Utilisation de l'humidité du sol comme indicateur de changement climatique

Abstract

In the current climate change context, Quebec should expect to see temperatures rise, particularly in winter, as well as liquid precipitation. This will have a significant impact on the hydrological cycle of watersheds in Quebec. The objective of this study is to assess if the soil moisture could be an indicator of climate change to reliably anticipate some changes in flows. The watershed studied, the Gatineau River in southwestern Quebec, has an area of 23 724 km2 and is mostly forest. The hydrological model Hydrotel, able to subdivide the basin into six sub-basins and 715 RHHU, and separating the soil into three layers, was used. Calibration was performed manually with an emphasis on summer and has given good results on four sub-basins with Nash-Sutcliffe coefficients of around 0.8. The soil moisture data used in this study were output from Hydrotel at a daily step for the three soil layers. The control period (1975-2001) has shown that soil moisture was more dependent on climatic conditions for some months (especially summer) while in spring, melting snow swamped almost always the three soil layers. The simulations at horizon 2056, carried through the CRCM climate data (2042-2068), showed that a decline in soil moisture during the summer and fall should be expected. The interannual variability should increase. At the spatial level, some areas in the south of the basin should be of particular behavior. The vegetation, soil type and climatic conditions have been identified as the main factors responsible for this spatial variability.

Date	29 Apr 2010
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	François Brissette (Supervisor) & Robert Leconte (Co-supervisor)