seawater intrusion (2)

Seawater Intrusion

About 41% of the world population lives in coastal areas where the impact of bore salinization resulting from seawater intrusion (SWI) in aquifers has caused significant losses of valuable water resources and in agricultural production globally. Moreover, in coastal aquifers both the freshwater and the recirculated seawater discharge into the ocean as Submarine Groundwater Discharge (SGD) having important consequences for the coastal water quality controls the distribution of algal blooms, the biogeochemical cycles and the aquatic habitats and fisheries associated. Thus, investigation of the seawater intrusion dynamics and the associated SGD is a principal challenge in hydrogeology. Since 2014 the GHS have been working in two specific projects founded by the Spanish government (MEDISTRAES I and II) in collaboration with several national and international Institutions. Also in this research line there is Marie-Sklodowska-Curie Innovative Training Network, ENIGMA, founded by European Commission.

Description

About 41% of the world population lives in coastal areas where the impact of bore salinization resulting from seawater intrusion in aquifers has caused significant losses of valuable water resources and in agricultural production globally. Due to density differences between freshwater and seawater, a convection cell is formed in which the freshwater tends to float on top of seawater and a mixing zone develops between them. Seawater is dispersed across the interface and subsequently is returned to the sea by freshwater discharge.

The freshwater and the recirculated seawater discharge together into the ocean as Submarine Groundwater Discharge (SGD). Chemical compounds and nutrients are then released with the SGD affecting the water quality in coastal areas which controls the distribution of algal blooms, the biogeochemical cycles and the aquatic habitats and fisheries associated.

Therefore, the study of the dynamics of groundwater coastal systems is important not only in determining sustainable management policies but also to understand the effect of SGD in coastal environments. As a result, the issues we investigate are:

Characterization of reactive transport processes and location of hotspots.
Quantification of the effect of spatial heterogeneity and connectivity on mixing in coastal aquifers.
Development of new methods to characterize and monitor seawater intrusion
Quantification of submarine groundwater discharge (SGD).
Aquifer characterization from the response to tidal fluctuations.
Numerical modeling and calibration from local to regional-scale coastal systems.
Derivation effective formulations and solutions to properly model and predict seawater intrusion problems.
Inverse problem.

Keywords

Density dependent flow, submarine groundwater discharge, mixing and dispersion, reactive transport, nutrients.

Projects

MhetScale (European Research Council, ERC)
MEDISTRAES I (Proyectos EXCELENCIA y Proyectos RETOS)
MEDISTRAES II (Proyectos EXCELENCIA y Proyectos RETOS)
ENIGMA (Marie-Sklodowska-Curie Innovative Training Network)

Publications

Pool, M., Dentz, M. and Post, V.E.A [2016] Transient forcing effects on mixing of two fluids for a stable stratification. Water Resources Research
Ledo, J., Bellmunt, F., Luquot, L., Bosch, D., Marcuello, A., Queralt, P., Folch, A., Martínez, L., Del Val, L., Carrera, J., Vázquez-Suñé, E., Pezard, P., García-Orellana, J., Saaltink, M.(2016) Cross-hole electrical resistivity tomography characterization and monitoring of seawater interface in an alluvial aquifer. 22nd European Meeting of Environmental and Engineering Geophysics, Near Surface Geoscience.
Pool, M. Carrera, J., Alcolea, A. and Bocanegra, E.M. [2015] A comparison of deterministic and stochastic approaches for regional scale inverse modeling on the Mar del Plata aquifer. Journal of Hydrology, Volume 531, Part 1, pp. 214-259
Pool, M., Post, V.E.A and Simmons, C.T. [2015] E_ects of tidal uctuations and spatial heterogeneity on mixing and spreading in spatially heterogeneous coastal aquifers. Water Resources Research, 51, pp. 1570-1585.
Pool, M., Post, V.E.A and Simmons, C.T. [2014] E_ects of tidal uctuations on mixing and spreading in coastal aquifers: Homogeneous case. Water Resources Research, 50, 6910-6926.
Pool, M., Carrera, J., Vilarrasa, V., Silva, O. and Ayora, C. [2013] Dynamics and design of systems for geological storage of dissolved CO2. Advances in Water Resources, 2013, Vol 62.Part C. 533-542.
Pool, M., J. Carrera, M. Dentz, J. Hidalgo and E. Abarca [2011]. Vertical average for modeling seawater intrusion. Water Resources Research, 47, W11506.

Pool, M., J. Carrera [2011]. A correction factor to account for mixing in Ghyben-Herzberg and critical pumping rate approximations of seawater intrusion in coastal aquifers. Water Resources Research, 47, pp.
Pool, M. and J. Carrera [2010], Dynamics of negative hydraulic barriers to prevent seawater intrusion. Hydrogeoly Journal, vol 18, Issue:1. doi:10.1007/s10040-009-0516-1
Pool, M, E. Abarca y J. Carrera [2007]. Simplificaciones en la modelación de la intrusión marina: validez y alcance. [Simplifications in modeling seawater intrusion: validity and scope]. Boletín Geológico y Minero, Número especial, gestión, Modelación y Recuperación de acuíferos costeros. Octubre 2007, vol. 118, pp 593-608
Vázquez - Suñè, E., E. Abarca, J. Carrera, B. Capino, D. Gámez, M. Pool, T. Simo, F. Battle, J.M. Niñerola, X. Ibañez, [2006], Groundwater modeling as a tool for the European Water Framework Directive (WFD) application. The Llobregat case. Physics and Chemistry of the Earth, vol. 31, pp. 1015-1029.

Collaboration

Collaboration in the research line of seawater intrusion (SWI) include several partners from different countries around the world. Phillipe Pezard (CNRS, France), Olivier Bour (Geosciences Rennes, France) and Juanjo Ledo (UB, Barcelona) for new SWI characterization and monitoring techniques, Linda Luquot (CNRS, France) for the study of reactive transport processes, Vincent E.A. Post (BGR, Germany) for sand tank experiments, Niklas Linde (University of Lausanne; Suiza) for the application of geophysical techniques and Tanguy Le Borgne (Geosciences Rennes, France) for the study of mixing and heterogeneity.