Mapping Bush Encroaching Species by Seasonal Differences in Hyperspectral Imagery

Remote Sensing

Jens Oldeland¹  Wouter Dorigo²  Dirk Wesuls¹ 

[1] Biocentre Klein Flottbek and Botanical Garden, University of Hamburg, Hamburg, Germany; E-Mails:;Institute of Photogrammetry and Remote Sensing, Vienna University of Technology, Vienna, Austria; E-Mail:

关键词: principal curve;    constrained ordination;    savanna;    change detection;    vegetation index differencing;    bush encroachment;    tree-grass ratio;    imaging spectroscopy;   

DOI  :  10.3390/rs2061416

来源: mdpi

【 摘 要 】

Bush encroachment is a form of land degradation prominent worldwide, but particularly present in semi-arid areas. In this study, we mapped the spatial distribution of the two encroacher species, Acacia mellifera and Acacia reficiens, in Central Namibia, based on their different phenological behavior. We used constrained principal curves to extract a one dimensional gradient of phenological change from two hyperspectral images taken in different seasons. Field measurements of species composition and cover values were statistically related to bi-temporal differences in hyperspectral vegetation indices in a direct gradient analysis. The extracted gradient reflected the relationship between species composition and cover values, and the phenological pattern as captured by the image data. Cover values of four dominant plant species were mapped and species responses along the phenological gradient were interpreted.

【 授权许可】

CC BY   
© 2010 by the authors; licensee MDPI, Basel, Switzerland.