The Development of Regional Bankfull Discharge Regression Curves from Rural and Urban Stream Streams in the Piedmont of Maryland and Delaware

摘要

Data from the field calibration of bankfull discharge in streams at 14 USGS gaging stations in the Piedmont Region of Maryland and Delaware were analyzed. Two sets of regression curves were developed, rural (imperviousness < 11%) and urban (imperviousness > 20%), expressing the relationship of drainage area (DA) to bankfull discharge (Q_(bf)) and to bankfull channel cross-sectional area (CX_(bf)). In comparing rural with urban curves a tendency toward convergence at larger drainage areas was evident in the discharge curves, but not in the cross sectional area curves. From these curves discharge and enlargement ratios of urban to rural streams were calculated. Statistical descriptors of the above results indicate they may be applicable to ungaged Piedmont reaches in estimating Q_(bf) and CX_(bf).