Since 1993 the U.S. Geological Survey (USGS) has worked with the Alaska Department of Transportation and Public Facilities (ADOT&PF) to provide hydraulic assessments of scour for bridges throughout Alaska. As part of this effort, repeat channel cross section surveys, or channel soundings, have been collected at either the upstream or downstream side of bridges on an annual or as needed basis. Streambed and bank elevations are measured using USGS sounding weights and reels, weighted measuring tapes, acoustic Doppler current profilers, multibeam echo sounders and light detection and ranging and are referenced to the datum of as-built plan set to provide context for the streambed elevations in relation to bridge structures. Channel soundings are collected on an annual basis at most sites, however, as need soundings are collected due to flooding or periods of scour at select sites. Repeat channel soundings are used to access stream stability related to seasons, stage, and long-term aggradation or degradation as well as providing greater context for fixed mount streambed elevation monitoring. New measurements are appended to this data release after they have undergone formal QA/QC processing. Please note the updated date in the suggested citation.

The U.S. Geological Survey in collaboration with the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL) collected topographic LiDAR surveys of four rivers in Alaska from August 8-9, 2017 to support research related to remote sensing of river discharge. Data were acquired for the Knik, Matanuska, Chena and Salcha Rivers using a Riegl VQ-580 LiDAR. The LiDAR was installed on a Robinson R44 Raven helicopter in a HeliPod that was designed and operated by CRREL. The LiDAR data included as part of this release include: a bare earth digital elevation model (DEM), an intensity or reflectence digital surface model (DSM) both in GeoTiff format, and compressed binary LAS files (LAZ) for each river surveyed.

The U.S. Geological Survey in collaboration with the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL) collected topographic LiDAR surveys of four rivers in Alaska from August 8-9, 2017 to support research related to remote sensing of river discharge. Data were acquired for the Knik, Matanuska, Chena and Salcha Rivers using a Riegl VQ-580 LiDAR. The LiDAR was installed on a Robinson R44 Raven helicopter in a HeliPod that was designed and operated by CRREL. The LiDAR data included as part of this release include: a bare earth digital elevation model (DEM), an intensity or reflectence digital surface model (DSM) both in GeoTiff format, and compressed binary LAS files (LAZ) for each river surveyed.

The U.S. Geological Survey in collaboration with the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL) collected topographic LiDAR surveys of four rivers in Alaska from July 24-26, 2019 to support research related to remote sensing of river discharge. Data were acquired for the Knik, Matanuska, Chena, Salcha, Tanana and Susitna Rivers using a Riegl VQ-580 LiDAR. The LiDAR was installed on a Robinson R44 Raven helicopter in a HeliPod that was designed and operated by CRREL. The LiDAR data included as part of this release include: a bare earth digital elevation model (DEM) in GeoTiff format and lidar point files in laz format for each river surveyed. Additionally, CRREL reports for each river surveyed are included as part of this data release. Several imagery data sets were collected coincident with the lidar surveys but will be part of a separate data release.

The U.S. Geological Survey in collaboration with the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL) collected topographic LiDAR surveys of four rivers in Alaska from July 24-26, 2019 to support research related to remote sensing of river discharge. Data were acquired for the Knik, Matanuska, Chena, Salcha, Tanana and Susitna Rivers using a Riegl VQ-580 LiDAR. The LiDAR was installed on a Robinson R44 Raven helicopter in a HeliPod that was designed and operated by CRREL. The LiDAR data included as part of this release include: a bare earth digital elevation model (DEM) in GeoTiff format and lidar point files in laz format for each river surveyed. Additionally, CRREL reports for each river surveyed are included as part of this data release. Several imagery data sets were collected coincident with the lidar surveys but will be part of a separate data release.

Scouring of streambed material surrounding bridge structures is a leading cause of bridge failure in the United States. Damages resulting from bridge failure oftentimes lead to financial burdens and loss of life. To date, there has been no comprehensive evaluation of the current (2016) effectiveness of the guidance or overall long-term performance of bridge-scour countermeasures provided in the Federal Highway Administration, Hydraulic Engineering Circular No. 23, Bridge Scour and Stream Instability Countermeasures. To that end, the U.S. Geological Survey, in cooperation with the Federal Highway Administration, obtained bathymetric, topographical, and other data at 14 of the surveyed sites across the United States to begin an evaluation of the effectiveness of bridge-scour countermeasures. This report presents survey site selection criteria, site-specific details, the bathymetric and topographical surveying methods used to collect data, and the compilation of the acquired data.

Scouring of streambed material surrounding bridge structures is a leading cause of bridge failure in the United States. Damages resulting from bridge failure oftentimes lead to financial burdens and loss of life. To date, there has been no comprehensive evaluation of the current (2016) effectiveness of the guidance or overall long-term performance of bridge-scour countermeasures provided in the Federal Highway Administration (FHWA), Hydraulic Engineering Circular No. 23, Bridge Scour and Stream Instability Countermeasures. To that end, the U.S. Geological Survey (USGS), in cooperation with the Federal Highway Administration, obtained bathymetric, topographical, and other data at 20 sites across the United States to begin an evaluation of the effectiveness of bridge-scour countermeasures. This data release contains the supplemental bathymetric and topographic data for Dudunake and others (2018).

Scouring of streambed material surrounding bridge structures is a leading cause of bridge failure in the United States. Damages resulting from bridge failure oftentimes lead to financial burdens and loss of life. To date, there has been no comprehensive evaluation of the current (2016) effectiveness of the guidance or overall long-term performance of bridge-scour countermeasures provided in the Federal Highway Administration, Hydraulic Engineering Circular No. 23, Bridge Scour and Stream Instability Countermeasures. To that end, the U.S. Geological Survey, in cooperation with the Federal Highway Administration, obtained bathymetric, topographical, and other data at 14 of the surveyed sites across the United States to begin an evaluation of the effectiveness of bridge-scour countermeasures. This report presents survey site selection criteria, site-specific details, the bathymetric and topographical surveying methods used to collect data, and the compilation of the acquired data.

The U.S. Geological Survey in collaboration with the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL) collected topographic LiDAR surveys of six rivers in Alaska from August 27- September 1, 2018 to support research related to remote sensing of river discharge. Data were acquired for the Knik, Matanuska, Chena, Salcha, Tanana and Snow Rivers using a Riegl VQ-480 LiDAR. The LiDAR was installed on a Robinson R44 Raven helicopter in a HeliPod that was designed and operated by CRREL. The LiDAR data included as part of this release include: a bare earth digital elevation model (DEM) and compressed binary LAS point cloud files (LAZ format) for each river surveyed.

The U.S. Geological Survey in collaboration with the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL) collected topographic LiDAR surveys of six rivers in Alaska from August 27- September 1, 2018 to support research related to remote sensing of river discharge. Data were acquired for the Knik, Matanuska, Chena, Salcha, Tanana and Snow Rivers using a Riegl VQ-480 LiDAR. The LiDAR was installed on a Robinson R44 Raven helicopter in a HeliPod that was designed and operated by CRREL. The LiDAR data included as part of this release include: a bare earth digital elevation model (DEM) and compressed binary LAS point cloud files (LAZ format) for each river surveyed.