Abstract
This study focuses on the dynamics of the Wan-Tzu-Liao sand barrier when it is struck by one typhoon, a group of typhoons or the whole season of typhoons and monsoon. In the framework of the KUN-SHEN project, 7 months of monitoring (2011-2012) provided 20 topobathymetric surveys (within a 200 m long segment of the barrier from the subtidal zone to the back-barrier) and acquisitions of offshore, nearshore and shallow water hydrodynamics including velocity profiling, free surface measurement and absolute pressure. Offshore waves were extracted at Cigu buoy (18 m of water depth). Nearshore waves were acquired from the current profiler deployed 400 m off the coast in 4 m of water depth and water level on the subaerial beach were acquired from two pressure sensors deployed in the lower part of the subtidal zone and the dune crest. Morphologic changes of the emerged beach were monitored using D-GPS each week during winter monsoon season and just before and after each event during summer typhoons season. Amongst the eight studied typhoons, TALIM is the most energetic event observed. Offshore wave height reached H s = 10.34 m (T p = 14.6 s) at Cigu buoy and H s = 2.3 m (T p = 13.4 s) at the profiler. Surface waves dynamics throughout surf and swash zones are progressively dominated by infragravity motions. A part of the dune is surged at the storm apex. Morphological changes include 6.7 m of dunefoot retreat and a sand transfer from a dune breach to wash-over deposits in the lagoon. More surprisingly, the foreshore was nourished (2261 m3 +/- 268 m3 ) as well as the whole sand barrier (+1920 m3 +/- 1071 m3 ). The sand input is concomitant to the redistribution of sand from the intertidal sandbars interpreted as the ultimate stage of the subtidal bars landward migration. Although winter are erosive season (-4995 m3 +/- 1071 m3 ), the summer results in an accretion period (3556 m3 +/-1071 m3 ) with a shoreline seaward shift about 10.4 m. Over the annual time period, the sand barrier recorded 18.4 m of retreat coupled with a small sand loss (-1439 m3 +/- 1071 m3 ) without any significant abrasion of the dune-top.References
Aagaard, T., Nielsen, J., and Greenwood, B. (1998). Suspended sediment transport and nearshore bar formation on a shallow intermediate-state beach. Marine Geology, 148(3-4):203 - 225.
Akima (1970). Interpolation and smooth curve fitting based on local procedures. Communications of the ACM (AssociationforComputingMachinery), 15:914-918.
Bagnold, R. (1941). The physics of blown sand and desert dunes. london: Methuen. page 265.
Campmas, L., Sabatier, F., Meulé, S., Liou, J. l., Petitjean, L., Boudin, F., Leroux-mallouf, R., Sous, D., and Bouchette, F. (2014). Multi-scale morphodynamics of sand barrier driven by monsoon/typhoon conditions. Paralia, 7:273-280. MIO:14-021 MIO:14-021.
Chang, Y.-C., Chu, P. C., Centurioni, L. R., and Tseng, R.-S. (2014). Observed near-surface currents under four super typhoons. Journal of Marine Systems.
Chang, Y.-C., Tseng, R.-S., and Centurioni, L. (2010). Typhoon-induced strong surface flows in the taiwan strait and pacific. Journal of Oceanography, 66(2):175-182.
Chen, W.-J. and Kuo, C.-T. (2008). Study on the evolution of sand barriers in taiwan coast. In River, Coastal and Estuarine Morphodynamics: RCEM 2007, Two Volume Set, pages 85-91-. Taylor & Francis.
Coco, G., Senechal, N., Rejas, A., Bryan, K., Capo, S., Parisot, J., Brown, J., and MacMahan, J. (2014). Beach response to a sequence of extreme storms. Geomorphology, 204:493 - 501.
Dean, R. and Walton, T. (2006). HANDBOOK OF COASTAL AND OCEAN ENGINEERING , Chapter1 Wave Setup. World Scientific, Co. Pte. Ltd.
Donnelly, J. P., Butler, J., Roll, S., Wengren, M., and III, T. W. (2004). A backbarrier overwash record of intense storms from brigantine, new jersey. Marine Geology, 210(1-4):107-121.
Dronkers, J. (2005). Dynamics of coastal systems. World Scientific.
Ferreira, (2005). Storm groups versus extreme single storms: Predicted erosion and management consequences. Journal of Coastal Research, pages pp. 221-227.
Ge, X., Li, T., Zhang, S., and Peng, M. (2010). What causes the extremely heavy rainfall in taiwan during typhoon morakot (2009) ? Atmospheric science letters, pages 46-50.
Houser, C., Hapke, C., and Hamilton, S. (2008). Controls on coastal dune morphology, shoreline erosion and barrier island response to extreme storms. Geomorphology, 100(3-4):223-240.
Jan, S., Wang, J., Chern, C.-S., and Chao, S.-Y. (2002). Seasonal variation of the circulation in the taiwan strait. Journal of Marine Systems, 35(3-4):249-268.
Komar, P. (1998). Beach Processes and Sedimentation. Prentice-Hall, London, UK.
Lallemand, S., Theunissen, T., Schnurle, P., Lee, C.-S., Liu, C.-S., and Font, Y. (2013). Indentation of the philippine sea plate by the eurasia plate in taiwan: Details from recent marine seismological experiments. Tectonophysics, 594:60-79.
Larson, M. and Kraus, N. C. (1994). Temporal and spatial scales of beach profile change, duck, north carolina. Marine Geology, 117(1-4):75 - 94.
Liao, H.-R., Yu, H.-S., and Su, C.-C. (2008). Morphology and sedimentation of sand bodies in the tidal shelf sea of eastern taiwan strait. Marine Geology, 248(3-4):161-178.
Lin, J.-W. (2013). An empirical correlation between the occurrence of earthquakes and typhoons in taiwan: a statistical multivariate approach. Natural Hazards, 65(1):605-634.
Lin, S., Tang, T., Jan, S., and Chen, C.-J. (2005). Taiwan strait current in winter. Continental Shelf Research, 25(9):1023 - 1042.
Liu, P., Chen, H., Doong, D., Kao, C., and Hsu, Y. (2008). Monstruous ocean waves during typhoon krosa. Annales Geophysicae, 26:1327-1329.
Masselink, G., Aagaard, T., and Kroon, A. (2011). Destruction of intertidal bar morphology during a summer storm surge event: Example of positive morphodynamic feedback. Journal of Coastal Research, 64:105-109.
Masselink, G. and Heteren, S. (2013). Response of wave-dominated and mixed-energy barriers to storms. Marine Geology.
Morton, R., Gibeaut, J., and Paine, J. (1995). Meso-scale tranfert of sand during and after storms : implications for prediction of shoreline movement. Marine geology, 126:161-179.
Ou, S.-H., Liau, J.-M., Hsu, T.-W., and Tzang, S.-Y. (2002). Simulating typhoon waves by {SWAN} wave model in coastal waters of taiwan. Ocean Engineering, 29(8):947 - 971.
Plant, N. and Stockdon, H. (2012). Probabilistic prediction of barrier-island response to hurricanes. Journal of Geophysical Research, 117.
Qi, H., Cai, F., Lei, G., Cao, H., and Shi, F. (2010). The response of three main beach types to tropical storms in south china. Marine Geology, 275(1-4):244-254.
Roberts, T. M., Wang, P., and Kraus, N. C. (2010). Limits of wave runup and corresponding beach-profile change from large-scale laboratory data. Journal of Coastal Research, 26(1):pp. 184-198.
Roberts, T. M., Wang, P., and Puleo, J. A. (2013). Storm-driven cyclic beach morphodynamics of a mixed sand and gravel beach along the mid-atlantic coast, usa. Marine Geology, 346:403-421.
Ruggiero, P., Kaminsky, G., Gelfenbaum, G., and Voigt, B. (2005). Seasonal to interannual morphodynamics along a high-energy dissipative littoral cell. Journal of Coastal Research, 21(3):553-578.
Sallenger, A. (2000). Storm impact scale for barrier islands. J. Coast.Res, 16 (3):890-895.
Short, A. (1999). handbook of beach and shoreface morpholodynamics. John wiley & sons, LTD.
Sous, D., Campmas, L., Meulé, S., Bouchette, F., and Liou, J-Y, R. V. T. J. (2013). Wave setup and watertable overheight in the cigu sand barrier (taiwan) during the talim tropical storm. In Coastal Dynamics 2013, Arcachon, France, pages 1517-1526.
Stockdon, H., Sallenger, J., Asbury, H., Holman, R., and Howd, P. (2007). A simple model for the spatially-variable coastal response to hurricanes. Marine Geology, 238:1-20.
Stone, G., Grymes, J., Steyer, K., Underwood, S., Robbins, K., and Muller, R. (1993). A chronologic overview of climatological and hydrological aspects associated with hurricane andrew and its morphological effects along the louisiana coast, usa. Shore and Beach, 61 (2):2-12.
Stone, G. W., Liu, B., Pepper, D. A., and Wang, P. (2004). The importance of extratropical and tropical cyclones on the short-term evolution of barrier islands along the northern gulf of mexico, usa. Marine Geology, 210(1-4):63-78.
Suppe, J. (1984). Kinematics of arc-continent collision, flipping of subduction, and back-arc spreading near taiwan. Memoir of the geological society of China, 6:21-33.
Tapia, M., Casarin, S., Ortiz, E., Balwin, M., Mancera, E., and Rentaria, F. (2014). Comparative morphodynamics and circulation patterns between a beach exposed to hurricane conditions and a beach protected by coral reefs. In 34th International Conference on Coastal Engineering, June 15-20, Seoul, Korea.
Wessel, P. and Smith, W. H. F. (1998). New, improved version of generic mapping tools released. Eos, Transactions American Geophysical Union, 79(47):579-579.
Wu, C. and Hsin, Y. (2005). Volume transport through the taiwan strait: a numerical study,. Terrestrial, Atmospheric and Oceanic Sciences, 16 (2):377-391.
Zhang, W., Hong, H., and Yan, X. (2013). Typhoons enhancing northward transport through the taiwan strait. Continental Shelf Research, 56.