Vegetation Pattern and Spatial Distribution of NDVI in the Yarlung Zangbo River Basin of China
Received date: 2014-10-23
Revised date: 2014-11-25
Online published: 2015-01-20
The range of elevation is over 7 000 meters a.s.l. in the Yarlung Zangbo River Basin, where climate conditions are very complex and types of ecosystem are diverse, the spatial pattern of vegetation distribution changes greatly. Based on 1:1 000 000 vegetation map, SPOT_VEGETATION NDVI data sets and digital elevation model (DEM), the dominant vegetation types and theirs spatial distribution in the basin were extracted and analyzed quantitatively with the help of Geographical Information System (GIS). Thereafter, combined with the elevation gradients and climate conditions in different wide valley sections of the basin, we discussed therelationship between vegetation pattern and spatialdistribution of NDVI. (1) There are 11 vegetation type groups (including coniferous forest, broad-leaved forest, bush, desert, grassland, meadow, alpine vegetation, etc.) and 25 vegetation types in the basin. The numbers of vegetation types in the Milin wide valley are the most, while the diversity of vegetation types among Shannan wide valley, Shigatse wide valley and Maquanhe wide valley showed a decrease trend totally from downstream to upstream. (2) The numbers of vegetation type groups and vegetation types both increase at first, and then decreased with the increase of altitude, of which, 3000-4 000 m and 4 000-5 000 m are the most, the vertical zonality of vegetation pattern in the basin is remarkable. (3) The spatial consistency between vegetation pattern and NDVI change isgood in the basin. The greatest NDVI value of coniferous forest, broad-leaved forest and grass vegetation are all in October-December, while the greatest and the least NDVI value of the other 8 vegetation type groups were all in July-September and January-March, respectively. The altitude of 3 000 m is a turning point at which vegetation pattern on the basin scale ofthe Yarlung Zangbo River change significantly.
Key words: vegetation types; NDVI; spatial distribution; GIS; Qinghai-Tibet Plateau
Chen Bin , Li Haidong , Cao Xuezhang , Shen Weishou , Jin Hang . Vegetation Pattern and Spatial Distribution of NDVI in the Yarlung Zangbo River Basin of China[J]. Journal of Desert Research, 2015 , 35(1) : 120 -128 . DOI: 10.7522/j.issn.1000-694X.2014.00170
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