WATERTABLE OVERHEIGHT DUE TO WAVE RUNUP ON A SANDY BEACH

The time averaged watertable in beaches stands considerably above the mean sea level due to waves and tidal effects. This is of practical importance for the stability of coastal structures, for the operation of coastal sewage disposal systems and for the accretion/erosion of the beach. The elevated watertable in coastal areas also influences hydrology, e.g., agricultural and soil conservation activities. The main factors for the overheight above the mean sea level are waves and tides as seen in Figure 1 (Nielsen et al. 1988; Aseervatham et al.,1993; Kang and Nielsen, 1994).