TY - JOUR
T1 - Chenier Formation Through Wave Winnowing and Tides
AU - Tas, Silke A.J.
AU - van Maren, Dirk S.
AU - Reniers, Ad J.H.M.
PY - 2022
Y1 - 2022
N2 - Cheniers are ridges consisting of coarse-grained sediments, resting on top of the fine sediment that forms the otherwise muddy coast. In this paper, we use Delft3D to explore how cheniers are formed through wave winnowing. We identify three phases of chenier development: (a) a winnowing phase, during which mud is washed out of the seabed initially consisting of a mixture of sand and mud, (b) a sand transport phase, when the sand in the upper layer is transported onshore, and (c) a crest formation phase, during which a chenier crest rapidly develops at the landward limit of onshore sediment transport. The main mechanism driving onshore sand transport is wave asymmetry. During calm conditions, sand transport takes place within a narrow band limiting the volume of sand delivered nearshore, and therefore no chenier develops. In contrast, average storm conditions mobilize sufficient sand for a crest to develop. Our results thus reveal that chenier formation through wave winnowing does not require extreme storm conditions. Furthermore, our study showed that chenier formation through wave winnowing is a relatively slow process, with the largest time scales associated with the winnowing and sand transport. Once sufficient sand is available in the intertidal zone, the crest develops rapidly.
AB - Cheniers are ridges consisting of coarse-grained sediments, resting on top of the fine sediment that forms the otherwise muddy coast. In this paper, we use Delft3D to explore how cheniers are formed through wave winnowing. We identify three phases of chenier development: (a) a winnowing phase, during which mud is washed out of the seabed initially consisting of a mixture of sand and mud, (b) a sand transport phase, when the sand in the upper layer is transported onshore, and (c) a crest formation phase, during which a chenier crest rapidly develops at the landward limit of onshore sediment transport. The main mechanism driving onshore sand transport is wave asymmetry. During calm conditions, sand transport takes place within a narrow band limiting the volume of sand delivered nearshore, and therefore no chenier develops. In contrast, average storm conditions mobilize sufficient sand for a crest to develop. Our results thus reveal that chenier formation through wave winnowing does not require extreme storm conditions. Furthermore, our study showed that chenier formation through wave winnowing is a relatively slow process, with the largest time scales associated with the winnowing and sand transport. Once sufficient sand is available in the intertidal zone, the crest develops rapidly.
KW - chenier
KW - Delft3D
KW - sediment transport
KW - wave asymmetry
KW - winnowing
UR - http://www.scopus.com/inward/record.url?scp=85141731524&partnerID=8YFLogxK
U2 - 10.1029/2022JF006792
DO - 10.1029/2022JF006792
M3 - Article
AN - SCOPUS:85141731524
SN - 2169-9003
VL - 127
JO - Journal of Geophysical Research: Earth Surface
JF - Journal of Geophysical Research: Earth Surface
IS - 10
M1 - e2022JF006792
ER -