地理研究 ›› 2017, Vol. 36 ›› Issue (11): 2129-2140.doi: 10.11821/dlyj201711008

• 羌塘高原研究 • 上一篇    下一篇

青藏铁路(格拉段)修建对沿线植被生态系统及其弹性的影响

李延森(), 周金星, 吴秀芹()   

  1. 北京林业大学水土保持学院,水土保持国家林业局重点实验室,北京 100083
  • 收稿日期:2017-05-20 修回日期:2017-09-27 出版日期:2017-11-20 发布日期:2017-11-20
  • 作者简介:

    作者简介:李延森(1991- ),男,云南西双版纳人,硕士,研究方向为3S技术在资源环境中的应用。E-mail:lys_zmz@126.com

  • 基金资助:
    林业公益性行业科研专项经费资助项目(201504401)

Effects of the construction of Qinghai-Tibet railway on the vegetation ecosystem and eco-resilience

Yansen Li(), Jinxing Zhou, Xiuqin Wu()   

  1. School of Soil and Water Conservation, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
  • Received:2017-05-20 Revised:2017-09-27 Online:2017-11-20 Published:2017-11-20

摘要:

青藏铁路穿越区生态脆弱,铁路修建会对沿线区域植被造成破坏。为客观评价铁路修建对沿线植被生态系统的影响,基于1995-2014年覆盖青藏铁路沿线10 km范围的212景Landsat TM/ETM+影像,利用Fmask算法结合STARFM模型去除云、阴影及条带,得到30 m NDVI数据,最后通过一元线性回归和序贯t检验,对10 km区域的NDVI时空演变、稳态转变以及各植被生态系统弹性特征进行分析。结果表明:① 20年间,青藏铁路沿线10 km范围内NDVI“稳中有升”,与青藏高原NDVI变化相符,空间上呈“南高北低”的分布特征;北部区域NDVI变化相对稳定,NDVI下降区域集中在那曲—当雄。② 将沿线10 km范围划分为7个缓冲区,发现铁路修建及附属设施占地对植被的破坏作用最明显,集中在青藏铁路两侧100 m内,并对青藏铁路沿线1 km范围内的植被生长有抑制作用,作用程度与铁路距离成反比。③ 城市及周边、河谷和牧区等人类活动较多的区域NDVI稳态转变最剧烈;各生态系统弹性大小依次为:裸地>荒漠>高山植被>草原>草甸>灌丛>湿地>农田。湿地是最易受外界干扰而改变的类型,是保护的重点类型,而荒漠和裸地生态系统弹性最高,最不易改变,也是生态恢复的难点。

关键词: 生态弹性, 青藏铁路, 植被, 年际变化

Abstract:

The Qinghai-Tibet Railway is constructed in an ecologically fragile area, and thus, the railway construction will impact the ecosystem around inevitably. To evaluate the effects of railway objectively, we carried out a study on the basis of 212 Landsat TM/ETM+ images captured in 1995-2014 during the peak period of vegetation growth along the railway and within a 10-km range of it. The Fmask method and the spatial and temporal adaptive reflectance fusion model (STARFM) were used to remove the cloud, shadow, and gap in those images to acquire clear 30-m NDVI images. Then, the linear regression and sequential T test of regime shifts (STARS) were used to analyze the spatial-temporal change, regime shift, and eco-resilience characteristics of the NDVI in the study area. Results show that: (1) the NDVI of the study area grew slightly in 20 years, similar to the NDVI growth in the whole Tibetan Plateau. The NDVI along the railway is higher in the north than that in the south. The NDVI in the northern part changes slightly, and the area of decline is concentrated in Naqu-Damxung; (2) The railway construction exerts no apparent effects on the ecological system. Both sides of the railway within the range of 1 km are influenced by the railway construction. Most significant damages to vegetation cover resulted by the railway and ancillary facilities construction are within the range of 100 m along the railway. (3) Regime shift and eco-resilience focused in the city and the surrounding valley and pastoral areas caused most dramatic changes in the region. The detection results of different ecosystem types of eco-resilience show that the eco-resilience order is as follows: bare > desert > alpine > grassland > meadow > shrub > wetland > farmland. The wetland ecosystem is the most vulnerable environment and the main type of ecosystem protection. In addition, restoring vegetation is most difficult in the desert ecosystem and bare ground.

Key words: eco-resilience, Qinghai-Tibet railway, vegetation, interannual variation