干旱是一系列极端气候事件中影响范围最广、造成损失最严重的自然灾害类型之一，深入研究干旱对气候变暖的响应并科学评估不同温升情景下的干旱风险变化特点，能为制定区域减灾方案措施提供决策依据。本研究以中国及其根据自然和气候条件划分的七个自然地区（东北湿润半湿润温带地区、华北湿润半湿润暖温带地区、华中华南湿润亚热带地区、华南湿润热带地区、内蒙草原地区、西北荒漠地区、青藏高原）为研究区，基于CMIP6的18个气候模式中的气象数据，计算了标准化降水蒸散指数（SPEI），基于SPEI识别干旱事件，提取了历史基准期以及未来2、3、4℃温升情景下的四个干旱事件指标（干旱频次、平均干旱历时、平均干旱强度、平均干旱峰值），综合四个干旱指标构建了干旱危险性指数，从而评估了历史和未来的干旱危险性并分析了未来干旱危险性变化情况。研究结果显示：(1)中国东部季风区的干旱频次呈现南高北低的分布规律，且干旱频次整体上随温升水平的增加而增大；青藏高原和西北荒漠地区的干旱频次则随温升水平的提高呈现先增后减的特点。平均干旱历时、平均干旱强度和平均干旱峰值在各阶段都呈西北高、东南低的分布规律，指标的数值整体上都随温升水平的增加而明显增大。(2)中国干旱危险性呈现出西北内陆与东南沿海相对较高的分布规律，干旱危险性最大的是西北荒漠地区，最小的是东北湿润半湿润温带地区。随着温升水平的增长，干旱危险性整体上不断增大，但青藏高原东南部从3℃到4℃温升情景的干旱危险性降低。(3)未来2、3、4℃温升情景下的干旱危险性指数相对于历史基准期的变化在全国各地区以增大为主，只有青藏高原东南部出现减小。西北荒漠地区的干旱危险性指数增加最为明显，东北湿润半湿润温带地区和华中华南湿润亚热带地区的增加值相对较小。干旱危险性指数变化值整体上随温升水平的增加而增大，但在4℃温升情景下青藏高原东南部干旱危险性指数减小的区域相对于2、3℃温升情景稍有扩大。

Drought is one of the most extensive and serious natural disasters among a series of extreme climate events. An in-depth study of the response of drought to climate warming and a scientific assessment of the characteristics of drought risk change under different global warming scenarios can provide a decision basis for formulating regional disaster mitigation programs and measures. In this study, China and its seven natural regions divided according to natural and climatic conditions (northeast humid/semi-humid temperate region, north China humid/semi-humid warm temperate region, central and southern China humid subtropical region, south China humid tropical region, Inner Mongolia grassland region, northwest desert region and Qinghai-Tibet Plateau) were used as the study area. The standardized precipitation evapotranspiration index (SPEI) was calculated based on meteorological data from 18 climate models of CMIP6. Based on the SPEI, drought events were identified, and four drought event indexes (drought frequency, average drought duration, average drought intensity and average drought peak value) in the historical reference period and temperature rise scenarios of 2, 3 and 4 ℃ in the future were extracted. The drought hazard index was constructed by synthesizing four drought indexes, then the historical and future drought risk was evaluated, and the change of drought risk in the future was analyzed.

The results show that: (1) The drought frequency in the eastern monsoon region of China shows a distribution pattern of high in the south and low in the north, and the drought frequency increases overall with the increase of warming level; while the drought frequency in the Qinghai-Tibet Plateau and the northwest desert region shows an increase and then decrease with the increase of warming level. The average drought duration, intensity and peak show a distribution pattern of high in the northwest and low in the southeast, and the values of the indicators increase significantly with the increase of warming level in general. (2) The drought hazard in China shows a distribution pattern of relatively higher in the inland northwest and coastal southeast. The highest drought hazard is in the northwest desert region, and the lowest is in the northeast humid/semi-humid temperate region. With the increase of warming level, the drought hazard increases overall, but the drought hazard decreases in the southeastern Qinghai-Tibet Plateau from 3 ℃ to 4 ℃ global warming scenario. (3) The changes of drought hazard index in the future 2, 3, and 4 ℃ global warming scenarios are mainly increasing relative to the historical base period in all regions of China, and only the southeastern Qinghai-Tibet Plateau shows a decrease. The increase of the drought hazard index is most obvious in the northwest desert region, and the increase in the northeast humid/semi-humid temperate region and the central and southern China humid subtropical region is relatively small. The change in drought hazard index values increased overall with the increase of warming level. However, under the 4 ℃ global warming scenario, the area where the drought hazard index decreases in the southeastern Qinghai-Tibet Plateau expands slightly relative to the 2 and 3 ℃ global warming scenarios.