Environmental Modeling & Risk Analysis

Environmental Modeling & Risk Analysis

Foreword

The increasing presence of harmful chemicals in the environment has led to a rapid growth of social concerns in Europe. Among such chemicals, the persistence of improper disposal of hazardous wastes such as chlorinated solvents, petroleum hydrocarbons and heavy metals is threatening the environment and public health over extended periods of time. In this context, the hydro-bio-geo-chemical complexity of a natural system typically causes the effectiveness of remedial efforts to be highly uncertain. Even well implemented in situ remediation projects are likely to fail clean-up goals, meaning the incapability of reaching target levels of contamination after treatment. Estimates of these levels of toxic compounds are difficult to know a priori, and thus the resulting water often exceeds the safe concentration of hazardous contaminants during site management; a situation that may eventually lead to an increase in the probability of developing cancer and/or neurological disorders of the nearby exposed population. Environmental modeling and risk assessment provides the scientific tools needed to quantify the actual threat that these potential hazards pose to human health and ecosystems, while at the same time can be seen as a translator of science problems to regulators by providing quantitative indicators of risk into decision making.

Research in this area tackles basic research questions as well as the development of new risk-based mathematical models and tools. Basic research aims to provide a full understanding of the joint effects caused by physical, chemical and biological processes, identifying, and better quantifying their uncertainties. This knowledge is introduced into mathematical models and risk analysis techniques designed to alleviate the high-dimensionality of the problem and to overcome existing numerical problems and conceptual flaws that comes from the integration of all components and processes across multiple scales. Research integrates different disciplines using either an experimental, numerical or a theoretical approach, and in some cases combinations of these three. Main research activities are:

(1)Environmental modeling of pollutants in water and soil.

(2)Multispecies reactive transport of organic and inorganic contaminants with particle tracking methods.

(3)Interactions between biochemical and physical processes across multiple scales.

(4)Probabilistic risk analysis and uncertainty quantification.

Selected Bibliography

X. Sanchez-Vila, S. Rubbol, A. Carles-Brangari, D. Fernàndez-Garcia (2013), An analytical solution to study substrate-microbial dynamics in soils, Advances in Water Resources, 54, 181-190, http://dx.doi.org/10.1016/ j.advwatres. 2013.02.004.
F.P.J. de Barros, D. Fernàndez-Garcia, D. Bolster, and X. Sanchez-Vila (2012), A risk-based probabilistic framework to estimate the endpoint of remediation: Concentration rebound by rate-limited mass transfer, Water Resour. Res., 49, 1–14, doi:10.1002/wrcr.20171, 2013.
E. Castro-Alcalá, D. Fernàndez-Garcia, J. Carrera, D. Bolster (2011), Visualization of pore-scale mixing processes in a heterogeneous sand box aquifer, Env. Sci. & Techn., x.doi.org/10.1021/es201779p, 46, 3228−3235
L. Martinez-Landaa, J. Carrera, M. Dentz, D. Fernàndez-Garcia, A. Nardi, M. Saaltink (2011), Mixing Induced Reactive Transport in Fractured Crystalline Rocks, Applied Geochemistry, doi: 10.1016/ j.apgeochem.2011.09.016.
X. Sanchez-Vila, D. Fernàndez-Garcia, A. Guadagnini (2010), Interpretation of column experiments of transport of solutes undergoing an irreversible bimolecular reaction using a continuum approximation, Water Resources Research, Water Resour. Res., 46, W12510, doi: 10.1029/ 2010WR009539.
D. Fernàndez-Garcia, X. Sanchez-Vila (2011), Optimal reconstruction of concentrations, gradients, and reaction rates from particle distributions, Journal of Contaminant Hydrology, 120-21 (2011) 99–114, doi: 10.1016 / j.jconhyd. 2010.05.001.
D. Bolster, M. Barahona, M. Dentz, D. Fernàndez-Garcia, X. Sanchez-Vila, P. Trinchero, C. Valhondo, and D. M. Tartakovsky (2009), Probabilistic Risk Analysis of Groundwater Remediation Strategies, Water Resour. Res., VOL. 45, W06413, doi:10.1029/2008WR007551.
Salamon, P., Fernàndez-Garcia, D., J. J. Gómez-Hernández (2006), Modeling mass transfer processes using random walk particle tracking, Water Resour. Res., VOL. 42, W11417, doi:10.1029/2006WR004927, 2006.