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 21 for “"stream networks"”.
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State-space models for stream networks
The natural branching that occurs in a stream network, in which two upstream reaches merge to create a new downstream reach, generates a tree structure. Furthermore, because of the natural flow of water in a stream network, characteristics of a downstream reach may depend on characteristics of …
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Theory of the growth and shape of Laplacian stream networks
Rivers self-organize into fractal river networks, with each river fed by smaller rivers, down to the scale of narrow rivulets. Certain groundwater-fed river networks develop stable and clearly delineated valley networks, which grow over time through headward erosion at the springheads. These …
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Scale dependent genetic structure of Idaho Giant salamanders (Dicamptodon aterrimus) in stream networks
Stream network structure constrains population processes of freshwater organisms, with individual, population and community level consequences. This consistent structure provides a framework in which examination of life-history influences on population genetic structure may provide general insight. …
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Scale dependent genetic structure of Idaho Giant salamanders (Dicamptodon aterrimus) in stream networks
Stream network structure constrains population processes of freshwater organisms, with individual, population and community level consequences. This consistent structure provides a framework in which examination of life-history influences on population genetic structure may provide general insight. …
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Fractal and Multifractal Analysis of Runoff Time Series and Stream Networks in Agricultural Watersheds
… of fractal scaling behavior of runoff and stream network morphometry in agricultural watersheds has not been previously reported. In the present study, fractal and multifractal scaling of daily runoff rate in four experimental agricultural watersheds and their associated sub-watersheds (32 …
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Effects of stream network topology on fish assemblage structure and bioassessment sensitivity in the mid-Atlantic highlands, USA
Stream fish assemblages exist within stream networks defined by the size and proximity of connected streams (i.e., stream network topology). The spatial position of sites within stream networks may therefore regulate opportunities for fish dispersal to access distant resources or colonize "new" …
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The role of dispersal networks in structuring biotic communities: A tale of streams and metacommunity theory
… may vary temporally and spatially. In dendritic stream networks, headwater streams are isolated when compared to more centrally located mainstem stream sections. I investigated the potential for stream networks to influence the relative influence of local and regional processes via a survey and …
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Geomorphic modeling and routing improvements for GIS-based watershed assessment in arid regions.
… of event-based hydrologic models for ephemeral stream networks declines significantly as watershed size increases. The second is that no single model is capable of simulating runoff, erosion, and geomorphic response in the channel network for multiple consecutive events. A diffusion-wave routing …
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Upstream Population Gradient Drives Freshwater Salinization in the Occoquan Watershed
… efforts, urbanization's relationship with in-stream salinity was analyzed, where its exerted influence was found to be dependent upon overland hydrologic flowpaths which connect urban areas to stream networks. The analysis was then broadened to Multiple Linear Regression models of urban and …
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Dynamic topography of the western Great Plains : geomorphic and 40Ar/39Ar evidence for mantle-driven uplift associated with the Jemez lineament, New Mexico and SE Colorado
… zone of broad (50-100km) convexities in stream profiles identified by an analysis of channel steepness (5) reorganization of stream networks from ESE-flowing streams, to a SSE flowing Canadian River that takes advantage of a relative base level fall in the SE, and (6) a ~150-km-long, …
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Influence of stream connectance and network spatial position on fish assemblage structure in the Kansas River basin, USA
Stream networks provide complex habitats for fish assemblages that can vary gradually along a gradient of stream size or abruptly at transition zones between large rivers and their tributaries. We evaluated the relative importance of these gradual and abrupt habitat transitions in regulating stream …
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Field delineation of geomorphic process domains along river networks in the Colorado Front Range
Many of the conceptual models developed for river networks emphasize progressive downstream trends in morphology and processes. Such models are well-suited for larger, low-gradient rivers, but fall short in describing the extreme variability associated with headwater streams, which occupy the …
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Intra- and Inter-Seasonal Variability of Supra-Glacial 1 Streams and Lakes over the West Greenland Ice Sheet 2 from High-Resolution Satellite Optical Data
… ice sheet. The spatial distribution of surface streams is poorly understood and their temporal variability is (to our knowledge) unknown. One of the reasons for the lack of knowledge on the temporal variability of such streams is related to the historical unavailability of satellite data that …
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Effects of Stream Order and Data Resolution on Sinuosity Using GIS
… research focuses on estimation and analysis of stream sinuosity using GIS. Fifty-five streams including 13 streams of order 0, 17 streams of order 1, 15 streams of order 2 and 10 streams of order 3 in Virginia were considered. Several GIS datasets from various sources, including the Virginia …
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A New Paradigm Of Modeling Watershed Water Quality
… and reactive chemical transport in river/stream networks of watershed systems; (2) sediment and reactive chemical transport in overland shallow water of watershed systems; and (3) reactive chemical transport in three-dimensional subsurface systems. Through the decomposition of the system …
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Interaction of Clay Wash Load With Gravel Beds
… The effects of excess fine sediment loading to streams on general water quality, contaminant transport, and benthic organism mortality has been well examined. A fundamental assumption in fluvial geomorphology and river engineering is that wash load particles ($d<63mu m$) do not deposit to stream …
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Application of Morphometric Relationships to Active Flow Networks Within the Mammoth Cave Watershed
… to describe the nature of surface-drainage networks. These parameters have been used in various studies of geomorphology and surface-water hydrology, such as flood characteristics, sediment yield, and evolution of basin morphology. Little progress has been made in applying these quantitative …
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Stormwater and organic matter in the urban stream continuum
… landscape (transporting DOM</p><p>from land to stream). This dissertation examines DOM in urban stream networks,</p><p>exploring its sources, bioavailability, and broad patterns throughout the continental</p><p>United States.</p><p>We determined the role of impervious infrastructure as a …
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Distributed Hydrologic Modeling of the Upper Roanoke River Watershed using GIS and NEXRAD
… Model results are evaluated against observed streamflow at seven USGS stream gage locations throughout the watershed. Runoff model inputs and parameters are developed from public domain digital datasets using commonly available GIS tools and public domain modeling software. Watersheds and …
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Multiscale Anthropogenic Impacts on Stream Condition and Fish Assemblages in Amazonian Landscapes.
… particular for the complex network of low-order streams that make up the vast majority of its watercourses. These streams connect terrestrial and aquatic ecosystems throughout landscapes and host much, if not the majority, of the freshwater fish fauna of the Amazon basin, which itself is one of …
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