TEMPORAL AND SPATIAL VARIABILITY OF DROUGHT BASED ON SPEI ANALYSIS IN SOUTHEASTERN ROMANIA Alexandra CHELU 1,2 , Liliana ZAHARIA 1 , Gabriela Ioana TOROIMAC 1 ABSTRACT. This study investigates the drought trends and their spatial variability in southeastern Romania, based on the Standardized Precipitation Evapotranspiration Index (SPEI) analysis (for 1, 3, 6 and 12 months), by using E-OBS precipitation and temperature gridded data between 1950-2018. Trends in the variability of SPEI are analyzed using the Mann-Kendall non-parametric test with the Theil-Sen method for slope estimation. Results show increasing wetness in autumn and dryness during the other seasons for SPEI at 3 months scale, with significant negative trends in winter at the higher altitudes in the study area and in the Danube Delta. SPEI cumulated for 6 months in September shows dryness trends over most of the study area, while SPEI for 6 months in March shows dryness trends only over the western part of the studied region. The results can be useful for designing or improving the regional adaptation practices in order to reduce the negative consequences of droughts in areas affected by drought intensification tendencies. Keywords: drought, SPEI, trends, southeastern Romania, Sen’s slope 1. INTRODUCTION Although at global scale the identified drought trends since the 1950’s appear to have low confidence (mainly due to issues related to methodology), hotspots of drought change have been observed regionally, such as in the Mediterranean region (IPCC, 2014). In Romania, drought trends have been investigated in several studies whose results showed spatial heterogeneity due to the variability of meteorological variables involved in the occurrence of this phenomenon. One of the most common indices for drought analysis worldwide and in Romania is the Standardized Precipitation Index (SPI) (McKee et al., 1993). Its values showed significant wetness trends in autumn in southeastern Romania, while during winter and spring there are several stations in the Danube Delta region with increasing dryness between 1961- 2010 (Cheval et al., 2014). Between 1962 and 2013, significant decreasing trends in SPI at 3, 6 and 12 months scale in the Danube Delta, and increasing trends in the southeast of Romania (south of Dobrogea region) have been found by Ioniță et al. 1 University of Bucharest (mariaalexandra.chelu@gmail.com) 2 University of Rennes 2 How to cite: Chelu, Al., Zaharia, L., Toroimac, I.G. (2020) Temporal and Spatial Variability of Drought Based on SPEI Analysis in Southeastern Romania. 2020 ”Air and Water – Components of the Environment” Conference Proceedings, Cluj-Napoca, Romania, p. 71-80, DOI: 10.24193/AWC2020_07. DOI: 10.24193/AWC2020_07