Research
Understanding and predicting the effects of human activity and climate change on groundwater resources is critical to designing effective groundwater management strategies and ensuring a sustainable future on this planet. To this end, an in-depth understanding of groundwater flow and contaminant transport in near-surface environments is extremely important, along with development of the corresponding numerical models for prediction. Traditional methods for determining subsurface properties for hydrological model building include the analysis of core samples and borehole logs, as well as larger-scale aquifer tests such as pumping and tracer experiments. Although such methods provide highly valuable information, they are often insufficient for reliably predicting hydrological behaviour, most notably contaminant transport, because of an inherent gap that exists between them in terms of spatial resolution and subsurface coverage. Whereas core sample and borehole log analyses provide high-resolution but sparse information regarding subsurface properties, larger-scale aquifer tests yield average hydraulic properties over a relatively broad region, and may not provide sufficiently detailed estimates of these properties to properly model the hydrological process(es) of interest. Environmental geophysical techniques have the potential to bridge this gap. The corresponding new and interdisciplinary field of research is normally referred to as "hydrogeophysics", and is one of the most rapidly growing domains at international scientific conferences such as the annual meetings of the American Geophysical Union (AGU) and European Geosciences Union (EGU).
Recently, my research in the field of hydrogeophysics has been focused on the stochastic estimation of subsurface geostatistical parameters and hydraulic properties using a variety of near-surface geophysical techniques. In particular, I have become very interested in the use of Bayesian Markov-chain-Monte-Carlo methods for this purpose, and most recently in a number of practical issues related to obtaining meaningful posterior statistics with these methods, such as properly accounting for the effects of data and model structural uncertainties. Another recent research interest is the joint use of multiple geophysical techniques, within a 3-D anisotropic inversion framework, to characterize the bulk geometrical characteristics of fractured sedimentary rock aquifers.