Evaluation of the effect of climate change on maize water footprint under RCPs scenarios in Qazvin plain, Iran

Abstract

Climate affects agriculture and the main effect of climate change on agriculture largely depends on two variables: temperature (T) and precipitation (P). In this study, the effect of climate change on maize yield and water footprint (WF) in Qazvin plain was investigated. Three scenarios (RCP2.6, RCP4.5, and RCP8.5) for 2021–2040, 2041–2060, 2061–2080, and 2081–2100, respectively, were generated by the LARS-WG model and compared with the baseline period 1986–2015. Yield (Y), water requirement (WR), and evapotranspiration (ET) of maize were simulated using the Aqua Crop model for baseline and future periods. In this study, the results of the scenarios were compared with the observed data of Qazvin plain for maize crop by using the statistical error criteria including coefficient of explanation (R2), normal square root means error (NRMSE), and mean absolute error (MAE). The simulation results of the LARS-WG model in the baseline showed that the model has more accurate in the simulation of minimum temperature (Tmin) and maximum temperature (Tmin) than P. Also, Our findings have investigated that the T will increase in future periods. P changes were seen as both decreasing and increasing. The results showed that the yield decreased in future periods, whereas the WR and ET increased in most of the models used. Also, the results showed that the maize WF will increase in future periods. The results obtained and the proposed method will help water managers, users, and agricultural developers for preparing new water-saving strategies and achieving agricultural sustainability.