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Detailed observations of stream, soil, and groundwater chemistry were used to determine the role of fire, permafrost and snowmelt processes on the fluxes of carbon, nitrogen and major solutes from interior Alaskan catchments. We examined an experimentally burned watershed and two reference watersheds that differ in permafrost coverage (high, 53%; medium-burn, 18%; and low, 4%) during the FROSTFIRE prescribed burn in July 1999. The fire elevated stream nitrate concentrations for a short period during the first post-fire storm, but nitrate declined thereafter, suggesting that less severe fires that leave an intact riparian zone may have only a short-term effect on stream chemistry. Nevertheless, we found fundamental...
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Pogo Mine Project: An Introduction The Project: The proposed Pogo Gold Mine would be located about 38 miles northeast of Delta Junction, Alaska, near the Goodpaster River (see figure 1). Teck-Pogo, Inc., the "applicant," plans to develop the mine on state-owned land. It would be an underground mine with a surface mill producing up to 500,000 ounces of gold each year. The applicant hopes to begin construction in 2002, and proposes to operate the mine 24 hours a day, 365 days a year, for about 12 years. This predicted mine-life is based on existing information; on-going exploration could increase the life of the mine. The project would employ up to 385 employees. Workers would be housed on site. An airstrip would...
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This paper examines changes in climate with respect to permafrost and engineering design in Arctic regions. Current understanding of climate changes, predictive modeling, and climate data were studied. Inconsistencies and differences were noted, discussed, and evaluated using comparisons of the resulting climate data and graphs. A graphical analysis was done to compare different methods of data analysis and different visual interpretations of historical climate trends. The graphical analyses in this paper should be used as a guide for determining the accuracy of thermal design parameters applied to current project designs. The methodology used to evaluate raw data can greatly affect the output values used in design....
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Permanent electrode arrays were set up at ten monitoring sites from Whitehorse, Yukon, to Fort St. John, British Columbia, in order to gain a clearer perspective of the effectiveness of electrical resistivity tomography (ERT) monitoring over an annual cycle of freezing and thawing. This research forms part of a longer-term project that is attempting to use ERT to examine changes in permafrost resulting from climate change. Inter-site and intra-site variability were examined by installing and maintaining data-loggers to monitor active layer and shallow permafrost temperatures, air temperatures, and snow depths at each site from August 2010-August 2011. Additional site information was collected on each ERT survey...
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We investigated spatial variability in the community structure of stream macroinvertebrates at six reaches within Caribou-Poker Creeks Research Watershed in the Alaskan taiga forest. Stream reaches differed most notably in river continuum position (stream orders 1–4) and influence of permafrost. Permafrost may underly much of an entire watershed or may be only locally present in valley bottoms. Permafrost distribution influences hydrology, water temperature, and riparian vegetation. We sampled benthic macroinvertebrates six times during the ice-free season between June 1995 and June 1996. Mean invertebrate abundance (range: 1160–14494 individuals/ m2) was significantly different among sites, the lower values occurring...
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Understanding the role of permafrost in controlling groundwater flow paths and fluxes is central in studies aimed at assessing potential climate change impacts on vegetation, species habitat, biogeochemical cycling, and biodiversity. Recent field studies in interior Alaska show evidence of hydrologic changes hypothesized to result from permafrost degradation. This study assesses the hydrologic control exerted by permafrost, elucidates modes of regional groundwater flow for various spatial permafrost patterns, and evaluates potential hydrologic consequences of permafrost degradation. The Yukon Flats Basin (YFB), a large (118,340 km super(2)) subbasin within the Yukon River Basin, provides the basis for this investigation....
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Provisional Tennessee State Wildlife Action Plan (TN-SWAP) terrestrial habitat priorities versus results of the population growth model developed by the Tennessee Chapter of The Nature Conservancy, 2008, converted to percent projected developed landcover in the year 2040. Spatial growth model was developed using population growth projections from the University of Tennessee Center for Business and Economic Research (UT-CBER), county urban growth boundaries, 2000 census blocks, and various ancillary datasets.
Snow covered area (SCA) observations from the Landsat Enhanced Thematic Mapper (ETM+) were used in combination with a distributed snowmelt model to estimate snow water equivalent (SWE) in the headwaters of the Rio Grande basin (3,419 km2) - a spatial scale that is an order of magnitude greater than previous reconstruction model applications. In this reconstruction approach, modeled snowmelt over each pixel is integrated over the time of ETM+ observed snow cover to estimate SWE. Considerable differences in the magnitude of SWE were simulated during the study. Basin-wide mean SWE was 2�6 times greater in April 2001 versus 2002. Despite these climatological differences, the model adequately recovered SWE at intensive...
A severe sustained drought in the Colorado River Basin would cause economic damages throughout the Basin. An integrated hydrologic-economic-institutional model introduced here shows that consumptive water users in headwaters states are particularly vulnerable to very large shortfalls and hence large damages because their rights are effectively junior to downstream users. Chronic shortfalls to consumptive users relying on diversions in excess of rights under the Colorado River Compact are also possible. Nonconsumptive water uses (for hydropower and recreation) are severely affected during the worst drought years as instream flows are reduced and reservoirs are depleted. Damages to these uses exceeds those to consumptive...
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Staff from Alaska Earthquake Center, Geophysical Institute and Alaska Division of Geological & Geophysical Surveys evaluated potential tsunami hazards for the city of Sand Point, on Popof Island in the Shumagin Islands archipelago. We numerically modeled the extent of inundation from tsunami waves generated by local and distant earthquake sources. We considered the results in light of historical observations. The worst-case scenarios are defined by analyzing results of the sensitivity study of the tsunami dynamics with respect to different slip distributions along the Aleutian megathrust. For the Sand Point area, the worst-case scenarios are thought to be thrust earthquakes in the Shumagin Islands region with magnitudes...
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Potential tsunami hazards for the Fox Islands communities of Unalaska/Dutch Harbor and Akutan were evaluated by numerically modeling the extent of inundation from tsunami waves generated by hypothetical earthquake sources and taking into account historical observations. Worst-case hypothetical scenarios are defined by analyzing results of a sensitivity study of the tsunami dynamics related to various slip distributions along the Aleutian megathrust. The worst-case scenarios for Unalaska and Akutan are thought to be thrust earthquakes in the Fox Islands region with magnitudes ranging from Mw 8.8 to Mw 9.1 that have their greatest slip at 30-40 km (18-25 mi) depth. We also consider Tohoku-type ruptures and an outer-rise...
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The purpose of this study is to evaluate tsunami hazard for the community of Seward and northern Resurrection Bay area, Alaska. This report will provide guidance to local emergency managers in tsunami hazard assessment. We used a numerical modeling method to estimate the extent of inundation by tsunami waves generated from earthquake and landslide sources. Our tsunami scenarios included a repeat of the tsunami of the 1964 Great Alaska Earthquake, as well as tsunami waves generated by two hypothetical Yakataga Gap earthquakes in northeastern Gulf of Alaska, hypothetical earthquakes in Prince William Sound and Kodiak asperities of the 1964 rupture, and local underwater landslides in Resurrection Bay. Results of numerical...
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The dataset represents the work of multiple states and Federal agencies as part of the US Gap Analysis and LandFire programs. Multi-season satellite imagery (Landsat ETM+) from 1999-2001 were used in conjunction with digital elevation model (DEM) derived datasets (e.g. elevation, landform) to model natural and semi-natural vegetation. The minimum mapping unit for this dataset is approximately 1 acre. Landcover classes are drawn from NatureServe's Ecological System concept. Five-hundred and fourty-four land cover classes composed of 12 cultural and 532 Natural/Semi-natural types are described. Land cover classes were mapped with a variety of techniques including decision tree classifiers, terrian modeling, inductive...
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The dataset represents the work of multiple states and Federal agencies as part of the US Gap Analysis and LandFire programs. Multi-season satellite imagery (Landsat ETM+) from 1999-2001 were used in conjunction with digital elevation model (DEM) derived datasets (e.g. elevation, landform) to model natural and semi-natural vegetation. The minimum mapping unit for this dataset is approximately 1 acre. Landcover classes are drawn from NatureServe's Ecological System concept. Five-hundred and fourty-four land cover classes composed of 12 cultural and 532 Natural/Semi-natural types are described. Land cover classes were mapped with a variety of techniques including decision tree classifiers, terrian modeling, inductive...
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The dataset represents the work of multiple states and Federal agencies as part of the US Gap Analysis and LandFire programs. Multi-season satellite imagery (Landsat ETM+) from 1999-2001 were used in conjunction with digital elevation model (DEM) derived datasets (e.g. elevation, landform) to model natural and semi-natural vegetation. The minimum mapping unit for this dataset is approximately 1 acre. Landcover classes are drawn from NatureServe's Ecological System concept. Five-hundred and fourty-four land cover classes composed of 12 cultural and 532 Natural/Semi-natural types are described. Land cover classes were mapped with a variety of techniques including decision tree classifiers, terrian modeling, inductive...
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This dataset represents the location and class density of potential annual grass risk within the Central Great Basin and Mojave Basin Ecoregion for the 2010 time period. This model represent a composite of multiple inductive (Maximum Entropy) models of varying annual grass cover using non-spectral landscape variables. Input Variables: elevation, aspect, distance to fire, geology, distance to hydric soils, distance to intermitant streams, landform, ombrotype, distance to perrenial streams, soil pH, density of primary roads, density of secondary/local roads, percent sandy soil, slope, thermotype. Classification of Model 0-No/Low Risk 1- < 5% Cover Risk 2- 5%-15% Cover Risk 3 - 15%-25% Cover Risk 4 - 25%-45% Cover...
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Both tabular and spatial models were used to predict fire regime departure at the sub-watershed scale (i.e., HUC 10 units). Integrating the fire regime models with predicted changes in climate envelopes provides a clearer understanding of how these ecological systems are likely to respond to multiple stresses. The natural range of variability for each CE was initially derived from LANDFIRE Vegetation Dynamics Development Tool (VDDT) models. The VDDT allows for the development of probabilistic quantitative model of CEs consisting of multiple ecological states with both deterministic and probabilistic drivers. For any defined suite of drivers, the models predict the relative abundance of each state within a defined...
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Both tabular and spatial models were used to predict fire regime departure at the sub-watershed scale (i.e., HUC 10 units). Integrating the fire regime models with predicted changes in climate envelopes provides a clearer understanding of how these ecological systems are likely to respond to multiple stresses. The natural range of variability for each CE was initially derived from LANDFIRE Vegetation Dynamics Development Tool (VDDT) models. The VDDT allows for the development of probabilistic quantitative model of CEs consisting of multiple ecological states with both deterministic and probabilistic drivers. For any defined suite of drivers, the models predict the relative abundance of each state within a defined...
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This dataset was derived from 'NatureServe L48 ESLF V2.7'. See process steps for additional information. The dataset represents the work of multiple states and Federal agencies as part of the US Gap Analysis and LandFire programs. Multi-season satellite imagery (Landsat ETM+) from 1999-2001 were used in conjunction with digital elevation model (DEM) derived datasets (e.g. elevation, landform) to model natural and semi-natural vegetation. The minimum mapping unit for this dataset is approximately 1 acre. Landcover classes are drawn from NatureServe's Ecological System concept. Five-hundred and fourty-four land cover classes composed of 12 cultural and 532 Natural/Semi-natural types are described. Land cover classes...


map background search result map search result map Influence of permafrost distribution on groundwater flow in the context of climate-driven permafrost thaw: Example from Yukon Flats Basin, Alaska, United States Seasonal cycling in electrical resistivities at ten thin permafrost sites, southern Yukon and northern British Columbia Geometry of oriented lakes in Old Crow Flats, northern Yukon Export of carbon, nitrogen and major solutes from a boreal forest watershed: The influence of fire and permafrost Landscape patterns and stream reaches in the Alaskan taiga forest: potential roles of permafrost in differentiating macroinvertebrate communities POGO Gold Mine EIS/NEPA Project Tsunami inundation maps of Seward and northern Resurrection Bay, Alaska Tsunami inundation maps of Fox Islands communities, including Dutch Harbor and Akutan, Alaska Tsunami inundation maps for the city of Sand Point, Alaska Provisional Tennessee State Wildlife Action Plan Potential Urban Growth BLM REA COP 2010 NatureServe National Landcover (v27) ColoradoPlateauMixedBedrockCanyonTableland_NatureServe_DIST_30m BLM REA COP 2010 NatureServe National Landcover (v27) InterMountainBasinsBigSagebrushShrubland_NatureServe_DIST_30m BLM REA MAR 2012 NatureServe Terrestrial Ecosystems v2.9  - MAR BLM REA MBR 2010 Risk Model of Invasive Annual Grasses BLM REA MBR 2010 Ecological System Fire Regime Departure 2060 - Great Basin Pinyon-Juniper Woodland BLM REA CBR 2010 Ecological System Fire Regime Departure - 2025 Inter-Mountain Basins Curl-leaf Mountain Mahogany Woodland and Shrubland BLM REA CBR 2010 NatureServe GBSemiDesertChaparral Terrestrial Ecological Systems Tsunami inundation maps for the city of Sand Point, Alaska Tsunami inundation maps of Seward and northern Resurrection Bay, Alaska POGO Gold Mine EIS/NEPA Project Tsunami inundation maps of Fox Islands communities, including Dutch Harbor and Akutan, Alaska Landscape patterns and stream reaches in the Alaskan taiga forest: potential roles of permafrost in differentiating macroinvertebrate communities Export of carbon, nitrogen and major solutes from a boreal forest watershed: The influence of fire and permafrost Geometry of oriented lakes in Old Crow Flats, northern Yukon BLM REA MAR 2012 NatureServe Terrestrial Ecosystems v2.9  - MAR Influence of permafrost distribution on groundwater flow in the context of climate-driven permafrost thaw: Example from Yukon Flats Basin, Alaska, United States Provisional Tennessee State Wildlife Action Plan Potential Urban Growth Seasonal cycling in electrical resistivities at ten thin permafrost sites, southern Yukon and northern British Columbia BLM REA MBR 2010 Risk Model of Invasive Annual Grasses BLM REA COP 2010 NatureServe National Landcover (v27) ColoradoPlateauMixedBedrockCanyonTableland_NatureServe_DIST_30m BLM REA COP 2010 NatureServe National Landcover (v27) InterMountainBasinsBigSagebrushShrubland_NatureServe_DIST_30m BLM REA CBR 2010 Ecological System Fire Regime Departure - 2025 Inter-Mountain Basins Curl-leaf Mountain Mahogany Woodland and Shrubland BLM REA MBR 2010 Ecological System Fire Regime Departure 2060 - Great Basin Pinyon-Juniper Woodland BLM REA CBR 2010 NatureServe GBSemiDesertChaparral Terrestrial Ecological Systems