Hydrogeological investigation of Chappice Lake, southeastern Alberta: Groundwater inputs to a saline basin

Three methods were employed to test the hypothesis that Chappice Lake, Alberta, is fed by a shallow groundwater system sensitive to changes to climate.;The dynamics and chemistry of water in the immediate vicinity of Chappice Lake were compared to known shallow and deep systems to determine the type of groundwater system sustaining Chappice Lake. Groundwater flow in the basin suggests discharge of a shallow system. Hydraulic head and water table elevations measured in piezometers and a watertable well showed strong fluctuations corresponding with seasonal changes in recharge.;The chemistry of waters sampled in the basin suggests a variety of potential sources including shallow and deep aquifers. Dilute waters with compositions similar to both shallow surficial aquifers and bedrock aquifers were found in springs, which are thought to be the main entry point of water to the lake. The ;Evaporation simulations using PHRQPITZ, a thermodynamic geochemical model, showed that the evaporation of water types found in tills and sandy surficial aquifers results in mineralogical assemblages and a final brine composition close to that observed at Chappice Lake.;The historical climatic sensitivity of groundwater inputs to the lake was investigated using a simple water budget. Fluctuations in the precipitation deficit were large relative to fluctuation in lake volumes. This relationship requires an almost equally large input from groundwater. (Abstract shortened by UMI.).