Long‐term spatial and temporal variations of vegetative drought based on vegetation condition index in China. Issue 8 (10th August 2017)

• Record Type: Journal Article
• Authors: Liang, Liang; Sun, Qin; Luo, Xiang; Wang, Jiahui; Zhang, Lianpeng; Deng, Meixia; Di, Liping; Liu, Zhixiao
• Is Part Of: Ecosphere. Volume 8:Issue 8(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-08-10
• Subjects: anomaly index analysis -- drought -- Mann‐Kendall method -- trend analysis -- vegetation condition index (VCI); Ecology -- Periodicals; Ecology; Periodicals; 577.05
• DOI: 10.1002/ecs2.1919
• Languages: English
• ISSNs: 2150-8925

Abstract

Abstract: Information concerning the spatial and temporal characteristics of vegetative drought is essential for decision‐making and for many environmental and agricultural applications. This study presents a comprehensive spatio‐temporal analysis of vegetative drought conditions that used the vegetation condition index (VCI) data product obtained from NOAA/AVHRR (National Oceanic and Atmospheric Administration/Advanced Very High Resolution Radiometer) to reveal the vegetative drought patterns across China from 1981 to 2015. Considering the characteristics of VCI as drought indicators, multiple methods were designed for these analyses, including drought frequency analysis, trend analysis, anomaly index analysis, and Mann‐Kendall testing. The results show that China is a country with high vegetative drought frequency, but that most areas experienced only slight or moderate periods of drought. In addition, drought has obvious seasonal and geographical differences and occurs with greater frequencies in regions that are highly affected by monsoons such as the northern and southern regions—particularly in the spring and autumn. In contrast, vegetative drought frequencies in regions less affected by monsoons such as the Tibetan Plateau and the northwestern regions were much lower except in northern Sinkiang, eastern Inner Mongolia, and southern Tibet. During 1981–2015, the VCI had an increasing trend in most areas of China (except in the southern region, where it decreased), indicating a reduced frequency of vegetative drought throughout the country. Moreover, the trend was wavelike rather than a one‐way change and could be divided into four phases: (1) a slowly increasing phase from 1981 to 1990, (2) an intensively fluctuating phase from 1991 to 2000, (3) a steadily increasing phase from 2001 to 2010, and (4) a slowly decreasing phase after 2010. Mann‐Kendall analysis further suggested that upward trends of the VCI were more evident in spring and autumn than in summer and that both trends mutated in 1997. Specifically, the trend reached the 0.05 level of significance in the spring.