Effect of El Niño on the subaerial beach Playas de Rosarito, B.C., Mexico

Abstract

Extensive beaches located near the Mexico-USA border play an important role in the economy of the city of Playas de Rosarito, Mexico. Intense beach erosion occurred during the winter 1998 as a result of a very energetic wave regime associated to ENSO-El Ninño event, in combination with high water levels. The severity of these conditions caused flooding and destruction of several houses on the beach. Recreational and protection capabilities of the beach were severely diminished. Profile comparison showed that maximum volume of sand removed from the subaerial beach was 66.9x10^-3 m³/m/day with an average recession of 2.3 m/day. The maximum shoreward displacement along the study period was 66 m. The profile height was up to 3.5 in lower than the initial profile, so a long period of mild wave conditions is needed to restore the initial profile height. The role played by the highly mobile gravel deposit along the northern portion of the study area need to be assessed.