Vegetation causes channel erosion in a tidal landscape
Temmerman, S.; Bouma, T.J.; van de Koppel, J.; van der Wal, D.; de Vries, M.B.; Herman, P.M.J. (2007). Vegetation causes channel erosion in a tidal landscape. Geology (Boulder Colo.) 35(7): 631-634 In: Geology. Geological Society of America: Boulder. ISSN 0091-7613; e-ISSN 1943-2682, more |  |
| Keywords | Earth sciences > Geology > Geomorphology
Erosion
Water bodies > Inland waters > Wetlands > Marshes > Salt marshes
Brackish water; Fresh water |
| Abstract | Vegetation is traditionally regarded to reduce the erosion of channels in both fl uvial and tidal landscapes. We present a coupled hydrodynamic, morphodynamic, and plant growth model that simulates plant colonization and channel formation on an initially bare, fl at substrate, and apply this model to a tidal landscape. The simulated landscape evolution is compared with aerial photos. Our results show that reduction of erosion by vegetation is only the local, on-site effect operating within static vegetation. Dynamic vegetation patches, which canexpand or shrink, have a contrasting larger scale, off-site effect: they obstruct the fl ow, leading to fl ow concentration and channel erosion between laterally expanding vegetation patches. In contrast with traditional insights, our fi ndings imply that in tidal landscapes, which are colonized by denser vegetation, channels are formed with a higher channel drainage density. Hence this study demonstrates that feedbacks between vegetation, fl ow, and landform have an important control on landscape evolution. |
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