Climatic water deficit and surplus between the Carpathian Mountains and the Dniester River (1961-2012)

The study addresses the climatic water deficit (WD) and surplus (WE) in the area located between the heights of the Eastern Carpathians (Romania) and the Dniester River (Moldova). The objective of this study is to discover the trend of WD/WE (past and future) and its variation in space. WD and WE were calculated as the difference between the amounts of precipitation (P) and the reference evapotranspiration (ET₀). The P-ET₀ trend, analyzed through Mann-Kendall and t tests, was negative for 83 and 80% of the analyzed stations and the Sen's slope had values between - 0.05 mm year^-1 (t test) and - 6.73 mm year^-1 (Mann-Kendall test). Seasonally, the slope values of P-ET₀ trends were negative during winter, spring, and summer and positive in autumn. The P-ET₀ index is positive (WE) only in the Carpathian and Eastern Subcarpathian areas, whereas for the rest of the investigated territory, we found negative values (WD). WD is more pronounced as we depart from the Carpathians towards the east, but also on a north to south direction, reaching the maximum in the southeastern part of the territory. In what concerns seasonal distribution, WE is identified everywhere only in winter, whereas, in spring, summer, and autumn, WD characterizes most of the territory, with the exception of the Carpathian and Subcarpathian areas. The increasing WD will have a growing negative influence on the agriculture of the studied area. For the year 2030, we anticipate a reduction in the climate water availability with 46 mm m^-2 (reference period: 1961-2012).