Canopy influence on snow depth distribution in a pine stand determined from terrestrial laser data

• Published in: Water resources research 2015-05, Vol.51 (5), p.3476-3489
• Main Authors: Revuelto, J., López-Moreno, J. I., Azorin-Molina, C., Vicente-Serrano, S. M.
• Format: Article
• Language: English
• Subjects: Accumulation; Canopies; Canopy; Distance; Distribution; Evolution; Forest canopy; Forests; High resolution; Lasers; Lidar; Melting; Pine; Principal components analysis; Pyrenees; Seasons; Snow; Snow accumulation; Snow depth; snow distribution; Snowpack; Spatial distribution; Technology; Temporal variability; Temporal variations; terrestrial laser scanning (TLS); Variability
• ISSN: 0043-1397; 1944-7973
• DOI: 10.1002/2014WR016496

In this study, we analyzed the effects of the forest canopy and trunks of a pine stand in the central Spanish Pyrenees on the snow depth (SD) distribution. Using LiDAR technology with a terrestrial laser scanner (TLS), high‐resolution data on the SD distribution were acquired during the 2011–2012 and 2012–2013 snow seasons, which were 2 years having very contrasting climatic and snow accumulation conditions. Average SD evolution in open and canopy areas was characterized. Principal component analysis was applied to identify days having similar spatial patterns of SD distribution. There was a clear contrast in the temporal variability of the snowpack in different areas of the forest stand, corresponding generally to beneath the canopy, and in open sites. The canopy and openings showed markedly different accumulation and melting, with higher snow accumulation found in openings. Differences ranged from 14 to 80% reduction (average 49%) in the SD beneath the canopy relative to open sites. The difference in SD between open and canopy areas increased throughout the snow season. The surveyed days were classified in terms of SD distribution, and included days associated with: high SD, low SD, intense melting conditions and periods when the SD distribution was driven by wind conditions. The SD increased with distance from the trunks to a distance of 3.5–4.5 m, coinciding with the average size of the crown of individual trees. Key Points: Canopy presence has a major effect on snow distribution (average reduction 49%) With thicker snowpack, smaller snow differences between open and canopy areas Snow difference (open‐canopy) is increased with time during the snow season