摘要
未来气候变化情景下,我国干旱事件发生的趋势具有诸多不确定性。基于国际耦合模式比较计划第五阶段(CMIP5)中6个GCM模式的未来气候变化情景数据,采用帕尔默干旱指数(Palmer Drought Severity Index,PDSI),评估了21世纪RCP(Representative Concentration Pathway)4.5和RCP 8.5情景下我国干旱事件发生的时空变化特征。结果表明:21世纪中后期,由于气候显著变暖而降水变化不稳定,我国将面临广泛的干旱化趋势,其中干旱频次、持续时间和强度都呈显著上升趋势。相对于基准期,干旱事件的空间格局也将发生变化,其中北方地区干旱事件历时和频次明显增加,而南方严重干旱事件的强度加剧。尽管未来气候变化情景下降水小幅增加,但仍不能扭转因增温所导致的区域干旱化趋势。因此,在制订和实施应对气候变化的旱灾预防、减缓及适应性方案和措施时,需要考虑气温和降水变化时空不匹配等因素的影响,从水热两方面调控干旱的不利影响。
There are great uncertainties in drought predication because of climate change. Based on climate change scenarios projected by six GCMs in CMIP5 project, the spatio- temporal patterns of drought indices （Palmer Drought Severity Index, PDSI） over the terrestrial China in the 21st century in IPCC RCP 4.5 and RCP 8.5 scenarios are evaluated. Due to climate warming and precipitation variability, the drying trends are predicted to be prevailing in the 21st century over the country. It is shown that frequency, duration and intensity of drought will all be aggravated significantly, especially in the RCP 8.5 scenario. Compared to the baseline, the drought frequency will increase 1.5 and 3 times in 2050s and 2090s, respectively in RCP 4.5. In RCP 4.5, the drought duration will extend 0.3 and 1.1 month longer, and drought intensity will aggravate 9.1% and 26.9% in 2050s and 2090s, respectively. Long duration droughts will be more frequent in northern China, and the drought intensity will be aggravated in the Northeast China. By separating the effects of precipitation and temperature on PDSI, it is recognized that air warming results in the increase of drought frequency in southern part, while precipitation increases drought frequency slightly. In northern China, even though the precipitation increases significantly, the effect of air warming still overtakes the effect of precipitation, giving rise to more serious drought condition. In the light of drying trends in climate change scenarios, precautious measures and policies for mitigation and avoidance of drought disasters should be highlighted.
作者
莫兴国
胡实
卢洪健
林忠辉
刘苏峡
MO Xing-guo;HU Shi;LU Hong-jian;LIN Zhong-hui;LIU Su-xia(Key Laboratory of Water Cycle and Related Land Surface Processes,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China;College of Resources and Environment /Sino-Danish Center,University of Chinese Academy of Sciences,Beijing 10049,China)
出处
《自然资源学报》
CSSCI
CSCD
北大核心
2018年第7期1244-1256,共13页
Journal of Natural Resources
基金
国家自然科学基金会项目(41471026)
科技部973项目(2017YFA0603702)
中国科学院地理科学与资源研究所特色所项目(TSYJS02)~~
