SWIM - Soil and Water Integrated Model
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 (two versions: GRASS and Map Windows). The model uses 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 a) more comprehensive than purely hydrological and precipitation-runoff models due to a more reliable representation of interlinked hydrological, vegetation and nutrient processes; b) driven by commonly available regional data and can be easier parametrized than more complex hydrological models.
Who maintains it?
What are the next steps in the development of the model architecture?
A version of SWIM, which considers wetlands processes at the river basin scale (SWIM-WET) (version A: additional evapotranspiration, and version B: additional evapotranspiration and nutrient uptake) is under development. Version A is ready. Responsible: Tobias Vetter.
An improvement of the snow module in the standard SWIM is done by Shaochun Huang. Now the snow and glacier modules are tested in the Tarim (Kyrgyzstan and China) and Lena (Russia) River basins.
Integrating in-stream processes for nutrients is done in order to enable better representation of river processes. Now it is tested in the Elbe basin. Responsible: Cornelia Hesse.
For the GLOWA-Elbe project, an “Elbe-Expert-Toolbox”-version of SWIM (EET-SWIM) is being interactively coupled with the water management model WBalMo of DHI-WASY by the OpenMI framework. It has refined groundwater representation, altered evapotranspiration calculus, and is capable of handling anthropogenic groundwater abstraction and recharge. Responsible: Tobias Conradt and Claus Rachimow.
SWIM is currently being coupled to the dynamical regional model CCLM to better reproduce the hydrological cycle in regional climate models including feedbacks of the landscape pattern to climate processes. Responsible: Jan Volkholz
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 process description than in the continental-scale terrestrial models, and in large-scale water resources models;
- simulation of vegetation processes: better than in many hydrological models, which normally do not consider dynamical vegetation processes;
- the latter are important in climate change studies due to interrelations between water and vegetation processes;
- simulation of water quality: better than in conceptual hydrological models which have no (or only minor) representation of soil processes;
- simulation of diffuse pollution: better than in other commonly used models because of a better temporal and spatial resolution and consideration of dynamical landscape processes;
- simulation of land use, agriculture management, crop yields and feedbacks of climate and land use changes: better than in other models with reduced representation of vegetation growth processes.
Krysanova, V., F. Hattermann, Sh. Huang, C. Hesse, T. Vetter, S. Liersch, H. Koch and Z. W. Kundzewicz, 2014. Modelling climate and land use change impacts with SWIM: lessons learnt from multiple applications. Hydrological Sciences Journal, accepted.
Krysanova, F. Wechsung, J. Arnold, R. Srinivasan, J. Williams, 2000. PIK Report Nr. 69 "SWIM (Soil and Water Integrated Model), User Manual", 239p. SWIM_Manual
Krysanova, V., Mueller-Wohlfeil, D.I., Becker, A., 1998. Development and test of a spatially distributed hydrological / water quality model for mesoscale water-sheds. Ecological Modelling, 106, 261-289.