摘要
以多期遥感图像为基本数据，借助3s技术，探讨了奇台绿洲的植被覆盖动态变化。结果表明，虽然弃耕面积与开荒面积之比从前期（1986～1997年）的7．56降为后期（1997-2005）的1．86，但植被覆盖类型的变化始终以开荒为主，大量非耕地转化为耕地。耕地面积由早期占总面积的11．74％增加到后期的40．15％。前期植被恢复面积是退化面积的130．13％，后期仅为37．5％。同时，荒漠转化为低草的比例较前期少，而低草转化为荒漠的比例增加，表明荒漠在不断扩大，反映出绿洲生态环境趋差。人类大面积开垦农田使用了大量的水资源，使得地下水位下降，荒漠边缘依靠地下水生存的低草枯萎，并转化为荒漠。这是导致后一时期绿洲生态环境恶化的决定性因素。
This article is in virtue of 3S technology, which research dynamic change and drive mechanism of Qitai vegetation coverage. The result indicates that all kinds of meadow are assarted to cropland continuously in the whole studying time. Although the ratio of the area of abandoning cropland to the area of assart reduced from 7.56（1986- 1997） to 1.86（1997-2005）, the most change of the kind of vegetation coverage is for assart, a great lot of no cropland is transformed intQ cropland. The ratio of the area of cropland to the total area increase from 11.74% in previous period to 40.15% in latter period. On the one hand, assart make the amounts of high grass and middle grass which have good environmental value decrease. On the other hand, abandoning cropland makes the amounts of low grass and desert increase. Increase in cropland used a great lot of water, make water table down, low grass which makes a living with groundwater wither away, and transform into desert. In previous period the ratio of area of renewing vegetation coverage to area of degenerating vegetation coverage is 130.13%, which reflect the progress of environment is good, and that is good for continual development. In the latter period the ratio of area of renewing vegetation coverage to area of degenerating vegetation coverage is 37.5%, the area of abandoning cropland is one times than the former. At the same time the ratio of the area of desert to the area of low grass is low, and the ratio of the area of low grass to the area of desert is high, that indicate the area of desert is increasing continually. The increase of the area of abandoning cropland and desert undoubtedly make environment and the stability of oasis which has worsened. Dimensional change of cropland is the definitive factor of the environment of oasis which has worsened, also is main drive of other kinds of vegetation coverage which changed.
出处
《生态经济》
CSSCI
北大核心
2014年第1期150-153,共4页
Ecological Economy
基金
国家自然科学基金(41171165)
北京市属高等学校高层次人才引进与培养计划项目(IDHT20130322)
北京联合大学人才强校计划资助项目(BPHR2012E01)
关键词
植被覆盖
绿洲
新疆
vegetation coverage
oasis
Xinjiang
