Since arid and semi-arid regions are sensitive and vulnerable to both climate change and human activities,studying the spatiotemporal evolution characteristics of droughts accelerates understanding disaster mechanism.The Hedong region(HDR)in Gansu Province is a typical arid and semi-arid region,which depends on precipitation to maintain agricultural production.Meteoro-logical and hydrological droughts are detected based on the standardized precipitation index and the standardized runoff index.The results show that:(1)Meteorological droughts in HDR mostly occur from spring to summer in the Longdong area,with a dura-tion of less than three months.(2)Hydrological droughts last longer compared to meteorological droughts and may occur at multi-year scales.(3)The propagation between meteorological and hydrological droughts is varied in different seasons.There is almost no lag time in spring and summer,about one month in autumn and four months in winter.(4)The areas affected by drought di-saster most are the Longzhong and Longdong regions.This study could provide scientific guidance for drought early-warning and prevention in arid and semi-arid regions.
关键词
气象干旱/水文干旱/历史干旱灾害/干旱半干旱区
Key words
meteorological drought/hydrological drought/historical drought disaster/arid and semi-arid regions
维普
万方数据