Document Type : Research Paper
Authors
1 PhD candidate, Department of Irrigation and Reclamation Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, Iran.
2 Professor, Department of Irrigation and Reclamation Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, Iran.
3 Associate Professor, Department of Irrigation and Reclamation Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj; Faculty Member at Imam Khomeini International University, Qazvin, Iran.
4 Assistant Professor, Agricultural Engineering Research Department, Safiabad Agricultural and Natural Resources Research and Education Center, Agricultural Research Education And Extention Organization, Dezful, Iran.
Abstract
Considering the strategic role of wheat in Iran's food security and its extreme vulnerability to climate change, investigating the effects of climate scenarios on water productivity and yield gaps in Khuzestan Province is a scientific and policy necessity. This study investigated the impact of climate change on wheat water productivity in the 2040 horizon and analyzed the productivity gap in Khuzestan Province. For this purpose, after wheat cultivation in two consecutive years under three irrigation treatments, the effects of SSP1-2.6, SSP2-4.5 and SSP5-8.5 climate scenarios were investigated using the AquaCrop 7.1 simulation model and climate data generated by LARS-WG 8 software (HadGEM3-GC31-LL model) in Khuzestan province. The results of the calibration and validation of the model demonstrated that AquaCrop has a high ability to simulate wheat yield (R² above 0.9 and NRMSE less than 5%). The findings, based on a weighted average for Khuzestan Province, showed that wheat yield increased by 4 to 12% under full irrigation, especially in the SSP5-8.5 scenario, where the highest yield (7050 kg ha-1) and water productivity (1.28 kg m-3) growth was observed. However, the productivity gap analysis revealed that the actual current yield (Ya) was lower than the potential yield (Yp) and the relative yield (RY) of 73%. The water productivity gap (WPG) was also estimated to be 420 g m-3 on average. These results highlight the importance of water resource management, state-of-the-art agricultural technologies, and farmer education to reduce the productivity gap and better adapt to climate change.
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