THE ROLE OF GROUNDWATER IN DELAYING LAKE ACIDIFICATION

Models used to study lake acidification generally divide a watershed into several zones or compartments (e. g. , soil and groundwater zones) through which water and chemicals are routed. To date most emphasis has been placed on the buffering of acid inputs by chemical reactions in the soil zone. Although buffering in the soil zone undoubtedly is important, the focus of this paper is the role of the groundwater system in delaying lake acidification. In this study, a deterministic approach was selected over the standard parametric modeling used in watershed models. Specifically, an advection-dispersion model of the groundwater system was linked to a simple groundwater-rain-lake mixing model, which in turn was linked to a geochemical speciation and reaction path model.