长江流域极端水文气象事件时空变化特征及其对植被的影响  

Spatial-temporal variabilities of the contrasting hydrometeorological extremes and the impacts on vegetation growth over the Yangtze River basin

作　　者：金佳鑫 肖园园 金君良 朱求安 雍斌[1,4] 季盈盈 JIN Jiaxin;XIAO Yuanyuan;JIN Junliang;ZHU Qiuan;YONG Bin;JI Yingying(School of Hydrology and Water Resources,Hohai University,Nanjing 210024,China;National Earth System Science Data Center,National Science&Technology Infrastructure of China,Beijing 100101,China;Yangtze Institute for Conservation and Development,Nanjing 210098,China;State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水文水资源学院,江苏南京210024 [2]国家地球系统科学数据中心,北京100101 [3]长江保护与绿色发展研究院,江苏南京210098 [4]河海大学水文水资源与水利工程科学国家重点实验室,江苏南京210098

出　　处：《水科学进展》2021年第6期867-876,共10页Advances in Water Science

基　　金：国家重点研发计划资助项目(2018YFA0605402);国家自然科学基金资助项目(41971374)。

摘　　要：利用1982—2015年高时空分辨率地面气象再分析数据,识别以降水和大气饱和水气压差(VPD)为指标的极端干旱(Dry-VPD和Dry-PRE)和极端湿润(Wet-VPD和Wet-PRE)事件,分析其年际变化趋势;结合归一化植被指数(NDVI),探讨植被与不同极端事件发生频数的相关关系与差异。结果表明:除Wet-VPD外,Dry-VPD、Wet-PRE和Dry-PRE总体呈上升趋势,特别是1998年以后Dry-VPD在长江上、下游流域显著增加;长江流域植被对极端干旱事件的敏感性(以负相关为主)高于极端湿润事件,且长江上游植被对Dry-VPD敏感,而中下游植被对Dry-PRE敏感。综上,长江流域极端干旱事件日趋严重,相较于降水干旱限制植被生长的传统认识,本研究指出在长江上游地区大气干旱对植被的负效应更加明显。This research aimed to determine the temporal and spatial variations of the hydrometeorological extremes,and their impacts on vegetation across the Yangtze River basin(YRB).First,a meteorological reanalysis dataset with high spatial and temporal resolution from 1982 to 2015 was used to identify and analyze the annual variation trends of the extreme drought(Dry-PRE or Dry-VPD)and extreme wetness(Wet-PRE or Wet-VPD),based on precipitation and vapor pressure deficit(VPD),respectively.Subsequently,the responses and sensitivities of vegetation growth(indicated by normalized difference vegetation index,NDVI)to the hydrometeorological extremes were explored.The results showed that the frequencies of Dry-VPD,Wet-PRE and Dry-PRE generally increased while that of Wet-VPD decreased during the study period.Particularly,Dry-VPD increased significantly in the upstream and downstream of the YRB after 1998.The vegetation across the YRB was more sensitive to extreme drought(mainly with a negative correlation)than extreme wetness.Moreover,the vegetation growth in the upstream was sensitive to Dry-VPD,while that in the midstream and downstream was sensitive to Dry-PRE.To summarize,this study found that extreme drought was on the rise across YRB.Different from the general notion that precipitation limits vegetation growth,our study indicates that vegetation in the upper reach of the YRB is more negatively impacted by atmospheric drought.

关 键 词：极端水文气象事件 饱和水气压差 干旱 湿润 归一化植被指数 长江流域 

分 类 号：P426.614[天文地球—大气科学及气象学]