Rao, X.; Li, L.; Amini, F., and Tang, H., 2012. Smoothed particle hydrodynamics modeling of combined wave and surge overtopping and hydraulic erosion of an articulated concrete block-strengthened levee system. Journal of Coastal Research, 28(6), 1500-1511. Coconut Creek (Florida), ISSN 0749-0208.Combined wave and surge overtopping may cause damage on earthen levees. Levee strengthened on the levee crest and landward-side slope can provide protection against the erosion damage induced by the combined wave and surge overtopping. In this paper combined wave overtopping and storm surge overflow of a levee with a trapezoidal cross section strengthened by an articulated concrete block (ACB) system was studied in a purely Lagrangian and meshless approach, two-dimensional smoothed particle hydrodynamics (SPH) model. By comparing with the results of full-scale experiment data, the model was verified, and the erosion parameters were calibrated. Time series of overtopping discharge and flow thickness at six locations on the levee crest and landward-side slope were calculated. New equations were developed for average overtopping discharge, mean flow thickness, root mean square (RMS) wave height, mean velocity, and velocity of the wave front down the landward-side slope. The shear stresses on the levee crest and landwardside slope were calculated. The characteristics of soil loss were given. Equations were also provided to estimate soil loss. The range of the application of these equations was discussed.ADDITIONAL INDEX WORDS: SPH method, combined wave and surge overtopping, articulated concrete block system, levee, soil erosion.