Modeling Water Balance of Dammed Lakes Using Computer Code Matlab-Simulink/ Modelowanie Bilansu Wodnego Piętrzonych Jezior Za Pomocą Programu Komputerowego Matlab-Simulink

The paper presents a water balance of a flow-through, dammed lake, consisted of the following terms: surface inflow, underground inflow/outflow based on the Dupuit’s equation, precipitation on the lake surface, evaporation from water surface and outflow from the lake at which a damming weir is located. The balance equation was implemented Matlab-Simulink®. Applicability of the model was assessed on the example of the Sławianowskie Lake of surface area 276 ha and mean depth - 6.6 m, Water balances, performed for month time intervals in the hydrological year 2009, showed good agreement for the first three months only. It is concluded that the balancing time interval should be shorter (1 day) to minimize the errors. For calibration purposes, measurements of ground water levels in the vicinity of the lake are also recommended.