Office of the Pacific Regional Director
Location
Modoc Hall, USGS
3020 State University Drive East
Sacramento
, CA
95819
USA
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We analyzed very-high-resolution imagery to assess status of Metrosideros polymorpha forests across an 83,603 hectare study area that experienced extensive canopy dieback in the 1970s on the eastern side of the island of Hawaii. Using GIS we generated 1170 virtual vegetation plots with a 100 m radius; 541 plots in areas mapped in 1977 with trees dead or mostly defoliated (dieback), and 629 plots in adjacent wet forest habitat, previously mapped as non-dieback condition. In each plot we estimated the percent of M. polymorpha trees dead or mostly defoliated, and percent of trees with healthy crowns. These results were combined with habitat data to produce a spatial model depicting probability of canopy dieback within...
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Several previously published reports and geographic information system (GIS) data layers were used to code information on site attributes for each assessment plot using the spatial join tool in ArcMap. This information was used for an analysis of dieback and non-dieback habitat characteristics. The results of this analysis are presented in this table which depicts the probability of heavy to severe canopy dieback occurring at some time at a particular 30 x 30 m pixel location within the study area.
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The U.S. Geological Survey’s Water Availability and Use Study Program (WAUSP) (https://water.usgs.gov/ogw/gwrp/activities/regional.html) supports quantitative assessments of groundwater availability in areas of critical importance. As part of a WAUSP study in the arid to semi-arid Northwest Volcanic Aquifer Study Area (NVASA), estimates of runoff and baseflow were determined for 312 streamflow-gaging stations from 1904 to 2015. Gages with complete water years (October to September) of continuous-streamflow record were used to partition streamflow into runoff and baseflow, which is that part of streamflow attributed to groundwater discharge. For each water year annual estimates of baseflow, runoff, and a base-flow...
Categories: Data;
Tags: California,
GWToolbox,
Idaho,
NVASA,
NVASA, All tags...
Oregon,
USGS Water Availability and Use Study Program,
baseflow,
hydrograph separation,
inlandWaters,
runoff,
volcanic aquifers, Fewer tags
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The U.S. Geological Survey’s Water Availability and Use Study Program (WAUSP) (https://water.usgs.gov/ogw/gwrp/activities/regional.html) supports quantitative assessments of groundwater availability in areas of critical importance. As part of a WAUSP study in the arid to semi-arid Northwest Volcanic Aquifer Study Area (NVASA), estimates of runoff and baseflow were determined for 312 streamflow-gaging stations from 1904 to 2015. Gages with complete water years (October to September) of continuous-streamflow record were used to partition streamflow into runoff and baseflow, which is that part of streamflow attributed to groundwater discharge. For each water year annual estimates of baseflow, runoff, and a base-flow...
Categories: Data;
Tags: California,
GWToolbox,
Idaho,
NVASA,
NVASA, All tags...
Oregon,
USGS Water Availability and Use Study Program,
baseflow,
hydrograph separation,
inlandWaters,
runoff,
volcanic aquifers, Fewer tags
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In March 2015, the U.S. Geological Survey acquired seismic reflection and refraction data along an approximately 2.8-km-long profile across northwest-trending San Andreas Fault splays located at the Dos Palmas Preserve east of Salton Sea. To acquire the reflection and refraction data, we collocated shots and geophones, spaced every 3 m along the profile. We used 933 SercelTM L40A P-wave (40-Hz vertical-component) geophones with a sensitivity of 22.34 volts/meter/second to record 925 P-wave shots. We generated P-wave data using one of two active sources: 400-grain Betsy-SeisgunTM shots at approximately every 90 m and a 3.5-kg sledgehammer and steel plate combination at every 3 m between the seisgun shots. All data...
Categories: Data;
Tags: Dos Palmas Spring,
Geophysics,
Mecca,
Salton Sea,
Seismology, All tags...
Structural Geology,
USGS Science Data Catalog (SDC),
Water Resources,
earthquake hazards,
faulting (geologic),
groundwater,
groundwater flow,
seismic reflection methods,
seismic refraction methods,
seismology, Fewer tags
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