Chin J Plant Ecol ›› 2005, Vol. 29 ›› Issue (6): 934-944.DOI: 10.17521/cjpe.2005.0115

• Research Articles • Previous Articles     Next Articles

LAND COVER CLASSIFICATION IN CHINA BASED ON THE NDVI-T<sub>S</sub> FEATURE SPACE

YU Feng1,2, LI Xiao-Bing1,*(), WANG Hong1, YU Hong-Jing1, CHEN Yun-Hao1   

  1. 1 Key Laboratory of Environmental Change and Natural Disaster of the Ministry of Education, Beijing Normal University, Beijing 100875, China
    2 Information Center of Ministry of Land and Resources, Beijing 100812, China
  • Accepted:2004-09-21 Published:2005-09-30
  • Contact: LI Xiao-Bing

Abstract:

Mapping and quantifying land use and land cover changes are important for evaluating recent changes in the regional and global environment and for simulating future changes under different climate change and human land use scenarios. The normalized difference vegetation index (NDVI) and surface temperature (Ts) are two important parameters used to describe the characteristics of land cover. The NDVI-Ts feature space combines these two parameters into one variable. By and large, Ts/NDVI is synchronized to the growing season of vegetation so it can approximate the different phases and status of vegetation growth. Compared to NDVI and Ts, NDVI-Ts contains more land cover information and should be more suitable for characterizing the distribution of vegetation or land cover.
The aim of this paper was to discuss the feasibility of using the NDVI-Ts feature space to better characterize the current distribution and changes in vegetation and land cover in China. We used several classification methods, including Principal Component Analysis (PCA), unsupervised classification and post-classification sustained based on digital elevation models (DEM). The results indicated that Ts/NDVI was highly sensitive and could discriminate different vegetation cover categories in China at large-scales. The accuracy of vegetation classification based on Ts/NDVI was 72.0%, a 3.3% improvement in accuracy as compared to NDVI images, using unsupervised classification, and the Kappa value increased 0.020 2. Moreover, because of the simplexity of remote sensing information, the classification based on seasonal Ts/NDVI data could not avoid completely the mixed classification phenomena. It was necessary to add other information, reflecting vegetation characteristic and its environment to implement post-classification, such as DEM.
When the inversing accuracy of Ts improved, Ts/NDVI data can precisely describe the status of vegetation or land cover in China and improve monitoring of land use changes. This technique has great research potential and practical value.

Key words: Ts, NDVI, Ts/NDVI, Land cover classification