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Filters: Tags: {"scheme":"None"} (X) > partyWithName: Jonathan M Friedman (X)

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This study uses growth in vegetation during the monsoon season measured from LANDSAT imagery as a proxy for measured rainfall. NDVI values from 26 years of pre- and post-monsoon season Landsat imagery were derived across Yuma Proving Ground (YPG) in southwestern Arizona, USA. The LANDSAT imagery (1986-2011) was downloaded from USGS’s GlobeVis website (http://glovis.usgs.gov/). Change in NDVI was calculated within a set of 2,843 Riparian Area Polygons (RAPs) up to 1 km in length defined in ESRI ArcMap 10.2.
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A study of arroyo evolution in northern New Mexico (Friedman and others, 2015) assessed geomorphic change in the Chaco Wash arroyo from the 1930s to 2000. As part of this study, in October 2000 a trench was excavated across the arroyo bottom and a high-precision (Real-time kinematic) GPS survey was conducted. GPS survey data were used to georeference a 1930s topographic map and to identify key geomorphic features, including the tops of the arroyo walls and the channel thalweg. Linear features were mapped in a GIS for use in extracting channel thalweg profiles, an arroyo cross section, and arroyo widths (1930s and 2000) as a function of distance down-valley. These features have been converted to shapefiles included...
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This dataset includes stable carbon isotope values, lignin, cellulose, and hemicellulose concentrations (expressed as percent of ash-free dry mass) for riparian cottonwood (Populus deltoides) tree rings growing on the Little Missouri River floodplain, Theodore Roosevelt National Park, North Dakota. Drought stress induces stomatal closure and the carbon isotope ratio of annual tree rings tends to be negatively correlated with water availability, especially in dry environments. However, lignin and hemicellulose can obscure annual trends in carbon isotope compositions as these wood components can differ in δ13C relative to pure cellulose. We measured δ13C of whole wood in annual tree rings from seven trees with oldest...
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The data archive contains the aerial photographs and channel delineations used in our analysis. The images have been geo-referenced to the 1995 digital orthophoto quarter quadrangles as described by Miller and Friedman (2009). The separate images for each year can be viewed as a composite along with that year’s channel delineation using a geographic information system (GIS). The 2003 IKONOS satellite imagery is proprietary and, therefore, cannot be served here. The channel delineations for all photo years (including 2003) and the delineation of the outer flood-plain boundary are stored as shapefiles. These shapefiles can be manipulated using GIS applications to reproduce the spatial analyses reported in Miller and...
    map background search result map search result map Shapefiles and Historical Aerial Photographs, Little Missouri River, 1939-2003 Mean of the Top Ten Percent of NDVI Values in the Yuma Proving Ground during Monsoon Season, 1986-2011 Chaco Canyon 1930s and 2000 geospatial data Stable carbon isotope and wood component concentration data for riparian cottonwood tree rings, Little Missouri River, North Dakota Chaco Canyon 1930s and 2000 geospatial data Mean of the Top Ten Percent of NDVI Values in the Yuma Proving Ground during Monsoon Season, 1986-2011 Shapefiles and Historical Aerial Photographs, Little Missouri River, 1939-2003