ИСТИНА

The analysis of the impact of observed and predicted climate variability on the total and groundwater runoff of the small river basin in humidal boreal conditions is considered on the basis of a physically based precipitation-runoff model. The model consists of two submodels. Surface precipitation transformations within a representative landscape element are simulated using the first SURFBAL submodel. It simulates the processes of snow accumulation on the surface of the earth, its melting in winter thaws and in spring, the formation of surface runoff and potential ET, taking into account freezing and melting of soil cover. The results of the calculations are transferred to the second submodel, the groundwater flow model, as the upper boundary conditions on the land surface for each landscape zone. The second model is based on MODFLOW 2005 using the UZF package. This submodel calculates the flow rate in the unsaturated zone, groundwater recharge and ET, and the formation of surface and groundwater runoff within the basin.