Spectral Analysis of Time Series of Carbonate Aquifer of Sierra Gorda - Luque-Espinar, Juan Antonio; Pardo-Iguzquiza, Eulogio; Gonzalez-Ramon, Antonio; Lopez-Chicano, Manuel; Duran-Valsero, Juan Jose; Pulido-Velazquez, David; Renard, P; Bertrand, C (EUROKARST 2016, NEUCHATEL: ADVANCES IN THE HYDROGEOLOGY OF KARST AND CARBONATE RESERVOIRS, 2017)