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Gansu Province is a high-incidence area for many meteorological disasters. In this research, using affected and covered risk indices for the main agro-meteorological disasters (drought, flood, wind hail, and frost), the variability characteristics of agro-meteorological disasters were analyzed and the risks calculated based on the information diffusion method against the background of climate change in Gansu Province. The results showed that of affected (crop yield reduced by >10%) and covered (crop yield reduced by >30%) areas for drought and frost tended to increase between 1978 and 2014, whereas those for flood and wind hail tended to decrease. The affected and covered risk indices for drought increased, those for flood and wind hail showed a slight decreasing trend, the frost affected risk index decreased, and the frost covered risk index increased. Comparing the four kinds of risk for agro-meteorological disasters, the estimated risk decreased as the affected and covered risk indices increased. The risk of drought was more serious than those for other agro-meteorological disasters for the same affected risk index, followed by frost, flood, and wind hail. The most serious disaster agro-meteorological covered risk was wind hail, followed by drought, flood, and frost. After a rapid change in temperature in 1994, the estimated affected risk values of drought and frost increased on average by 17.56 and 96.83%, respectively, whereas the estimated risks of flood and wind hail decreased on average by 15.59 and 5.90%, respectively. After the temperature jump, the estimated covered risk of drought increased on average by 19.57%, whereas those of flood, wind hail, and frost decreased on average by 3.02, 1.78, and 26.10%, respectively. These new scientific discoveries are significant for agro-meteorological disaster prevention in Gansu Province. [ABSTRACT FROM AUTHOR]

Agro-meteorological (AM) disasters have been reported to be more frequent with climate change. In this study, the spatial and temporal changes in the frequency of major AM disasters affecting maize production are investigated by analyzing observed records at 224 national AM stations in China from 1991 to 2009. To investigate the temporal changes of the disasters with climate warming, the whole study period was separated into a cool period (1991-2000) and a warmer one (2000-2009). We found drought was the most common disaster with a frequency of 49 %, followed by chilling injures (19.46 %). The frequency of disasters affecting maize increased significantly during the reproductive growth period than the vegetative growth period. Spatial patterns of major disaster frequency were characterized by region-specific, with more cold stress in northeastern China, drought in northern and western China, and rainstorms in southwestern China. Our study highlighted that the frequency and scope both increased significantly, implying a potential increasing risk for maize production. It is critical and important for local farmers and governors to take reasonable and timely adaptation measures based on the latest disasters' features to mitigate the potential yield loss from AM disasters in order to ensure food security in China. [ABSTRACT FROM AUTHOR]