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Christian Torgersen

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Abstract Dams have been a fundamental part of the U.S. national agenda over the past two hundred years. Recently, however, dam removal has emerged as a strategy for addressing aging, obsolete infrastructure and more than 1,100 dams have been removed since the 1970s. However, only 130 of these removals had any ecological or geomorphic assessments, and fewer than half of those included before- and after-removal (BAR) studies. In addition, this growing, but limited collection of dam-removal studies is limited to distinct landscape settings. We conducted a meta-analysis to compare the landscape context of existing and removed dams and assessed the biophysical responses to dam removal for 63 BAR studies. The highest...
Categories: Publication; Types: Citation
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This dataset includes georeferenced, high-resolution, airborne thermal infrared (TIR) and high-resolution true-color imagery, a polyline shapefile of the channel centerline, a polyline shapefile with TIR sample points for longitudinal stream temperature profiles, and a tabular file with longitudinal stream temperature profiles for the Donner und Blitzen River and its tributaries, Oregon. The aerial TIR surveys were conducted with a helicopter by NV5 Geospatial and are published as 17 raster mosaics in GeoTiff format with a resolution of 0.3 meters (m). The TIR mosaics contain corrected surface temperatures in degrees Celsius (C) (multiplied by 10 to create an unsigned integer pixel type). The longitudinal stream...
Water temperature data were collected in summer 2018 and 2019. Temperature data loggers were deployed in tributary confluences and the mainstem of the lower Priest River between Priest Lake Outlet Dam and the confluence with the Pend Oreille River. Data loggers were checked every 2 to 3 weeks throughout the summer. Data for Lagrangian longitudinal thermal profiles were obtained on August 21, 2018 and August 7, 2019.
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This dataset includes georeferenced high-resolution, airborne thermal infrared (TIR) imagery, a polyline shapefile of the channel centerline, and a tabular file with longitudinal stream temperature profiles for Hat Creek, California. The two aerial TIR surveys were conducted with a helicopter by NV5 Geospatial (formerly Quantum Spatial, Inc.) and are published as two raster mosaics in GeoTiff format with a resolution of 0.5 m. The TIR mosaics and longitudinal stream temperature profiles contain corrected surface temperatures in degrees C (multiplied by 10 to create an unsigned integer pixel type). The TIR dataset encompasses a 64.6-km reach of Hat Creek that extends from 50 m upstream of the confluence with Lost...
This data release combines seven airborne thermal infrared (TIR) remote sensing data sets of stream temperature collected along the mainstem of the Middle Fork John Day River (MFJD) in Oregon from 1994 to 2003. Years 1994, 1995, 1996, 1998, and 2002 have single datasets. Year 2003 has two data sets. Most of the TIR data covered the upstream half of the MFJD mainstem between river km 50 and 110, while the 2002 profile covers the lower half starting at the confluence of the MFJD with the North Fork John Day River through river kilometer 64. All TIR data sets were collected by helicopter in an upstream direction in August with the intent of capturing data at or near the maximum summer daily stream temperature. Ground-truthing...
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