FN Archimer Export Format
PT J
TI Exceptional rates and mechanisms of muddy shoreline retreat following mangrove removal
BT 
AF BRUNIER, Guillaume
   ANTHONY, Edward J.
   GRATIOT, Nicolas
   GARDEL, Antoine
AS 1:1;2:2;3:3,4;4:5;
FF 1:;2:;3:;4:;
C1 Univ Brest, CNRS, UMS 3113, IFREMER,UBO,IRD,PSO,IUEM, Rue Dumont DUrville, F-29280 Plouzane, France.
   Aix Marseille Univ, CNRS, IRD, INRA,Coll France,CEREGE, Aix En Provence, France.
   Univ Grenoble Alpes, CNRS, IRD, IGE, F-38000 Grenoble, France.
   Ho Chi Minh City Univ Technol, VNU, CARE, Ho Chi Minh City, Vietnam.
   UG, CNRS, IFREMER, LEEISA,Ctr Rech Montabo,USR 3456, Cayenne, French Guiana.
C2 UBO, FRANCE
   UNIV AIX MARSEILLE, FRANCE
   UNIV GRENOBLE ALPES, FRANCE
   UNIV HO CHI MINH, VIETNAM
   CNRS, FRANCE
UM LEEISA
IN WOS Cotutelle UMR
   copubli-france
   copubli-univ-france
   copubli-int-hors-europe
   copubli-sud
IF 3.694
TC 23
UR https://archimer.ifremer.fr/doc/00504/61521/85712.pdf
LA English
DT Article
DE ;Mangrove protection;mangrove removal;coastal erosion;Amazon-influenced muddy coast;mud banks;cheniers
AB Probably the largest regular shoreline fluctuations on Earth occur along the 1500 km-long wave-exposed Guianas coast of South America between the mouths of the Amazon and Orinoco Rivers, the world's longest muddy coast. The Guianas coast is influenced by a succession of mud banks migrating northwestward from the Amazon. Migrating mud banks dissipate waves, partially weld onshore, and lead to coastal progradation, aided by large-scale colonization by mangroves, whereas mangrove-colonized areas between banks (inter-bank areas) are exposed to strong wave action and undergo erosion. On large tracts of this coast, urbanization and farming have led to fragmentation and removal of mangroves, resulting in aggravated shoreline retreat. To highlight this situation, we determined, in a setting where mangroves and backshore freshwater marshes have been converted into rice polders in French Guiana, shoreline change over 38 years (1976-2014) from satellite images and aerial orthophotographs. We also conducted four field experiments between October 2013 and October 2014, comprising topographic and hydrodynamic measurements, to determine mechanisms of retreat. The polder showed persistent retreat, at peak rates of up to -200 m/yr, and no recovery over the 38-year period of monitored change. Notwithstanding high erosion rates, mangrove shorelines show strong resilience, with recovery characterized by massive accretion. Retreat of the polder results in a steep wave-reworked shoreface with a lowered capacity for bank welding onshore and mangrove establishment. Persistent polder erosion is accompanied by the formation of a sandy chenier that retreats landwards at rates largely exceeding those in inter-bank situations. These results show that anthropogenic mangrove removal can durably modify the morphodynamics of muddy shorefaces. This limits the capacity for shoreline recovery and mangrove re-establishment even when there is no sustained long-term deficit in mud supply, as in the case of the Amazon-influenced Guianas coast. (c) 2019 John Wiley & Sons, Ltd. 
PY 2019
PD JUL
SO Earth Surface Processes And Landforms
SN 0197-9337
PU Wiley
VL 44
IS 8
UT 000470920000004
BP 1559
EP 1571
DI 10.1002/esp.4593
ID 61521
ER

EF