TEMPORAL VARIATIONS OF MULTI-DAY PRECIPITATION EXTREMES IN SOUTHERN ROMANIA: 1961-2014

Abstract

The ECA dataset of daily precipitation observations was used to study the temporal variability of seasonal extreme precipitation amounts over a 54-year time period in the southern plain areas of Romania. Extreme events resulting in exceptional precipitation amounts cumulated over one to three consecutive days and the frequency of very heavy precipitation events (as defined by the ETCCDI) were analyzed to reveal the changes in the seasonality of precipitation torrentiality and its frequency. The nonparametric Mann-Kendall test (MK) and Sen's slope method were used to test the statistical significance, spatial robustness of the observed trends and their magnitude. A clear change signal was found for autumn, winter and autumn, with a high number of sites with statistically significant trends. The upward trends suggesting more intense precipitation events in these seasons were found at most sites as compared with summer, for which the MK statistics returned less consistent changes. There is a negative trend in the number of wet days associated with a dominantly upward in R20 frequency, for autumn and winter.

Keywords

• multi-day precipitation
• extremes
• very heavy precipitation days