Resumo

PEREZ-VILLARREAL, José; AVILA-OLIVERA, Jorge Alejandro  e  ISRADE-ALCANTARA, Isabel. Analysis of flux systems in an aquifer disturbed by growndwater extraction. Case of the Morelia-Capula area, Michoacán. Bol. Soc. Geol. Mex [online]. 2018, vol.70, n.3, pp.675-688. ISSN 1405-3322.  https://doi.org/10.18268/bsgm2018v70n3a5.

The Morelia-Capula zone depends entirely on groundwater for the supply of its more than 120000 inhabitants. The groundwater extraction has caused a decrease in the piezometric level estimated at more than 45 meters in a period of 21 years. Because of the importance of the aquifer system of the Morelia-Capula zone it is necessary to have a complete understating of the system, therefore, this study is carried out from the perspective of the Tothian flow systems. Three parameters are used to identify the groundwater dynamics, temperature, major ions, and depth (static level). Groundwater samples were analyzed in a total of 35 sites (29 wells and 6 springs), consisting of 26 intermediate, 8 local, and 1 regional flows. The local flow system is located in the upper strata of the aquifer system and can be seen within the shallow wells and springs. The intermediate flow system is located throughout the study area below the local flow system where most wells are extracting water from this system. The local and intermediate flow systems are localized in the terrigenous and volcanic units. The regional flow system is only in the volcanic unit that underlies the terrigenous unit. A few wells have come in contact with this system. A depletion trend shows that in the next few years this flow system will provide water to this zone. It was found that intensive extraction and the presence of geological faults favor the mixture of flows. Most of the water supply in the zone depends on the intermediate flow system. The static level in the zone descends 2.13 m/year. The flow direction of local and intermediate systems generally follows the topography of the zone, although there are local alterations due to the formation of depletion cones. Results indicate the need to implement strategies to avoid contaminating local flows and to reduce the water pressure derived from extraction toward the intermediate and regional systems.

Palavras-chave : Flow systems; groundwater; temperature; major ions; depletion; Morelia-Capula zone.