Filters: Tags: EVI (X)
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In many places along the lower Colorado River, saltcedar (Tamarix spp) has replaced the native shrubs and trees, including arrowweed, mesquite, cottonwood and willows. Some have advocated that by removing saltcedar, we could save water and create environments more favourable to these native species. To test these assumptions we compared sap flux measurements of water used by native species in contrast to saltcedar, and compared soil salinity, ground water depth and soil moisture across a gradient of 200?1500 m from the river's edge on a floodplain terrace at Cibola National Wildlife Refuge (CNWR). We found that the fraction of land covered (fc) with vegetation in 2005?2007 was similar to that occupied by native...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: EVI,
Ecohydrology,
MODIS,
Pluchea,
Populus,
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...
These data were compiled for monitoring riparian zone trends and changes in the Lower Colorado Delta as part of the Minute 139 of the 1944 Water Treaty between the United States and Mexico. The quality and quantity of the Delta’s riparian and aquatic ecosystems have been dramatically reduced over the past century, due largely to significant alterations to natural hydrologic and sediment regimes. The Minute 319 Agreement states that 130 million cubic meters of water was to be released during the spring of 2014. Water was released from Morelos Dam at the Northern International Border (NIB) near Yuma, Arizona, to the river’s delta in Mexico, allowing water to reach the Gulf of California for the first time in 13 years...
These data are a compilation of four mask layers (regions), and enhanced vegetation indices calculated from airborne or satellite imagery. The mask layers were used created to extract satellite EVI data from the four airborne or satellite imagery datasets. The Enhanced Vegetation Index (EVI) is a key Earth science parameter used to assess vegetation, originally developed and calibrated for the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra and Aqua satellites. With the impending decommissioning of the MODIS sensors by the year 2020/2022, alternative platforms will need to be used to estimate EVI. These data were created to compare Landsat 5 (2000–2011), 8 (2013–2016) and the Visible Infrared...
Categories: Publication;
Types: Citation;
Tags: EVI,
Grasslands and Plains,
Greater Yellowstone Ecosystem,
Landscapes,
NDVI,
These data were compiled for monitoring riparian zone trends and changes in the Lower Colorado Delta as part of the Minute 139 of the 1944 Water Treaty between the United States and Mexico. The quality and quantity of the Delta’s riparian and aquatic ecosystems have been dramatically reduced over the past century, due largely to significant alterations to natural hydrologic and sediment regimes. The Minute 319 Agreement states that 130 million cubic meters of water was to be released during the spring of 2014. Water was released from Morelos Dam at the Northern International Border (NIB) near Yuma, Arizona, to the river’s delta in Mexico, allowing water to reach the Gulf of California for the first time in 13 years...
These data were compiled for evaluating plant water use, or river-reach level evapotranspiration (ET) 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 data in Reach 2 and Reach 4, as specified under Minute 323 of the 1944 Water Treaty. Objectives of our study were to measure the peak growing season evapotranspiration (ET) for the average of...
This tabular data set represents Enhanced Vegetation Index compiled for two spatial components of the NHDPlus version 2.1 data suite (NHDPlusv2) for the conterminous United States; 1) individual reach catchments and 2) reach catchments accumulated upstream through the river network. This dataset can be linked to the NHDPlus version 2.1 data suite by the unique identifier COMID. Units are 0-1, 0 being low vegetation, 1 being high vegetation. Reach catchment information characterizes data at the local scale. Reach catchments accumulated upstream through the river network characterizes cumulative upstream conditions. Network-accumulated values are computed using two methods, 1) divergence-routed and 2) total cumulative...
These spatially explicit Enhanced Vegetation Index (EVI) and evapotranspiration (ET) map derived from time series Landsat images, maps, and associated ancillary data were compiled as part of ongoing research aimed at quantifying the riparian vegetation greenness and water use in the lower Colorado River Delta in Mexico. In order to create trend and anomaly maps that characterize these ecosystems, both EVI and ET from-Landsat-OLI were processed over time and space along seven pre-defined reaches that capture different natural states and management conditions. We used EVI from the Landsat operational land imager (OLI) sensor (30 m) as an input to our ET algorithm that was previously based on coarser resolution EVI...
These data were compiled for evaluating river-reach level plant water use, or evapotranspiration (ET), and vegetation greenness, or Normalized Difference Vegetation Index (NDVI), 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 evapotranspiration and vegetation greenness data in Reach 2 and Reach 4, as specified under Minute 323 of the 1944 Water...
Improving the quality of habitat for western big-game species, such as elk and mule deer, was identified as a priority by the Department of the Interior in 2018. Maintaining healthy herds not only supports the ecosystems where these species are found, but also the hunting and wildlife watching communities. For example, in Wyoming, big game hunting contributed over $300 million to the state’s economy in 2015. Yet as climate conditions change, the quantity, quality, and timing of vegetation available to mule deer, elk, and other ungulates, known as forage, could shift. It’s possible that these changes could have cascading impacts on the behavior and population sizes of many species. A key strategy used by managers...
Categories: Project;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: 2018,
CASC,
Completed,
EVI,
IRG,
These data were created as part of a hydrologic study to characterize groundwater budgets and water quality in the Diamond Valley Flow System (DVFS), central Nevada. This dataset represents the mean Enhanced Vegetation Index (EVI) of two Landsat 5 Thematic Mapper scenes from the summer of 2010 in the DVFS. The data were used to evaluate and estimate groundwater discharge by evapotranspiration by relating the mean of EVI calculated from July 24 and August 25, 2010 Landsat scenes to evapotranspiration measured at 4 eddy-covariance sites located in phreatophytic vegetation of varying types and densities in Kobeh Valley, Nevada. Evapotranspiration was extrapolated for all valleys in the study area using the relation...
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