Sylvain Jutras

Implementation of a Peatland-Specific Water Budget Algorithm in HYDROTEL

HYDROTEL, a distributed hydrological model, was used to simulate streamflows of the Necopastic watershed (N53°40.6’; W78°09.8’), James Bay, Quebec. Because of the prevalence of peatlands in the studied environment, important issues regarding soil parameterization in the vertical, three-layer, water budget sub-model (BV3C) of HYDROTEL were raised. Since BV3C was originally developed for mineral soils, an alternative, peatland-specific, water budget sub-model (PHIM) was integrated into HYDROTEL. Basic data requirements included a description of the organic soil structure and a water-table/discharge relationship. PHIM was calibrated with data collected on a peatland complex located within the Necopastic watershed. Preliminary results of observed and simulated streamflows using both the original and the adapted versions of HYDROTEL compared well, therefore leading the way to future simulations of North-Boreal watersheds.

A review of ground-penetrating radar studies related to peatland stratigraphy with a case study on the determination of peat thickness in a northern boreal fen in Quebec, Canada

Ground-penetrating radar (GPR) is a non-intrusive geophysical observation method based on propagation and reflection of high-frequency electromagnetic waves in the shallow subsurface. The vertical cross-sectional images obtained allow the identification of thickness and lithologic horizons of different media, without destruction. Over the last decade, several studies have demonstrated the potential of GPR. This paper presents a review of recent GPR applications to peatlands, particularly to determine peat stratigraphy. An example study of acquisition and comparison of peatland soil thickness of a fen-dominated watershed located in the James Bay region of Quebec, using (1) a meter stick linked to a GPS RTK and (2) a GSSI GPR, is given. A coefficient of determination (r2 ) of 56% was obtained between the ordinary krigings performed on data gathered using both techniques. Disparities occurred mainly in the vicinity of ponds which can be explained by the attenuation of GPR signal in open water. Despite these difficulties – the higher time required for analysis and the error margin – it seems more appropriate to use a GPR, instead of a graduated rod linked to a GPS, to measure the peat depths on a site like the one presented in this study. Manual measurements, which are user-dependent in the context of variable mineral substrate densities and with the presence of obstacles in the substrate, may be more subjective.