不同温升情景下中国旱灾风险变化评估

Assessment of drought risk changes in China under different temperature rise scenarios

干旱是致灾最为严重的极端气候事件之一,研究未来气候变暖背景下旱灾风险的变化有利于科学推进防灾减灾工作部署。利用第六次国际耦合模式比较计划的20个气候模式数据计算了标准化降水蒸散指数,提取了基准期及全球2℃、3℃、4℃温升情景下中国的干旱特征变量并计算干旱危险性指数,基于承灾体预估数据计算干旱暴露度指数和干旱脆弱性指数,综合计算旱灾风险指数,从而分析中国旱灾风险分布格局并基于地理探测器对未来旱灾风险变化进行空间归因分析。结果表明:干旱危险性指数、干旱暴露度指数和干旱脆弱性指数的空间分布分别表现为西北和东南相对较高、东高西低、西高东低;旱灾风险指数具有东高西低的分布特点,呈现以高值集聚和低值集聚为主的空间正相关;随着温升水平的升高,未来旱灾风险以增加为主,东部沿海地区增加最为明显;人口数量变化、GDP变化和耕地占比变化是影响旱灾风险变化的主导因素。

Drought is one of the most disastrous extreme climate events.Studying the changes in drought risk against the background of future global warming is beneficial for scientifically advancing disaster prevention and reduction work deployment.The standardized precipitation evapotranspiration index was calculated using data from 20 climate models from the sixth phase of the Coupled Model Intercomparison Project.Drought characteris-tic variables were extracted for the baseline period and global temperature rise scenarios of 2℃,3℃,and 4℃in China,and the drought hazard index(DHI)was calculated.Based on the disaster-bearing body projection data,the drought exposure index(DEI),drought vulnerability index(DVI),and drought risk index(DRI)were compre-hensively calculated.The distribution pattern of drought risk in China was further analyzed,and a spatial attribu-tion analysis of future drought risk changes was performed using a geodetector.The results showed that the spa-tial distribution of DHI,DEI,and DVI exhibited higher values in the northwest and southeast,a pattern of being high in the east and low in the west,and a trend of being high in the west and low in the east,respectively.Based on this,the DRI specially showed a spatial positive correlation dominated by high-and low-value clustering.With an increase in the temperature rise level,the future drought risk will mainly increase across China,and the increase in the eastern coastal areas would be the most obvious.Changes in population,gross domestic product,and the proportion of cultivated land were found to be the main factors affecting changes in drought risk.