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 20 of 29 for “"environmental flows"”.
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Some problems in low Reynolds number environmental flows
This thesis investigates some problems in environmental fluid dynamics in which the role of inertia is negligible relative to viscous stresses and buoyancy forces. Simple models are developed to provide insight into the physics governing the flows and to determine the dependencies on a few …
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Environmental flows for English rivers: a focus on modified catchments
… have focused attention on the need to determine environmental flows (e-flows) to protect and sustain river ecosystems. Internationally there have been several advances but within England an anthropocentric approach to water resources management has led to polices that set minimum flows founded in …
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Buoyancy force driven mixing in environmental flows: Theory, observations and numerical modeling
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-05-01
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Planning for water scarcity in Jordan Valley : in defense of environmental flows in arid climates
… that restoring the river goes beyond direct flows and should be defined to include critical ecosystems that affect the hydrological cycle of the entire basin, including buffer systems and conservation reserves that support local communities. In the absence of fair reallocation mechanisms and …
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Ecologically relevant low flows for riverine benthic macroinvertebrates: characterization and application
… biotic response, particularly for determining environmental flows. While invertebrate response to floods has received most attention, in this thesis the aim was to identify and characterize low flows that constituted various degrees of physical disturbance to benthic macroinvertebrate …
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Incipient motion of mixed sediment load on the Rio Chama
… vegetative establishment and ecological impacts. Environmental flows are a way to find a middle ground for water resource managers and the physical and ecological needs of the river. The Rio Chama, between El Vado Dam and Abiquiu Reservoir was designated as a Wild and Scenic River in 1988. Along …
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Environmental Flow Regime Recommendations for the Promotion of Salicaceae Seedling Recruitment in California’s Central Valley
… with the receding instream and groundwater flows. Timing of these rates should correspond with Salicaceae seed release which range from mid-April to late May for Populus fremontii and from mid-May to late June for Salix spp. While much research has been conducted to prescribe environmental …
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Effects of water temperature on life history traits of selected South African Aquatic insects: implications for the ecological reserve
… thermal guidelines into legislation regarding environmental flows and associated water management plans. In South Africa radical new legislation introduced in 1996 resulted in rivers and aquatic ecosystems being given a right to water of their own- essentially environmental flows, required to …
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Study of the role of differential diffusion and equation of state on the features of stably stratified turbulent channel flow using direct numerical simulations
Stably stratified turbulent flows are observed in many systems, ranging from engineering applications to environmental flows. The density variation in such flows, particularly that observed in water bodies depends on temperature and salinity (salt content) through an equation of state (EoS). The …
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Modelling Transient Air-water Flows in Civil and Environmental Engineering
… of air‐water interactions in transient flows. A particular emphasis is set on phenomena relevant in civil and environmental engineering, like rivers, pipes, and hydraulic structures. Theoretical results of this doctoral research may be summarized in two main propositions. First, I show …
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Some Solutions to a Lens Model With Applications to Warm-Core Eddies
… for one asymmetric mode as well as specified environmental flows. The solution scheme is a polynomial expansion of the field variables. When inserted into the hydrographic equations, the expansion yields eight first-order differential equations for the time dependent amplitudes. This system of …
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A new optimization method for reservoir systems
… reliability of meeting water supply targets and environmental flows, flood risk, and reservoir depletion and recovery during and after droughts, among others) in detailed, head-to-head, simulations with HEC-ResSim, an independent modeling system developed by the U.S. Army Corps of Engineers. …
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Wind Induced Ground Motion
… for estimating ground surface shear stress under environmental flows in studies of soil erosion and sediment transport. Measurement results show that mounting the geophones flush with the ground provides a significant reduction in wind noise on all three components of the geophone. Further …
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Open channel turbulent boundary layers and wall jets on rough surfaces
For many industrial and environmental flows, the momentum and convective heat transfer rates at the surface are determined by the turbulence structure in the near-wall region. Although many flows of practical interest occur on rough surfaces, our understanding and ability to predict rough wall …
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Multiscale environmental flow dynamics: particle settling, turbulence modulation, and tornadic vortices
Environmental flows form the basis of processes that span sediment transport in rivers, drag reduction in pipelines, and the evolution of severe atmospheric vortices. Despite significant efforts to address related phenomena, a predictive, mechanistic description of how particles, non‑Newtonian …
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Beneficial use, sustaining rivers and good governance: at the interface of international and national water law - the case of South Africa as a riparian state
… processes for basin-wide agreement on environmental flows, and to introduce provisions to facilitate greater participation among rural and previously disadvantaged sections of society. The case studies demonstrate that the framework provides a robust tool for examining the interface …
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Energetics of Turbulence Explains Physical Transport Processes in the Environment
… of turbulent transport processes in environmental flows for a broad spectrum of applications, such as river restoration, sediment transport, and wetland design, is a widely acknowledged fact. Notably, turbulent eddies exert a substantial influence on transport phenomena, warranting …
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Modeling Flood Reduction Scenarios for a Small Coastal Community
… provides water for drinking, agriculture, and environmental flows; to characterize hydraulics of the Oceano Lagoon; and to explore scenarios for flood mitigation. Objectives of the study are to provide a better understanding of the causes of the historical floodings; map the extent of floodings …
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Feedbacks between plants, flow, and particle fate
Environmental flows carry a wide variety of particles that interact with vegetation. Vegetated canopies are anchored by sediment, release pollen and seeds to colonize new ground, rely on nutrients carried by sediment, and may be killed by disease spores. While the influence of vegetation on flow …
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Morphogenetic landscapes :
… creation of systems that respond to selective environmental conditions in extreme environments resulting in varying levels of habitation. The development of these morphogenetic landscapes was arrived at through two parts. The first was a rigorous analysis of the role that biology, ecology, …
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