LAND COVER OF ASIA
Ryutaro Tateishi
Center for Environmental Remote Sensing(CEReS)
Chiba University
Japan
E-mail: tateishi@rsirc.cr.chiba-u.ac.jp
KEY WORDS: Land cover, AVHRR, Asia, NDVI, surface temperature
ABSTRACT
30 arc-second grid land cover data set of the whole Asia was developed by the Land Cover Working Group(LCWG) of
the Asian Association on Remote Sensing(AARS). The used satellite data are Normalized Difference Vegetation
Index(NDVI), channel 4, and channel 5 of NOAA AVHRR from April 1992 to March 1993 which were produced by the
United States Geological Survey(USGS). Other used data/information are global digital elevation data(GLOBE) as
auxiliary data for classification, the Digital Chart of the World(DCW) for geometric registration and eighteen thematic
maps for ground truth collection. Classification was done mainly using phenological information by clustering of
monthly ratio of surface temperature and NDVI. Clustering result of this ratio, maximum monthly NDVI, minimum
monthly NDVI, and elevation were used in determining decision tree classification rules. Members of the
LCWG/AARS have supported for ground truth collection and post-classification modification. The produced land cover
data set will be distributed with ground truth data by CD-ROM.
1. INTRODUCTION
Land cover is one of key environmental variables for
global change studies such as carbon circulation and is
important variable for global/continental scale land use
planning in order to keep food supply for human and
domestic animals and to keep sustainable environment in
the present age of human population eruption. However
there was no reliable land cover data in global/continental
scale. But fortunately, land cover is one of the main
features of the terrestrial environment which can be
extracted by remote sensing technique. Therefore there are
several organizations/groups such as IGBP, UNEP/FAO,
CORINE which are trying to develop land cover data set
of global or continental area. The Land Cover Working
Group(LCWG) of the Asian Association on Remote
Sensing(AARS) also aims to develop Asia land cover data
set. The LCWG/AARS has developed land cover data set
to meet both scientific needs (global change studies) and
social needs(global/continental scale land use planning).
2. AARS LAND COVER
CLASSIFICATION SYSTEM
The AARS land cover classification system, which is
shown in Table 1, was developed through discussion with
members of the LCWG/AARS. Since the developed land
cover classification system is well described in the
author's paper, Tateishi( 1997a), only main characteristics
of the classification system is described in this paper.
(1) Class code
The classification system of this CD-ROM consists of 59
classes including 47 classes for vegetation, 8 classes for
non vegetation, and 4 classes for water. Addition of new
classes up to 255 is possible. Class code is recorded in
one byte.
(2) Hierarchical system
Hierarchical system itself has been well adopted method
for a classification system. In some hierarchical
classification systems, classes of the same level has
similar characteristics. However, in the AARS
classification system of this CD-ROM, the same level in
the hierarchy does not necessarily have the same classified
level. For example, Oil palm and Coconut are in the 7th
level and Paddy and Wheat are in the 4th level. This is
because classes of forest are divided more than classes of
grassland.
(3) Interpretability
Continental or global land observation by satellite is
often carried out by AVHRR data with the resolution of
lkm. In the future, MODIS of EOS-AM1 and GLI of
ADEOS-II with 250m resolution will be available. In the
classes of forest or shrubland, more easily interpretable
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