摘要
干旱指数是评估干旱严重程度的重要指标.本文基于FastICA(Fast Independent Component Analysis)反演模式,利用GPS垂向位移反演了云南省2011—2020年的等效水高GPS-EWH(GPS Equivalent Water Height),并根据GPS-EWH、GRACE Mascon产品与自校正帕默尔干旱指数SCPDSI(Self-Calibrating Palmer Drought Severity Index)产品,分别计算了GPS干旱指数GPS-DSI(GPS Drought Severity Index)、GRACE干旱指数GRACE-DSI(GRACE Drought Severity Index)及归一化SCPDSI,用于定量分析云南省干旱时空分布特征.研究结果表明,在滇中、滇西北与滇西南地区GPS-DSI、GRACE-DSI及归一化SCPDSI具有较高相关性,因此在该地区GPS-DSI可作为分析干旱事件的补充数据.但在滇东南与滇东北地区,GPS-DSI与GRACE-DSI、归一化SCPDSI的相关性极差,通过分析GPS站点分布特征,其原因可能是滇东南与滇东北地区GPS站点空间分布稀疏,因此分析该区域干旱事件时主要参考GRACE-DSI与归一化SCPDSI.GPS-DSI、GRACE-DSI与归一化SCPDSI的结果表明,2011—2020年间发生了三次显著的干旱事件,其中2019—2020年特大干旱事件持续的时间最长,共持续约20个月.具体分析此次干旱事件的时空特征,2019年全区以中度干旱为主,2020年大部分地区以极端干旱为主,其中滇西南地区2020年为异常干旱.
Drought severity indices(DSI)are vital for assessing the severity of drought.Here,the equivalent water height(EWH)during 2011—2020 in Yunnan is determined by the GPS vertical displacements using the fast independent component analysis-based(FastICA)inversion strategy.Then the GPS-EWH,the GRACE Mascon products,and the self-Calibrating Palmer drought(SCPDSI)index products are used to calculate the GPS-DSI,the GRACE-DSI,and the normalized self-Calibrating Palmer drought index(SCPDSI-Z).These three indices are finally used to quantitatively analyze the spatiotemporal distribution features of drought in Yunnan Province.It is found that the GPS-DSI,GRACE-DSI,and SCPDSI-Z are highly correlated with each other in the central,southwestern,and northwestern Yunnan,indicating that GPS-DSI can be applied as supplementary data for analyzing drought events.The GRACE-DSI and SCPDSI-Z have poorly correlated with the GPS-DSI in southeastern and northeastern Yunnan,probably due to the sparse spatial distribution of the GPS stations.Thus,the GPS-DSI is not suitable for analyzing drought events in southeastern and northeastern Yunnan.The results of the GPS-DSI,GRACE-DSI,and SCPDSI-Z show three significant drought events during 2011—2020.Particularly,the extreme drought during 2019—2020 lasts the longest duration(~20 months).In this drought event,the whole province was dominated by moderate drought in 2019,and most areas of Yunnan were dominated by extreme drought in 2020,of which Southwest Yunnan was an abnormal drought in 2020.
作者
杨兴海
袁林果
姜中山
冯显杰
汤苗
李长海
YANG XingHai;YUAN LinGuo;JIANG ZhongShan;FENG XianJie;TANG Miao;LI ChangHai(Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu 611756,China;Institute of International Rivers and Eco-Security,Yunnan University,Kunming 650091,China)
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第8期2828-2843,共16页
Chinese Journal of Geophysics
基金
国家自然科学基金(42074021,41904015)资助。
关键词
GPS垂向位移
格林函数
陆地水储量
水文干旱
干旱指标
GPS vertical displacement
Green′s function
Terrestrial water storages
Hydrological drought
Drought indicator
