Evaluation of the FORHYM2 model for prediction of hydrologic fluxes and soil temperature at the Lake Clair Watershed (Duchesnay, Quebec)

Abstract

Incident precipitation, snowpack height, throughfall, soil and subsoil water content, soil temperature, and streamflow were monitored at the Lake Clair forest watershed, near Quebec City (Que., Canada). Data were collected for the 1989–1994 period. Distinct and regular seasonal trends were observed in soil moisture and in streamflow: an important peak occurred in the spring during the rise of snowmelt while a lower peak was observed in the fall, where precipitation was more abundant and tree transpiration reduced. The lowest soil moisture values were observed from January to April, when infiltration was negligible. Monthly hydrologic fluxes and soil temperatures at different depths were simulated for the watershed using the FORHYM2 hydrologic model. Simulated monthly values of throughfall, snowpack height, soil and subsoil water contents, lake outlet streamflow, and soil temperature were generally in good agreement with observed values in terms of temporal synchronicity and magnitude. From 1989 to 1994, absolute mean monthly differences between observed and simulated values ranged from 1 (soil water and subsoil water contents) to 8% for streamflow. This is the first study confirming the ability of FORHYM2 to adequately simulate monthly soil and subsoil water contents for complete years over a relatively long period of time.