Snow distribution patterns in clearings and adjacent forest

Snow accumulation patterns were determined for clearings and adjacent forest at Marmot Creek experimental watershed and James River, Alberta. At maximum accumulation snow water equivalent (SWE) was greater in clearings than in forest whether clearings were large, as in 8‐ to 13‐ha blocks where SWE averaged 20% more than in the forest, or small as in the ¼ to 6‐H (height) diameter circular clearings where SWE was 13–45% greater than in the forest. SWE was 42 to 52% less in north than in south sectors of 2–6 H clearings. These differences increased with clearing size and time since beginning of accumulation period and are caused by snow ablation (melt and evaporation), a function of direct solar radiation reaching the snowpack. In such situations the snow that has accumulated on the ground cannot be considered a measure of the snow that has actually fallen there. For water balances and hydrologic modeling, snow measurements in partially cleared watersheds must be adjusted for temporal and spatial factors specific to the watershed.