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Reports

Browse more than 82,000 reports authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.

Filter Total Items: 85089

A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites

This descriptive model for magmatic iron-titanium-oxide (Fe-Ti-oxide) deposits hosted by Proterozoic age massif-type anorthosite and related rock types presents their geological, mineralogical, geochemical, and geoenvironmental attributes. Although these Proterozoic rocks are found worldwide, the majority of known deposits are found within exposed rocks of the Grenville Province...
Authors
Laurel G. Woodruff, Suzanne W. Nicholson, David L. Fey

A five-year study of Hawaiian hoary bat (Lasiurus cinereus semotus) occupancy on the island of Hawai`i A five-year study of Hawaiian hoary bat (Lasiurus cinereus semotus) occupancy on the island of Hawai`i

Using acoustic recordings of the vocalizations of the endangered Hawaiian hoary bat (Lasiurus cinereus semotus) collected over a five-year period (2007–2011) from 25 survey areas across the island of Hawai`i, we modeled the relationship between habitat attributes and bat occurrence. Our data support the conclusion that hoary bats concentrate in the coastal lowlands of Hawai`i during the
Authors
Marcos P. Gorressen, Frank J. Bonaccorso, Corinna A. Pinzari, Christopher M. Todd, Kristina Montoya-Aiona, Kevin W. Brinck

A historical perspective on precipitation, drought severity, and streamflow in Texas during 1951-56 and 2011 A historical perspective on precipitation, drought severity, and streamflow in Texas during 1951-56 and 2011

The intense drought throughout Texas during 2011 resulted in substantial declines in streamflow. By April 2011, nearly all of the State was experiencing severe to extreme drought according to data from the University of Nebraska–Lincoln Drought Monitor. By the end of July 2011, more than 75 percent of the State was experiencing exceptional drought. The worst of the drought occurred...
Authors
Karl E. Winters

A landscape-based assessment of climate change vulnerability for all native Hawaiian plants A landscape-based assessment of climate change vulnerability for all native Hawaiian plants

In Hawaiʽi and elsewhere, research efforts have focused on two main approaches to determine the potential impacts of climate change on individual species: estimating species vulnerabilities and projecting responses of species to expected changes. We integrated these approaches by defining vulnerability as the inability of species to exhibit any of the responses necessary for persistence...
Authors
Lucas B. Fortini, Jonathan Price, James Jacobi, Adam Vorsino, Jeff Burgett, Kevin W. Brinck, Fred Amidon, Steve Miller, Sam `Ohukani`ohi`a Gon, Gregory Koob, Eben H. Paxton

A manual for remote sensing of Maine lake clarity A manual for remote sensing of Maine lake clarity

The purpose of this manual is to support use of satellite-based remote sensing for statewide lake water-quality monitoring in Maine. The authors describe step-by-step methods that combine Landsat and MODIS satellite data with field-collected Secchi disk data for statewide assessment of lake water clarity. Landsat can be simul­taneously used to assess more than Maine 1,000 lakes ≥ 8 ha...
Authors
Ian M. McCullough, Cyndy Loftin, Steven A. Sader

A model for evaluating effects of climate, water availability, and water management on wetland impoundments--a case study on Bowdoin, Long Lake, and Sand Lake National Wildlife Refuges A model for evaluating effects of climate, water availability, and water management on wetland impoundments--a case study on Bowdoin, Long Lake, and Sand Lake National Wildlife Refuges

Many wetland impoundments managed by the U.S. Fish and Wildlife Service (USFWS) National Wildlife Refuge System throughout the northern Great Plains rely on rivers as a primary water source. A large number of these impoundments currently are being stressed from changes in water supplies and quality, and these problems are forecast to worsen because of projected changes to climate and...
Authors
Brian A. Tangen, Robert A. Gleason, John F. Stamm

A national streamflow network gap analysis A national streamflow network gap analysis

The U.S. Geological Survey (USGS) conducted a gap analysis to evaluate how well the USGS streamgage network meets a variety of needs, focusing on the ability to calculate various statistics at locations that have streamgages (gaged) and that do not have streamgages (ungaged). This report presents the results of analysis to determine where there are gaps in the network of gaged locations...
Authors
Julie E. Kiang, David W. Stewart, Stacey A. Archfield, Emily B. Osborne, Ken Eng

A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 11a: giant sequoias A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 11a: giant sequoias

For natural resource managers in the southern Sierra Nevada, giant sequoia requires very little introduction. It receives great attention as an icon of western forests and as a common namesake with the areas where it occurs. While it is a single component of a very complex system, its attention in this assessment and in general is well deserved. Giant sequoia is one of the few...
Authors
Robert A. York, Nathan L. Stephenson, Marc Meyer, Steve Hanna, Moody Tadashi, Anthony C. Caprio, John J. Battles

A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 14: plants of conservation concern A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 14: plants of conservation concern

Sequoia and Kings Canyon National Parks are located in the California Floristic Province, which has been named one of world‘s hotspots of endemic biodiversity (Myers et al. 2000). The California Floristic Province is the largest and most important geographic floristic unit in California and extends from the Klamath Mountains of southwestern Oregon to the northwestern portion of Baja...
Authors
Ann Huber, Adrian Das, Rebecca Wenk, Sylvia Haultain

A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 22: climatic change A natural resource condition assessment for Sequoia and Kings Canyon National Parks: Appendix 22: climatic change

Climate is a master controller of the structure, composition, and function of biotic communities, affecting them both directly, through physiological effects, and indirectly, by mediating biotic interactions and by influencing disturbance regimes. Sequoia and Kings Canyon National Park’s (SEKI’s) dramatic elevational changes in biotic communities -- from warm mediterranean to cold alpine...
Authors
Adrian J. Das, Nathan L. Stephenson

A one-dimensional diffusion analogy model for estimation of tide heights in selected tidal marshes in Connecticut A one-dimensional diffusion analogy model for estimation of tide heights in selected tidal marshes in Connecticut

A one-dimensional diffusion analogy model for estimating tide heights in coastal marshes was developed and calibrated by using data from previous tidal-marsh studies. The method is simpler to use than other one- and two-dimensional hydrodynamic models because it does not require marsh depth and tidal prism information; however, the one-dimensional diffusion analogy model cannot be used...
Authors
David M. Bjerklie, Kevin O’Brien, Ron Rozsa

A preliminary assessment of streamflow gains and losses for selected stream reaches in the lower Guadalupe River Basin, Texas, 2010-12 A preliminary assessment of streamflow gains and losses for selected stream reaches in the lower Guadalupe River Basin, Texas, 2010-12

The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers–Fort Worth District, the Texas Water Development Board, the Guadalupe-Blanco River Authority, and the Edwards Aquifer Authority, investigated streamflow gains and losses in the lower Guadalupe River Basin during four selected base-flow periods in March 2010, April 2011, August 2011, and, for a stream reach...
Authors
Loren L. Wehmeyer, Karl E. Winters, Darwin J. Ockerman
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