During dry periods, the flow of medium and small streams is significantly
reduced and equal to groundwater flow. Since the base flows provide
information about aquifer characteristics and retention characteristics of a
basin, the possibilities of analysis and simulation of base flows gain
importance under the conditions of intensive water use and the increasing
demand for adequate water quality protection. In this paper, a model was
established and used for the description of the principles governing the
changes of base runoff on the basis of a streamflow hydrograph registered at
the outlet of the basin on the example of the Kolubara basin up to the
?Valjevo? profile. Since the amount of base runoff from a basin cannot be
measured, the results of base flows obtained using the local minimum method
were adopted as the criterion for the comparison of the modelled values of
base runoffs. The created model was applied for making simulations of the
base runoff hydrograph during three characteristic years (rainy 1970, average
1985, and dry 1990). Deviations between the base flow values obtained using
the established model and by applying the local minimum method are acceptable
from the standpoint of general hydrological accuracy.
The Value of Forest Conservation for Water Quality Protection
