Vulnerability assessment of wheat and maize production affected by drought and climate change

Agricultural vulnerability can be referred to the degree that agricultural systems may experience harm due to a stress. A simulation study was conducted to assess the vulnerability of wheat (irrigated and rainfed) and maize production due to drought and climate change in the Northeast of Iran. UNEP Aridity Index (AIU) was calculated to measure drought situation in five agricultural centers including Birjand, Bojnourd, Mashhad, Sabzevar and Torbat Heydarieh. Projected changes in climate variables were simulated by two General Circulation Models: HadCM3 and IPCM4 under three scenarios (A1B, A2 and B1), simulated by LARS-WG. The Cropping System Model (CSM)-CERES-Wheat and (CSM)-CERES-Maize were used for crop growth simulation under projected climate conditions. In order to quantify the magnitude of vulnerability to varying drought conditions, vulnerability was considered as a function of sensitivity, well-being state relative to its damage threshold and exposure. Vulnerability was calculated considering severe droughts in the selected years and the expected vulnerability considering the expected frequency of drought. The results showed that in all the study locations the wheat and maize production have been affected extremely by severe droughts during the base period and both crops were extremely sensitive to drought. It was also projected that crop production will be extremely vulnerable to probable droughts during the projected years the same as the base period.