Constraining a density-dependent flow model with the transient electromagnetic method in a coastal aquifer in Mexico to assess seawater intrusion | Contrainte d’un modèle d’écoulement dépendant de la densité avec la méthode électromagnétique transitoire dans un aquifère côtier au Mexique pour évaluer l’intrusion d’eau de mer Restricción de un Modelo de flujo dependiente de la densidad con el método electromagnético transitorio en un acuífero costero en México para evaluar la intrusión de agua de mar 墨西哥沿海含水层中采用瞬变电磁法约束密度依赖的流动模型评估海水入侵 Formando um modelo de fluxo dependente da densidade com método eletromagnético transiente em aquífero costeiro no México para avaliar intrusão de água do mar
2019
Torres Martínez, Juan Antonio | Mora, Abrahan | Ramos Leal, Alfredo | Morán Ramírez, Janete | Arango-Galván, Claudia | Mahlknecht, Jürgen
Saltwater intrusion is one of the most pressing environmental concerns in coastal areas with increased water demands. Water extraction decreases the level of fresh groundwater, reducing the water pressure and allowing saltwater to flow further inland. Tools for simulating, monitoring and managing saltwater intrusion can provide valuable support in decision-making for management options. In this work, such a tool was developed for the arid coastal aquifer of La Paz in Baja California, Mexico. A geomodel was generated by using a transient electromagnetic method (aquifer geometry, saltwater intrusion). This geomodel, in turn, was used to construct a three-dimensional density-dependent flow model to simulate groundwater flow and saltwater intrusion during the past decades. The results confirmed that a large cone of depression had formed due to excessive pumping in the agricultural area. This successively led to the inversion of the hydraulic gradient and seawater intrusion advancement on the order of 6–8 km inland in the northern-central portion of the aquifer. Freshwater recharge mostly originates from the mountainous southeastern portion of the basin. It supplies water for the city of La Paz and counteracts the saltwater intrusion advancement. The alternation of advancement and retreat of the freshwater–saltwater interface could be attributed to changing climate effects and/or policy changes.
显示更多 [+] 显示较少 [-]