IMPACT OF CONSTRUCTION ACTIVITIES ON SEDIMENT RESPONSE IN A SMALL DRAINAGE BASIN,WESTERN NEW YORK

The sediment response of a small drainage basin affected by construction is compared with that of an adjacent unaffected basin. Multiple regression analyses of both basins indicate that construction activities not only increase the suspended sediment concentration in storm runoff, but reduce the tendency for transportable sediments to become exhausted during a storm. The analyses further reveal that rainfall intensity is the most useful precipitation variable in explaining the variation in suspended sediment concentration in both basins, and that this variable accounts for a higher proportion of the variation in sediment concentration in the basin affected by construction than in the one unaffected. The latter occurs because construction activities increase both the extent of Hortonian overland flow and the availability of transportable sediment.