Agricultural risk assessment of compound dry and hot events in China

Abstract

Compound dry and hot events or extremes (CDHEs) can cause reduced crop yield, posing threat to food security. Their impacts can be even higher than their univariate counterparts due to the compounding effects of the two extremes. As such, understanding the agricultural risk of CDHEs is critical for devising adaptation measures for the agricultural sector under global warming. However, previous studies mainly focus on changes in the hazard-related characteristics of CDHEs, while the risk assessment encompassing hazards, exposure, and vulnerability is still lacking. In this study, we assess changes in the risk of CDHEs to cropland in historical and future periods across the mainland of China, which incorporates cropland exposure and socio-economic vulnerability at regional scales. Along with increased hazards of CDHEs and heterogeneous changes of vulnerability, the risk of CDHEs was shown to increase across large regions of the country (e.g., Northeast China, North China, and East China) for the historical period from 1967 to 2014. Based on CMIP6 simulations, the agricultural risk of CDHEs is projected to increase in the future period 2053–2100 (by a factor of 1.3) compared with that in the historical period. This study provides a useful basis for agricultural risk assessments of CDHEs and developing adaptation measures in China under global warming.