The base ̄ow and storm ̄ow hydrology of a precambrian shield headwater peatland

A hydrological investigation was conducted in a small headwater peatland located in the Experimental Lakes Area, north-western Ontario, Canada, to determine the subsurface and surface ̄ow paths within the peatland, and between the peatland and an adjacent forested upland during base ̄ow and storm ̄ow conditions. Distinct zones of groundwater recharge and discharge were observed within the peatland. These zones are similar to those found in much larger ̄ow systems even though the peatland was only in ̄uenced by local groundwater ̄ow. Groundwater emerging in seeps and ̄owing beneath the peatland sustained the surface wetness of the peatland and maintained a constant base ̄ow. The response of the peatland stream to summer rain events was controlled by peatland water table position when the basin was dry and antecedent moisture storage on the uplands when the basin was wet. The magnitude and timing of peak runo€ during wet conditions were controlled by the degree of hydrological connectivity between the surrounding upland terrain and the peatland. # 1998 John Wiley Sons, Ltd. Hydrol. Process., Vol. 12, 57±72 (1998)