A new methodology for planning snow drift fences in alpine terrain

•A new methodology for the evaluation of snow drift constructions is presented.•The method contains of a high resolution approach using TLS and wind field modelling.•Approximately 5560 m3 of snow was additionally deposited compared to the state before.

The planning of snow fence constructions in alpine terrain is site-specific and lacks published guidelines. A methodology of snow drift analysis for the evaluation of snow drift constructions is presented. The background to the methodology are recent findings of time series of spatial snow depth maps obtained by laser scanning over a period of several years, where snow accumulation patterns over a whole winter season were similar in different years of observation. It could be concluded that the knowledge of spatial snow distribution at annual peak accumulation provides a reliable basis for the planning of drift constructions. It was hypothesized that snow accumulation patterns at a new project site could be assessed using a combination of snow mapping via terrestrial laser scanning and high resolution numerical wind field modelling. Modelling results localized areas of large vertical and horizontal wind speeds, which coincide with extrema of wind stress on the snowpack surface. TLS surface maps provided the spatial snow depth distribution, and erosional and depositional zones were apparent. Insufficiencies in fence functioning at the study site were determined and adaptations to fence constructions using existing recommendations could be applied. The functionality of the fences was significantly improved using the presented methodology, so it is recommended that future construction projects consider a similar site evaluation.