摘要
以1991、2000、2009年3期TM影像为数据源,通过基于NDVI的像元二分模型,分析南流江流域19年来的植被覆盖时空特征,同时将这3期植被覆盖度图与流域地质图进行叠加,进而分析地质地层对植被覆盖度的影响。结果表明:(1)19年来南流江流域植被覆盖度变化显著,前10年间流域植被质量有所下降,自2000年来流域平均植被覆盖度呈上升趋势。(2)植被覆盖度与流域内地质地层联系紧密,流域内花岗岩(γ)地层,植被覆盖度较高,优于其他地层;岩溶区植被覆盖度较低,植被易发生退化,但恢复缓慢;该流域内的第四系地层植被覆盖度最低。(3)南流江流域植被以稳定、恢复为主,植被覆盖得到较大好转,在空间分布上变化较为显著。
With 1991,2000 and 2009,the three years of TM images as a data source,this paper calculates and analyses the characteristics of the change and spatial distribution about the vegetation in the Nanliujiang River watershed in 1991-2009 by using the dimidiate pixel model based on NDVI.Overlaying the vegetation coverage map and the divided lithology geological map,the impact on vegetation coverage exerted by geological structure is analyzed.The results can be described in the following three aspects：（1）Vegetation coverage of the Nanliujiang River watershed changes significantly during the recent 19 years.The river watershed vegetation quality declined in the first 10 years,but the average vegetation coverage in the river watershed is on the rise since 2000.（2）Vegetation coverage and geological strata within the river watershed are closely linked.Vegetation coverage of granite（γ） formation is higher than other strata,while in the area of karst,vegetation coverage is lower and vegetation is prone to degraded,but recovers slowly;the vegetation coverage in the Quaternary strata of this basin is the lowest.（3）the Nanliujiang River watershed vegetation mainly keeps stable and being restored,which has been greatly improved.The change of vegetation coverage＇s spatial distribution is significant in the Nanliujiang River watershed.
出处
《广西师范学院学报（自然科学版）》
2012年第4期52-59,共8页
Journal of Guangxi Teachers Education University(Natural Science Edition)
基金
广西北部湾重大基础研究专项(2011GXNSFE018003和2012GXNSFEA053001)
关键词
植被覆盖度
NDVI
像元二分模型
南流江流域
vegetation fractional cover
NDVI
dimidiate pixel model
the Nanliujiang watershed
