Research was based on the karst aquifer situated in the Pegalajar and the Mojón Blanco ranges. The aquifer occupies the northern side of the Betica mountain range, and was provisionally declared overexploited in 1992 because a local spring dried up completely, due to the exploitation of the water resources in the province of Jaén, Spain.
These scientists have shown that important rivers such as Guadalbullón are not insurmountable barriers for ground water flows, as previously believed. The analysis of piezometric, hydrochemical and isotopic data from ground water flows revealed that they cross the Guadalbullón River from one bank to the other due to a certain geological structure which prevents the ground water from being influenced by the river flow.
Analyzed DataThis research is based on the analysis of environmental isotopes, and both piezometric and hydrochemical data collected from the aquifers located in the Pegalajar and the Mojón Blanco ranges and from others nearby, in addition to the piezometric information available and the information added by previous studies. The analysis of the combined information has made it possible to create a new hydrogeological model, which explains most of the current mysteries. It also has made it possible to accurately identify which water resources depend on these aquifers and to design a new exploitation model that does not affect important springs such as the one at La Reja.
“The hydrogeological model which results from this research has been a useful basis for the development of a program which controls the exploitation of the Mancha Real – Pegalajar aquifer. This program aims to solve the social problems related to the exploitation of the groundwater in that area,” according to the author of the study.
Some measures included in this program already have been put into practice. Also, other measures are being implemented in order to restore the spring of La Reja. The research has shown the importance of accurate knowledge of geological structures to explain the stages of storage and circulation of ground water in severely folded and fractured karst aquifers.