Filters: Tags: Normalized difference vegetation index (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...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service,
Shapefile;
Tags: California,
California South,
Google Earth Engine,
Landsat,
Normalized Difference Vegetation Index,
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.
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Arizona,
Landsat TM,
NDVI,
Normalized Difference Vegetation Index,
Sonoran Desert,
These data are aerial image-derived, classification maps of tamarisk (Tamarisk spp.) in the riparian zone of the Colorado River from Glen Canyon Dam to Separation Canyon, a total river distance of 412 km. The classification maps are published in GIS vector format. Two maps are published: 1) a classification of tamarisk from a 0.2 m resolution multispectral image dataset acquired in May 2009 (Tamarisk Classification 2009), and 2) a classification of tamarisk impacted by the tamarisk beetle (Diorhabda carinulata) from a 0.2 m resolution multispectral image dataset acquired in May 2013 (Beetle Impact Classification 2013). Tamarisk presence in 2009 was classified using the Mahalanobis Distance method with a total of...
These data were compiled to understand the effects of riparian vegetation health on local abundance and species diversity of land birds. The primary objective of our study was to to determine the effects of riparian restoration on birds in the Colorado River delta. These tabular data represent vegetation indices and evapotranspiration (ET) data at varying spatial scales that correspond to avian use circles of 100 to 2000 meters. Three vegetation reflectance indices (VIs): NDVI, EVI, and EVI2 were obtained from Landsat imagery with a biweekly temporal frequency, and covering the entire period of bird surveys (2002-2020). The Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) and two-band...
This set of sixteen Landsat Thematic Mapper (TM)and Operational Land Imager (OLI)(Path 014 and Rows 032 and 033) surface reflectance data sets were collected between 2000 and 2015. This data presents a time-series analysis that uses linear spectral unmixing of composite Normalized Difference Vegetation Index, Normalized Difference Water Index, and Normalized Difference Soil Index data, to estimate the percentages of marsh vegetation, water, and exposed marsh substrate on the New Jersey intracoastal marshes. We used the composition of the marshes in terms of the percentage of marsh vegetation, water, and marsh substrate to produce Marsh Surface Condition Index (MSCI) maps consisting of three classes of marshes: severely...
Types: Citation;
Tags: Atlantic County,
Barnegat Bay,
Cape May County,
Coastal Zone,
Environmental restoration,
This USGS Data Release represents geospatial data sets which were created to produce an Unvegetated to Vegetated Ratio (UVVR) for coastal wetlands of the conterminous United States (2014-2018). The following listed image products were generated 1) Annual spatial datasets (rasters) from 2014 to 2018 each containing 4 bands (Band 1: Unvegetated land fraction; Band 2: Vegetated land fraction; Band 3: Water fraction; Band 4: UVVR clipped into 3 coastal regions (Atlantic (ATL) Gulf of Mexico (GOM) and Pacific (PAC). 2) Calibration/Validation Datasets - datasets which were used in the calibration and validation of the above datasets 3) Mean of masked, multiyear composite - Mean vegetated fraction in coastal wetlands in...
These data were compiled for evaluating river-reach level vegetation greenness data in the riparian corridor of the Colorado River delta as specified under Minute 319 of the 1944 Water Treaty. The seven reach areas from the Northerly International Boundary (NIB) to the end of the delta at the Sea of Cortez were defined for research activities. Also, these seven reaches are being monitored under Minute 323 of the 1944 Water Treaty. Additionally, these data were compiled for evaluating restoration-level vegetation greenness data in Reach 2 and Reach 4, as specified under Minute 323 of the 1944 Water Treaty. Objectives of our study were to measure satellite vegetation index data, specifically using the Enhanced Vegetation...
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...
Categories: Data;
Types: Citation,
Downloadable,
GeoTIFF,
Map Service,
Raster;
Tags: Atlantic County,
Barnegat Bay,
Cape May County,
Coastal Zone,
Environmental restoration,
This USGS Data Release represents geospatial data sets that were created for the analysis of the effect of Hurricane Sandy on New Jersey Atlantic Coastal Marshes. The following listed image products were generated: 1) Fifteen marsh surface condition index (MSCI) data sets were calculated from yearly summer collections of ETM+ image data from 2000 to 2015. Three classes described the results of the MSCI mapping; classs1-severely impacted, class 2-moderately impacted, and class 3-intact marsh. 2) Marsh change data product using Landsat images of July 14, 2011 (before) and July 19, 2013 (after) Hurricane Sandy is based on the difference in the percentage of vegetation. It shows a pattern of an increasing loss of marsh...
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...
Categories: Data;
Types: Citation,
Downloadable,
GeoTIFF,
Map Service,
Raster;
Tags: Atlantic County,
Barnegat Bay,
Cape May County,
Coastal Zone,
Environmental restoration,
The Green Wave Hypothesis posits that herbivore migration manifests in response to waves of spring green-up (i.e., green-wave surfing). Nonetheless, empirical support for the Green Wave Hypothesis is mixed, and a framework for understanding variation in surfing is lacking. In a population of migratory mule deer (Odocoileus hemionus), 31% surfed plant phenology in spring as well as a theoretically perfect surfer, and 98% surfed better than random. Green-wave surfing varied among individuals, and was unrelated to age or energetic state. Instead, the greenscape, which we define as the order, rate, and duration of green-up along migratory routes, was the primary factor influencing surfing. Our results indicate that...
These raster and tabular data were compiled to develop time series data of the lower Colorado River (LCR) vegetation greenness, water use, and phenology since the year 2000. An objective of our study was to evaluate short and long-term effects of drought and biocontrol on LCR riparian and aquatic ecosystems south of Hoover Dam. These data represent spatially explicit average Enhanced Vegetation Index (EVI2) derived evapotranspiration (ET) difference, and scaled normalized difference vegetation index (NDVI*) difference maps between two decades (2000 to 2010 and 2011 to 2020) and two 5 year periods (2000 to 2005 and 2016 to 2020). The time-series period statistics data provide estimates of the riparian woodland area...
These normalized difference vegetation index (NDVI) raster data were compiled to develop time series data of the lower Colorado River (LCR) riparian corridor vegetation greenness and phenology since the year 2000. An objective of our study was to evaluate short and long-term effects of drought and biocontrol on LCR riparian and aquatic ecosystems south of Hoover Dam. These data represent spatially explicit scaled normalized difference vegetation index (NDVI*) difference maps between two decades (2000 to 2010 and 2011 to 2020) and two 5 year periods (2000 to 2005 and 2016 to 2020). NDVI* is an additional correction to the NDVI to account for the illumination conditions; it is a processing correction step to improve...
Normalized Difference Vegetation Index (NDVI) for the western United States, from 1989-2002.
Categories: Data;
Types: Downloadable,
GeoTIFF,
Map Service,
Raster;
Tags: Arizona,
California,
Colorado,
Idaho,
Montana,
These full time-series period statistics data were compiled for monitoring riparian zone trends and changes in the lower Colorado as part of a study to document riparian ecosystem health and its water use. Our study evaluated the short and long-term effects on the river's vegetation of drought and hydrological processes in this dryland region. Because of the landscape changes, we explored remote sensing-based change analysis techniques and data to develop time series data of the Colorado River riparian corridor vegetation greenness, phenology, and water use since the year 2000. We divided the river into five Reaches (R3..R7) to separate between the different land covers, management conditions, and general geospatial...
Mapping salt-affected soils in remote rangelands is challenging. We used Landsat 7 ETM data to facilitate digital mapping of gypsic and natric soil areas in the upper Colorado River drainage. Optimum index factor band combinations were used to explore the scene. Normalized difference ratio models and threshold values were developed by comparing spectral signatures with gypsic and natric soil areas verifi ed in the fi eld. Gypsic soil areas were mapped using the normalized difference ratio of Bands 5 and 7 with a threshold >0.11, probably related to the spectral refl ectance of gypsum within a few centimeters of the surface. All sites predicted to be gypsic soil areas were determined to be gypsic by fi eld assessment,...
Seed sourcing strategies that incorporate spatially explicit genetic information promote effective revegetation by reducing genetic risk factors, such as maladaptation, outbreeding, and inbreeding depression. Molecular markers represent an increasingly robust and cost- efficient data source for uncovering patterns of adaptive divergence in high-priority species to support restoration decision making. This project uses marker-based genetic analyses to develop empirical seed transfer zones for species that have been genotyped at a wide range of sites in the Mojave Desert. Empirical seed transfer zones delineate areas within which seeds may be transferred with limited risk of maladaptation or outbreeding depression....
This product consists of 29 datasets of tabular data and associated metadata for watershed characteristics of 1,530 study sites of the Surface Water Trends (SWT) project of the U.S. Geological Survey’s (USGS) National Water Quality Program (NWQP). The project is conducting national studies of trends in water quality of streams and rivers for periods ranging from 10 to 40 years, between 1972 and 2012. The data here include both static and time-series characteristics. Static data include primarily physical characteristics which have changed little over this period, such as geology, soils, and topography. Time-series data represent characteristics which may or may not have changed over time, such as land use, agricultural...
Categories: Data;
Types: Citation;
Tags: Atmospheric Deposition,
Basin Morphology,
Census of Agriculture,
Conterminous US,
Crop Practices,
These data were simulated using the SOILWAT model and were intended to characterize soil-water conditions at different ecological sites on the Southern Colorado Plateau. SOILWAT is a daily, site-specific, multi soil-layer, ecosystem water-balance model, driven by daily meteorology, as well as site soil texture and vegetation. The sites simulated correspond with Inventory and Monitoring (I&M) plots established by the National Park Service’s (NPS) Southern Colorado Plateau Network (SCPN), which were established to capture the range of ecosystem conditions present in this network. Plant communities of the Southern Colorado Plateau Network (SCPN) are a vital sign for this region, enhancing habitat, stabilizing soils,...
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...
Categories: Data;
Types: Citation,
Downloadable,
GeoTIFF,
Map Service,
Raster;
Tags: Alaska,
Icy Bay,
Icy Bay,
NDVI,
Taan Fiord,
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