New data about the water budget generated with a flow model in the aquifer of Vega de Granada

En este trabajo se aportan nuevos datos sobre el balance hídrico del acuífero detrítico de La Vega de Granada a partir de los resultados obtenidos con la realización de un modelo de flujo en dos dimensiones y en régimen transitorio. El modelo ha sido calibrado y validado satisfactoriamente y arroja unos valores de recursos medios anuales de 132 hm3, cifra que queda por debajo de la propuesta por otros autores. Asimismo, se observa una tendencia descendente durante los últimos 50 años en los aportes al acuífero justificada por la menor recarga que se produce a partir del retorno de riegos debido a la sustitución de los campos de cultivo por zonas urbanizadas. La explotación del acuífero mediante bombeos no refleja, sin embargo, una tendencia paralela en este mismo periodo de tiempoIn this paper new data about the water budget in the detrital aquifer of La Vega de Granada are presented based on the results of a 2D transient flow model. The model has been calibrated and validated successfully. The water budget obtained presents 132 Mm3 as annual resources that are lower than the results obtained in previous studies. Furthermore, during the last 50 years a decreasing trend in the inputs to the aquifer is detected that is related to a decrease in the recharge due to the land use change from crops to urban areas. Nevertheless the pumping in the aquifer is not changing during the same period of tim

Assessing the Uncertainties of the Water Budget in the Torrevieja Aquifer (Southeast Spain)

Congress on Groundwater and Global Change in the Western Mediterranean (2018. Granada)The frequent scarcity of water in the coastal aquifers of the Mediterranean areas makes essential the adequate management of groundwater with a good knowledge of the inputs and the outputs of the aquifers. The establishment of the water budget of aquifers is often hindered by uncertainties in the connection with other aquifers and the sea, or the permeability of layers that can disconnect hydraulically parts of the system. In the study of these regions, a common challenge is the lack of information at deep locations or disperse data in time and space that do not allow to provide reliable answers. Under these circumstances, the construction of simplified numerical models simulating groundwater flow can be used to verify or deny different hypothesis. In this study, the characteristics of Torrevieja aquifer (South East of Spain) have been analyzed proposing alternative conceptual models to explain the annual deficit of 4.4 Mm3 between inputs and outputs. The effect of a semipermeable top layer and the differentiation of the aquifer in two parts with distinct recharge sources was tested and compared with the hydrochemical information of groundwater samples to provide new perspectives about the characteristics of this aquifer. This study also shows how to use common hydrogeological tools and information of databases to address the uncertainties in the study of coastal aquifers.Department of Geoscience, Aarhus University, DinamarcaAljibe Consultores S.L, EspañaInstituto Geológico y Minero de España, EspañaDepartamento de Geodinámica, Universidad de Granada, Españ

Artesian wells in the discharge zone of unconfined coastal aquifers: effects on the freshwater-saltwater interface

La presencia de flujos verticales en las zonas de descarga de acuíferos costeros responde a una configuración específica y bastante común de los patrones de flujo en estas áreas. En el acuífero costero Motril-Salobreña ha sido constatado gracias a la perforación de un sondeo surgente cerca del borde costero. Se han realizado diferentes modelos matemáticos de flujo en 3D con densidad variable mediante SEAWAT para reproducir los efectos de la apertura del sondeo surgente sobre la configuración del flujo y la distribución de salinidad en el entorno de la interfase agua dulce-agua salada. Los resultados muestran un mejor ajuste a los datos observados (en el sondeo surgente y en otros sondeos cercanos) cuando el sondeo es modelado como un dren respecto a un bombeo. La afección principal detectada resulta determinante en la distribución de salinidades, provocando una mayor expansión de la zona de mezcla hacia el interior del acuífero y una intrusión de agua salobre en el mismo sondeo. La disposición de los tramos filtrantes y la altura piezométrica en el sondeo determinan las profundidades de mayor aporte de agua surgente, junto con la anisotropía y heterogeneidad definida en el modeloThe presence of vertical flow in the discharge zones of coastal aquifers is regarding to specific configuration and quiet common of the flow patterns in these areas. In Motril-Salobreña coastal aquifer it has been verified through the drilling of an artesian well near the shoreline. There have been several 3D mathematical flow models with variable density by SEAWAT to reproduce the effects of the opening of the artesian well on the flow configuration and salinity distribution around the saltwater-freshwater interface. Results show a better fit with observed values (in the artesian well and other nearby points) when the artesian well is modelled as a drain with respect to a pumping well.The main detected affection is determinant in the salinity distribution, causing further expansion of the mixing zone into the aquifer and intrusion of brackish water into the well. The distribution of the slotted intervals and the piezometric head in the drain well determine the depths of greatest contribution of the upwelling water, together with the defined anisotropy and heterogeneity in the mode

Utilización de funciones de transferencia para simular los procesos hídricos que intervienen en las reservas naturales de las lagunas Amarga y Dulce (Córdoba)

On the base of the equation of water balance some empirical functions have been adjusted to simulate the processes of water transfer between the elements that can intervene into water dynamics of wetlands. In this article the used methodology has been described and also the results of the application for two lagoons: "Amarga" and "Dulce", both came from South of Córdoba, are showed. In the simulation of the water functioning other processes have been included like for example drainage of "Dulce" lagoon by means of the construction of drains towards "Amarga" lagoon or like for example the natural opening by hydraulic overcharge. The large period of simulation has allowed to obtain statistically representative values of some interesting variables for the management of the lagoons such averages, ranges and percentage distribution of the flooded surface and stored volume. Also it has been possible to simulate the new water situation after the recent elimination of the drainage of "Dulce" lagoon towards "Amarga" lagoon. This communication gathers a part of the taken works carried out by "Consejería de Medio Ambiente de la Junta de Andalucía" in the "Estudio hidrogeológico de las lagunas del Sur de Córdoba: Lagunas del Rincón y Santiago, Lagunas Amarga y Dulce (NET 291875/1)" inside the general Project "Life-Naturaleza conservación de Humedales Andaluces (LIFE NAT 03/E000055)".Sobre la base de la ecuación del balance hídrico se han ajustado unas funciones empíricas para simular los procesos de transferencia de agua entre los distintos elementos que pueden intervenir en la dinámica hídrica de los humedales. En este artículo se describe la metodología empleada y se recogen los resultados de su aplicación a las lagunas Amarga y Dulce del Sur de Córdoba. En la simulación del funcionamiento hídrico se han incluido otros procesos tales como la desecación de la laguna Dulce mediante la construcción de drenes hacia la laguna Amarga o la apertura natural de sumideros debido a la sobrecarga hidráulica. El largo periodo de simulación realizado ha permitido obterner valores estadísticamente representativos de algunas variables interesantes para la gestión de las lagunas, tales como medias, rangos y distribución porcentual de la superficie inundada y del volumen almacenado. También se ha podido simular la nueva situación hídrica generada tras la reciente eliminación del drenaje de la laguna Dulce hacia la laguna Amarga. Esta comunicación recoge una parte de los trabajos llevados a cabo por la Consejería de Medio Ambiente de la Junta de Andalucía en el Estudio hidrogeológico de las lagunas del Sur de Córdoba: Lagunas del Rincón y Santiago, Lagunas Amargas y Dulce (NET 291875/1) dentro del proyecto general Life-Naturaleza conservación de Humedales Andaluces (LIFE NAT 03/ E000055)

Estimation of Groundwater Resources According to Watershed and Groundwater Divide

Presentado en la International Conference on Water Resources Management and Sustainability: Solutions for Arid Regions, 22–24 marzo, 2022, Dubai, Emiratos Árabes Unidos.[EN] This paper estimates groundwater resources in four groundwater bodies shared between different planning areas, specifically the hydrographic basins of the Segura and Jucar rivers that transit entirely within the Spanish State and flow into the Mediterranean Sea. Three of these masses are overexploited, while the fourth has increased its resources thanks to the excess irrigation that is carried out mostly with surface water. This comes from a transfer that takes place between the Tagus and Segura rivers. Given that Spanish legislation considers that the recharge of an aquifer is assimilable to groundwater resource. These have been determined, both for the undisturbed state (without pumping) and for the disturbed (with pumping and irrigation returns) by means of the code RENATA. The calculations have been made not only from the perspective of the watershed divide, but also from the point of view of the groundwater divide. The results that have been obtained have revealed a remarkable and significant casuistry. In this regard, it should be noted, among the conclusions that have been drawn, that the concept of groundwater divide makes sense to use it only when aquifers discharge water into the surface hydrographic network or into the sea, since when aquifers are overexploited and springs and groundwater discharges to rivers have dried up, the notion of recharge as a renewable resource does not make any sense, since the recharge that takes place in the aquifer only contributes to alleviating or palliate the consumption that is being made of its reserves.Peer reviewe