Paper No. JAWRA-09-0107-P of the Journal of the American Water Resources Association (JAWRA). Discussions are open until six months from print publication.
The Effect of Channelization on Floodplain Sediment Deposition and Subsidence Along the Pocomoke River, Maryland1
Article first published online: 9 APR 2010
© 2010 American Water Resources Association. No claim to original U.S. government works
JAWRA Journal of the American Water Resources Association
Volume 46, Issue 4, pages 686–699, August 2010
How to Cite
Kroes, D. E. and Hupp, C. R. (2010), The Effect of Channelization on Floodplain Sediment Deposition and Subsidence Along the Pocomoke River, Maryland. JAWRA Journal of the American Water Resources Association, 46: 686–699. doi: 10.1111/j.1752-1688.2010.00440.x
- Issue published online: 26 JUL 2010
- Article first published online: 9 APR 2010
- Received July 27, 2009; accepted February 11, 2010.
- floodplain isolation;
- fluvial processes;
Kroes, Daniel E. and Cliff R. Hupp, 2010. The Effect of Channelization on Floodplain Sediment Deposition and Subsidence Along the Pocomoke River, Maryland. Journal of the American Water Resources Association (JAWRA) 46(4): 686-699. DOI: 10.1111/j.1752-1688.2010.00440.x
Abstract: The nontidal Pocomoke River was intensively ditched and channelized by the mid-1900s. In response to channelization; channel incision, head-cut erosion, and spoil bank perforation have occurred in this previously nonalluvial system. Six sites were selected for study of floodplain sediment dynamics in relation to channel condition. Short- and long-term sediment deposition/subsidence rates and composition were determined. Short-term rates (four years) ranged from 0.6 to 3.6 mm/year. Long-term rates (15-100+ years) ranged from −11.9 to 1.7 mm/year. 137Cs rates (43 years) indicate rates of 0.24 to 7.4 mm/year depending on channel condition. Channelization has limited contact between streamflow and the floodplain, resulting in little or no sediment retention in channelized reaches. Along unchannelized reaches, extended contact and depth of river water on the floodplain resulted in high deposition rates. Drainage of floodplains exposed organic sediments to oxygen resulting in subsidence and releasing stored carbon. Channelization increased sediment deposition in downstream reaches relative to the presettlement system. The sediment storage function of this river has been dramatically altered by channelization. Results indicate that perforation of spoil banks along channelized reaches may help to alleviate some of these issues.