ABSTRACT
The aquifer in northwestern Yucatan contains a freshwater lens that floats above a denser saline water wedge that penetrates more than 40 km inland [Back and Hanshaw, 1970; Durazo et al., 1980; Back and Lesser, 1981; Gaona et al., 1985; Perry et al., 1989]. Recently, it has been shown that the penetration is more than 110 km [Perry et al., 1995; Steinich and Marin, 1996]. The aquifer, which is unconfined except for a narrow band along the coast [Perry et al., 1989], is the sole freshwater source in northwestern Yucatan. Development of industry and agriculture, and other land use changes, pose a potential threat to the quantity and quality of freshwater resources in the Yucatan Peninsula. This chapter reports field investigations used for the construction of a groundwater flow model developed for the purpose of increasing our understanding of the groundwater system, and estimating the hydraulic response to aquifer stresses. The groundwater flow model is also useful in detailed studies of saltwater intrusion, and the tracking of contaminants from industrial or agricultural sources. Ultimately, it can serve as a basic information source for local groundwater resources management.
