Crop yield and production responses to climate disasters in China

In recent decades, climate disasters, especially droughts and floods, have disrupted food production and caused yield losses. Crop models cannot identify quantitative changes of crop yield and production caused by climate disasters directly, and empirical approaches possibly underestimate the effects due to the use of the entire world or an individual nation as the unit of study. Here, we quantified the losses of crop yield and production resulting from droughts and floods across China during 1982-2012 using the superposed epoch analysis (SEA) method. We defined the actual-occurred and control composited series using provincial-level data in China, i.e., covered area (CA), affected area (AA), and sown area (SA) from 1982 to 2012, and crop yields and production of maize, rice, soybean, and wheat from 1979 to 2015. The results showed that maize and soybean in China suffered serious damage from droughts, with reductions in yields and production ranging from 7.8% to 11.6% between 1982 and 2012. Droughts and floods significantly decreased wheat yield by 5.8% and 6.1%, respectively. Moreover, rice yield and production were sensitive to both droughts and floods, with reductions of 4.5-6.3%. Among the MGPA, crops cultivated in NEC and the Huang-Huai-Hai Plain (HHH) were more easily affected by droughts. Among the four main crops and the three types of rice in the mid-lower reaches of the Yangtze River (MLYR), the yield and production of only early rice were sensitive to floods. The quantitative identification of the spatial responses of crop yields and production to droughts and floods can help us better understand the impacts of climate disasters on food security in China and the whole world, which is essential for addressing potential adaptation strategies.