Building a 3D geomodel for water resources management: case study in the Regional Park of the lower courses of Manzanares and Jarama Rivers (Madrid, Spain)

Water resources management of protected sites requires a powerful tool to analyze the process and changes that are occurring in the environment. This paper describes a 3D geomodel design of the Jarama River Detrital Aquifer located in Madrid (Spain). That hydrogeological unit is included in the "Parque Regional de los Cursos Bajos de los Rios Manzanares y Jarama" (Regional Park of the Lower Courses of Manzanares and Jarama Rivers). The goal of this work is to define a method by which a three-dimensional (3D) model can be created with hydrogeologic geometry real of main aquifer, to accomplish an adequate management of the groundwater resources. All data used in this study were integrated in a geographic database: geological and hydrogeological information, geological map (1:25,000), eleven cross-sections, piezometric maps and a digital elevation model. The constructed 3D model of the Jarama Aquifer shows geometric features and spatial distribution and variations of geologic units. Thus, the 3D model allows the assessment of volumes of each unit, the depth and thickness variations of the main aquifer, and the spatial and temporal variations of water tables. From the 3D model, the most suitable areas (in terms of groundwater protection) for managed recharge and mining works have been identified.