ABSTRACT
Floods are among the most important natural extremes occurring in the Czech Republic. They cause not only great material damage, but also loss of human life. Changes in climatic patterns have to be taken into consideration in the evaluation of fluctuations in floods. Floods are significantly influenced by changes in land use that give rise to alterations in the retention capacity of the landscape. Such matters may be described with appropriate accuracy only from the early 19th century onwards. Various types of water-management structure, mainly reservoirs, play key roles in increasing the retention capacity of a given catchment. Examination of fluctuations in floods on Czech rivers shows that they repeat with significantly higher and lower frequency and magnitude, something that reflects the non-stationary behaviour of such series. Modifications to channels of rivers in the Czech Republic have largely taken the form of channel straightening, i.e. elimination of bends and meanders with the intention of accelerating runoff during floods.
