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 10 of 10 for “"Topographic Index"”.
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Effect of Spatial Scale on Hydrologic Modeling in a Headwater Catchment
… of elevations used for the calculation of the topographic index, ln(a/tan b). The hydrographs generated by TOPMODEL with each grid cell size were compared in order to assess the sensitivity of TOPMODEL hydrographs to grid cell size. An increase in grid cell size from 15 to 120 meters resulted …
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The development of a methodology for the identification of potential wet grassland restoration sites in south west England
… topography was expressed as the ln(a/tan^) topographic index, in which 'a' is the upslope area draining through the point for which the index is calculated and 'fi' is the local slope angle. Culm grassland sites were generally found on positions with a topographic index larger than eight. A …
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Enhanced Soil Moisture and Streamflow Estimation in Ungauged or Data-Scarce Watersheds
… mechanism dominate. Chapter 2 proposes the topographic index (TI) as a tool to represent the spatial soil moisture patterns. Using unsupervised machine learning on in-situ soil moisture data from a 4.2 ha field, three distinct soil moisture groups were identified. TI values were classified …
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Comparison Watershed Selection When Applying the AllForX Approach for Sediment TMDL Development
… relationship between Virginia Stream Condition Index (VSCI) scores and AllForX values (a unit-less multiplier that is the ratio of a modeled existing sediment load divided by a modeled all-forested load condition) for an impaired watershed and several comparison watersheds to develop sediment …
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Identification of catchment runoff processes as a basis for defining water quality protection zones
… wetness distributions predicted by the Kirkby topographic index show significant discrepancies with the observed soil moisture distributions. A conceptual model for defining hydrology-based protection zones for overland flow combines areas of highest pollutant source risk with areas likely to …
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Essays on Water Quality Management for the Chesapeake Bay Watershed
… of best management practices (BMPs) based on topographic index (TI) to determine how targeting would affect costs of meeting nitrogen (N) loading goals for Mahantango watershed, Pennsylvania. We use the results from two climate models and the mean of the ensemble of seven climate models to …
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Observation-Based Algorithm Development For Subsurface Hydrology In Northern Temperate Wetlands
… positions has been represented</p> <p>using a topographic index approach. By incorporating a water table gradient into the VIC grid cell, subsurface-surface water exchange within the wetland can also be represented, dependent on land surface class. This algorithm was developed and evaluated …
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The ecology of eastern small-footed bats at Shenandoah National Park
… Park, Virginia, modeled bat abundance by topographic variables, and predicted bat abundance to talus slopes throughout the park to talus slopes classified with algorithms utilizing high-definition imagery and a topographic index measuring terrain ruggedness. Eastern small-footed bats were …
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Wetland landscape dynamics and its socio-ecological implications
… secondary terrain attributes using the compound topographic index (CTI) and the stream power index (SPI) generated from the United States Geological Survey (USGS) digital elevation model (DEM). The third part involved metric calculations, which were implemented based on the spatial patterning of …
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Improved Environmental Characterization to Support Natural Resource Decision Making: (1) Distributed Soil Characterization, and (2) Treatment of Legacy Nutrients
… including slope, catchment area, and topographic wetness, are derived from several DEMs. In chapter 2, these characteristics are spatially compared, and we found that small resolution rasters result in narrow flow paths relative to coarser rasters. In chapter 3, we isolate the analysis …