GROUNDWATER VULNERABILITY IN SHALE GAS EXTRACTION AREAS FROM A BASIN IN THE NORTHEAST OF MEXICO, BASED ON A GIS DRASTIC MODEL

The unconventional extraction of hydrocarbons, based on the shale gas, represents an ecological threat for the integrity of water bodies; this is explained by the high rate of contaminant fluids generated during the process of extraction and the large volume of water required, also known as hydraulic fracture or fracking. Because of this process, it causes a harmful environmental degradation in the ground and surface water, particularly on the storage, transport and treatment areas next to exploitation. The study area is located in the Burgos Basin (northeast of Mexico) and is considered the seventh biggest reserve of shale gas and crude oil in the world. The use of Geographic Information Systems (GIS) to determinate risk areas based on the hydrogeophysics regional characteristics, are demonstrated be an useful tool. On example of a methodology used in GIS is the DRASTIC model, which consist in categorize geophysical variables in numbers from 1 to 10 and importance weights from 1 to 5 where after applying an equation are obtained numbers closer to zero, are low indices of vulnerability, while the greater the number result of the index, the greater the number Vulnerability index. The aim of this study was allocate the best area for the location of a infrastructure of hydrocarbons extraction, based on DRASTIC model, for the Burgos Basin area. The product of this research it was provide a powerful map, which there are represented 5 ranks of classification for water vulnerability, obtained from geologic, edaphologic and hydraulic parameters. These results will serve for the stakeholder and planning managers of this area and will allow a better environmental decision-making.