Wind speed interpolation for evapotranspiration assessment in complex topography area

Wind speed and direction are fundamental data for many application fields, suchas power generation and hydrological modelling. Wind measurements are usuallyfew and sparse; hence, spatial interpolation of wind data is required. However, inmountainous areas with complex orography, accurate interpolation of wind datashould consider topographic effects. Dueto computational constraints, fully phys-ically based methods that solve thermodynamic and mass conservation equationsin three dimensions cannot be applied for long-time simulations or very largeareas, while fast empirical methods seem more suitable. The aim of this work isto compare fast empirical methods to interpolate wind speed against a physicallybased full atmospheric model in order to assess the impact of the introducedapproximation in estimating the wind field and the potential evapotranspiration.Comparison is carried out over the area of the upper Po River basin, a predom-inantly alpine region located in northern Italy. Results show that empiricaltopographic correction can increase accuracy of interpolated wind speed in areaswith complex topography, but it requires about 50% more computational timethan simpler empirical methods that do not consider topography.