What does the model do? 
SWIM was specifically developed to investigate climate and land use change impacts at the regional scale, where the impacts are manifested and adaptation measures take place. The model simulates interlinked processes at the mesoscale such as runoff generation, plant and crop growth, nutrient and carbon cycling, and erosion. It provides numerous model outputs such as river discharge, crop yield, and nutrient concentrations and loads. The approach allows simulation of all interrelated processes within a single model framework at a daily time step using regionally available data (climate, land use and soil) and considering feedbacks. The model setup and postprocessing are supported by a GIS interface (based on GRASS).
The model uses a 3-level disaggregation scheme: basin – subbasins – hydrotopes. The results are presented as time series and maps for a number of variables. SWIM is a model of intermediate complexity for the river basin and regional scale, because it is:
- more comprehensive than purely hydrological and precipitation-runoff models due to a more reliable representation of interlinked hydrological, vegetation and nutrient processes;
- driven by commonly available regional data and can be easier parametrized than more complex hydrological models.
Who maintains it?
SWIM is maintained and further developed by the working group Hydroclimatic Risks on PIK’s GitLab source code repository . The development is coordinated by Fred Hattermann .
In what way is the model different from other models in the community?
- simulation of hydrological cycle (water discharge, groundwater level): the same or better than in other comparable ecohydrological and hydrological models;
- simulation of hydrological cycle at the river basin scale: better and more detailed than in continental-scale terrestrial models and large-scale water resources models;
- simulation of vegetation processes: better than in many hydrological models that do not consider dynamic vegetation processes;
- these vegetation processes are important in climate change studies due to interrelations between water and vegetation processes;
- simulation of water quality: better than in conceptual hydrological models with weak soil process representation;
- simulation of diffuse pollution: better temporal/spatial resolution and dynamic landscape processes;
- simulation of land use, agricultural management, crop yields and climate/land-use feedbacks: better than in many models with simplified vegetation;
- simulation of reservoirs and hydropower production;
- simulation of glacier and snowmelt.
Where is the model currently applied?
The model is applied in a range of climatic regimes and regions worldwide at medium to large scales. It has been applied in Europe, Africa and Central Asia.
The most recent version of the SWIM manual can be found here.
Key publications
Krysanova, V., Hattermann, F., Huang, Sh., Hesse, C., Vetter, T., Liersch, S., Koch, H. & Kundzewicz, Z.W., 2014. Modelling climate and land use change impacts with SWIM: lessons learnt from multiple applications. Hydrological Sciences Journal.
Krysanova, V., Wechsung, F., Arnold, J., Srinivasan, R., Williams, J., 2000. PIK Report Nr. 69: “SWIM (Soil and Water Integrated Model), User Manual”, 239 p. SWIM_Manual
Krysanova, V., Mueller-Wohlfeil, D.I., Becker, A., 1998. Development and test of a spatially distributed hydrological / water quality model for mesoscale watersheds. Ecological Modelling, 106, 261–289.
The extended publication list is available here .
