OGS Winter School 2020

Catchment Scale Groundwater Modelling

07.12-09.12.2020, Videoconference

Initiated by the joint CRAES-UFZ Groundwater Research Center and supported by Digital Earth (https://www.digitalearth-hgf.de/de )

Day Time Topic Lecturer
1 Morning Introduction to OpenGeoSys, QGIS and the study area; short QGIS tutorial Erik Nixdorf (EN), Olaf Kolditz
  Afternoon Model geometry and FEM mesh generation on the catchment scale EN
2 Morning Creation of OGS6 project files and definition of boundary condition and material property fields EN, Sally Stuart
  Afternoon Stationary model simulations and result exploration with ParaView EN
3 Morning Simulation of different scenarios and evaluation of derived field parameters (e.g. travel times, fluxes) EN
  Afternoon Introduction to reactive-transport modelling schemes with OGS6 Vanessa Montoya / Renchao Lu
Background and Scope

The importance to model subsurface processes on the catchment scale has been increasingly recognized for many applications in hydrology and water resources management. In contrast to small models on the study site scale (~m²), different challenges appear when developing deterministic groundwater flow models for larger catchments e.g.:

  • Appropriately represent a complex topographic and aquifer geometry on a necessarily relatively coarse FEM mesh
  • Correctly assign spatially heterogeneous material properties and spatial-temporal heterogeneous boundary conditions (e.g. recharge patterns, water level of lakes) to the model set-up
  • Optimize computational demands by adjusting required spatial and temporal resolutions
  • Post-process, visualize and explore model output to prove feasibility over the entire domain (e.g. detecting inundated areas)

The intention of the training course is to give PhD students and researchers working in the field of hydrology and groundwater management insights and support how to address their challenges using deterministic groundwater flow modelling embedded in a pre and post-processing workflow.

Exemplary, we will show in the course how vector and raster information provided in “standard formats” (ESRI Shape and GeoTIFF) can be used to generate the model geometries, the FEM mesh and the boundary conditions of a groundwater flow model. Hereby we introduce and apply QGIS and ParaView, which are both open-source programs with a sophisticated graphical user interface. Subsequently different groundwater flow model set-ups (e.g. confined/unconfined flow, stationary/transient mode, heterogeneous/homogeneous subsurface) are developed and tested using OpenGeoSys 6 to solve the underlying partial differential equations of water transport in porous media. Furthermore, we demonstrate how to derive secondary output variables (e.g. water parcel travel times, velocity fields, fluxes) from the simulation results and how to visualize and verify the results on the catchment scale using ParaView.

Finally, this course should further enable participants to become an active part within the OGS user community