@article{fdi:010065522,
  title = {{R}esponse of the {B}ight of {B}enin ({G}ulf of {G}uinea, {W}est {A}frica) coastline to anthropogenic and natural forcing : {P}art 1 : {W}ave climate variability and impacts on the longshore sediment transport},
  author = {{A}lmar, {R}afa{\¨e}l and {K}estenare, {E}lodie and {R}eyns, {J}. and {J}ouanno, {J}ulien and {A}nthony, {E}. {J}. and {L}aibi, {R}. and {H}emer, {M}. and {P}enhoat du, {Y}ves and {R}anasinghe, {R}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he short, medium and long-term evolution of the sandy coastline of the {B}ight of {B}enin in the {G}ulf of {G}uinea, {W}est {A}frica, has become a major regional focal point due to the rapid socio-economic development that is occurring in the region, including rapid urbanization and a sharp increase in harbor-based trade. {H}arbors have a significant impact on the present evolution of this coast, notably by affecting longshore sediment transport. {H}owever, little is known of the environmental drivers, notably the wave climate, that governs longshore sediment transport and the ensuing pattern of shoreline evolution of this coastal zone. {T}his article aims to address this important knowledge gap by providing a general overview of coastal evolution in the {B}ight of {B}enin and the physical processes that control this evolution. {H}ere, the 1979-2012 {ERA}-{I}nterim hindcast is used to understand the temporal dynamics of longshore sediment transport. {O}blique waves (annual average {H}-s,=1.36 m, {T}-p=9.6 s, {S}-{SW} incidence) drive an eastward drift of approximately 500,000 m(3)/yr. {T}he waves driving this large longshore transport can be separated into two components with distinct origins and behavior: wind waves generated locally in the {G}ulf of {G}uinea and swell waves generated in the southern hemisphere sub- (30-35 degrees {S}), and extra-tropics (45-60 degrees {S}). {T}he analysis undertaken here shows that the contribution to the gross annual longshore transport from swell wave-driven longshore currents is an order of magnitude larger than the local wind wave-driven longshore currents. {S}well waves are dominantly generated by westerlies in the 40-60 degrees {S} zone and to a lesser extent by trade winds at 30-35 degrees {S}. {T}he longshore sediment drift decay (-5% over 1979-2012) is found to be linked with a decrease in the intensity of westerly winds associated with their southward shift, in addition to a strengthening of the trade winds, which reduces the eastward sediment transport potential. {T}he equatorial fluctuation of the {I}nter-{T}ropical {C}onvergence {Z}one ({ITCZ}) is found to explain most of the variability in transport induced by wind waves, while the {S}outhern {A}nnular {M}ode ({SAM}), an extra-tropical mode, has a predominant influence on transport induced by swell waves. {T}he {ITCZ} and {SAM} have, respectively, a negative and positive trend over the period 1979-2012 that explains the decrease in both wind- and swell-wave-induced transport. {F}or future scenarii, {G}eneral {C}irculation {M}odels ({GCM}s) predict a stabilization of the {SAM}, and, thus, a non-substantial or weak change in longshore sediment transport can be expected on the coast of the {B}ight of {B}enin.},
  keywords = {{L}ongshore drift ; {C}oastal erosion ; {R}egional wave climate ; {S}outh {A}tlantic {O}cean ; {S}outhern {A}nnular {M}ode ; {I}nter-{T}ropical {C}onvergence {Z}one ; {ATLANTIQUE} {SUD} ; {GUINEE} {GOLFE} ; {BENIN} {GOLFE} ; {ZONE} {TROPICALE}},
  booktitle = {},
  journal = {{C}ontinental {S}helf {R}esearch},
  volume = {110},
  numero = {},
  pages = {48--59},
  ISSN = {0278-4343},
  year = {2015},
  DOI = {10.1016/j.csr.2015.09.020},
  URL = {https://www.documentation.ird.fr/hor/fdi:010065522},
}