The hydrogeological function of kettle lakes on the Oak Ridges Moraine, Ontario, Canada.

摘要

Rapid urbanization of the Oak Ridges Moraine (ORM) has raised concern over potential impacts on the quality and quantity of the groundwater in the underlying Oak Ridges Aquifer Complex (ORAC). In recent years, the hydrogeological behavior of the ORM surficial sediments has been well documented and the relationship between land use change and direct land-based recharge is now generally well established. Less well understood, however is the hydrogeological significance of the kettle lakes that dot the moraine, particular in terms of their recharge function.; To better understand the hydrogeological function of the kettle lakes, hydrochemical and water balance investigations were carried out for Bond Lake and Philips Lake. The water balance was calibrated to daily-observed lake water level fluctuations to provide reliable predictions of the lakes' water levels over time. Water balance results indicate that Bond Lake and Philips Lake provide approximately 141,960 and 72,693 m3/year respectively to the ORAC. These volumes are equivalent to recharge rates of approximately 223 mm/yr and 335 mm/yr, approximately 80--180 mm/yr higher than the surrounding land-based recharge rate. The research shows that the study area lakes are important sources of recharge to the ORM and in need of appropriate protection.