摘要
基于Google Earth Engine(GEE)云平台和Landsat系列遥感影像,以归一化植被指数(NDVI)和增强型植被指数(EVI)及其植被绿度线作为指标,分析了1987~2020年黄土高原生长季植被绿度以及植被绿度线推移的时空演变特征.结果表明:1987~2020年黄土高原生长季NDVI和EVI年均增速分别为0.0042a^(-1)(P<0.01)和0.0023a^(-1)(P<0.01),2000年后的平均增速是2000年前的3~4倍;空间分布上,NDVI和EVI变化趋势以显著上升和极显著上升为主,面积占比分别为78.78%和69.21%;1987~2020年黄土高原植被绿度线VGLNDVI和VGLEVI分别以5.52和4.59km/a的速率向北推移;1987~2020年VGLNDVI和VGLEVI分别平均北移173.93和131.62km,北移量变化主要发生在2005~2010年,北移量最大区域分布在陕西榆林和延安地区、山西西北部、内蒙古中南部等黄土高原中北部区域,最大北移距离分别达到532.12和471.57km.
The temporal and spatial evolution patterns of the vegetation greenness index and its spatial distribution in the Loess Plateau hold significant scientific importance in gaining comprehensive insights into the dynamic changes of vegetation and assessing the effectiveness of ecological restoration.Although previous studies have explored the factors influencing spatiotemporal variations in vegetation greenness,the limited spatial resolution of remote sensing products poses challenges in capturing fine-scale characteristics and dynamic shifts in vegetation greenness lines.In the study,the Google Earth Engine(GEE)cloud platform,combined with a series of Landsat remote sensing images,is used to calculate the Normalized Difference Vegetation Index(NDVI),Enhanced Vegetation Index(EVI),along with their Vegetation Greenness Lines,as indicators to characterize the spatiotemporal evolution of vegetation greenness during the growing season on the Loess Plateau from 1987 to 2020.The results show that the annual average growth rates of NDVI and EVI in the Loess Plateau were 0.0042a-1(P<0.01)and 0.0023a-1(P<0.01)from 1987 to 2020,respectively.Notable,the average growth rates after the year 2000 were approximately three to four times higher than those observed before 2000.In terms of spatial distribution,the trends in NDVI and EVI predominantly exhibited significant and highly significant increases,with respective area percentages of 78.78%and 69.21%.Over the period from 1987 to 2020,the vegetation greenness lines VGLNDVI and VGLEVI exhibited a northward movement in the Loess Plateau at rates of 5.52 and 4.59 km/year,respectively.Over the same period,the average northward movements for VGLNDVI and VGLEVI were 173.93km and 131.62km,respectively.The most significant northward shift was primarily observed between 2005 and 2010,with the largest movement of the VGLNDVI and VGLEVI occurring in the Yulin and Yan'an areas of Shaanxi Province,northwest Shanxi Province,and central and southern Inner Mongolia,reaching maximum distances of 532.12km and 471.57km,respectively.
作者
谢佩君
宋小燕
孙文义
穆兴民
高鹏
XIE Pei-jun;SONG Xiao-yan;SUN Wen-yi;MU Xing-min;GAO Peng(Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University,Yangling 712100,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第12期6518-6529,共12页
China Environmental Science
基金
国家自然科学基金项目(42177328,42330506)
中国科学院“西部青年学者”(XAB2022YW02)
中央高校基本科研业务费专项资金资助(2023HHZX001)。
关键词
植被指数
植被绿度线
GEE
黄土高原
vegetation index
vegetation greenness line
GEE
Loess Plateau
