地理研究

地理研究 ›› 2006, Vol. 25 ›› Issue (4): 587-595.doi: 10.11821/yj2006040004

• 论文 • 上一篇    下一篇

基于遥感的民勤绿洲植被覆盖变化定量监测

高志海1, 李增元1,2, 魏怀东1, 丁锋2   

  1. 1. 中国林业科学研究院资源信息研究所林业遥感与信息技术国家林业局重点实验室,北京100091;
    2. 甘肃省治沙研究所,甘肃武威733000
  • 收稿日期:2005-08-21 修回日期:2006-03-20 出版日期:2006-08-15 发布日期:2006-08-15
  • 作者简介:高志海(1963-),男,内蒙古太卜寺旗人,研究员,博士。主要从事土地退化(荒漠化)遥感评价与 监测方面的研究。
  • 基金资助:

    国家科技攻关项目(2005BA517A07);国家自然科学基金项目(30100145)

Quantitative monitoring of vegetation cover change by using remotely sensed data over Minqin Oasis,Gansu

GAO Zhi-hai1, NI Shao-xiang1,2, LI Zeng-yuan1, WEI Huai-dong2, DING Feng2   

  1. 1. The Research Institute of Forest Resources Information Techniques,Chinese Academy of Forestry,Key Laboratory of Foresty Remote Sensing and Information Technology,State Forestry Administration,Beijing 100091,China;
    2. Gansu Desert Control Research Institute,Wuwei 733000,Cnina
  • Received:2005-08-21 Revised:2006-03-20 Online:2006-08-15 Published:2006-08-15

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104 | 14

摘要：

基于混合像元条件下的TM影像植被覆盖度遥感反演,定量研究了甘肃省民勤绿洲1987年至2001年植被覆盖时空变化的规律与特点。结果表明,15年中,民勤绿洲的植被覆盖发生了很大的变化,农田植被(耕地)面积增加了53.11%,而中、高盖度植被的面积却减少了25.21%,这对民勤绿洲的长久生态安全构成了严重的威胁。民勤绿洲植被覆盖变化的空间转化过程复杂,但总体属于开垦—植被退化型。15年中因开垦和植被退化而损失的中、高盖度植被达42204.81hm2,占原面积的81.73%,而且损失的主要是绿洲边缘的防风固沙植被,其中因开垦损失的面积为18776.08hm2,占损失面积的44.5%。超采地下水引起的地下水位快速下降是导致绿洲边缘天然和人工灌丛植被退化的主要原因。控制开垦并培育相对稳定的灌丛型植被,应该是研究区生态环境建设的重点。

关键词: 民勤绿洲, 遥感, 植被覆盖变化, 开垦, 植被退化

Abstract:

The spatial and temporal changes of vegetation cover from 1987 to 2001 over Minqin Oasis,Gansu Province,were studied quantitatively based on the retrieval of vegetation coverage from remotely sensed TM images in the situation of mixed pixels. The result of the study shows that the vegetation cover over Minqin Oasis has greatly changed since 1987,with the increase of the area of the cultivated vegetation（farmlands） by 53.11% and decrease of the area of the medium and high cover vegetation by 25.11%,which indicates that the bush belt around the Oasis is fading away with the constant increase of cultivated vegetation and constant decrease of medium and high cover vegetation,and the long-term ecological security of the Oasis is being threatened severely.The spatial transform processes of vegetation cover in Minqin Oasis are complicated.The spatial transform process for whole Oasis is categorized in a type of reclamation and vegetation degradation,and there are differences for spatial transform processes of vegetation cover among diverse sub-areas of the Oasis,categorized in one type of reclamation and vegetation degradation in the central and southern parts,and another type of vegetation rehabilitation and reclamation in the northern part.The main reasons for the loss of medium and high cover vegetation are reclamation of desertified lands and vegetation degradation.About 42204.81hm2of medium and high cover vegetation lost during the 15 years due to over-reclamation and vegetation degradation in Minqin Oasis,accounting for 81.73% of the original area.The lost vegetation covers are mainly wind protecting and sand binding plants on the edges of the Oasis.The lost vegetation area is larger than the rehabilitated area of vegetation of the corresponding period of time.The lost area of medium and high cover vegetation by reclamation reaches 18776.08hm2,accounting for 44.5% of the total lost area.The decline of groundwater table resulted in by over pumping of groundwater for irrigation is the main cause for vegetation degradation,and the observable rehabilitation of halophytic vegetation in the northern part of the Oasis was probably related to the drastic drop of groundwater table.Controlling reclamation and breeding the steady-going bush vegetation should be the key target for eco-environmental construction in Minqin Oasis.

Key words: Minqin Oasis, remote sensing, vegetation cover change, reclamation, vegetation degradation