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In large river ecosystems, the timing, extent, duration and frequency of floodplain inundation greatly affect the quality of fish and wildlife habitat and the supply of important ecosystem goods and services. Seasonal high flows provide connectivity from the river to the floodplain, and seasonal inundation of the floodplain governs ecosystem structure and function. River regulation and other forms of hydrologic alteration have altered the connectivity of many rivers with their adjacent floodplain – impacting the function of wetlands on the floodplain and in turn, impacting the mainstem river function. Conservation and management of remaining floodplain resources can be improved through a better understanding of...
Concern about spread of non-native riparian trees in the western USA has led to Congressional proposals to accelerate control efforts. Debate over these proposals is frustrated by limited knowledge of non-native species distribution and abundance. We measured abundance of 44 riparian woody plants at 475 randomly selected stream gaging stations in 17 western states. Our sample indicates that Tamarix ramosissima and Elaeagnus angustifolia are already the third and fourth most frequently occurring woody riparian plants in the region. Although many species of Tamarix have been reported in the region, T. ramosissima (here including T. chinensis and hybrids) is by far the most abundant. The frequency of occurrence of...
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The effects of climate change have the potential to impact slope stability. Negative impacts are expected to be greatest at high northerly latitudes where degradation of permafrost in rock and soil, debuttressing of slopes as a result of glacial retreat, and changes in ocean ice-cover are likely to increase the susceptibility of slopes to landslides. In the United States, the greatest increases in air temperature and precipitation are expected to occur in Alaska. In order to assess the impact that these environmental changes will have on landslide size (magnitude), mobility, and frequency, inventories of historical landslides are needed. These inventories provide baseline data that can be used to identify changes...
Long-term, non-contact river velocity measurements have been made using a UHF RiverSonde system for several months at each of two locations having quite different flow characteristics. Observations were made on the Cowlitz River at Castle Rock, Washington from October 2003 to June 2004, where the unidirectional flow of the river ranged from about 1.0 to 3.5 m/s. The radar velocity was highly correlated with the stage height which was continually measured by the U. S. Geological Survey. The profile of the along-channel velocity across the water channel also compared favorably with in-situ measurements performed by the Survey. The RiverSonde was moved to Threemile Slough, in central California, in September 2004 and...
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These GIS grids were produced from NOAA and NRCC precipitation frequency estimates for North America based on precipitation data collected from 1816 to 2014. The grids provide estimated rainfall data for 2-, 5-, 10-, 25-, 50-, 100-, 20-0, and 500-year recurrence periods for a 24-hour duration. Grid value units are inches * 1000.
Mandatory targets for biofuels have led to their rapid global adoption, but ethical problems with their large-scale production are widely reported. Research is underway to find new biofuel technologies that mitigate climate change and can be produced sustainably and economically. Following an 18-month inquiry, the Nuffield Council on Bioethics has developed an ethical framework for biofuels policy-making. Based on a number of widely held ethical values, six ethical principles are introduced that should be considered in biofuels policy-making. Many current biofuels policies fail this ethical ‘test’. An overarching ethical standard for biofuels is proposed that includes the protection of human rights and the environment,...
    map background search result map search result map GCPO Inundation Frequency Mosaic (2017) Inventory of rock avalanches in western Glacier Bay National Park and Preserve, Alaska, 1984-2016: a baseline data set for evaluating the impact of climate change on avalanche magnitude, mobility, and frequency The frequency of extreme rainfall intensities over a 24-hour duration Inventory of rock avalanches in western Glacier Bay National Park and Preserve, Alaska, 1984-2016: a baseline data set for evaluating the impact of climate change on avalanche magnitude, mobility, and frequency The frequency of extreme rainfall intensities over a 24-hour duration GCPO Inundation Frequency Mosaic (2017)