基于CI指数的江苏省近50 年干旱的时空分布规律

根据江苏省54 个气象台站1960-2009 年实测气象资料，利用气象干旱复合指数(compositeindex, CI) 对江苏省近50 年的干旱特征进行了时空分析。通过计算各站历年逐日的CI 指数值，统计近50 年各站点出现的干旱过程，分析江苏省各地区干旱发生的频率、范围和强度，揭示了江苏省干旱发生的时空分布规律。研究结果表明：(1) 江苏省全年和各季干旱发生频率都是北高南低，四季中，冬旱发生频率最高，夏旱发生频率最低，秋旱南北差异不显著。(2) 冬季江苏省干旱大范围发生的年份最多，夏季最少；近50 年来，全年和四季干旱覆盖范围的线性变化趋势不明显。(3) 这50 年中，江苏省逐年干旱持续日数和干旱强度虽然存在着明显的年际波动，但线性变化趋势不明显。(4) 江苏省各等级干旱日数总体上呈现冬季多夏季少、北部多南部少的规律。

Temporal and Spatial Patterns of Droughts for Recent 50 Years in Jiangsu Based on Meteorological Drought Composite Index

In this paper, the observed meteorological data of 54 meteorological stations from 1960 to 2009 in Jiangsu Province of China were collected and a composite index (CI) of meteorological drought was used to analyze the temporal and spatial characteristics of droughts in the province. Based on the daily CI values of each station in the 50 years, the drought processes of each station were confirmed one by one and the occurrence frequencies, scopes and severities of the meteorological droughts were computed and ...