Abstract
The rapid sedimentation at the entrance of Paresar intake basin is studied, in which unnatural wrack accumulation at the coast, combined with the existing sand, resulted in a major increase in the actual Longshore Sediment Transport (LST) rate. Considering the volume of updrift fillet at the northwest of main breakwater and the estimated LST rate, the advancement of updrift shoreline was highly unexpected. Sands and vegetative wracks were observed only 3 years after constructing the rubble mound breakwaters, resulting in water depth decrease at the entrance. Employing field measurements and numerical modeling, it is revealed that general wind-induced currents in Caspian Sea, which were ignored in the design, have a small effect on increasing LST rate. The unusual sedimentation can be mainly related to the high percentage of wrack particles at updrift coast.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/UNNnjDHL41k
References
Bohluly A., Namin M.M., Teheri A.A., 2014. Simulation of wind-driven currents pattern in the Caspian Sea using PMODynamics, 11th International Conference on Coasts, Ports & Marine Structures, ICOPMAS, pp. 60-63
Clift, R., Grace, J.R., Weber, M.E., 2005. Bubbles, drops, and particles. Courier Corporation.
Engelund, F., Fredsøe, J., 1976. A sediment transport model for straight alluvial channels. Hydrology Research, 7, 293-306. https://doi.org/10.2166/nh.1976.0019.
Fredsoe, J., Andersen, O.H., Silberg, S., 1985. Distribution of suspended sediment in large waves. Journal of waterway, port, coastal, and ocean engineering, 111, 1041-1059. https://doi.org/10.1061/(ASCE)0733-950X(1985)111:6(1041).
Fredsøe, J., Deigaard, R., 1992. Mechanics of coastal sediment transport. Singapore: World scientific, 3, 369. https://doi.org/10.1142/1546.
Le Roux, J.P., 1998. Entrainment threshold of natural grains in liquids determined empirically from dimensionless settling velocities and other measures of grain size. Sedimentary Geology, 119, 17-23. https://doi.org/10.1016/S0037-0738(98)00022-0.
Oldham, C.E., Lavery, P.S., McMahon, K., Pattiaratchi, C., Chiffings, T., 2010. Seagrass wrack dynamics in Geographe Bay, Western Australia. Report to Western Australian Department of Transport, and Shire of Bussleton, 214.
Rubey, W.W., 1933. Settling velocity of gravel, sand, and silt particles. American Journal of Science, 148, 325-338. https://doi.org/10.2475/ajs.s5-25.148.325.
Zyserman, J.A., Fredsøe, J., 1994. Data analysis of bed concentration of suspended sediment. Journal of Hydraulic Engineering, 12, 1021-1042. https://doi.org/10.1061/(ASCE)0733-9429(1994)120:9(1021).