Article
Channel response to sediment release: insights from a paired analysis of dam removal
Earth Surface Processes and Landforms
(2017)
Abstract
Dam removals with unmanaged sediment releases are good opportunities to learn about channel response to abruptly increased bed material supply. Understanding these events is important because they affect aquatic habitats and human uses of floodplains. A longstanding paradigm in geomorphology holds that response rates to landscape disturbance exponentially decay through time. However, a previous study of the Merrimack Village Dam (MVD) removal on the Souhegan River in New Hampshire, USA, showed that an exponential function poorly described the early geomorphic response. Erosion of impounded sediments there was two-phased. We had an opportunity to quantitatively test the two-phase response model proposed for MVD by extending the record there and comparing it with data from the Simkins Dam removal on the Patapsco River in Maryland, USA. The watershed sizes are the same order of magnitude (102 km2), and at both sites low-head dams were removed (~3–4 m) and ~65 000 m3 of sand-sized sediments were discharged to low-gradient reaches. Analyzing four years of repeat morphometry and sediment surveys at the Simkins site, as well as continuous discharge and turbidity data, we observed the two-phase erosion response described for MVD.
Disciplines
Publication Date
2017
DOI
DOI: 10.1002/esp.4108
Citation Information
Peter Richard Wilcock. "Channel response to sediment release: insights from a paired analysis of dam removal" Earth Surface Processes and Landforms Vol. 42 Iss. 11 (2017) p. 1636 - 1651 Available at: http://works.bepress.com/peter_wilcock/161/