Small Streams Matter: Mapping Non-Classified Drainages and Flood Susceptibility on Mount Rose Swanson, British Columbia, Canada

This study mapped NCDs and evaluated the effects of incorporating these small channels on flood susceptibility in the Mount Rose Swanson study area in British Columbia, Canada. High-resolution LiDAR data were used to generate a digital elevation model and delineate two stream network scenarios: one including non-classified drainages and one excluding them.

Flood susceptibility was then mapped using a multi-criteria approach with topographic, hydrologic, and land surface variables. Including small headwater channels substantially increased drainage network complexity, with total stream length and drainage density increasing by 48.4%. These changes resulted in a shift toward higher flood susceptibility across the watershed.