Simulation of unsteady flow in the Roanoke River from near Oak City to Williamston, North Carolina

A one-dimensional, unsteady-flow model was calibrated, validated, and applied to a 30.4-mile reach of the Roanoke River between State Highway 42-11 bridge near Oak City (river mile 67.0) and the U.S. Highway 17-13 bridge at Williamston (river mile 36.6) North Carolina. The model was calibrated and validated for flows ranging from about 2,000 to 12,000 cubic feet per second. The model was used to compute daily mean flows at selected locations in the study reach for water years 1988-90. Flows were calculated for the range of conditions for which the model was calibrated and validated. Simulated monthly mean flows at river mile 67.0 were within 5 percent of measured flows at a gaging station at river mile 137.0, after adjustment of inflow from the intervening drainage area, for months having mean flows less than 14,000 cubic feet per second.