How will the yield of rainfed wheat respond to the future climate over Iran

Grain production is one of the most important factors affecting food security. This study aimed to estimate food security in Iran, focusing on the past situation of the yield of rainfed wheat (YRW) and what to expect in the future. This purpose was fulfilled by quantifying the effect of uncertainties in climate change scenarios on the YRW. Monthly precipitation and temperature data recorded in 45 weather stations throughout the country along with the YRW data averaged over the country (kg.ha-1), during 1981-2010, were considered to perform the study. To simulate the future climate, monthly outputs of regional climate simulations in combination with a stochastic weather generator were employed. The analysis was based on the calculation of the Standardized Precipitation Evapotranspiration Index (SPEI) and the construction of a multi-linear regression (MLR) between the SPEI predictors and the YRW anomalies to analyze the climate change impact. The MLR increased adjusted R2 compared to the simple linear regression (0.776 vs. 0.51 for training and 0.687 vs. 0.452 for validation). Furthermore, findings confirmed that the YRW tends to be decreased over the country in the range of 1.3-44%. It will affect the food security and therefore, adaptation strategies to control these consequences should be taken into account by decision-makers.

کلیدواژه ها:

Climate Change ، Food Security ، Multi-linear Regression ، SPEI ، Weather Generator.