摘要
植被覆盖变化在新疆山地-绿洲-荒漠系统(MODS)共存、平衡演变机制中扮演着重要角色。基于1982—2006年G IMMS/NDVI数据,提取新疆地区年最大植被覆盖指数(fvc),针对新疆MODS的基本格局,通过先地理分区再因海拔而异讨论,划分出山地、绿洲、荒漠子系统,对比分析不同分区不同子系统下fvc变化趋势、变率、变幅、变异性等时空动态特征。结果表明:新疆植被覆盖总体呈显著上升趋势,可分为1982—1995年的剧烈波动期和1996—2006年的相对平稳期,不同分区和子系统差异显著;在变幅和变异性上,东、南疆地区>北疆、伊犁地区,荒漠>山地>绿洲,植被覆盖度低的地区>植被覆盖度高的地区;显著改善的地区位于绿洲内部、绿洲的周边地区及部分山地,显著退化的地区大多位于东、南疆的荒漠区;不同植被覆盖度下植被覆盖变化具有不同特征,植被覆盖度低的地区,植被退化趋势明显,植被覆盖度高的地区,植被改善趋势明显。
Dynamics of vegetation cover plays an important role in the coexistence and balance evolution mechanism of mountain-oasis-desert system（MODS） in Xinjiang.Based on the satellite-derived NDVI data,produced by GIMMS（Global Inventory Monitoring and Modeling Studies） group,derived from the NOAA/AVHRR（National Oceanic and Atmospheric Administration/the Advanced Very High Resolution Radiometer） land dataset,the fractional vegetation cover（fvc） was calculated at a spatial resolution of 8 km×8 km and at a 15-day interval,for the period January 1982 to December 2006 and then the annual maximum fvc was obtained by the maximum value composites（MVC） method.Under the basic pattern of MODS in Xinjiang,the fvc spatial-temporal dynamics characteristics of trends,rate,amplitude,and variability of 25 years in Xinjiang were analyzed by dividing the whole region into four subregions in terms of regional differentiation,and mountain,oasis,desert system in every subregion by altitude and landuse.The results showed that the fvc dynamics increased significantly in general,but fluctuated remarkably in the period from 1982 to 1995 and relatively stable from 1996 to 2006,varied significantly with different subregions,and subsystems of mountain,oasis and desert,in which the vegetation cover of oasis increased mostly rapidly,but desert decreased most obviously.On the amplitude and variability,the eastern and southern subregions exceed the northern and Yili subregions,desertmountainoasis,and the lower fvc is larger than the higher fvc.The significant improved subregions are located in oasis,its surrounding areas and part of mountains,but the degenerated subregions are mostly situated in desert of eastern and southern Xinjiang.There are different change characteristics in different fvc subregions,that is,the vegetation degenerated in lower fvc subregions and improved in higher fvc subregions.
出处
《自然资源学报》
CSSCI
CSCD
北大核心
2011年第4期609-618,共10页
Journal of Natural Resources
基金
新疆维吾尔自治区自然科学基金项目(200821127)
新疆科技支撑项目(201033122)
