Abstract

The relationship between forest cover, snow depth and snow density is central to determining snow water equivalence in forested catchments.  Most modeling, research and forecasting are based on a limited number of measurements made in non representative areas of the mountainous west. Thus the problem of understanding snow distribution at large spatial extents and frequent time steps has not been solved.  Snow accumulation in forested environments is a result of the multiple feedbacks between precipitation, topography, and vegetation. Here we present and analysis of snow accumulation from the Wolverton Basin, Southern Sierra Critical Zone Observatory.  Continuous snow depth measurements collected from 26 stratified locations over the 2008‐2010 water years are compared to canopy gap fraction as determined by hemispherical photographs. Canopy gap fraction and snow accumulation are found to be highly correlated, R2 =0.6 to 0.9 dependant on time interval and area of integration. Snow depths measured at point locations are also compared with snow depth data computed from snow on and snow off 1m digital elevation models, derived from the 2010 CZO LiDAR over‐flights. Additional analysis of canopy density derived from 30m Landsat products and the 1m LiDar product is also presented. Canopy density and elevation are found to be the most significant factor in determining snow depth at peak accumulation and provide a robust physically based approach to estimating accumulation in areas with forest snow cover.

Citation

Kirchner, P. B., Bales, R. C., Musselman K. N., Flanagan J., and Guo, Q. (2011): "Seeing the Snow Through the Trees: Accumulation in forested catchments as determined from snow depth sensor and LiDAR measurements. National CZO Program 2011 All Hands Meeting.

This Paper/Book acknowledges NSF CZO grant support.