The impact of climate variability and change on water resources in the western coastal zone of the Black Sea

Climate variability and change during the 20th century in the western coastal zone of the Black Sea (including east Bulgaria and northwest Turkey) were investigated. Air temperature increased during the last decade. Annual precipitation as well as runoff and groundwater decreased during the last decades. Because of the drier conditions, irrigation demands increased during the last two decades. The effect of the North Atlantic Oscillation on variability of winter precipitation over the studied region was also considered. HadCM3 climate change scenarios for the western coastal zone of the Black Sea were created. Air temperature was simulated to increase, but precipitation was projected to decrease during the 21st century across the region of interest. These changes will have negative impacts. on water resources in eastern Bulgaria and northwest Turkey. The influence of warming and precipitation changes on the elements of the soil water 'balance was estimated by a decision support system.