Spatio-Temporal Characteristics and Hazard Assessment of Chilling Injury on Millet in Northern China

ABSTRACT Under the background of climate change, agricultural meteorological disasters occur frequently in northern China, which has seriously threatened the production safety of millet in this area. Therefore, it is urgent to find out the danger of major agricultural meteorological disasters in millet, and provide reference for the formulation of measures for preventing and reducing millet disasters. The chilling injury which has great influence on millet was selected as the disaster-causing factor, and based on the meteorological data of 314 meteorological stations in the first millet planting area of northern China from 1960 to 2019, combined with the data of millet growth period, the chilling injury was identified and quantified. Using the method of index discrimination combined with disaster data, the weight coefficient was extracted from the influence differences of different growth periods and different chilling injury degrees in typical disaster years, and the risk assessment of millet chilling injury in northern China was carried out to preliminarily explore its response to climate change. The results show that: (1) In the whole growth period of millet, severe chilling injury mainly occurred, with the highest frequency in the early growth period and the lowest frequency in the late growth period. The high incidence areas of chilling injury were located in Northeast China and Gansu Province. (2) The areas with high risk of chilling injury in each growth period are similar to those with high disaster value. From the whole growth period, the risk of chilling injury in most areas in the study area is below moderate, and it shows the spatial distribution characteristics of high in the north and low in the south, high in the west and low in the east. (3) The interdecadal change of millet chilling injury risk is basically consistent with the change of climate resources, showing negative feedback response.