Geomorphic mapping and UAV lidar of debris flow fans in southwestern British Columbia, Canada

The data consists of geomorphic fan mapping completed at 29 debris flow fans in southwestern British Columbia, Canada, and uncrewed aerial vehicle (UAV) lidar at three of these fans. This dataset was used to study the spatial record of debris-flow impacts on fans for hazard and risk assessments. The fan mapping geodatabase contains fan boundaries, fan apexes, watershed boundaries, impact areas (any area below the fan apex that has been overrun by a debris flow since the last observation record), and flow paths (the channel or main flow path associated with an impact area). Fan mapping was completed using orthorectified airphotos, satellite imagery, topographic base maps, lidar data, orthophotos, and field observations. UAV lidar was collected at three of the 29 fans in the fall of 2019 for the purposes of geomorphic mapping and change detection analysis. One of the fans is located near Mt. Currie (Currie D) and two are located near Lillooet (Fountain N, Fountain S). Lidar for Currie D was flown on October 1 and 2, 2019, and has an average point density of 6.7 points per square meter, an average point spacing of 0.38 meters, and covers and area of 0.5 square kilometers. Lidar for Fountain N was flown on October 23, 2019, and has an average point density of 8.1 points per square meter, an average point spacing of 0.35 meters, and covers and area of 0.95 square kilometers. Lidar for Fountain S was flown on September 18-19, 2019, and has an average point density of 8.1 points per square meter, an average point spacing of 0.35 meters, and covers and area of 0.44 square kilometers. The lidar is provided as classified point clouds (LAS files), NAD83 / UTM zone 10N.