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Channel- and lens-shaped deposits of non-eolian red sandstone are enclosed within the eolian Leche-e Member of the Page Sandstone in south-central Utah. Detailed analysis of lithology and geometry, and regional correlation of the red sandstone deposits suggests that the channel-shaped scours and in-filling deposits were formed by ephemeral stream processes, in contrast to earlier interpretations that suggested a marine estuarine origin. We hypothesize that ephemeral streams transporting volcanic debris flowed toward the north and northeast along the western edge of the Page erg. Local avulsion, possibly caused by eolian damming of an adjacent drainage, led to stream flow into low areas of the Page erg. Entrainment...
Channel- and lens-shaped deposits of non-eolian red sandstone are enclosed within the eolian Leche-e Member of the Page Sandstone in south-central Utah. Detailed analysis of lithology and geometry, and regional correlation of the red sandstone deposits suggests that the channel-shaped scours and in-filling deposits were formed by ephemeral stream processes, in contrast to earlier interpretations that suggested a marine estuarine origin. We hypothesize that ephemeral streams transporting volcanic debris flowed toward the north and northeast along the western edge of the Page erg. Local avulsion, possibly caused by eolian damming of an adjacent drainage, led to stream flow into low areas of the Page erg. Entrainment...
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The dataset includes ecoregion specific species distribution models for 149 common fluvial fishes of the Conterminous U.S. Species models were developed for fluvial fishes considered common and native in each of the nine EPA Wadeable Streams Assessment program aquatic ecoregions (Herlihy et al. 2008) in which the species occurred. Common native species were identified as being geographically widespread and relatively abundant within ecoregions and utilize a wide variety of habitat types. Boosted regression tree models were used to develop presence/absence predictions for each of the National Hydrography Plus Dataset Version 1.0 (NHDPlusV1) stream reaches. The text files provided can be linked to the NHDPlusV1 data...
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This project, with funding support by the North Pacific Landscape Conservation Cooperative andpartners, will address the need to better understand the impact that climate change will have on oursalmon subsistence resources in southeast Alaska. Working with federal and state agencies, as well ascommunity-based organizations and tribal governments, this project will 1) build a network that supportslocal organizations in their efforts to collect stream temperature data, and 2) coordinate those efforts sothat the data will inform and empower management agencies, researchers, and communities to adapt tochanging conditions for fish in the freshwater stages of their lifecycles.
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This surficial-geologic map shows the distribution of unconsolidated deposits and undifferentiated bedrock in the Faith Creek area in the Circle A-4, A-5, B-4, and B-5 quadrangles. This map was prepared principally by the interpretation of 1:63,360-scale, false-color, infrared aerial photographs taken in 1979 and 1981 and is locally verified by ground observations during field work in 2007.
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Alaska Division of Geological & Geophysical Surveys (DGGS) has conducted 1:63,360-scale geologic mapping of the Sagavanirktok B-1 Quadrangle (640 square km�equivalent to four 7.5 minute quadrangles). This mapping project reinterprets micropaleontologic correlations for 17 Sagavanirktok Quadrangle wells, and reprocesses data from the one publicly-available seismic line. Surface geologic mapping, subsurface-to-surface stratigraphic age control, and seismic framework are required to reliably decipher the complex geology of this key area of the Brooks Range. Outcrops within the Sagavanirktok B-1 Quadrangle are the closest surface expressions of Prudhoe Bay source and reservoir rocks. This study yields critical petroleum-related...
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This report provides detailed (1:63,360-scale) mapping of portions of U.S. Geological Survey Circle B-2 (1955), B-3 (1955), B-4 (1952), C-2 (1955), C-3 (1955), and C-4 (1952) quadrangles. The area is part of the Circle mining district and adjacent to the Fairbanks mining district. This report includes detailed geologic, structural, stratigraphic, and geochronologic data. Based on the resulting geologic maps, field investigations, and laboratory materials analyses, the project has also generated derivative maps of geologic construction materials and geologic hazards.
Tags: Aereal, Aerial Photography, Aeromagnetic Survey, Age Dates, Alaska, State of, All tags...
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This 1:50,000 scale geologic map describes the distribution of unconsolidated deposits, identifies local geologic hazards, and provides information about the depositional environment and basic engineering properties of common surficial-geologic materials in and around Shaktoolik, Alaska. Map units are the result of combined field observations and aerial imagery interpretation. A suite of local ground observations were collected over a two-week period in July 2011 by a helicopter-supported team of DGGS geologists and collaborators. Field investigations included soil test pits, sample collection, soil and rock description, oblique aerial photography, and documentation of landscape morphology.
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Alaska Division of Geological & Geophysical Surveys (DGGS) has conducted 1:63,360-scale geologic mapping of the Sagavanirktok B-1 Quadrangle (640 square km�equivalent to four 7.5 minute quadrangles). This mapping project reinterprets micropaleontologic correlations for 17 Sagavanirktok Quadrangle wells, and reprocesses data from the one publicly-available seismic line. Surface geologic mapping, subsurface-to-surface stratigraphic age control, and seismic framework are required to reliably decipher the complex geology of this key area of the Brooks Range. Outcrops within the Sagavanirktok B-1 Quadrangle are the closest surface expressions of Prudhoe Bay source and reservoir rocks. This study yields critical petroleum-related...
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The Alaska Division of Geological & Geophysical Surveys (DGGS), in partnership with the U.S. National Cooperative Geologic Mapping Program, mapped approximately 450 mi2 of the Talkeetna Mountains region of central Alaska at 1:50,000 scale over the course of six weeks in 2014. This area contains significant exposures of Late Triassic mafic volcanics and gabbro sills that have been the focus of region-wide exploration for the Strategic and Critical platinum-group elements (PGEs). The area also exposes numerous inactive and possibly active faults which project through the area of proposed hydropower development. The resulting geologic map offers an improved understanding of the geology, structural history, and mineral...
Tags: 40Ar/39Ar, Aerial Geology, Aerial Photography, Alluvial, Alluvial Deposits, All tags...
The geomorphic effectiveness of extreme floods increases with aridity and decreasing watershed size. Therefore, in small dry watersheds extreme floods should control the age structure and spatial distribution of populations of disturbance-dependent riparian trees. We examined the influence of extreme floods on the bottomland morphology and forest of ephemeral streams in a semiarid region. Along six stream reaches on the Colorado Piedmont we examined channel changes by analyzing a rectified sequence of aerial photographs spanning 56 yr, and we investigated the spatial distribution of different-aged patches of forest by aging 189 randomly sampled cottonwood trees. Channel change in these ephemeral sand-bed streams...
Summary Relations between seepage flux and hydraulic properties are difficult to quantify in fluvial settings because of the difficulty in measuring these variables in situ. Tests conducted in a 1.5-m diameter by 1.5-m tall sediment-filled tank indicate that hydraulic gradient increased and hydraulic conductivity (K) decreased following the onset of downward seepage but both parameters were little changed following the onset of upward seepage. Reductions in K during downward seepage were more pronounced when surface-water current was sufficient to mobilize sediment on the bed. Averaged ratios of K determined during upward seepage to K determined during downward seepage (Kup/Kdown) through a sand-and-gravel bed increased...
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These data are remote sensing image-based classification maps of unvegetated river-derived sand along the Colorado River. One map is based on imagery acquired in May 2013 and is a classification of sand located above the wetted river channel in the imagery which was acquired at the approximate contemporary low-flow river discharge of 8,000 cubic feet per second (227 cubic meters per second) and extends from Glen Canyon Dam at Lake Powell to Separation Canyon at Lake Mead, a total distance of approximately 255 river miles (410 river kilometer). Three other maps are based on imagery acquired in May 2002, 2009, and 2013, respectively, and are classifications of sand located above the wetted river channel (at river...
Categories: Data; Tags: Arizona, Colorado River, Diamond Creek, GIS vector data, Geography, All tags...
Summary Seepage meters provide one of the most direct means to measure exchange of water across the sediment–water interface, but they generally have been unsuitable for use in fluvial settings. Although the seepage bag can be placed inside a rigid container to minimize velocity head concerns, the seepage cylinder installed in the sediment bed projects into and disrupts the flow field, altering both the local-scale fluid exchange as well as measurement of that exchange. A low-profile seepage meter designed for use in moving water was tested in a seepage meter flux tank where both current velocity and seepage velocity could be controlled. The conical seepage cylinder protrudes only slightly above the sediment bed...
Categories: Publication; Types: Citation; Tags: Ground water, Hyporheic, fluvial, seepage
Seepage rate and direction measured with a seepage metre modified for use in flowing water were greatly variable along a 300-m reach of a shallow, gravel-bed river and depended primarily on the local-scale bed topography. The median value of seepage measured at 24 locations was 24 cm/day, but seepage measured at specific sites ranged from −340 to +237 cm/day. Seepage also varied substantially over periods of hours to days and occasionally reversed direction in response to evolution of the sediment bed. Vertical hydraulic conductivity was related to seepage direction and was larger during upward seepage than during downward seepage; with differences ranging from 4 to 40% in areas of active sediment transport to more...
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Alaska Division of Geological & Geophysical Surveys (DGGS) has conducted 1:63,360-scale geologic mapping of the Sagavanirktok B-1 Quadrangle (640 square km�equivalent to four 7.5 minute quadrangles). This mapping project reinterprets micropaleontologic correlations for 17 Sagavanirktok Quadrangle wells, and reprocesses data from the one publicly-available seismic line. Surface geologic mapping, subsurface-to-surface stratigraphic age control, and seismic framework are required to reliably decipher the complex geology of this key area of the Brooks Range. Outcrops within the Sagavanirktok B-1 Quadrangle are the closest surface expressions of Prudhoe Bay source and reservoir rocks. This study yields critical petroleum-related...
Soil erosion is driven by not only aeolian but also fluvial transport processes, yet these two types of processes are usually studied independently, thereby precluding effective assessment of overall erosion, potential interactions between the two drivers, and their relative sensitivities to projected changes in climate and land use. Here we provide a perspective that aeolian and fluvial transport processes need to be considered in concert relative to total erosion and to potential interactions, that relative dominance and sensitivity to disturbance vary with mean annual precipitation, and that there are important scale-dependencies associated with aeolian–fluvial interactions. We build on previous literature...
The recognition of terminal fluvial systems, otherwise termed ‘terminal fans’ or ‘distributary fluvial fan systems’, preserved in the ancient rock record is based primarily on the recognition of facies characteristics indicative of a progressive downstream decrease in: (i) fluvial discharge; (ii) channel depth and width; (iii) lateral and vertical connectivity of channel-fill elements; and (iv) evidence for channellized flow and a systematic increase in: (i) evidence for sheetflood deposition; (ii) aeolian and/or playa deposits; and (iii) channel bifurcation. However, despite these criteria having been applied previously to a variety of outcrop successions, there is still no unifying facies model that adequately...


map background search result map search result map Developing a Southeast Alaska community-based stream temperature monitoring network Geologic map of the Dalton Highway (Atigun Gorge to Slope Mountain) area, southern Arctic Foothills, Alaska Geologic map of the Talkeetna Mountains C-4 Quadrangle and adjoining areas, central Alaska Surficial geology of the Dalton Highway (Itkillik-Sagavanirktok rivers) area, southern Arctic foothills, Alaska Geologic map of the Circle mining district, Alaska Interpretive bedrock-geologic map of the Sagavanirktok B-1 Quadrangle, eastern North Slope, Alaska Reconnaissance surficial-geologic map of the Sagavanirktok B-1 Quadrangle, eastern North Slope, Alaska Reconnaissance engineering-geologic map of the Sagavanirktok B-1 Quadrangle, eastern North Slope, Alaska Surficial-geologic map of the northern Fairbanks mining district, Circle Quadrangle, Alaska Surficial geologic map of the Shaktoolik area, Norton Bay Quadrangle, Alaska Sand classifications along the Colorado River in Grand Canyon derived from 2002, 2009, and 2013 high-resolution multispectral airborne imagery Ecoregion Based Aquatic Gap Distribution Models for Common Fluvial Fishes of the Conterminous U.S. Surficial-geologic map of the northern Fairbanks mining district, Circle Quadrangle, Alaska Interpretive bedrock-geologic map of the Sagavanirktok B-1 Quadrangle, eastern North Slope, Alaska Reconnaissance surficial-geologic map of the Sagavanirktok B-1 Quadrangle, eastern North Slope, Alaska Reconnaissance engineering-geologic map of the Sagavanirktok B-1 Quadrangle, eastern North Slope, Alaska Geologic map of the Talkeetna Mountains C-4 Quadrangle and adjoining areas, central Alaska Geologic map of the Circle mining district, Alaska Geologic map of the Dalton Highway (Atigun Gorge to Slope Mountain) area, southern Arctic Foothills, Alaska Surficial geology of the Dalton Highway (Itkillik-Sagavanirktok rivers) area, southern Arctic foothills, Alaska Developing a Southeast Alaska community-based stream temperature monitoring network Surficial geologic map of the Shaktoolik area, Norton Bay Quadrangle, Alaska Sand classifications along the Colorado River in Grand Canyon derived from 2002, 2009, and 2013 high-resolution multispectral airborne imagery Ecoregion Based Aquatic Gap Distribution Models for Common Fluvial Fishes of the Conterminous U.S.