Monitoring the spatio-temporal dynamics of the wetland vegetation in Poyang Lake by Landsat and MODIS observations

	Monitoring the spatio-temporal dynamics of the wetland vegetation in Poyang Lake by Landsat and MODIS observations
	Mu, Shaojie; Li, Bing; Yao, Jing; Yang, Guishan; Wan, Rongrong; Xu, Xibao
刊名	SCIENCE OF THE TOTAL ENVIRONMENT
	2020
卷号	725
英文摘要	Poyang Lake, the largest freshwater lake of China, provides critical ecological functions for water circulation and biodiversity conservation as a dynamic wetland system. However, recent climate change and human activities exerted strong pressures on this ecosystem. In this paper, we applied object-based image analysis (OBIA) and RadomForests (RF) classifier to ten Landsat images to examine the land cover composition and its change during 1987-2017 low water season at Poyang Lake. NDVI time series (2000-2017) derived from MODIS imagery was used to document the changes of vegetation growth status. To investigate the potential drivingmechanismof the inundation patterns, we differentiated the spatial-temporal changes of vegetation coverage and NDVI accumulation on eight elevation bands. Major result indicates that the vegetation area increased by 15.5% of the lake area during 1987-2017. A much faster-increasing rate (58.0 km(2) year(-1)) can be observed during 2001-2009 as compared to that of the overall study period (18.4 km(2) year(-1)). Analysis of NDVI accumulation showed that 42.1% of the lake's area displayed a significant increasing trend during 2000-2017. Spatially, the increase of vegetation area and NDVI accumulation mainly took place in the 11-12 m elevation band in the lower lake center. Early dry season and prolonged exposure period after the operation of Three Gorges Dam(TGD) was themajor reason for the spatio-temporal evolution of the wetland vegetation in Poyang Lake. The Lake'swater level started to fall below 12 m before 9th November might cause a boost of vegetation growth in the low lake center, and in turn, triggering xerophilization for the vegetation in the highlands and a shift in foraging patterns ofwaterbirds due to phenology variations. The findings of this study provide a clear reference for sustaining the inter-annual stability of the ecosystem by controlling the depth of water in the lake. (C) 2020 Published by Elsevier B.V.
内容类型	期刊论文
源URL	[http://159.226.73.51/handle/332005/20131]
专题	中国科学院南京地理与湖泊研究所
推荐引用方式 GB/T 7714	Mu, Shaojie,Li, Bing,Yao, Jing,et al. Monitoring the spatio-temporal dynamics of the wetland vegetation in Poyang Lake by Landsat and MODIS observations[J]. SCIENCE OF THE TOTAL ENVIRONMENT,2020,725.
APA	Mu, Shaojie,Li, Bing,Yao, Jing,Yang, Guishan,Wan, Rongrong,&Xu, Xibao.(2020).Monitoring the spatio-temporal dynamics of the wetland vegetation in Poyang Lake by Landsat and MODIS observations.SCIENCE OF THE TOTAL ENVIRONMENT,725.
MLA	Mu, Shaojie,et al."Monitoring the spatio-temporal dynamics of the wetland vegetation in Poyang Lake by Landsat and MODIS observations".SCIENCE OF THE TOTAL ENVIRONMENT 725(2020).