Colorado River at Windy Gap near Granby, CO - 2021/07/27 Water Surface Velocity Map Using Particle Image Velocimetry

The dataset consists of a shapefile of measurements of surface velocity magnitude and direction at the Colorado River at Windy Gap near Granby, CO, on July 27, 2021. The dataset contains approximately 1 km of river length. The surface velocity measurements were made by applying Large-Scale Particle Image Velocimetry (LSPIV) techniques, using overlapping videos collected by small Unmanned Aircraft Systems (sUAS). Total time to capture all videos was one hour and ten minutes, 11:05am to 12:15pm local time, and all frames (except frame 1, see Process Steps below) from all videos were used. Additional attributes, including divergence, curl, shear, and strain, were calculated from the surface velocity measurements and are included in the dataset. This data is ideal for instantaneous discharge, shear, strain, and divergence, but less so for eddies and mean reach values. This is because the frame rate of 30-frames-per-second more accurately profiles and averages instantaneous values seen during the capture interval as opposed to the stability of an eddy or representative mean values of a longer capture interval.