Determination of flood hydrographs for streams in South Carolina: Volume 1. Simulation of flood hydrographs for rural watersheds in South Carolina

A method is given for simulating a typical (average) flood hydrograph corresponding to a peak discharge of specific recurrence interval for ungaged rural basins having drainage areas less than 500 sq mi in South Carolina. Dimensionless hydrographs were developed for three regions on the basis of 188 storm events at 49 stations that represent a wide range of drainage area sizes and basin conditions. The design peak discharge and a basin lagtime (which has been adjusted to produce correct hydrograph volume) are required to apply the technique. The standard errors of estimate for simulated hydrograph widths at 50 and 75%, respectively, of observed stormflow were +/-14.1 and +/-18.3% for basins in the Blue Ridge physiographic province, +/-29.2 and +/-36.2% for basins in the Piedmont province, and +/-17.8 and +/-22.8% for basins in the Coastal Plain provinces. (USGS)