Groundwater Inrush Caused by the Fault Reactivation and the Climate Impact in the Mining Gafsa Basin (Southwestern Tunisia)

Abstract

The Gafsa mining basin district in Southwestern Tunisia is one of the most important producers of phosphate in the world. The exploitation of this district started at the beginning of the twentieth century a few years after the first discovery of this valuable resource. The over-exploitation of groundwater to wash the phosphate caused water-level decline in the main aquifers and the corollaries of drying springs, loss of artesian condition, and water quality degradation, presumably due to mixing with relatively highly mineralized deep groundwater. The beginning of the Tunisian revolution bumped things up: total stopping of phosphate washing by groundwater during an important period. Following significant rainfall events, which regenerated the initial state of the natural and the artificial springs in the mining basin. The objective of the present work is to explain the process and the model simulation of groundwater inrush caused by reactivation fault in the Gafsa basin (Phosphate mining industry of the Company of phosphate of Gafsa) (Southwestern Tunisia-North Africa). The probability of the groundwater inrush caused by faults associated with the faults reactivation in deep underground is more than shallow underground. The climate impact (natural and anthropogenic) plays an important role in this neoformation of this lake in the Gafsa area.