Fachbereich Geowissenschaften

Validity of Travel-Time Based Reactive Transport Models

Under which conditions can computationally expensive 3-D reactive transport models be replaced by approaches based on travel and exposure times?

PhD Researcher: Alicia Sanz Prat
Supervisors: Olaf Cirpka (University of Tübingen), Chuanhe Lu (University of Tübingen), David Blowes (University of Waterloo)

The objective of this research theme is to increase the understanding of the conditions in which travel and exposure time controls reactive transport processes at catchment scale. Based on several scenarios of different conceptualized water catchments, coupled flow and transport processes between surface and groundwater will be modeled.

Because of the usefulness of implementing travel time models for complex dynamic systems, we will be focused on the simulation of hydrological dynamics and different types of reactive systems in three dimensional domains.

Regarded the following assumptions, travel and exposure time models can provide reliable and representative values of concentration of reactive species:

  • Transport mechanisms of dispersion and diffusion should be neglected, such that particles should cross the domain along idealized streamtubes.
  • Well mixed solution of reactants, as reactivity does not depend on travel time when transverse mixing process exists.
  • Velocity of hydrodynamic processes should allow self-organization of reactive zones within the subsurface.

Through the input signal at the inlet of the domain, tracking particles across the subsurface and taking into account how long they stay in reactive zones, we obtain travel time distribution function of the reactants to estimate the concentration at the outlet of the domain.


  • Sanz-Prat, A. Lu, C., Amos, R.T., Finkel, M., Blowes, D.W., Cirpka, O.A. (2016): Exposure-Time Based Modeling of Nonlinear Reactive Transport in Porous Media Subject to Physical and Geochemical Heterogeneity. J. Contam. Hydrol., doi: 10.1016/j.jconhyd.2016.06.002
  • Sanz-Prat, A., Lu, C., Finkel, M., Cirpka, O.A. (2016): Using Travel Times to Simulate Multi-Dimensional Bioreactive Transport in Time-Periodic Flows. J. Contam. Hydrol. 187, 1-17, doi: 10.1016/j.jconhyd.2016.01.005
  • Sanz-Prat, A., Lu, C., Finkel, M., Cirpka, O.A. (2015): On the validity of travel-time based nonlinear bioreactive transport models in steady-state flow. J. Contam. Hydrol. 175-176, 26-43, doi: 10.1016/j.jconhyd.2015.02.003