Operational analysis of the spatial distribution and the temporal evolution of the snowpack water equivalent in southern Québec, Canada

A technique for obtaining an operational regional analysis of the temporal evolution of the snowpack water equivalent in southern Québec (Canada) is proposed and implemented on a 0.1° grid. The technique combines the output of the snowpack model included in the HYDROTEL hydrological model, forced by observed temperatures and precipitations, with observed snow survey data. A strategy based on observed snow density, snowpack water equivalent and streamflow is used for model calibration. A comparison of various calibration strategies showed that the same model parameters can be used for the whole of southern Québec. It was also shown that, for operational purposes, it is sufficient to rely solely on automatic stations and to use 3 h time steps. Because snow surveys are made in deciduous forests, model parameters were adjusted to account for open areas and coniferous trees by comparing observed and simulated streamflow, using all components of the hydrological model. An assimilation technique which updates simulated water equivalent and snow density at grid points from the available snow survey data completes the operational system. An example of spring streamflow simulated using the proposed snow analysis illustrates the usefulness of the technique.