地理学报 ›› 2008, Vol. 63 ›› Issue (4): 364-376.doi: 10.11821/xb200804001

• 土地利用 •    下一篇

近30 年来青海三江源地区草地退化的时空特征

刘纪远, 徐新良, 邵全琴   

  1. 中国科学院地理科学与资源研究所, 北京100101
  • 收稿日期:2007-10-23 修回日期:2007-12-24 出版日期:2008-04-25 发布日期:2010-08-04
  • 作者简介:刘纪远(1947-), 男, 研究员, 博士生导师, 主要研究方向:土地利用/ 土地覆被变化及其环境效应。 E-mail: liujy@igsnrr.ac.cn
  • 基金资助:

    中国科学院西部行动计划项目(KZCX2-XB2-06-03); 国家科技支撑计划项目(2006BAC08B00)

The Spatial and Temporal Characteristics of Grassland Degradation in the Three- River Headwaters Region in Qinghai Province

LIU Jiyuan, XU Xinliang, SHAO Quanqin   

  1. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
  • Received:2007-10-23 Revised:2007-12-24 Online:2008-04-25 Published:2010-08-04
  • Supported by:

    The CAS Action-plan for West Development, No.KZCX2-XB2-06-03; National Key Project of Scientific and Technical Supporting Programs, No.2006BAC08B00

摘要:

在20 世纪70 年代中后期MSS 图像、90 年代初期TM 图像和2004 年TM/ETM 图像支 持下, 通过三期遥感影像的直接对比分析, 获得了三江源地区草地退化空间数据集, 并在此 基础上分析了70 年代以来青海三江源地区草地退化的主要时空特征。结果表明: 三江源地区 草地退化是一个在空间格局上影响范围大, 在时间过程上持续时间长的连续变化过程。研究 发现, 三江源草地退化的格局在70 年代中后期已基本形成, 70 年代中后期至今, 草地的退 化过程一直在继续发生, 总体上不存在90 年代至今的草地退化急剧加强现象。草地退化的过 程在不同区域和地带有明显不同的表现, 如在湿润半湿润地带的草甸类草地上, 发生着草地 破碎化先导, 随后发生覆盖度持续降低, 最后形成黑土滩的退化过程; 在干旱、半干旱地带 的草原类草地上, 发生着覆盖度持续降低, 最后形成沙地和荒漠化草地的退化过程。三江源 地区草地退化具有明显的区域差异, 草地退化可以分为7 个区, 各区草地退化在类型、程度、 范围与时间过程方面具有明显不同的特点。

关键词: 三江源, 青海, 草地退化, 遥感, 空间格局, 时间过程

Abstract:

Using MSS images in the middle and late 1970s, TM images in the early 1990s and TM/ETM images in 2004, grassland degradation in the Three-River Headwaters Region is interpreted through analysis on RS images in two time series, then the spatial and temporal characteristics of grassland degradation since the 1970s in the Three-River Headwaters Region are analyzed. The results show that grassland degradation in the Three-River Headwaters Region is a continuous changing process which has large area of influence and long time scale, and the drastic intensification phenomenon does not exist in the 1990s as a whole. Grassland degradation pattern in the Three-River Headwaters Region took shape initially in the middle and late 1970s, since the 1970s, this degradation process has taken place continuously, characterizing obviously different rules in different regions. Such as, in humid and sub-humid meadow grassland, grassland firstly fragmentizes, then the degree of vegetation coverage decreases continuously, and finally "black-soil-patch" degraded grassland formed. But in semiarid and arid steppe regions, the degree of grassland vegetation coverage decreases continuously, and finally desertification formed. Because grassland degradation has obvious regional diversity, grassland degradation in the Three-River Headwaters Region could be classified into seven regions, and each region has different characteristics in type, grade, scale and time process of grassland degradation.

Key words: Three-River Headwaters Region, grassland degradation, remote sensing spatial pattern, temporal process, Qinghai