Snow redistribution for the hydrological modeling of alpine catchments

Abstract

Modeling snow redistribution by wind and avalanches in hydrological studies in alpine catchments is important, as the spatial variability of the snow cover has an impact on timing and magnitude of the snowmelt runoff. Disregarding snow redistribution in models can lead to the formation of ‘snow towers,’ i.e., multi‐year accumulation of snow at high elevations and an incorrect water balance. The reviewed approaches to deal with snow redistribution in hydrological models were first broadly grouped by the represented physical processes: (1) the correction of the precipitation input data to account mainly for preferential deposition, (2) the description of all wind‐driven processes based on wind field data, (3) the description of gravitational transports and/or wind‐driven processes based on topographic information, and (4) the statistical description of the variability of the snow water equivalent (SWE) to account for all types of snow redistribution. The review further assessed the implementation of these approaches in physically based and bucket‐type hydrological models. Generally, snow redistribution consideration has improved the simulation of snow patterns and SWE and consequently the prediction of discharge in mountain catchments worldwide. Snow redistribution approaches still have some limitations and a large gap exists between the knowledge and processes in highly detailed physically based snow models and the widely used bucket‐type hydrological models used for water resources and climate change studies. There is a real need to bridge this gap using the knowledge earned by snow redistribution modeling with established physically based models to develop more conceptual approaches for the application in bucket‐type models. WIREs Water 2017, 4:e1232. doi: 10.1002/wat2.1232This article is categorized under: Science of Water > Hydrological Processes Science of Water > Methods Science of Water > Water and Environmental Change