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. It combines the relevant ecohydrological processes at the mesoscale such as runoff generation, nutrient and carbon cycling, river dis-charge, plant growth and crop yield, and erosion. 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 feed-backs. 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: - more comprehensive than purely hydrological and precipitation-runoff models (more reliable representation of vegetation processes and climate and land use change impacts); - driven by commonly available regional data ( easier parametrization than for more detailed hydrological models like MIKE SHE), and - more reliable as hydrological tool compared to large scale climate models like RCMs, continental-scale terrestrial models like LPJ, and large-scale water resources models like WaterGap.
Who maintains it?
V. Krysanova, F. Hattermann and T. Vetter; C. Rachimow and T. Conradt take care about SWIM under Subversion.
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 underway. Now it is a simple degree-day method with snow accumulation. Responsible: Shaochun Huang Integrating in-stream processes for nutrients is underway in order to enable better representation of river processes. 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 The SWIM version, which includes full carbon cycle, was developed by Joachim Post. It has to be updated. Responsible: Joachim Post (guest) and Claus Rachimov 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 other comparable ecohydrological and hydrological mod-els, such as SWAT, HBV, HBV-D, INCA, HSPF;
- simulation of hydrological cycle at the river basin scale – better and more de-tailed process description than in large scale climate models like RCMs, in continental-scale terrestrial models like LPJ, and in large-scale water resources models like WaterGap;
- simulation of vegetation processes – much better than many hydrological models, which normally do not consider vegetation processes; the latter are important in climate change studies due to interrelations between water and vegetation;
- simulation of water quality – better than hydrological models like HBV which have no (or only minor) representation of soil processes;
- simulation of diffuse pollution – better than other commonly used models like MONERIS because of a better temporal and spatial resolution and consideration of dynamical landscape processes;
- simulation of land use, farm management, crop yields and feedbacks of climate and land use changes – better than other models with reduced representation of vegetation growth processes (like HBV, ARC-EGMO).
a key publication
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.
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
