Response of Empirically Managed Sites to Winter Storms. Case Study: La Mancha, Veracruz, Mexico

Abstract

The coastal lagoon of La Mancha, Veracruz, Mexico is significantly affected by winter storms, meteorological events known as Nortes. Because of the influence of the wind on beach sediment transport and therefore on the dynamics of the inlet, four topographic surveys were made, three during winter storms (November 2013, November 2014 and February 2015) and one more in the dry season (May 2014). Physicochemical parameters at the mouth were registered during November 2014. The circulation patterns of the lagoon were obtained using the numerical model H2D. The beach morphology field data shows that the beach is resilient to the effects of winter storms, as long as sediment availability is not interrupted. The circulation patterns of the lagoon indicate that winds and waves induce the opening and closing of the inlet. The governing force in the lagoon patterns is the tidal oscillations, as corroborated by the physical parameters measured. However, these natural cycles are interrupted by the actions of the local fishermen, who empirically manage the lagoon opening the inlet once or twice a year. We found that the environmental resilience of the estuarine-lagoon system is susceptible to the change in the frequency of the opening of the mouth, so the anthropogenic interference threats the dynamics of the natural system.