DRY SPELLS ON THE ROMANIAN BLACK SEA COAST
A.E. CROITORU, B.C. CHIOTOROIU, V. TORICA
ABSTRACT. - Dry spells on the Romanian Black Sea coast. The main goal of this paper was to identify and analyse the dry spells in the driest region in Romania: the Black Sea coast. Daily precipitation data sets from 3 weather stations (Constanta, Sulina and Tulcea) for a period of 49 years were used. A dedicated software was employed to identify dry spells and to calculate their main parameters. Then, Mann-Kendall test and Sen’s slope estimation were used to detect trends in those parameters. Two of the three weather stations (Constanta and Tulcea) show a similar behaviour with higher numbers of dry spells and lower duration values. Sulina shows different results: the lowest number of dry spells, the highest values of cumulated and average duration and the multi-annual maximum duration of dry spells. The Tulcea inland station has the highest number of dry spells. Duration parameters at Constanta follow those identified at Sulina. All dry spells parameters show statistically significant trends for Sulina data sets: decreasing in the annual number of dry spells and increasing in all duration-related parameters. The short and very short dry spells are most frequent in the area, while considering multi-annual cumulated duration; very short, short and medium dry spells have similar frequency values (24-30 %). Long and very long dry spells have the highest frequency both as case number and for cumulated duration at Sulina.
Keywords: precipitation, dry spell, trend, Mann-Kendall test and Sen’s slope, Romanian Black Sea Coast.