明代陕南地区旱灾时空特征分析

The research on characteristics of the drought disaster in Southern Shaanxi in Ming Dynasty

通过对历史文献资料的搜集和整理,对明代自公元1369年到1644年的276年间陕南地区旱灾在等级、年际、季节和空间上的分布规律和特征及其成因进行了研究。统计分析结果显示,该地区以轻度、中度旱灾为主,发生次数占旱灾发生总数的43%、28%,大旱灾和特大旱灾发生频率分别占旱灾总数的22%和7%;明代陕南地区洪涝灾害共发生112次,平均每2.46年发生一次。根据Hurst指数显示这一时期旱灾整体上呈一个逐渐增强的状态。明代多干旱灾害发生,这主要与气候的异常和降水的变率有关;旱灾具有明显的季节性特征,以春旱和夏旱最多,分别占旱灾总数的30%和45%,其次为秋旱和冬旱。在空间上旱灾主要发生在商洛地区,汉中地区旱灾较少,这主要是受地形的影响。

Through the collection and reorganization to the historical document materials, the grades, the annual, the seasonal and the spatial distribution rules and the characteristics and the origin of the drought disasters in Ming Dynasty from 1369 to 1644 in South Shaanxi area Were studied. The results showed that the mild and moderate drought disaster occupied the total drought disaster by 43% and 28%, the serious drought and the extraordinary drought disasters accounted for the total drought separately 22% and 7% ; The Hurst index demonstrated that in this period the drought disaster showed increasing trend. The occurrence of drought disaster in Ming Dynasty was mainly related with the climate. The drought accurred mainly in the spring and summer. The drought mainly occurred in the Shangluo area.