“Natural Flood Management – Understanding the complex processes involved”
Testing piping and erosion processes in managed realignment sites through a newly designed apparatus – Dr Heidi Burgess and Florence Van Vaerenbergh
Managed realignment is a relatively new scheme of coastal defence, aiming to use natural environments to protect our coastlines and reduce the maintenance cost of hard defences. Research so far has focused on vegetation development and sediment transport processes to assess the success of given schemes at reproducing an intertidal habitat. There is however very little information on the impact of exposing a previously protected ground to tidal cycles on the erosion processes and the formation of drainage channels through piping.
For my final year project, I am using an entirely new apparatus which is based on previous piping apparatus, designed for dam application, and adapted to reproduce a tidal sequence that could be found in a managed realignment site. I now can observe how a soil mix, representative of the studied habitat, responds to flooding and draining cycles over time.
Seeing the soil surface dipping and eroding, and cracks forming within the soil itself; observing how the soil water level varies throughout draining cycle and how the drainage speed and behaviour gradually changes over time, is a rewarding process which provides valuable insights on how a newly designed managed realignment sites might behave during the first few tidal cycles.
Knowing that this is something that has never been attempted before also makes the whole process more interesting, as it might open a path to better designed managed realignment schemes in the future and lead to a better understanding of the piping and drainage processes in intertidal habitats.