Effects of forest-management activities on runoff components and ground-water recharge to Quabbin Reservoir, central Massachusetts

摘要

The effects of forest-management activities (timber cutting and herbicide application) on runoff components (total streamflow, direct runoff, and base flow) and on ground-water recharge per unit area were evaluated for two separate paired drainage basins of Quabbin Reservoir in central Massachusetts. The Cadwell Creek study area, studied from 1962-1973, included an experimental basin (Upper Cadwell Creek) and a control basin (Lower Cadwell Creek). In the experimental basin, herbicide was applied to mixed oaks, northern hardwoods, and understory vegetation in different riparian zones during the summers of 1967 and 1968, and some pine plantations were thinned or clear-cut during the winter of 1967-1968. These forest-management activities decreased the total basal area by about 34%. The decrease in total basal area resulted in an increase in total streamflow, direct runoff (total streamflow minus base flow), and ground-water recharge for six dormant seasons (October-April) and six growing seasons (May-September) during 1968-1973. Base flow increased for three dormant seasons and two growing seasons during 1968-1970 and the dormant seasons of 1971 and 1973. Base flow accounted for 34% and direct runoff accounted for 66% of the 94 mm (15%) increase in total streamflow during water years 1968-1973. Sixty-one percent of this increase in total streamflow occurred in the dormant seasons.