Drainage systems and their water management function with regard to probable climatic and hydrological changes

Some scenarios of probable climatic changes in the Czech Republic and the anticipated effect of these changes on the components of the hydrologic water discharge from drained agricultural and forest catchments are studied. The function of drainage systems on selected experimental lands is examined. The effect of climatic changes on the hydrologic balance and/or on the runoff from the catchments significantly varies up to +/-150% provided that we compare the average runoff. The influence of changes in the way of farming on the hydrologic balance manifests itself in a more concrete, but negative way. Single-function and obsolete drainage systems should be converted into systems with controlled drainage and irrigation functions - the double-function control systems.