Calibration of a distributed hydrological model for simulations of remote glacierized Himalayan catchments using MODIS snow cover data

The objective of this study is to investigate the suitability of remote sensing data to calibrate a distributed hydrological model of a Nepalese Himalayan headwater catchment. Snow cover data from the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite are used to calibrate the snow and glacier routine of the conceptual hydrological model TAC. The snow cover information is useful to constrain the hydrological model in the calibration phase, especially in data-scarce regions. Simulation results using the MODIS calibrated parameter sets are evaluated against independent observations measured discharge data and glacier mass balance measurements of the Langtang Khola catchment. The constraint posed in the calibration phase by the spatially distributed observations allows a reduction in the equifinality problem, thus producing a better balance among the modelled processes and a more plausible partitioning of the different runoff components. Accordingly, we demonstrate that the use of a remote sensing-based additional source of information allows enhancing streamflow predictions for data scarce areas, thus also allowing water resources assessment in remotely located regions.