DROUGHT CHARACTERIZATION ELEMENTS IN CALAFAT-BĂILEŞTI-DĂBULENI AREA (1971-2010)
I. ONȚEL
ABSTRACT: - Drought characterization elements in Calafat-Băileşti-Dăbuleni area (1971-2010). The extreme weather events caused by scarce rainfalls and high air-temperatures have increased throughout the last decade, seriously damaging agriculture. In order to characterize droughts which negatively affect agriculture in the area of reference, a 40 years’time series meteorological data (1971-2010) were used from the Calafat, Bechet and Băileşti weather stations. The average annual rainfall amounts total about 540 l/m2 and air-temperatures means oscillate around 11.5°C. According to the Walther-Lieth climograms, the dry period lasts for more than three months at all three weather stations, while the drought period lasts for little more than one month (August). The same droughty month (August) is also reflected by the Péguy climograms. The Standardized Precipitation Anomaly shows a cyclic occurrence of heavy and scarce rainfall periods, in which the 1983, 1985, 1992, 1993 and 2000 years could be considered as droughty years and the 1979, 1999 and 2005 years, as rainy and very rainy years. The so-called normal years represent more than 60% of the total time-series years, the droughty years totaling a second-order share. Both the Hellman criterion and the deciles method which have been applied in the analysis, clearly highlights that the 1994, 2000, 2002 and 2007 years went to extremes. The high air-temperatures greatly increase the evapotranspiration rates, which combined with a large moisture deficit in the soil, can cause the most severe pedological drought.
Keywords: Drought, Walther-Lieth and Péguy climograms, Standardized Precipitation Anomaly, Hellman Criterion, Deciles.