Die Bodenkultur - Journal for Land Management, Food and Environment

J.C. Draxler, G. Klammler and J. Fank:

Comparison of simulation models CANDY and STOTRASIM for the unsaturated zone


Qualitative and quantitative effects of nitrogen leaching into groundwater can be evaluated by simulation of different land use and tillage scenarios on arable land. Models for unsaturated water flow have to be tested for predominant climatic, soil hydraulic and agrarian conditions in an investigation area. Thus, we assess water flow of two software tools for unsaturated zone: Darcy model SIMWASER/STOTRASIM and capacity model CANDY. On the one hand we consider water balance in unsaturated soil with data of the lysimeter station in Wagna (Austria), on the other hand we compare all required input data and availability for regional modelling. In conclusion, both simulations show high agreements to lysimeter observations. Also the concepts of the models are qualified for a regional application. However, for Murtal aquifer an application of SIMWASER/STOTRASIM appears more feasible. Key words: STOTRASIM, CANDY, Wagna lysimeter, regional modelling, model-input data.