Drought continuously affects agricultural production. Agricultural
vulnerability can be referred to the degree that agricultural systems may experience harm due to a stress. Global concernsabout climate change have intensified the fear from the drought effects. In this study UNEPAridity Index (AIU) was calculated to measure
drought intensity (rate of average number ofannual continuous hyper arid days in the whole year), drought duration (average number ofannual continuous hyper arid days) and drought occurrence timing for the base period (١٩۶١- 2009) and the projected years. Five study locations were Birjand, Bojnourd, Mashhad, Sabzevar and Torbat Heydarieh. Projected changes in climate variables were simulated by HadCM٣model under three scenarios (A1B, A2 and B1 for three periods 2011-2030, 2046-2065 and 2080-2099) simulated by LARS-WG. The Cropping System Model (CSM)-CERES-Wheat wasused for rainfed wheat growth simulation under projected climate conditions. In order toquantify the magnitude of
vulnerability to varying drought conditions,
vulnerability was considered as a function of
sensitivity (SEN), well-being state relative to its damage threshold and exposure. Vulnerability was calculated considering severe droughts in the selected years (VEXPL and VEXPS) and the expected
vulnerability (EVEXP) considering the expected frequency of drought. The results of drought evaluation showed that in Birjand and Mashhad the timing ofdrought will not differ from the base period but in three other locations the timing of dry period will change. In Bojnourd the drought will occur two months earlier than the base period and in Sabzevar and Torbat Heydarieh one month later than the base period. Also it was projected thatin all the study locations
drought intensity and duration will decrease in the future. The results of rainfed wheat
vulnerability showed that in all the study locations the wheat production was extremely sensitive to drought (SEN> 200). It was also projected that crop production will be extremely vulnerable to probable droughts during the projected years, with VEXPL, VEXPS and EVEXP values > 20, the same as the base period. The results of this study emphasis on strategies to mitigate the negative results of climate change and drought.