Providing a non-deterministic representation of spatial variability of precipitation in the Everest region
Abstract. This paper provides a new representation of the effect of altitude on precipitation that represent spatial and temporal variability of precipitation in the Everest region. Exclusive observation data are used to infer a piecewise linear function for the relation between altitude and precipitation and significant seasonal variations are highlighted. An original ensemble approach is applied to provide non deterministic water budgets for middle and high mountain catchments. Physical processes at the soil-atmosphere interface are represented through the ISBA surface scheme. Uncertainties associated with the model parametrization are limited by the integration of in-situ measurements of soils and vegetation properties. Uncertainties associated with representation of the orographic effect are shown to account for up to 16 % of annual total precipitation. Annual evapotranspiration is shown to represent 26 % ± 1 % of annual total precipitation for the mid-altitude catchment and 34 % ± 3 % for the high-altitude catchment. Snow fall contribution is shown to be neglectible for the mid-altitude catchment and it represents up to 44 % ± 8 % of total precipitation for the high-altitude catchment. These simulations at the local scale enhance current knowledge of the spatial variability of hydro-climatic processes in high- and mid-altitude mountain environments.