摘要
利用新疆维吾尔自治区且末绿洲1998年、2001年、2006年、2011年4期TM/ETM+图像,基于森林郁闭度制图模型FCD模型(forest canopy density mapping model,FCD)构造复合植被指数,对且末绿洲地区近13 a的植被覆盖度进行了反演,得到植被覆盖度等级图,分析并揭示出且末绿洲植被覆盖的时空变化特征,对其变化的影响因素进行了探讨。总体来说,且末绿洲13 a来总植被覆盖面积增加了742.64 km2,绿洲在向外扩张;各阶段的植被覆盖度变化表现出波动性,1998—2001年、2006—2011年间植被恢复面积(植被向较高覆盖度转移)分别是植被退化面积(植被向较低覆盖度转移)的2.98倍和1.79倍,植被恢复状态较好,而2001—2006年间出现较严重的植被退化状况,植被退化面积为435.3 km2,植被恢复面积仅为5.41 km2;且末绿洲植被覆盖度的变化受春夏季温度、降水及大规模的防护林、灌溉系统建设等多重因素的影响。
Using the TM images of Qiemo oasis, Xinjiang Uygur Autonomous Region, obtained in August of 1998, 2001, 2006 and 2011, the authors built the complex vegetation index VBSI based on FCD model. This index contains vegetation index （NDVI）, bare soil index （BI）, and shadow index （SI）. Furthermore, the vegetation coverage in Qiemo oasis in 1998, 2001,2006 and 2011 was calculated separately according to the dimidiate pixel principal and then the vegetation coverage graduation maps were compiled. Based on statistical diagrams and transfer matrices, the authors have drawn some conclusions ： ① The overall vegetation coverage area increased 742.62 km2 in the 13 years, and Qiemo oasis was expanding; ②The vegetation coverage showed a fluctuation change during the period. Vegetation was restored well from 1998 to 2001 and from 2006 to 2011. The area of recovered vegetation （vegetation transferred to higher coverage） was 2.98 and 1.79 times the area of degraded vegetation （ vegetation transferred to lower coverage） from 1998 to 2001 and from 2001 to 2006; Nevertheless, it degraded heavily from 2001 to 2006, the area of degraded vegetation was 435.3 km2, whereas the recovered vegetation area was only 5.41 km2; ③ The vegetation coverage change in Qiemo oasis was influenced by such factors as temperature, precipitation in spring and summer, population and anti -desertification projects.
出处
《国土资源遥感》
CSCD
北大核心
2013年第2期131-137,共7页
Remote Sensing for Land & Resources
基金
国家自然科学基金项目(编号:41271427)
国家科技支撑计划项目(编号:2012BAH27B05)共同资助
关键词
复合植被指数
植被覆盖
遥感反演
FCD模型
且末绿洲
composite vegetation index
vegetation coverage
remote sensing inversing
FCD model
Qiemo oasis
