基于日气象干旱综合指数的56a西南地区干旱时空分布特征

Spatial and Temporal Distribution Characteristics of Drought in Southwest China in 56a Based on Daily MCI

摘要: 本文依据2017年修订的《气象干旱等级》国家标准，计算了西南地区86个气象站点的逐日MCI指数，利用ArcGIS进行空间插值，主要分析了整个西南地区以及重庆、四川、云南、贵州四省市56年不同季节的干旱特征。结果表明：云南大部，四川西部以及重庆北部是西南干旱的多发区，四川中部，贵州大部干旱日数相对较少；四川和云南地区干旱主要出现在春、冬季节，重庆地区干旱主要发生在夏末秋初，贵州地区的干旱主要发生在夏季。1962~2017年西南地区干旱日数总体呈增加趋势，重庆增加趋势最强，为0.97 d/a。近56a来，秋旱发生的频率最高，云南省的干旱强度最高，而贵州省最小。

Abstract: According to the national standard of meteorological drought classification revised in 2017, the daily MCI index of 86 meteorological stations in Southwest China was calculated, and the spatial interpolation was carried out by ArcGIS, mainly analyzing the drought characteristics of the whole southwest region and Chongqing, Sichuan, Yunnan and Guizhou provinces in 56 years. The results show that most of Yunnan, the west of Sichuan and the north of Chongqing are drought prone areas in Southwest China, while the number of drought days in Central Sichuan and most of Guizhou is relatively small; the drought in Sichuan and Yunnan mainly occurs in spring and winter, the drought in Chongqing mainly occurs in late summer and early autumn, and the drought in Guizhou mainly occurs in summer. From 1962 to 2017, the number of dry days in Southwest China showed an increasing trend, and Chongqing showed the strongest increasing trend, which was 0.97 d/a. In recent 56 years, the frequency of autumn drought is the highest, the intensity of drought is the highest in Yunnan Province, and the lowest in Guizhou Province.