Decision tree as a tool for the management of coastal aquifers of limited saturated thickness

In this work, a decision tree is presented—constructed on the basis of hydrogeological characteristics (water table depth, freshwater thickness, surface area required and distance between wells)—in order to choose the optimal groundwater extraction method in the case of a coastal unconfined aquifer. A comparison is made of the groundwater extraction methods in a freshwater aquifer of limited thickness occurring in coastal dunes in the eastern region of the Province of Buenos Aires (Argentina). The negative effects brought about by the wrong use of the groundwater extraction methods are analysed, since—as a result of excessive extraction—such methods lead to the dramatic decrease of the freshwater reserves. The decision tree is a useful tool to assist decision-makers as it suggests the most suitable groundwater extraction method options (vertical wells or wellpoints), as well as identifying areas that are unsuitable for sustainable groundwater extraction.