Abstrakt
This study investigates the temporal evolution of annual and seasonal low-flow regimes of 144 Czech river basins for the 1961-2005 period. Summer and winter low-flow seasons are identified and delimited.
The gauging stations are classified into two categories, mountain and lowland, according to their low-flow regime. The standard and modified versions of the Mann-Kendall trend test were used in the study to detect trends in several low-flow variables.
These include 7-day annual, summer and winter low flows, number of days with discharge under two low-flow thresholds and deficit volumes delimited with the same two low-flow thresholds. At majority of stations, trends in low-flow variables are not significant.
Among significant trends, decreasing summer low flows, increasing winter low flows and increasing drought durations as well as deficit volumes are observed.