基于短时间尺度自适应帕尔默干旱指数的中国干旱演变特征分析EI北大核心CSCD

以帕尔默干旱指数(PDSI)为基础,构建融合Penman-Monteith潜在蒸散发公式且具有短时间尺度效应的自适应帕尔默干旱指数scPDSI_(pm),分析了1951—2016年中国旱涝演变趋势及干旱特征的空间分布规律和历史干旱事件的时空演变过程,并结合实际旱情记录资料验证了指数的可靠性。结果表明:空间上,中国东北、华北、华中、西北呈变旱趋势,西北和东南少数地区为变涝趋势;中国大部分地区旱情开始时间集中在6—7月,北部地区干旱历时长且干旱烈度大,南部地区干旱历时短、干旱烈度小;scPDSI_(pm)能够很好地指示旱情发生时间和区域,准确地捕捉到旱情中心的转移过程。

Drought characteristics analysis in China based on self-calibrating Palmer drought severity index in a short time scale

Based on the Palmer drought severity index (PDSI), a modified variant of the self-calibrating PDSI, which uses the Penman-Monteith equation for calculating the potential evapotranspiration and has a short time scale effect (denoted as scPDSI_pm), was proposed. The drying/wetting trends and drought characteristics of spatial distribution and temporal evolution of historical drought events in China during 1951-2016 were analyzed. The reliability of scPDSI_pm is verified based on the recorded drought events. Results showed that, from the prospective of spatial distribution, there is a drying trend from the northeast of China, through north and central, to the southwest of China, while a wetting trend exists in the northwest and the southeast of China. For most regions in China, droughts likely start from June or July. Droughts in north China have long duration and high severity, whereas droughts in south China have short duration and low severity. The scPDSI_pm is capable of capturing the onset time, affected area and migration process of drought.