Estimación de la difusividad hidráulica en acuíferos costeros utilizando la oscilación mareal inducida extraída de los registros piezométricos

Zusammenfassung

Tidal Response Methods (TRMs) have been applied and assessed to obtain hydraulic diffusivity (D) values in Motril-Salobreña coastal aquifer. Results was compared i) using Tidal efficiency (TE) and Delay methods, ii) using directly the measured groundwater head (GWH) affected by tide and the same dataset pre-filtered, removing the nontidal component, iii) the use of maximum and minimum groundwater peaks comparing with tide peaks to obtain delay values, and iv) assessing the impact of measuring at different depths into the aquifer. The obtained D indicates that the previous filtering of the groundwater levels provides better results when the TE method is used. The application of the Delay method depends whether maximum or minimum peaks are used. The analysis of minimum peaks yields in D values closer to values obtained by TE. Hydraulic diffusivity could be overestimated in unconfined coastal aquifers applying TRMs if the non-tidal components are not removed from the groundwater levels series. Likewise, the use of maximum peak delays can overestimate D and it is recommended to use minimum peak delays in the application of Delay method.