1901-2015年华北平原干旱时空转移特征及热点区域探测

Spatiotemporal transferring characteristics of drought and its hotpots detection in North China Plain during 1901~2015

描述百年来华北平原干旱发生频率与事实,揭示干旱时空转移规律与发展趋势,对理解全球变暖背景下华北平原干旱过程形态与演化模式具有重要的科学意义,对华北平原制定科学合理的御灾减灾措施具有重要的科学指导意义。文中利用1901至2015年逐月标准化降水蒸散指数(SPEI)数据分析华北平原不同级别干旱发生频率;利用空间探索性分析方法探究华北平原不同级别干旱分布的"集聚"区,并运用干旱质心表征华北平原干旱时空转移方向;利用马尔科夫链分析华北平原不同时期不同级别干旱的发展概率。结果表明:1901至2015年,华北平原干旱最严重的时期为1920-1950年;华北平原特旱和重旱发生频率空间分布主要集聚在山东半岛南部、河南北部;干旱(轻旱及以上)呈现从东北往西南降低的趋势;华北平原各级别干旱呈现显著的"集聚"空间分布特征,干旱(轻旱及以上)热点区域集中分布在华北平原东北部,包括河北中部及北部、北京、天津和山东北部及西部地区;华北平原干旱形势略有恶化趋势,轻旱和中旱面积明显上升。

Describing the frequency and facts of drought in the North China Plain(NCP)over the past 100 years,revealing the temporal and spatial transitions and development trends of the drought in the North China Plain from 1901 to 2015,have scientific significant meaning for understanding the evolution pattern of the drought process in the NCP under the background of global warming,and also be of great scientific guiding significance to formulate scientific and reasonable measures for disaster mitigation.In this paper,the data of Standardized Precipitation Evapotranspiration Index(SPEI)with the time scale of three-month was used to analyze the occurrence frequency of drought and drought evolution trend in the NCP,and the spatial exploratory analysis method was used to explore the"aggregation"area of different drought levels in NCP,and the drought center of gravity was used to characterize spatiotemporal transition direction of the NCP,eventually,Markov chain was used to analyze the development probability of different drought levels in different periods in the NCP.Results showed that the most severe drought period in the NCP was 1920 s-1950 s from 1901 to 2015;the spatial distribution of frequency of extreme drought and heavy drought in the NCP mainly concentrated in the southern Shandong Peninsula and northern Henan,drought area(above light drought)showed a trend of decreasing from northeast to southwest.The drought distribution of all drought levels in the NCP showed a significant spatial characteristic of"aggregation".The drought hotspots(above light lrought)were concentrated in the northeastern part of the NCP,including the central and northern Hebei,Beijing,Tianjin,and northern and western Shandong.The drought situation in the NCP has slightly deteriorated,and the drought areas of light drought and moderate drought have increased significantly.