Numerical Modeling of Evapotranspiration from Montane Vegetation with Verification from Actual Surface Energy Balance Measurements.

Estimating actual evapotranspiration (ETa) is an important, yet challenging task in arid montane ecosystems. We employed a numerical model (Hydrus 1D) to estimate actual evapotranspiration from water content measurements following snowmelt in the Wasatch Range of mountains. The study area includes three watersheds in the Northern Utah equipped with eleven weather stations, each reporting soil moisture, net radiation, relative humidity, air and soil temperature and precipitation. Estimates of ETa were taken as the sum of root water uptake and evaporation, which were compared with ET calculated from surface energy balance. Measurements of net radiation, sensible heat flux and soil heat flux were used to obtain ETa as the residual latent heat flux (LET). These estimates are expected to provide ETa estimation taking account of the soil - vegetation characteristics for improved climate modeling boundary conditions.