Rainfall and runoff regime trends in mountain catchments (Case study area: the upper Hron River basin, Slovakia)
Abstrakt
This contribution presents tested trends of selected hydrometeorological factors using parametric (linear regression) and non-parametric procedures (Mann-Kendall test). The tests were conducted in the upper Hron River basin in the central part of Slovakia for the period between 1931 and 2010.
The 1980 - 1990 period was a turning point for runoff development. A more marked period of runoff increase was observed from the second half of the 1960s until the mid-1980s, when its gradual decrease began.
A more pronounced decreasing tendency was recorded after 2000. This fact was also confirmed by the higher frequency and extremity of flood events in the period before 1980.
The MK test 1931-2010 data series showed a significant decrease in runoff in the winter period, while the most pronounced decrease was seen at lower and middle altitudes. A considerable increase in air temperature occurred at all the assessed stations; the highest summer temperatures were recorded in August, and the highest winter temperatures were recorded in January.
Results of this study provide good indicators of local climate change, and they contribute to our knowledge of changes in rainfall-runoff regimes in the context of climate warming and human impact.