Evaluation of the Effect of Climate Change on Biomass and Evapotranspiration of Maize (Case Study: Qazvin)

Climate affects agriculture and the main effect of climate change on agriculture largely depends on two variables: temperature and precipitation. In this study, the effect of climate change on biomass and evapotranspiration of maize in Qazvin plain has been investigated. For evaluation, from the general circulation models in the LARS-WG model (EC-Earth, GFDL-CM3, HadGEM2-ES, MIROC5, MPI-ESM-MR) and the scenarios of RCP2.6, RCP4.5 and RCP8.5 in the base period 2015-1986 and used in the following periods: 2040-2021, 2060-2041, 2080-2061 and 2100-2081. Evapotranspiration and corn biomass in baseline and future periods were calculated with Aqua Crop software. In this study, the results of the scenarios were compared with the data of Qarvin station for maize crop by statistical error criteria including explanatory coefficient statistics (R2), root mean square error (NRMSE) and absolute mean error (MAE). The simulation results of LARS-WG model in the base period showed that the model has more minimum and maximum temperature simulation accuracy than precipitation. Studies also show that the temperature will increase in future periods. Rainfall changes were seen as both decreasing and increasing. The simulation results showed that the biomass decreased compared to the baseline period in the following periods and transpiration evaporation increased in most of the models used.