Data on the hydrologic properties of aquifers are frequently not available or are spatially limited; additionally, their determination through aquifer tests is often logistically complicated and economically expensive. This study aimed to estimate aquifer properties by analyzing the water level response for the effects of barometric pressure and earth tide. Harmonic analysis of the time series of water level and barometric pressure recorded in three boreholes in the Mexicali aquifer provided reasonable values of porosity, specific storage, transmissivity, and compressibility of the rock materials that constitute the alluvial aquifer. The representative values of porosity (14-20%), specific storage (1.74-6.23 × 10 −6 m-1), transmissivity (8.57-8.66 × 10 −7 m 2 •s-1), and compressibility (3.90-8.21 × 10 −10 Pa-1) were obtained. These values were consistent with the sediment types identified in the proximity of the wells analyzed. The results of this study show that the analysis of water level response to natural phenomena is a low-cost tool that provides reasonable estimates of aquifer properties. This advantage is particularly relevant in the study of aquifers where the available hydrological information is insufficient.

<p class="Resumen"><span lang="ES">Con el objetivo de estudiar la respuesta del nivel del agua relacionada a las variaciones de la presión barométrica y a la acción de la marea terrestre teórica, en pozos de monitoreo en el Valle de Mexicali. Técnicas de análisis en los dominios del tiempo y la frecuencia son planteadas e implementadas, para obtener como resultado del cálculo de funciones de transferencia y análisis de armónicos, valores de eficiencias barométrica y de sensibilidad a la marea terrestre, con los cuales bajo condiciones de respuesta confinada–estática teórica, fue posible obtener estimaciones de algunas propiedades geohidrológicas y geofísicas como: porosidad, almacenamiento específico, y compresibilidad. En cinco pozos considerados en este trabajo se obtuvieron estimaciones de las propiedades del acuífero en un estado previo y posterior a un sismo. Este trabajo ha permitido un mejor conocimiento de los parámetros que controlan los procesos que suceden en la zona de estudio.</span></p>

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Determining hydrogeological properties of the rock materials that constitute an aquifer through stress tests or laboratory tests presents inherent complications. An alternative tool that has significant advantages is the study of the groundwater-level response as a result of the pore-pressure variation caused by the internal structure deformation of the aquifer induced by barometric pressure and solid Earth tide. The purpose of this study was to estimate the values of the physical/hydraulic properties of the geological materials that constitute the Guadalupe Valley Aquifer based on the analysis of the groundwater-level response to barometric pressure and solid Earth tide. Representative values of specific storage (1.27 × 10−6 to 2.78 × 10−6 m−1), porosity (14–34%), storage coefficient (3.10 × 10−5 to 10.45 × 10−5), transmissivity (6.67 × 10−7 to 1.29 × 10−4 m2∙s−1), and hydraulic conductivity (2.30 × 10−3 to 2.97 × 10−1 m∙d−1) were estimated. The values obtained are consistent with the type of geological materials identified in the vicinity of the analyzed wells and values reported in previous studies. This analysis represents helpful information that can be considered a framework to design and assess management strategies for groundwater resources in the overexploited Guadalupe Valley Aquifer.

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