Three-dimensional meteorological drought characteristics and associated risk in China

Drought as a hazardous natural disaster has been widely studied based on various drought indices. However, the characteristics of droughts have not been robustly explored considering its dual nature in space and time across China in the past few decades. Here, we characterized meteorological drought events from a three-dimensional perspective for the 1961-2018 period in the mainland of China, and attributed the variation of drought intensity to its influencing factors. We further assessed associated drought risk with socioeconomic data for the 2002-2018 period. We found that drought events with high intensity, large area, and long duration are mainly distributed in western and northern China, especially in Inner Mongolia, Xinjiang, Tibet, and Qinghai. The drought intensity and affected area anomalies present a six-phase pattern of 'negative-positive-negative-positive-negative-positive' during 1961-2018. The intensity of drought events showed a decreasing trend but the affected area and duration showed an increasing trend in 2009-2018. Over the decades, the centers of high drought intensity and long duration tend to move eastward and northeastward, respectively. The PET variations contributes larger than precipitation variations to drought intensity variations in the arid regions while being opposite in the humid southern regions. Drought risk assessment further indicates that high drought risk areas are concentrated in northern China, including Inner Mongolia, Xinjiang, Gansu, Sichuan, Hebei, and Heilongjiang. Increasing trends in drought risk for the 2002-2018 period are detected in Inner Mongolia, Xinjiang, Sichuan, Henan, Gansu, Hunan, Shanxi, Qinghai. Our findings provide scientific guidance for policymakers to develop adaptive disaster prevention measures.