Abstract:
It is of great significance to accurately identify the spatiotemporal characteristics of the increasingly severe drought events in China for disaster mitigation and agricultural production. This study proposes a method for determination of drought events based on comprehensive indicators (precipitation and soil water). Based on the Chinese daily surface precipitation grid dataset (V2.0) and the global soil water dataset GLDAS NOAH025 from 1961 to 2020, the frequency, covered area proportion, and intensity of drought events in China were analyzed by decade and season. The results reveal that the total frequency of drought events in China from 1961 to 2020 ranged from 0 to 154 times, mainly occurred in the center, southeast and northwest of China, with covered area proportion of 50.5% for the highest drought frequency between 51 and 100 times. The drought intensity was moderate or below. The frequency of drought events in each decade was mainly concentrated between 6 to 15 times, and the intensity of drought is moderate or below. Over time, the frequency and intensity of drought events in China have shown an overall increasing trend. The frequency of drought events was the highest in summer, with an average annual drought frequency of 0.97 times. The intensity of drought events increased in the order of spring > summer > winter > autumn. The findings can provide scientific basis for risk analysis and mitigation of drought in China.