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Eric K Waller

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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...
USGS researchers with the Patterns in the Landscape – Analyses of Cause and Effect (PLACE) project are releasing a collection of high-frequency surface water map composites derived from daily Moderate Resolution Imaging Spectroradiometer (MODIS) imagery. Using Google Earth Engine, the team developed customized image processing steps and adapted the Dynamic Surface Water Extent (DSWE) to generate surface water map composites in California for 2003-2019 at a 250-m pixel resolution. Daily maps were merged to create 6, 3, 2, and 1 composite(s) per month corresponding to approximately 5-day, 10-day, 15-day, and monthly products, respectively. The resulting maps are available as downloadable files for each year. Each...
This page contains NetCDF files of the Spring Leaf and Bloom Indices spanning 1880-2013. These files were created and are maintained by the USA National Phenology Network (www.usanpn.org). The Extended Spring Indices are mathematical models that predict the "start of spring" (timing of leaf out or bloom for species active in early spring) at a particular location (Schwartz 1997, Schwartz et al. 2006, Schwartz et al. 2013). These models were constructed using historical observations of the timing of first leaf and first bloom in a cloned lilac cultivar (S. x chinensis 'Red Rothomagensis') and two cloned honeysuckle cultivars (Lonicera tatarica 'Arnold Red' and L. korolkowii 'Zabelii'). Primary inputs to the model...
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This raster data depicts the modeled distribution of three grassland states: Biocrust, Grass-bare, and Annualized-bare. We developed models of bare ground, total vegetation, exotic grasses and biological soil crust using spectral data from three year composites of growing season (March-October) Landsat data in Google Earth Engine and field data that were collected over the same period at monitoring sites. The resulting regression models were used to characterize the spatial distribution of putative grassland ecological states across our 251,430 ha study area in and around Canyonlands National Park, UT. This model illustrates how a remote sensing approach to land-cover change can be implemented to guide dryland ecosystem...
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This data release contains a single vector shapefile and two text documents with code used to generate the data product. This vector shapefile contains the locations of 365 “plugged and abandoned” well sites from across the Colorado Plateau with their respective relative fractional vegetation cover (RFVC) values. Oil and gas pads are often developed for production, and then capped, reclaimed, and left to recover when no longer productive (collectively termed “plugged and abandoned”). Understanding the rates, controls, and degree of recovery of these reclaimed well sites (well pads) to a state similar to pre-development conditions is critical for energy development and land management decision processes. We used...
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