【摘要】 利用1961—2013年华北地区0.5°×0.5°降水和气温格点数据资料,选用标准化降水蒸散指数,分析了华北地区不同时间尺度干旱事件发生的时空变化特征,并从大气环流和全球变化两个方面分析了气象干旱的主要成因。结果表明:(1)华北地区年、春、夏、秋、冬及月尺度上均有干旱发生。夏季干旱最为严重。华北地区以20世纪90年代干旱最为严重,2000年以来的干旱次之。年尺度干旱发生频率呈现北高南低的分布规律,就四季而言,干旱主要发生在河南西北部及东南部、山东半岛西北部、山西、河北中南部及京津冀地区;(2)京津冀地区ENSO事件强度与降水量呈显著的负相关性,强度增大时降水量下降,减弱时降水量上升。整个华北地区ENSO事件强度与气温呈显著的正相关性,强度增大时温度有上升趋势,减小时温度有下降趋势。其中El Niňo对气温有抬升的趋势,La Niňa对气温有降低的趋势。从全球变化方面来看,影响华北地区气象干旱发生的原因主要是快速城镇化和全球变暖。更多还原

【Abstract】 Based on the data of 0.5°×0.5° precipitation and temperature grids in North China from 1961 to 2013, we selected the standardized precipitation evapotranspiration index and analyzed the temporal and spatial variation characteristics of drought events at different time scales in North China, and analyzed the main causes of meteorological drought in some aspects according to atmospheric circulation and global changes. The results show that:(1) drought occurred on the annual, spring, summer, autumn, winter and monthly scales in North China, the summer drought was the most serious; the drought in North China was the most severe in the 1990 s, followed by drought since 2000; the frequency of drought on the annual scale showed the distribution pattern of high frequency in the north and low frequency in the south; in the four seasons, the drought mainly occurred in the northwest and southeast of Henan, the northwestern part of Shandong Peninsula, Shanxi, central and southern Hebei, and the Beijing—Tianjin—Hebei region;(2) There was a significant negative correlation between ENSO event intensity and precipitation in Beijing-Tianjin-Hebei; when the intensity increased, the precipitation decreased, and when it weakened, the precipitation increased; the intensity of ENSO events in the whole North China region was significantly positively correlated with the temperature; when the intensity increased, the temperature increased, and when the intensity decreased, the temperature decreased; among them, El Niňo had a tendency of temperature rise, and La Niňa had a tendency of temperature decrease. From the perspective of global change, the main causes of meteorological drought in North China were rapid urbanization and global warming.更多还原