近20年玛纳斯河流域南山山区植被覆盖的遥感动态变化监测
2016-10-19贾青芝郭鹏马秀秀孙晓清刘雅清
贾青芝 郭鹏 马秀秀 孙晓清 刘雅清
摘要:利用1990、2000和2005年的TM影像和2012年的ETM+影像提取了玛纳斯河流域南山山区植被的覆盖区域,并对植被的退化情况进行了分析和探讨。结果表明,从1990 — 2012年植被覆盖度指数绝对值来看,研究区植被稳定性有降低的趋势;1990 — 2000年中度以上退化区域在总面积中所占比例为16.41%,2000 — 2005年為13.38%,2005 — 2012年为28.06%,表明近10年研究区植被的分布面积在逐年减小;研究区植被与非植被类型互有转化,差异最大的时间段为2005 — 2012年,植被转出和转入间的差额为638.25 km2;研究区植被年平均面积变化速率逐渐减小,空间变化度先减小后增大,整体规模趋于减小。
关键词:植被;覆盖度;退化;动态变化;遥感;玛纳斯河流域南山山区
中图分类号:Q948.1 文献标识码:A 文章编号:0439-8114(2016)05-1121-04
DOI:10.14088/j.cnki.issn0439-8114.2016.05.009
Dynamic Monitoring of Vegetation Change in South Mountain of Manas River Basin in Recent 20 Years Relying on Remote Sensing
JIA Qing-zhi, GUO Peng, MA Xiu-xiu, SUN Xiao-qing, LIU Ya-qing
(College of Science, Shihezi University, Shihezi 832003, Xinjiang, China)
Abstract: The coverage area of vegetation was extracted with TM images in 1990, 2000, 2005 and ETM+ images in 2012, and the process of degradation in this region was analyzed and discussed. The results showed that the vegetation stability in this area had decreased in 1990 to 2012 according to the absolute value of the coverage index. The area of moderate and severe degradation of the region accounted for 16.41% of the total area in 1990 to 2000, and was 13.38% and 28.06% for the period of 2000 to 2005 and 2005 to 2012 respectively, which indicated that the distribution area of vegetation was reducing year by year in recent 10 years. The type of vegetation and non-vegetation in the study area transformed with each other, the largest gap happened in 2005 to 2012, and was 638.25 km2. Average annual change rate of vegetation area decreased gradually, and spatial variation decreased first and then increased, in the whole, the region of vegetation tended to reduce in general.
Key words:vegetation;coverage degree;degradation;dynamical change;remote sensing;South Mountain of Manas River Basin
玛纳斯河流域位于天山北坡,是新疆重要的绿洲,其南部山区则是该流域植被种类以及碳储量最大的区域。但是由于该地区生态环境相对比较脆弱,以及人类对植被生态系统不合理的利用或破坏,使得流域植被呈现一种逐步退化的现象[1]。杨萍等[2]利用多年归一化植被指数(Normalized difference vegetation index,NDVI)数据研究了玛纳斯县植被覆盖的变化,通过分析长时间序列的NDVI来反映区域植被覆盖的时空动态变化特征。刘艳等[3]对玛纳斯河流域荒漠化进行长期监测,结果表明植被覆盖具有显著的空间差异性,与地形因素、水分、热量、地貌形态和土壤理化性质等气候环境因子存在联系。同时,随着社会经济的发展,玛纳斯河流域森林资源正在逐步缩小,遭到日益严重的人为砍伐破坏[4]。……
