THE BASEFLOW AND STORM FLOW HYDROLOGY OF A PRECAMBRIAN SHIELD HEADWATER PEATLAND

A hydrological investigation was conducted in a small headwater peatla nd located in the Experimental Lakes Area, north-western Ontario, Cana da, to determine the subsurface and surface flow paths within the peat land, and between the peatland and an adjacent forested upland during baseflow and storm flow conditions. Distinct zones of groundwater rech arge and discharge were observed within the peatland. These zones are similar to those found in much larger flow systems even though the pea tland was only influenced by local groundwater flow. Groundwater emerg ing in seeps and flowing beneath the peatland sustained the surface we tness of the peatland and maintained a constant baseflow. The response of the peatland stream to summer rain events was controlled by peatla nd water table position when the basin was dry and antecedent moisture storage on the uplands when the basin was wet. The magnitude and timi ng of peak runoff during wet conditions were controlled by the degree of hydrological connectivity between the surrounding upland terrain an d the peatland. (C) 1998 John Wiley Sons, Ltd.