Combining gradual and abrupt analysis to detect variation of vegetation greenness on the loess areas of China  

作　　者：Panxing HE Zongjiu SUN Dongxiang XU Huixia LIU Rui YAO Jun MA 

机构地区：[1]Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology,College of Grassland and Environment Sciences,Xinjiang Agricultural University,Urumqi 830000,China [2]Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering,Institute of Biodiversity Science,Fudan University,Shanghai 200438,China [3]School of Earth and Environmental Sciences,University of Queensland,Queensland 4072,Australia [4]Hubei Key Laboratory of Critical Zone Evolution,School of Geography and Information Engineering,China University of Geosciences,Wuhan 430074,China

出　　处：《Frontiers of Earth Science》2022年第2期368-380,共13页地球科学前沿（英文版）

基　　金：This research was funded by the National Natural Science Foundation of China(Grant Nos.31760694 and 41601181).

摘　　要：The annual peak growth and trend shift of vegetation are critical in characterizing the carbon sequestration capacity of ecosystems.As the well-known area with the fastest vegetation growth in the world,the Loess Plateau(LP)lands find an enhanced greening trend in the annual and growing-season.However,the spatiotemporal dynamics of vegetation peak growth and breakpoints characteristics on time series still needs to be explored.Here,we performed tendency analysis to characterize recent variations in annual peak vegetation growth through a satellite-derived vegetation index(NDVI_(max),Maximum Normalized Difference Vegetation Index)and then applied breakpoint analysis to capture abrupt points on the time series.The results demonstrated that the vegetation peak trend had been significantly increasing,with a growth rate at 0.68×10^(-2)·a^(-1) during 2001-2018,and most pixels(70.81%)have a positive linear greening trend over the entire LP.In addition,about 83%of the breakpoint type on the monthly NDVI time series is a monotonic increase at the pixel level,and most pixels(57%)have detected breakpoints after 2010.Our results also showed that the growth rate accelerates in the northwest and decelerates in the southeast after the breakpoint.This study indicates that combining abrupt analysis with gradual analysis can describe vegetation dynamics more effectively and comprehensively.The findings highlighted the importance of breakpoint analysis for monitor timing and shift using time series satellite data at a regional scale,which may help stakeholders to make reasonable and effective ecosystem management policies.

关 键 词：vegetation greenness gradual trend BREAKPOINT BFAST algorithm the Loess Plateau area 

分 类 号：Q94[生物学—植物学]