地理科学进展 ›› 2009, Vol. 28 ›› Issue (3): 391-397.doi: 10.11820/dlkxjz.2009.03.010

• 土地利用变化 • 上一篇    下一篇

青藏高原植被覆盖变化的地域分异特征

于伯华1|吕昌河1|吕婷婷2,3|杨阿强1,4|刘闯1   

  1. 1. 中国科学院地理科学与资源研究所|北京 100101; 2. 北京师范大学资源学院|北京 100875;
    3. 地表过程与资源生态国家重点实验室 北京师范大学|北京 100875; 4. 中国科学院研究生院|北京 100049
  • 出版日期:2009-05-25 发布日期:2010-08-08
  • 作者简介:于伯华(1974-)|男|山东枣庄人|博士|助理研究员|研究方向:环境整治、土地利用。E-mail:yubh@igsnrr.ac.cn
  • 基金资助:

    国家科技攻关计划项目(2006BAC01A01-02)

Regional Differentiation of Vegetation Change in the Qinghai-Tibet Plateau

YU Bohua1|LU Changhe1|LU Tingting2,3|YANG Aqiang1,4|LIU Chuang1   

  1. 1. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
    2. Collage of Resources Science and Technology, Beijing Normal University, Beijing 100875, China;
    3. State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China;
    4. Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Online:2009-05-25 Published:2010-08-08

摘要:

植被的空间分布及其变化都具有明显的地域分异特征。本研究以1981-2006年间的GIMMS/NDVI产品为主要数据源,在地理信息系统技术的支持下,分别从植被空间分布、植被波动和植被变化等方面,探讨了青藏高原植被覆盖变化的水平地域分异特征。研究结果显示,1981-2006年间,雅鲁藏布江河谷区、错那县和墨脱县的西北部、柴达木盆地南缘、三江源地区的顶端和青海南山北麓等区域地表植被年际波动较大。反映区域植被盖度时间变化趋势的SLOPE值以及植被盖度,具有从南部、东南部向北、西北部“下降—上升—不变”的规律。植被盖度下降显著的区域主要分布在喜马拉雅山南麓和青海湖南部,其次是三江源中南部地区;植被没有明显变化的区域主要分布在藏北高原和柴达木盆地。植被指数显著上升的区域集中在雅鲁藏布江河谷区,植被指数明显上升区域主要分布在人迹罕至的唐古拉山和念青唐古拉山等山间盆地区,轻微上升的区域分散在明显改善区的周围。依据SLOPE值的空间分异特征将整个高原划分为4个一级区:帕米尔高原植被指数上升区、藏北高原—阿里高原—柴达木盆地植被指数稳定区、高原中部—雅鲁藏布江中上游河谷植被指数上升区和三江源—横断山区植被指数下降区。

关键词: NDVI;植被变化;区域分异;青藏高原

Abstract:

The spatial distribution and change of vegetation have an obvious characteristic of regional differentiation, which is always affected by global climate change and local human activities. This study explores regional differentiation characteristics of vegetation changes including the spatial distribution and annual variation of vegetation in the Qinghai-Tibet Plateau using 1981-2006 time-series GIMMS/NDVI as the main data source. The results showed that the vegetation coverage was the highest in the Metok and Tsona counties on the southern slope of the Himalayas, and next in the junction area of three provinces of Qinghai, Sichuan and Tibet, while it was much lower in the northern Qinghai-Tibet Plateau, the Qaidam Basin and Ali Plateau. From 1981 to 2006, the mean annual NDVI in the whole plateau showed an increasing trend, reflecting an improvement of vegetation coverage. The standard deviation(SD) of NDVI change was generally decreased, indicating a small difference among different areas and different vegetation types. The following areas, located on the fringe of all kinds of ecotone, have a lager value of SD, i.e., the Yalung Zangbo Valley, the northwestern part of Metok and Tsona counties, southern margin of the Qaidam Basin, head of the Source Areas of the Three Rivers and northern slope of the Nanshan Mountain in Qinghai; these places should be given more attention from scientists, governments of various levels and other stakeholders. SLOPE was one of the widely used indicators reflecting long time trends of vegetation coverage change. The annual values of SLOPE had a spatial distribution trend from decline to increase and then stable (no change) from south-east  to north-west. Regionally,  the  vegetation coverage had a significant decline on the southern slope of the Himalayas and the southern part of Qinghai, a moderate decline in middle and southern part of the SATR and a slight decline in its northern part and Ali Plateau. No significant vegetation changes happened in the Northern Tibetan Plateau and the Qaidam Basin, which accounted for 40% of the total area. Vegetation was significantly improved in the Yalung Zangbo Valley, and the intermontane basins of the Tanggula Ranges and Nyantsentanglha Mountains. Based on the spatial difference of SLOPE values, the plateau was divided into four regions: Ⅰ) the Pamirs Region, with an increasing vegetation index; Ⅱ) the Northern Tibetan Plateau-Qaidam Basin Region, with a stable vegetation index; Ⅲ) the Central Tibetan an Plateau-the Upper and Middle Reaches of the Yalung Zangbo River Region, with an increasing  vegetation  index,  and Ⅳ)  the  Source  Areas of  the Three Rivers-the Hengduan Mountains Region, with an decreasing vegetation index. The paper did not give a detailed description of the reasons for vegetation change in the Qinghai-Tibet Plateau due limited space. However, under the background of NDVI increase regarding the plateau as a whole, vegetation change in Region Ⅳ should be given special attention because of the controllable human activities.

Key words: NDVI;vegetation change;regional differentiation;Qinghai-Tibet Plateau