The spatial variability of snow water equivalent

T. Skaugen (1, 2)

1 NVE - Norwegian Water Resources and Energy Directorate
2 Department of Geosciences [Oslo]

The spatial distribution of snow water equivalent (SWE) is modelled as a two parameter gamma distribution. The parameters of the distribution are dynamical in that they are functions of the number of accumulation and ablation events and the temporal correlation of accumulation and ablation events. The estimated spatial variability is compared to snow course observations from the alpine catchments Norefjell and Aursunden in Southern Norway. A fixed snow course at Norefjell was measured 26 times during the snow season, which showed that the spatial coefficient of variation change during the snow season with a decreasing trend from the start of the accumulation period and a sharp increase in the ablation period. The gamma distribution with dynamical parameters reproduced the observed spatial statistical features of SWE well both at Norefjell and Aursunden. Also the shape of simulated spatial distribution of SWE agreed well with the observed at Norefjell. The temporal correlation tends to be positive for both accumulation and ablation events. However, at the start of ablation, a better fit between modelled and observed spatial standard deviation of SWE is obtained by using negative correlation between SWE and melt.

Domaines: Interfaces continentales, environnement; Océan, Atmosphère; Sciences de la Terre

T. Skaugen. The spatial variability of snow water equivalent. Hydrology and Earth System Sciences Discussions, 2007, 4 (3), pp.1465-1489. ⟨hal-00298841⟩