Tidal asymmetry and mud transport in Oualidia Lagoon:Actual conditions in 2012 and rehabilitation scenarios  

作　　者：V.Koutitonsky J.A.Zyserman B.Zourarah A.Orbi K.El Khalidi A.Benali 

机构地区：[1]Hydrosoft S.A.,Saint-Zotique,QC J0P-1Z0,Canada [2]Universitédu QuébecàRimouski,Rimouski,QC G5L-3A1,Canada [3]DHI Water&Environment Inc.,Solana Beach,CA 92075,USA [4]Facultédes Sciences,UniversitéChouaib Doukkali,El-Jadida 24000,Morocco [5]nstitut National de Recherche Halieutiques(INRH),Casablanca 20100,Morocco [6]Atlantic Dredging Maroc S.A.,Casablanca 20100,Morocco

出　　处：《Water Science and Engineering》2024年第4期344-351,共8页水科学与水工程(英文版)

基　　金：supported by the Funding from the Ministry of Equipment and Transport,Kingdom of Morocco.

摘　　要：Oyster aquaculture in Oualidia Lagoon,Morocco,has suffered from poor water quality and water confinement in its upstream region.Tidal asymmetry(TA)has been suggested as a possible cause,and a sediment trap was dredged in 2011 to mitigate this condition.This study addresses TA in the lagoon using field measurements and numerical modeling in the presence of the sediment trap.Results indicate that the lagoon is flood-dominated mostly in its upstream end,where frictional forces exceed inertia accelerations during the tidal cycle and fine sediments settle on the tidal flats and inside the sediment trap.However,this study shows that a large mass of suspended sediments is exported to the ocean,which is contrary to expectations in flood-dominated lagoons.Defining the sediment trap as the rehabilitation scenario S1,the impacts of three additional scenarios on TA are examined.These are scenario S2(dredging the upstream section of the main channel),scenario S3(dredging the channels surrounding the flood delta near the inlets),and scenario S4(raising the ocean level by 0.5 m following climate change predictions).Results show that none of these scenarios modify the tidal flood dominance in the lagoon,although scenarios S2 and S4 decrease its intensity in the upstream region.Nevertheless,all scenarios still contribute to a significant export of sediments to the ocean.This suggests that lagoon management activities should not rely on tidal asymmetry analyses that normally predict upstream sediment transport in flood-dominated lagoons.

关 键 词：Oualidia lagoon Tidal asymmetry Rehabilitating scenarios Hydrodynamic modeling Sediment transport modeling 

分 类 号：P73[天文地球—海洋科学]