草业学报2016，Vol.25Issue(3)：1-8,8.DOI:10.11686/cyxb2015378
基于 NDVI 的藏北地区草地退化时空分布特征分析
Temporal and spatial distribution of grassland degradation in northern Tibet based on NDVI
摘要
Abstract
An expansive alpine grassland ecosystem dominates the landscape in Northern Tibet,and the status of this grassland has significant implications for the major Asian rivers,and for the climate and eco-environ-ment of Tibet and the wider region.The harsh natural environment and fragile ecosystem,together with in-creasing frequency and intensity of human activities such as pastoralism,and climate change,have resulted in increasing reports of degradation of the grassland ecosystem.We used vegetation cover as main indicator of eco-system health,and with remote sensing monitoring,calculated the grassland degradation index (GDI)and e-valuated grassland degradation in Northern Tibet from 2000 to 2010.The analysis was based on the Normalized Differential Vegetation Index (NDVI)data from the Advanced Very High-Resolution Radiometer (AVHRR) with a spatial resolution of 8 km from 1981 to 1985 and from Moderate Resolution Imaging Spectroradiometer (MODIS)with a spatial resolution of 0.25 km of 2000-2010.Then,we have analyzed the temporal and spatial distribution of grassland degradation in Northern Tibet from 2000 to 2010.It was found that grassland degra-dation in Northern Tibet was still severe.The GDI was 1.97 in 2010,near to seriously degraded status.The extremely seriously degraded and seriously degraded categories occupied 6.5% and 19.0% of the study area, respectively.The moderately and slightly degraded grassland categories accounted for 15.1% and 12.1%,re-spectively.Undegraded grassland occupied 41.8% of the total grassland area in 2010.The extent of extremely seriously degraded and seriously degraded categories was greatly increased in the data from 2000-2010,com-pared with the period from 1981 -1985.However,the increase in grassland degradation in Northern Tibet from 2000 to 2010 was slight,with the mean value of the GDI being 1.84 in 2010,representing a change from light degradation to moderate degradation in Northern Tibet from 2000 to 2010.关键词
草地退化/NDVI/植被盖度/藏北地区Key words
grassland degradation/NDVI/vegetation cover/northern Tibet引用本文复制引用
曹旭娟,干珠扎布,梁艳,高清竹,张勇,李玉娥,万运帆,旦久罗布..基于 NDVI 的藏北地区草地退化时空分布特征分析[J].草业学报,2016,25(3):1-8,8.基金项目
国家科技支撑课题（2012BAC01B02），国家自然科学基金项目（31170460）和西藏那曲地区与中国农业科学院合作项目资助。 （）
