Effect of coast slope on solitary breaking waves attenuation by coastal vegetation

Document Type : Research Paper


1 MSc. Graduated / Shahid Chamran University of Ahwaz

2 Professor / Shahid Chamran University of Ahwaz


Every year, long waves attacks such as tsunamis cause coastal erosion and destruction and bring irreparable damages to the life and properties of people. Recent approaches of coastal protection are based on environmental balance. Of the new methods of coastal protection against destructive force of waves is planting coastal forest known as green belt. Coast slope is one of effective factors which contributes with the wave breaking condition and wave run-up. Hence, the aim of present study is to investigate the effect of coast slope on solitary breaking waves attenuation by coastal forest. To this purpose, a sloping coast and a coastal vegetation model were installed in a flume equipped to a frictionless force measurement system. The experiments were conducted in four different coast slopes in both with coastal vegetation and without coastal vegetation mode. The results indicated that increase of the coast slope causes the waves to break faster into vegetation area, hence more wave force absorption. The amount of the wave force reduction in presence of vegetation in comparison with the non-vegetated condition in different coast slopes was 17 percent on average.


Main Subjects

Anonymous (2013). Guidelines on Design & Construction of Coastal Prptection Structures, No. 629.
Bernard, E. N., Mofjeld, H. O., Titov, V., Synolakis, C. E., and Gonzalez, F. I. (2006). Tsunami: Scientific frontiers, mitigation, forecasting and policy implications. Philosophical Transaction of the Royal Society A, 364, 1989-2007
Chegini, V. (1998) Guidelines of Breakwater Design. Tehran: Jahad Corporation of Water and Watershed Research Publication. (In Farsi)
Danielsen, F., Sorensen, M. K., Olwig, M. F., Selvam, V., FaizalParish, Neil, D., Burgess, et al. (2005). A Protective Role for Coastal Vegetation, Science, New Series, Vol. 310, No. 5748, 643.
Esteban, M., Thao, D. N., Takagi, H., and T. Shibayama (2008). Analysis of rubble mound foundation failure of a caisson breakwater subjected to tsunami attack. 18th Offshore and Polar Engineering Conference, Vancouver.
Fathi-Moghadam., M. (1996). Momentum absorption in non- rigid, non- submerged, tall vegetation along rivers. Ph. D. dissertation, University of Waterloo. Canada.
Furukawa, K., Wolanski, E. and Mueller, H., (1997). Currents and sediment transport in mangrove forests, Estuarine and Coastal Shelf Science, 44(3), 301–310.
Ghanbari Adivi, E. (2014). Dynamic interaction of the breaking long waves in sloping shoreline with green belt. Ph. D. dissertation, Shahid Chamran University of Ahwaz, Iran. (In Farsi)
Harada, K. and Imamura, F., (2006). Experimental study on the resistance by mangrove under unsteady flow, Proc. Congress. Asian and Pacific Coastal Engineering Dalia, 984-975.
Hirashi, T. and Harada, K., (2003). Green belt tsunami prevention in South- Pacific region, Report of the Port and Airport Research Institute, 42(2), 23p.
Husrin, S., Strusinska, A., and Oumeraci, H., (2012). Experimental study on tsunami attenuation by mangrove forest. Earth Planets Space Journal. 64: 973- 989.
Iida, K., (1969). The Generation of Tsunamis and the Focal Mechanism of Earthquakes, Tsunamis in Pacific Ocean (W.M. Adams, Editor) East-West Center Press. University of Hawaii, 3-18.
Kathiresan, K., Rajendran, N., (2005). Coastal mangrove forests mitigated tsunami. Estuarine, Coastal and Shelf Sciences, 67(3), 601–606.
Lashkar-Ara, B. (2009). Determination of Shear Stress in Rectangular Channel Using Momentum and Energy Approaches. Ph. D. dissertation, Shahid Chamran University of Ahwaz, Iran. (In Farsi)
Lashkar-Ara, B. and Fathi-Moghadam, M. (2014). Analysis of Shear Stress in Rectangular Channel Using Force Balance Approach. Journal of Hydraulics, 9(3), 33-44. (In Farsi)
Mascarenhas, A., Jayakumar, S., (2008). An environmental perspective of the post tsunami scenario along the coast of Tamil Nadu, India: Role of sand dunes and forests, Journal of Environment Management 89(1), 24–34.
Mendez, F.J. and Losada, I. J., (2004). An empirical model to estimate the propagation of random breaking and nonbreaking waves over vegetation fields, Coastal Engineering, 51(2), 103-118.
Mokhtari, M. and Hajizadeh Zaker, N. (2005). Makran (Sea of Oman) a Tsunami Prone Area for Iranian Coasts, 6th A/O Regional Meeting of IAPH, 1-4 Feb, Tehran, Iran.
Quartel, S., Kroon A., Augustinus, P. G.E.F., Van Santen P. and Tri N. H., (2007). Wave attenuation in coastal mangroves in the Red River Delta, Vietnam, Journal of Asian Earth Sciences, 29(4), 576-584.
Rastgoftar, E., Akbarpoor Janat, M., Chegini, V. and Rostami, M., (2012). Investigation of Chabahar Gulf flooding due to tsunami in the Makran area. 10th International Conference on Coasts, Ports and Marine Structures, Tehran, Iran.
Russell, J. S. (1845). Reports on Waves made to the meetings of the British Association in 1842-43. London.
Sorensen, R. M., (2006). Basic Coastal Engineering, New York: Springer Science & Business Media.
Vice Presidency for Strategic Planning and Supervision (2013) Guidelines on Design and Construction of Coastal Protection Structures, Publication No. 629. (In Farsi)
Wiegel, R. L., (1970). Tsunamis, Earthquakes Engineering (R.L. Wiegel, Editor), Prentice Hall, Englewood Cliffs, NJ, 253-306.