Department Surface Waters - Research and Management


Simstrat is a one-dimensional physical lake model for the simulation of stratification and mixing in deep stratified lakes. The model was originally developed by Goudsmit et al. (2002) and has been successfully applied to lakes with different physical properties. For a few examples, see the key publications below.
Simstrat has also been applied to a range of lakes in Switzerland. The results are regularly updated, and simulated temperatures for the current year are compared to long-term means.
The Simstrat code is freely available on Github .

Main properties of the Simstrat Model

  • 1-dimensional physical lake model (resolving the vertical dimension)
  • simulates temperature, salinity, stratification and ice cover in lakes and reservoirs
  • k-ε model for turbulent mixing
  • includes energy transfer to mixing via internal seiches
  • inflows can be added at specified depths or with density-dependent intrusions
  • variable lake levels
  • programmed in object-oriented Fortran 2003
  • parameter estimation using PEST is implemented

Key publications

Gaudard, A.; Råman Vinnå, L.; Bärenbold, F.; Schmid, M.; Bouffard, D. (2019) Toward an open access to high-frequency lake modeling and statistics data for scientists and practitioners - the case of Swiss lakes using Simstrat v2.1, Geoscientific Model Development, 12(9), 3955-3974, doi:10.5194/gmd-12-3955-2019, Institutional Repository
Schmid, M.; Ostrovsky, I.; McGinnis, D. F. (2017) Role of gas ebullition in the methane budget of a deep subtropical lake: What can we learn from process-based modeling?, Limnology and Oceanography, 62(6), 2674-2698, doi:10.1002/lno.10598, Institutional Repository
Gaudard, A.; Schwefel, R.; Vinnå, L. R.; Schmid, M.; Wüest, A.; Bouffard, D. (2017) Optimizing the parameterization of deep mixing and internal seiches in one-dimensional hydrodynamic models: a case study with Simstrat v1.3, Geoscientific Model Development, 10(9), 3411-3423, doi:10.5194/gmd-10-3411-2017, Institutional Repository
Råman Vinnå, L.; Wüest, A.; Bouffard, D. (2017) Physical effects of thermal pollution in lakes, Water Resources Research, 53(5), 3968-3987, doi:10.1002/2016WR019686, Institutional Repository
Fink, G.; Schmid, M.; Wüest, A. (2014) Large lakes as sources and sinks of anthropogenic heat: capacities and limits, Water Resources Research, 50(9), 7285-7301, doi:10.1002/2014WR015509, Institutional Repository
Goudsmit, G. -H.; Burchard, H.; Peeters, F.; Wüest, A. (2002) Application of k-ϵ turbulence models to enclosed basins: the role of internal seiches, Journal of Geophysical Research C: Oceans, 107(C12), 3230 (13 pp.), doi:10.1029/2001JC000954, Institutional Repository