Salinity change in the coastal lagoon of Chabihau, Yucatan, Mexico. Effects of hurricane Isidoro and the constrution of bridges in the coastal dune

Abstract

In order to obtain basic information for the hydraulic management of the zone, a periodic monitoring of water salinity was made in the swamps of San Crisanto, Chabihau and Santa Clara (in the coastal lagoon of Chabihau) from 1999 to 2002, and from 2004 to 2005. Spatial and temporal salinity variations in response to hurricane Isidore (September 2002), and to the construction of bridges on the coastal dune of Chabihau are described. A change in the Chabihau swamp dynamics was observed, with a longer euhaline (30-40 ups) flooded period, and a reduction of the hypersaline period (> 40 ups) during the dry season. On the other hand, conditions of hypersalinity in the dry and flooded season began to appear in the Santa Clara swamp, considered a signal of risk in a zone that used to present polyhaline (18-30 ups) and euhaline conditions. Therefore, it is recommended that marine water inflow be controlled, particularly at the Porvenir bridge, near Santa Clara.