A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Eng.) - Asian Institute of Technology, 1982

One- Line Theory is a simple mathematical model which is capable of predicting change in the plan shape of a beach following the construction of a coastal defense work or variation in the wave climate along the coast. In this research, an analytical solution for the beach deformation in the vicinity of groins based on One-Line Theory is presented. Change of wave characteristics, i.e. wave refraction, wave diffraction, and wave reflection are not included in the analytical solution. However, to include the effect of refraction, diffraction, in predicting the beach deformation in the vicinity of the groin and behind the offshore breakwater, a numerical model of One-Line Theory is used. The method of solution is an explicitly finite difference scheme. The comparison of the results from the mathematical model with results from the experiment show good agreement for t he beach deformation in the presence of groins. However, for the offshore breakwater, the results from the mathematical model agree with the results from t he experiment only in the case where breakwater is located close to the shoreline. As the distance of breakwater from the initial shoreline increase the comparison show large difference.