基于植被健康指数的中国干旱动态变化及其对大气环流因子的响应研究
Dynamic Changes of Drought Based on Vegetation Health Index and Its Response to Atmospheric Circulation Factors in China
贾敏敏 1王飞 2徐明立 1宋一鸣1
作者信息
- 1. 河南省济源水文水资源测报分中心,河南 济源 459099
- 2. 华北水利水电大学水利学院,河南 郑州 450046
- 折叠
摘要
为明晰中国干旱时空变化特征及大气环流因子对干旱的驱动机制,基于全国 1982～2020 年遥感植被健康指数(VHI)数据,采用极点对称模态分解方法(EPSMD)分析干旱动态变化特征,结合像元尺度趋势检验方法(PMK)挖掘干旱趋势特征,运用交叉小波技术揭示干旱与大气环流因子间响应关系.结果表明,1982～2020 年全国干旱整体呈减轻趋势;研究时段内干旱最严重的年份为 1989 年,该年度夏季干旱程度较轻,冬季干旱相对较重,VHI均值分别为 0.47、0.38;春季、夏季、秋季和冬季 VHI 的趋势特征值分别为 0.70、0.48、0.59、0.48,春季干旱的减缓趋势最为明显;厄尔尼诺和南方涛动(ENSO)对干旱的影响最显著.研究结果可为中国干旱成因机制的进一步研究提供参考.
Abstract
In order to clarify the spatiotemporal variation characteristics of drought and the driving mechanism of at-mospheric circulation factors on drought in China,based on the remotely sensed vegetation health index(VHI)data from 1982 to 2020,the extreme-point symmetric mode decomposition(EPSMD)was used to analyze the dynamic variations of drought.The pixel-scale Mann-Kendall(PMK)was applied to identify the drought trend characteristics,and the cross wavelet technique was adopted to reveal the response relationship of drought to atmospheric circulation factors.The re-sults indicate that the drought showed an overall decreasing trend during 1982-2020 in China;The most severe drought during the research period occurred in 1989,with a relatively mild drought in summer(VHI=0.47)and a relatively se-vere drought in winter(VHI=0.38);The trend characteristic values of VHI in spring,summer,autumn,and winter were 0.70,0.48,0.59,and 0.48,and the most obvious drought mitigation trend occurred in spring;The El Niño-Southern Oscillation(ENSO)had the most significant impact on drought.The research results can provide reference for further research on the causes and mechanisms of drought in China.
关键词
干旱/植被健康指数/大气环流因子/交叉小波/中国Key words
drought/vegetation health index/atmospheric circulation factor/cross wavelet/China引用本文复制引用
基金项目
中国水科院开放基金项目(IWHR-SKL_KF202207)
国家自然科学基金项目(52179015)
出版年
2024
NETL
NSTL
万方数据