Application of a Logit Model for Water well site location in fractured-bedrock aquifers in northeastern Brazil

Wells drilling process in fractured-bedrock aquifers is a difficult task. Extreme variations in lithology and structure features, as well productive water zones sited at preferential points make geological and geophysical investigations difficult. To contribute to the understanding of the process of groundwater zones occurrence in fractured-bedrock aquifers, this paper develops a drilling prospective model by using regression analysis, whose parameters were calibrated according to the photogeological and cartographic analysis of 113 drilling points in the states of Rio Grande do Norte, Paraíba, and Ceará. The effectiveness of the resulting model was assessed through a sample of 43 additional drillings, which were carried out aiming at the distribution of water to the communities in the semiarid region of Brazil. The obtained results indicate the model as an important tool in the drilling process, with direct implications on the logistics costs of water well site location and consequent attendance to the population that needs the water