Exploring snow distribution dynamics in steep forested slopes with UAV-borne LiDAR

Mapping snow in forests is important for understanding the cover dynamics these environments view of hydrological applications and water resources management. Today, Uncrewed Aerial Vehicles (UAVs) are widely used studies due to their rather cheap flexible operation. UAV-borne Light detection ranging (LiDAR) systems a promising technology sub-canopy mapping at high temporal resolutions, concurrently providing information on both canopy below-canopy surface. In this pilot study, we UAV-LiDAR system investigate within two steep forested slopes opposing aspects Swiss Alps spatial resolution unprecedented resolution. Using Distance Canopy Edge (DCE) algorithm characterize local forest structure, depth was analyzed terms relative position variable cover. The north-exposed site had higher mean depths throughout season compared south-exposed site, especially gaps. Whereas depletion rate consistent much faster gaps slope. Correlation coefficients between closure were weaker (between ?0.5 ? 0.7) than ?0.7 0.9), rapidly deteriorated right after peak winter This indicates shortwave radiation dominates snowmelt processes which thought be spatially uncorrelated cover, unlike accumulation melt slope that generated patterns with correlation entire season. Calculations incoming (SWR) sites confirmed assumption. While our findings encourage use LiDAR further investigations slopes, also outline discuss technical challenges specific application. Our insights allow deriving useful recommendations future using over similar environment. • First time series based maps opposed Alps. At correlated until mid-ablation. Sun exposure led complex Recommendations UAV-based terrain provided.