Kauno HE tvenkinio hidrodinaminio modelio kalibravimas remiantis neapibrežtumo analize.

Uncertainty analysis has been applied for some years at the Lithuanian Energy Institute, this far only to complex technical systems when estimating the uncertainty of thermal hydraulic calculation result. However, calculations of uncertainties could be applied also to natural systems. Modelling of hydrological and hydrodynamic processes usually faces the problem of not precisely known parameters and physical phenomena. Quantitative uncertainty analysis might be used to quantify the underlying uncertainties that might arise due to initial data, mathematical model or solution methods. The ordinary calibration procedure of the MIKE 21 HD computer code evaluates only the influence of mathematical equations' parameters (coefficients of bed resistance resistance and turbulence) on modelling results, but uncertainty due to initial data is not taken into account. This paper presents uncertainty and sensitivity analysis in the calibration process of hydrodynamic modelling of the Kaunas Reservoir using the SUSA computer code. The calibration of the model was done in the following order: estimation of initial data and the MIKE 21 HD code parameters that have an impact on calculation results: generation of input data sets and hydrodynamic calculation of the Kaunas Reservoir using the generated sets; sensitivity analysis of modelling results to determine most significant calibration parameters. It has been determined that the basic input parameters in the calibration process are the coefficients of bed resistance and turbulence and the water discharge of the Nemunas river as a boundary condition of the model. The influence of the other input parameters is less significant. [ABSTRACT FROM AUTHOR]