Flood data from 205 unregulated rural drainage basins ranging in size from 0. 012 to 5, 993 mi 2 were analyzed to determine whether main-channel or ientation had any effect on flood peaks. No significant effect on flood peaks was found for unregulated rural streams in Ohio except for steep basins (mainchannel slope> approximately 1 percent) that flow in nearly the same direction as the prevailing storm movement (< 20-degree deviation). These basins in general produce higher flood peaks than those predicted by the US Geological Survey regional regression equations for Ohio.

Numerous studies (, l-12) have addressed the fact that storm patterns affect peak runoff rates for small drainage basins. Abraham et al.<. lll and Masch (_!!) showed that storms traveling in the same direction as the main-channel flow of the basin produce flood peaks of shorter duration and greater magnitude than storms traveling directly opposite the flow of the main channel. This effect is normally increased with an increase in the ratio of length to drainage area of the basins. For most areas of the United States there is a prevailing direction of rainstorm movement (15, 16). Considering the foregoing, it would be reasonable to question whether streams flowing in the same direction as the prevailing direction of storm movement would have significantly different flood peaks than streams flowing in the opposite direction.