Water scarcity is the key challenge in arid regions, which exacerbates under climate change (CC) and must be considered to assess the impacts of CC on cropping systems. A climate-crop modeling approach was employed by using the CSM-CERES-Wheat model in some arid regions of northeast Iran to project the effects of CC on irrigated winter wheat production. Current climate data for 1990-2019 and climate projections of three climate models for the near-future climate period of 2021-2050 under RCP4.5 and RCP8.5 emission scenarios were used to run the crop model. Two irrigation scenarios with different irrigation efficiencies were also simulated to investigate the impacts of water scarcity associated with changing climate and irrigation management on winter wheat productivity. Results indicated that mean temperature is projected to increase in the range of 1.74-2.73 degrees C during the reproductive growth period of winter wheat over the study areas. The precipitation projections also indicated that the precipitation rates would decrease over most of the wheat-growing period. The length of the vegetative growth period will extend in some regions and shorten in others under the near future climate period due to a cooling and warming trend, respectively. However, the grain filling duration will be reduced by about 2-4 days across all regions. The mean seasonal potential evapotranspiration is expected to decrease by about 24 mm from 2021 to 2050 in Mashhad, Sabzevar, and Torbat-e Jam. A mean overall reduction in winter wheat yield due to future climate conditions would be about 12.3% across the study areas. However, an increase of 15-30% in the irrigation efficiency will be able to offset yield reductions associated with limited water supply under future climate scenarios. The results suggest that CC will exacerbate limited irrigation water resource availability, so implementing high-efficiency irrigation systems should be a priority to adapt to climate change in the arid cropping system of north-east of Iran.
Saberali, SF; Shirmohammadi-Aliakbarkhani, Z; Nasrabadi, HN
Simulating winter wheat production potential under near-future climate change in arid regions of northeast Iran
Theoretical And Applied Climatology