Abstract
Equilibrium bay is a bay that its shoreline is stable and does not change with time in long term. This concept can be applied for coastal protection. Experiments on dynamic equilibrium bay planform are conducted in a laboratory. There is one location of sediment supply source into a bay near upcoast headland and its magnitude vary from case to case. Wave obliquity varies from small to moderate values. These are two main parameters while wave condition is kept constant. The final bay planforms are investigated and recorded once they reach equilibrium with condition that sediment transport gradient approaches zero and no further shoreline change are observed. The parabolic equation similar to that for static equilibrium is newly proposed. The coefficients are originally derived and found to be a function of wave obliquity and the ratio of sediment supplied into bay to longshore sediment transport. The new dynamic equilibrium bay equation can be used and applied to study morphology change with variation of supplied sediment from inland.References
Chatchai, P. (2005), Experimental Study on Development of Dynamic Bay Shape M. Eng. Thesis No. WM-04-07, Asian Institute of Technology, Bangkok,Thailand
Hsu, J.R.C. and Evans C. (1989), Parabolic bay shapes and applications, Proc . Institute of Civil Engineers, London, Part 2, 87:557-570
Kamphuuis, J.W.(1991), Alongshore Sediment Transport Rate. J. Waterway, Port, Coastal and Ocean Eng., Vol.117:624-640http://dx.doi.org/10.1061/(ASCE)0733-950X(1991)117:6(624)
Klein, A.H.F., Vargas A., Raabe A.L.A. and Hsu J.R.C. (2003), Visual assessment of bayed beach stability with computer software, Computer & Geosciences, 29:1249-1257http://dx.doi.org/10.1016/j.cageo.2003.08.002
Tan, S.K. and Chiew, Y.M. (1993), Bayed beaches in dynamic equilibrium, Advances in Hydro-Science and Engineering, I : 1737-1742
Vithana, H.P.V, Weesakul,S. and Gunasinghe, A.A.S.K. (2000), " Sand Spit formation in a Simulated River Mouth", 27th International Conference on Coastal Engineering, Sydney, p.3817-3828
Xiam, V.D (2004), Development of Dynamic Bay Shape, M.Eng, Thesis no. WM-03-08, Asian Institute of Technology, Bangkok, Thailand