| The relationship between soils, soil water and stream chemistry was investigated for a first order stream in a small forested watershed in the southern Laurentians, Quebec. The study was restricted to near-stream processes, particularly how the chemistry of water leaving a hillslope influenced stream chemistry. For snowmelt, 1986, a number of naturally occurring chemical elements were used to separate stream flow into three subsurface flowpaths: groundwater, solum and upwelling flow. By quantifying upwelling flow, we introduced a new approach to identify solutions forced from the groundwater up through the solum before entering the channel. In upwelling flow, we found that dissolved silicon was reactive and total aluminum, monomeric aluminum, hydronium, magnesium and fluoride were non-reactive. For spring storms, 1992, we used an end member mixing approach to describe streamwater as a combination of chemically distinct solutions from different depths in the soil. Solutions were defined by concentrations of calcium, magnesium, sodium and dissolved silicon. The contributions of water from each soil depth were estimated using the variations in end member chemistry that were measured during the storms. Hydrological reconstructions of the events were possible and it was found that the contribution of water from each depth in podzols is related to the height of the water table in the near-stream soils. |
