The effects of climate change on crop yields using RCP scenarios with SWAT agro-hydrological model in Maharlu Basin (Fars Province - Iran)

Climate change is one of the most important issues that have been raised in water sources and agriculture limiting the crop production. In this study, the northern part of the Maharlu Lake in the central plateau of Iran is simulated using a semi-distributed SWAT model during 1980-2013. Then, using the LARS-WG, future climate information is obtained based on RCP 4.5 and RCP8.5 scenarios. Furthermore, assessment of the effects of climate change showed that the average annual temperature of the basin in the future period (2021-2040) will increase about 1.5°C and 1.8°C for the RCP4.5 and RCP8.5 scenarios, respectively compared with the baseline period. Simulations and the calculation of the long-term average of temperature and precipitation, and the model combination were used to estimate crop yields using the semidistributed SWAT model. NSE showed acceptable range of SWAT model accuracy (~0.65) .Results of crop yields showed that in future wheat yield will increase from 3.4 ton/ha to 4 and 4.4 ton/ha. In addition, almond, tomato, apple, and olive will face decreased yields.