Trends in seasonal snowpack and their relation to climate variables in mountain catchments in Czechia
Abstract
This study investigated trends in snowpack for the period 1965-2014 in 40 catchments located in five mountain regions in Czechia. We analysed daily series of air temperature, precipitation, and snow water equivalent (SWE) which were simulated with a conceptual model.
The Mann-Kendall test showed strong increasing trends in air temperature at all elevations, mostly at the end of the cold season. This increase caused a decrease in snowfall fraction and SWE.
Maximum SWE decreased mainly in western parts of Czechia (by up to -45 mm/decade). The length of the snow-covered period decreased by up to -6.8 days/decade, mainly due to earlier melt out.
Snowpack was more sensitive to changes in air temperature at elevations below 900 m a.s.l., while precipitation had a larger impact on snowpack at elevations above 1200 m a.s.l. The relative importance of air temperature on snow variability increased at all elevations in the last decades.