Dynamics of erosion and deposition events on an intertidal mudbank at Burringham, River Trent, UK

Abstract

Abstract:Measurements using an automatic bank level monitoring technique [the photoelectronic erosion pin (PEEP) system] over a 70-day period between 16 March and 27 May 1997 have revealed a complex pattern of erosion and deposition on an intertidal mudbank on the River Trent at Burringham. Comparison of mean daily changes in bank elevation at upper and lower bank positions suggest that wave activity induced by high wind speeds causes erosion, while high tidal range leads to deposition as a result of higher suspended solids concentrations. A greater variability in mean daily erosion and deposition events at the lower bank compared with the upper bank appears to indicate that higher bed shear stresses, as well as a greater availability of sediment for settling, owing to higher concentrations and a greater depth of water, lead to a more dynamic exchange of material at this position. The PEEP data also show longer term trends in sedimentation, with the mean deposition for the period exceeding mean erosion. Manual erosion pin measurements at a lower frequency over a longer, seven-month period con®rm this, and also highlight the advantage of the PEEP system in monitoring events at a ®ner temporal resolution.

Fluvial erosion measurements of streambank using Photo-Electronic Erosion Pins (PEEP)

“…Both subsurface flows and swelling are key components of subaerial processes reconfirming our earlier suggestion that mass erosion remains the controlling agent during and after the June 19 th event at Site 1. This suggestion is similar to the observation made by Mitchell et al (1999). was taken the day after the event.…”

“…Bank erosion exacerbates during post-event, which typically corresponds to the falling limb of the hydrograph. The excess bank erosion is believed to be the cumulative impact of the rapid drawdown of the hydrograph, a similar observation has been made by Mitchell et al(1999) in UK Streams and Darby et al (2007) in the Sieve River, Italy. All the pre-described features were not observed at Site 1.…”

Bank erosion processes in streams in the U.S. Midwest

“…Mass erosion inetnsifies during the event or post-event, which typically corresponds to the falling limb of the hydrograph. The excess bank erosion is believed to be the cumulative impact of the rapid drawdown of the hydrograph and the impact of the hydraulic forces, a similar observation has been made by Mitchell et al(1999) in U.K. Streams and Darby et al (2007) in the Sieve River, Italy.…”

The importance of high-resolution monitoring in erosion and deposition dynamics studies: examples from estuarine and fluvial systems

“…Indeed, high-resolution approaches with PEEP systems are now being applied by several research teams to different geomorphological and hydrological problems across the world, including beaches, tidal systems, drainage ditches and artificial channels, and snow ablation and accumulation studies (e.g. Mitchell et al, 1999;Stott, 1999;Prosser et al, 2000). However, substantial scope exists for applications to gully, arroyo, dune and hillslope erosion systems too.…”