Hydrologic response simulation of a snow-covered alpine catchment using a travel time distribution model coupled to alpine3D
Fully distributed models of alpine catchment surface processes typically use the geomorphological information provided by digital maps for describing the dynamics of rain, snow, soil and vegetation with much detail. These models are largely used to provide reliable estimations of the total amount of water that can be stored in alpine catchments in relation to different climate change scenarios. Many applications of the model Alpine3D have shown a good agreement between numerical results and local measurements of snow height distribution and runoff production, thanks to the physically based description of surface energy balance and mass balance. The simulation of streamflow generation at catchment scale would also require a detailed description of the sub-surface characteristics, which is hardly available. This motivates the testing of a spatially-explicit hydrologic response model based on geomorphologic travel time distributions, in connection with the detailed description of alpine surface processes as provided by Alpine3D. In this contribution we characterize the hydrologic response, considering patchy snow covers, in the Dischma catchment (Grisons, Switzerland) during the time period 2001 - 2006. We show that the spatially-explicit hydrological response model, which explicitly accounts for geomorphologic travel time distributions, reacts adequately to spatially varying water input from melting snow. In fact, a good agreement with the measurements is obtained both in terms of daily and seasonal cycles of discharge. Moreover, the direct physical meaning of the model parameters turns out to be a great advantage in the calibration of the model, supporting the conclusion that a travel time distribution approach is an interesting new avenue for the hydrologic response simulation in Alpine3D.
Record created on 2014-03-13, modified on 2016-08-09