近50年中国气象干旱危险性的时空格局探讨

以降水量距平百分率作为气象干旱指标,通过对1961~2010年中国585个气象站逐月降水资料进行干旱过程识别,得到由干旱频次、干旱历时和干旱烈度构成的用于衡量气象干旱危险性的综合指数,并以此分析了中国近50年气象干旱危险性的时空格局特征。结果表明,近50年来,中国气象干旱危险性整体呈现南北分异的格局,北部地区远高于南部地区;1961~1970、1961~2000、2001~2010年三个时段所呈现的南北分异、北高南低的总体格局基本保持不变,但2001~2010年较其他两个时段的危险性高值区域变化显著,主要向华北中部、东北西部、内蒙古东部扩展,而向西北西部收缩,为全国干旱区划以及旱灾风险管理提供了科学依据。

Temporal and Spatial Patterns of Meteorological Drought Hazard in China for Recent 50 Years

Based on the meteorological drought index of percentage of precipitation anomalies, the observed meteorological data of 585 meteorological stations from 1961 to 2010 in China are collected and the index called MDHI that is consisted of drought frequency, drought duration and drought severity is used to reveal the temporal and spatial characteristics of meteorological drought hazard in China. The results show that the meteorological drought hazard in China appears apparent north south difference during the recent 50 years, with the northern part of China being far more hazardous than the southern part; the typical temporal and spatial patterns of meteorological drought hazard during the periods 1961 1970, 1961 2000 and 2001 2010 are the same; while the high hazard areas change more obviously in the period 2001 2010 compared with the other periods, which shows the tendency of extension to the central north China, west of northeast China, east of inner Mongolia and the tendency of contraction to the west of northwest China. All the results can provide scientific support for the national drought zoning and drought risk management.