文献类型：期刊文献

英文题名：Effects of multi-time scales drought on vegetation dynamics in Qaidam River Basin, Qinghai-Tibet Plateau from 1998 to 2015

作者：Sun, Yongxiu[1] Liu, Shiliang[1] Dong, Yuhong[2] Dong, Shikui[1] Shi, Fangning[1]

第一作者：Sun, Yongxiu

通信作者：Liu, SL[1]

机构：[1]Beijing Normal Univ, Sch Environm, State Key Lab Water Environm Simulat, Beijing 100875, Peoples R China;[2]Chinese Acad Forestry, Res Inst Forestry, Key Lab Tree Breeding & Cultivat, State Forestry Adm, Beijing 100091, Peoples R China

年份：2020

卷号：141

期号：1-2

起止页码：117-131

外文期刊名：THEORETICAL AND APPLIED CLIMATOLOGY

收录：;Scopus(收录号：2-s2.0-85083062233);WOS:【SCI-EXPANDED(收录号:WOS:000524393400001)】；

基金：The work was supported by the second scientific expedition to the Qinghai-Tibet Plateau (No. 2019QZKK0405-05), National Key Research and Development Project (No. 2016YFC0502103) and National Natural Sciences Foundation of China (No. 41571173).

语种：英文

外文关键词：Drought; NDVI; SPEI; Qaidam River Basin

摘要：Quantifying drought variations at multi-time scales is important to assess the potential impacts of climate change on terrestrial ecosystems, especially vulnerable desert grassland. Based on the normalized difference vegetation index (NDVI) and standardized precipitation evapotranspiration index (SPEI), we assessed the influences of different time-scales drought (SPEI-3, SPEI-6, SPEI-12, SPEI-24, and SPEI-48 with 3, 6, 12, 24, and 48 months, respectively) on vegetation dynamics in the Qaidam River Basin, Qinghai-Tibet Plateau. Results showed that (1) temporally, annual and summer NDVI increased, while spring and autumn NDVI decreased from 1998 to 2015. Annual, spring, and summer SPEI increased, and autumn SPEI decreased. (2) Spatially, annual, spring, summer, and autumn NDVI increased in the periphery of the Basin, with 45.98%, 22.68%, 43.90%, and 30.80% of the study area, respectively. SPEI showed a reverse variation pattern with NDVI, with an obvious decreasing trend from southeast to northwest. (3) Annual vegetation growth in most areas (69.53%, 77.33%, 86.36%, 90.19%, and 85.44%) was correlated with drought at all time-scales during 1998-2015. However, high spatial and seasonal differences occurred among different time-scales, with the maximum influence in summer under SPEI24. (4) From month to annual scales, NDVI of all land cover types showed higher correlation to long-term drought of SPEI24 or SPEI48. Vegetation condition index (VCI) and SPEI were positively correlated at all time-scales and had a more obvious response in summer. The highest correlation was VCI of grassland (June-July) or forest (April-May, August-October) and SPEI48. This study contributes to exploring the effect of drought on vegetation dynamics at different time scales, further providing credible guidance for regional water resources management.