temperate regions may receive significant inputs of terrestrially derived carbon via autumnal leaf litter. This...
2016-03-01
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Food-web effects of winterkill are difficult to predict as the enhanced mortality of planktivorous fish may be counterbalanced by an even higher mortality of piscivores. We hypothesised that a winterkill in a clear and a turbid shallow lake would...
2015-05-01
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This study examines a natural, rapid, fivefold increase in dissolved organic carbon (DOC) concentrations in a temperate shallow lake, describing the processes by which increased DOC resulted in anoxic conditions and altered existing carbon cycling...
2014-07-01
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Lake ecosystems are strongly linked to their terrestrial surroundings by material and energy fluxes across ecosystem boundaries. However, the contribution of terrestrial particulate organic carbon (tPOC) from annual leaf fall to lake food webs has...
2014-05-01
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Ecological regime shifts and carbon cycling in aquatic systems have both been subject to increasing attention in recent years, yet the direct connection between these topics has remained poorly understood. A four-fold increase in sedimentation...
2013-11-20
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Regime shifts are commonly associated with the loss of submerged macrophytes in shallow lakes; yet, the effects of this on whole-lake primary productivity remain poorly understood. This study compares the annual gross primary production (GPP) of...
2013-11-01
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Surface carbon dioxide (CO2) emissions exhibit a high degree of spatial heterogeneity in the young boreal Eastmain-1 hydroelectric reservoir, located in northern Quebec, Canada. Estimates of the individual components of net CO2 production within...
2012-03-01
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[1] Lakes and reservoirs typically emit CO2to the atmosphere as a result of respiration in excess of primary production. For reservoirs, this respiration is often assumed to be primarily of benthic origin, associated with drowned vegetation and...
2012-03-01
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Over the last 20 years there has been a surge of interest in paleolimnology and as a result a large accumulation of lake sedimentation records. This emerging archive has allowed us to develop empirical models to describe which variables explain...
2008-11-01
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Water resources are increasingly impacted by growing human populations, land use, and climate changes, and complex interactions among biophysical processes. In an effort to better understand these factors in semiarid northern Utah, United States,...
2017-08-31
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[1] Previous flume-based research on braided channels has revealed four classic mechanisms that produce braiding: central bar development, chute cutoff, lobe dissection, and transverse bar conversion. The importance of these braiding mechanisms...
2013-06-01
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Previous studies have identified water meter inaccuracy at low flows in mechanical metering technologies; however, little has been done to measure the inaccuracy of electronic metering technologies at low flows. This study confirms previous...
2016-06-01
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Experimental and simulated performance factors for a 48-in.-diameter butterfly valve were compared for various valve openings and flow conditions to determine the validity of using computational fluid dynamics (CFD) to predict butterfly valve...
2015-01-01
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Although accurate flow measurement is a requirement in many applications, flowmeters are often installed in unfavorable conditions. Any time a flowmeter is installed close to a flow disturbance, such as a pipe fitting or a valve, the installation...
2016-08-01
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The use of fixed-cone valves (FCV) to dissipate energy has proven to be very effective for medium to high heads. Because of the large area required for energy dissipation through dispersion, a hood or other structure may be used to contain the...
2015-01-01
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Fixed-cone valves, also known as Howell-Bunger valves, are devices often used to dissipate energy from flow discharged at dams with medium to high heads. If the hood is not precisely placed, a phenomenon known as backsplash will occur. In low...
2014-01-01
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Nonsymmetric bifurcations, commonly used in piping systems to divert flow from one pipe to another, see considerable use in hydroelectric power applications and low-level outlet works at dams. Under normal operation, cavitation at the bifurcation...
2014-01-01
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The writers examine possible remediation options to mitigate the dangers found at low-head dams, using computational fluid dynamics and physical model tests. The objective was to identify an option that could be relatively simple to implement,...
2014-04-01
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