Creek systems in restored coastal wetlands: Morphological evolution and design implications.

Autor: Chirol C; School of Ocean and Earth Sciences, National Oceanography Centre Southampton, University of Southampton, Southampton SO14 3ZH, UK; Université Paris-Saclay, INRAE, AgroParisTech, UMR ECOSYS, 91120 Palaiseau, France. Electronic address: clementine.chirol@inrae.fr., Pontee N; School of Ocean and Earth Sciences, National Oceanography Centre Southampton, University of Southampton, Southampton SO14 3ZH, UK; Jacobs, Bristol BS2 0ZX, UK. Electronic address: Nigel.Pontee@jacobs.com., Gallop SL; School of Science, University of Waikato, Tauranga 3110, New Zealand; Environmental Research Institute, University of Waikato, Hamilton 3240, New Zealand. Electronic address: shari.gallop@waikato.ac.nz., Thompson CEL; School of Ocean and Earth Sciences, National Oceanography Centre Southampton, University of Southampton, Southampton SO14 3ZH, UK. Electronic address: celt1@noc.soton.ac.uk., Kassem H; School of Ocean and Earth Sciences, National Oceanography Centre Southampton, University of Southampton, Southampton SO14 3ZH, UK. Electronic address: hachem.kassem@soton.ac.uk., Haigh ID; School of Ocean and Earth Sciences, National Oceanography Centre Southampton, University of Southampton, Southampton SO14 3ZH, UK. Electronic address: I.D.Haigh@soton.ac.uk.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Apr 15; Vol. 921, pp. 171067. Date of Electronic Publication: 2024 Feb 18.
DOI: 10.1016/j.scitotenv.2024.171067
Abstrakt: Saltmarsh restoration such as managed realignment (MR) projects often include excavation of simplified tidal creek networks to improve drainage and marsh functioning, but their design is based on limited evidence. This paper compares the morphological evolution of creek networks in current MR projects in the UK with creek networks in natural saltmarshes, in order to provide improved guidance. The evolution of creek networks was monitored for 2-20 years post-breach at 10 MR sites across the UK by semi-automatically extracting 12 morphological creek parameters from lidar. The rates of creek evolution in MR sites are linked to the initial tidal, morphological and sedimentological conditions using principal component analysis, then compared with power law relationships of morphological equilibrium defined from 13 mature natural saltmarshes. MR creeks evolved into larger, more complex, better distributed systems, with a total creek length and volume statistically similar to their natural counterparts. However, the creek volume remains poorly distributed, with a mean distance between creeks ranging from 33 to 101 m versus 5-15 m for natural mature saltmarshes. MR creeks are also clustered around the breach area, leaving the marsh interior poorly drained. MR creek network morphologies remain strongly influenced by the initial creek template, as evidenced by unnaturally straight creeks inherited from former drainage ditches. A combination of external conditions (i.e., tidal range, sediment concentration in the wider estuary) and local conditions (i.e., site elevation, topographical heterogeneity, soil compaction) controls how easily creeks can form within MR sites. This in turn determines the amount of engineering effort required to help achieve reference site conditions. The end goal of creek design is to create MR sites that closely resemble reference site conditions, however the final design is also likely to be affected by a range of practical factors (e.g. engineering/cost) unique to each site and project.
Competing Interests: Declaration of competing interest The authors declare no conflict of interest.
(Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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