摘要
基于高空间分辨率的气候数据,计算黄土高原地区的标准化降水蒸散指数(SPEI),分析该地区干旱变化趋势、干旱等级转换以及干旱发生频率的时空变化.结果表明,与历史时期(1901-2017年)相比,未来时期(2018-2100年)的干旱发生次数增加,其中中旱发生次数明显增多;在RCP2.6、RCP4.5和RCP8.5情景下,未来时期整个黄土高原的SPEI将分别以0.120、0.096和0.206/10 a的速率显著下降.在地理空间上,未检测到未来时期呈显著上升的SPEI趋势,而干旱趋势显著加重的区域占黄土高原面积的51.62%~99.90%;在本世纪末(2071-2100年),该比例为44.54%~84.25%;这些区域主要分布于黄土高原的北部和西部.从当前时期(1981-2010年)到本世纪末,黄土高原超过80%的地区将发生无旱到轻旱的等级转换,黄土高原西北部将发生无旱到中旱的等级转换.气候变化将增加极端干旱发生频率空间分布的差异,在RCP8.5情景下,黄土高原西北部的极端干旱发生频率较高.
Based on a high spatial resolution climate dataset,the standardized precipitation evapotranspiration index(SPEI)of the Loess Plateau(LP)region was calculated,and the spatiotemporal changes in drought trend,transformation of drought severity,and drought frequency were analyzed.The results showed that,compared with the historical period(1901-2017),the number of droughts in the future period(2018-2100)would increase,particularly for moderate droughts.Under the RCP2.6,RCP4.5 and RCP8.5 scenarios,future SPEI of the LP would significantly decrease with 0.120/10 a,0.096/10 a,and 0.206/10 a,respectively.In the geographical space,a significant upward trend in SPEI was not detected in the future period,while the area where the drought trend was significantly aggravated accounted for 51.62%-99.90%of the area of the LP;by the end of the century(2071-2100),the area ratio would be 44.54%-84.25%;these areas would be mainly distributed in the north and west region of the LP.From the current period(1981-2010)to the end of this century,most areas of the LP(more than 80%of the region)would experience a transformation from no to light droughts,while the northwest region of the LP would encounter a transformation from no to moderate droughts.Climate change would increase the spatial heterogeneity in the frequency of extreme drought on the LP.Under the RCP8.5 scenario,extreme drought would occur more frequently in the northwest region of the LP.
作者
师玉锋
彭守璋
Shi Yu-feng;Peng Shou-zhang(College of Resources and Environment,Northwest A&F University,Yangling 712100,Shaanxi,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University,Yangling 712100,Shaanxi,China)
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
2020年第6期785-792,共8页
Journal of Lanzhou University(Natural Sciences)
基金
国家自然科学基金项目(42077451)
