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Filters: Tags: Normalized difference vegetation index (X) > Types: Map Service (X)

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To determine if invasive annual grasses increased around energy developments after the construction phase, we calculated an invasives index using Landsat TM and ETM+ imagery for a 34-year time period (1985-2018) and assessed trends for 1,755 wind turbines (from the U.S. Wind Turbine Database) installed between 1988 and 2013 in the southern California desert. The index uses the maximum normalized difference vegetation index (NDVI) for early season greenness (January-June), and mean NDVI (July-October) for the later dry season. We estimated the relative cover of invasive annuals each year at turbine locations and control sites and tested for changes before and after each turbine was installed. These data were used...
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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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These are two land cover datasets derived from Landsat Thematic Mapper and Operational Land Imager (spatial resolution 30-m)Path 014 and Rows 032 and 033 surface reflectance data collected on July 14, 2011 and July 19, 2013, before and after Hurricane Sandy made landfall near Brigantine, New Jersey on October 29, 2012. The two land cover data sets provide a means of evaluating the effect of Hurricane Sandy of data sets collected at times that represent or approach peak vegetation growth. The most accurate results of the land cover classification are based on twelve classes, some of which occur adjacent to the marshes but not on the New Jersey intracoastal marshes. Twelve classes were used in the supervised maximum...
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The change detection data is the classified difference in the percentage of vegetation on the July 14, 2011 Landsat Thematic Mapper(TM) data set collected before Hurricane Sandy and the July 19, 2013 Landsat Operational Land Imager (OLI)data set collected after Hurricane Sandy. Hurricane Sandy made landfall near Brigandine, New Jersey on October 29, 2012. The actual difference in the percentage of vegetation is used in the calculation, not the three-class classification that is the basis of the Marsh Surface Condition Index data. The eleven classes consist of five classes (5-20%,>20%-40%,>40%-60%,>60%-80%,>80%)with decreases in the percentage of vegetation cover after Hurricane Sandy, Three classes (5-20%,>20%-40%,>40%-60%)with...
Normalized difference vegetation index (NDVI) is an indicator of vegetation health and density. High NDVI values generally correspond to dense vegetation and low NDVI values generally correspond to sparsely vegetated or barren areas. NDVI was calculated for pan-sharpened Landsat 8 Operational Land Imager images acquired on May 13, 2015 and May 15, 2016 for the region around Icy Bay, Alaska. NDVI results from 2015 were subtracted from results for 2016 to produce a change image. The change image can be used to assess changes in vegetation patterns resulting from a landslide that occurred near Tyndall Glacier in October, 2015 and generated a tsunami in Taan Fiord, an arm of Icy Bay. Positive change in NDVI generally...
    map background search result map search result map Average Normalized Difference Vegetation Index (NDVI) for the western United States (1989-2002) Mean of the Top Ten Percent of NDVI Values in the Yuma Proving Ground during Monsoon Season, 1986-2011 Marsh change dataset Land cover classification dataset Data supporting Landsat time series assessment of invasive annual grasses following energy development Mean of the Top Ten Percent of NDVI Values in the Yuma Proving Ground during Monsoon Season, 1986-2011 Marsh change dataset Land cover classification dataset Data supporting Landsat time series assessment of invasive annual grasses following energy development Average Normalized Difference Vegetation Index (NDVI) for the western United States (1989-2002)