Ivaky: Index of vulnerability to pollution of yucatecan karstic aquifer

Abstract

The index of the vulnerability of the Yucatecan karstic aquifer (IVAKY) is proposed. The IVAKY was built based on a geomorphopedological map scale of 1:50 000, which contains the density and type of karst depressions and soil associations in each geomorphopedological unit. The climate factor is included through the length of the rainy period that considers amount, distribution and intensity of the rain. The three factors (topography, soils and climate) were weighted with the process of hierarchical analysis (AHP) using ArcGis 9.1. It was identified that the ring of sinkholes and part of the northeast of Yucatan state have the extreme level of vulnerability, where dominated sinkholes in contact with the aquifer and soil as Nudilithic Leptosols, Lithic Leptosols and Rendzic Leptosols, occupying 19% of the state surface. Low and very low levels of vulnerability are located in southern Yucatan in areas of equal or greater than 50 masl, with low to medium density of karstic depressions (uvala and poljes) and Luvisols, Vertisols and Stagnosols associated with Leptosols (12% of the state surface).