Baseline geomorphic map and land-surface parameters, derived from integrated topobathymetric elevation data, for the mainstem Klamath River corridor downstream of Iron Gate Dam, CA, 2018

This data release includes a file geodatabase with high-resolution geospatial products that illustrate the geomorphology and various land-surface parameters along a 313-kilometer segment of the mainstem Klamath River corridor downstream of Iron Gate Dam, CA. The geospatial products were derived from topobathymetric elevation data collected to document baseline topography and bathymetry before the removal of four hydro-electric dams. The elevation survey included aerial lidar, using an integrated topobathymetric sensor (with near-infrared and green wavelengths), and boat-based sonar measurements of water depths. Acquisition dates for the aerial topobathymetric lidar spanned 06/01/2018 to 06/14/2018. For the bathymetric sonar survey, data collection in the lower reaches spanned 08/27/2018 to 09/04/2018 and data collection in the upper reaches spanned 10/02/2018 to 10/07/2018. A seamless topobathymetric digital terrain model (DTM) was published by NV5 Geospatial (formerly QSI Inc.) at Open Topography (https://doi.org/10.5069/G9DN436N). Hydroflattened digital elevation models (DEMs) were published by the U.S. Geological Survey on The National Map (https://nationalmap.gov/). Geoprocessing methods are described in detail in the metadata record. The file geodatabase includes a map of geomorphic features and files that characterize various land-surface parameters (thalweg, centerline, channel width, channel depth, water surface slope, surface roughness, and river complexity). The geomorphic map and land-surface parameters document baseline geomorphic conditions prior to dam removal and the channel centerline provides a longitudinal reference system for measuring linear distances downstream from Iron Gate Dam. Using the channel centerline, the study area was discretized into 1-kilometer reaches and the longitudinal variation in geomorphic features and land-surface parameters were summarized (Summary_Table_Geomorphology_and_Land_Surface_Parameters_Klamath_River_California_2018.csv). The USGS Integrated Water Availability Assessments (IWAAs) Program funded generation of these high-resolution digital products.