Mark obtained his engineering degree from the Civil Engineering Department in Delft in 1989 and his Ph.D. from the Department of Civil Engineering of the University of Minnesota in 1994.

• Modeling groundwater dynamics with impulse response functions Approximate response functions are being developed for the efficient and accurate simulation of groundwater dynamics. Parameters in the approximate function are computed by matching temporal moments obtained from groundwater models calibrated with results from time series analysis.
• Analytic element modeling of multi-aquifer flow. The computer program TimML allows for the analytic computation of heads and velocities anywhere in the aquifer system. Applications include the three-dimensional modeling of radial collector wells, and the modeling of capture zones in regional multi-aquifer systems.
• Seawater Intrusion Modeling. The the SeaWater Intrusion (SWI) package was developed for the modeling of regional seawater intrusion with MODFLOW. SWI makes it possible to model seawater intrusion without the need for vertical discretization of the aquifer; only the water is discretized into zones of different densities.
• Analytic element modeling of unsaturated flow. Analytic element modeling of steady unsaturated flow makes it possible to simulate flow through inhomogeneities in the vadose zone extremely accurate. The analytic element method is a mesh-free approach. Boundary conditions along circular and elliptical inclusions are met up to machine accuracy.
• Groundwater whirls.Groundwater flow through layered anisotropic aquifers may result in bundles of spiraling flow lines that are termed groundwater whirls. These groundwater whirls may have a strong effect on the spreading of contaminants in the aquifer.
• Transient groundwater flow in aquifers with periodic boundary conditions