Estimating the snow water equivalent from snow depth measurements in the Italian Alps

Abstract

The Snow Water Equivalent (SWE), combining the information of snow depth (Hs) and snow bulk density (ρb) is a necessary variable for snow-hydrological studies and applications, as well as, for ecological function or avalanche forecasting. The SWE direct measurement is challenging, and estimating the SWE from the single Hs measurements presents many advantages compared to the direct SWE measurement or the implementation of complex model needing to be fed by local meteorological data. In this study we propose a spatial and temporal variability description of the SWE, Hs and ρb and compare existing approaches over the Italian Alps. Finally, we propose a simple parametrization, introducing non-linearity in the snow bulk density variability. The resulting overall uncertainty on SWE is 15.6%. The proposed model has the potential to be a valuable tool to estimate the SWE from the only HS measurement in the Italian Alps, presenting even better performances during the late season (13.9%, 12.9% and 14.3% in March, April and May, respectively) that makes it particularly suitable for snow-hydrology studies.