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UPDATING TOPOGRAPHIC MAP IN SOUTHERN CHINA 
BY USING SATELLITE IMAGE AND ANCILLARY DATA 
X. Yu, L. Matikainen, R. Kuittinen 
Finnish Geodetic Institute, Finland 
Commission IV, Working Group 3 
KEY WORDS: Land Use, Interpretation, Updating, Segmentation, Rule-based System. 
ABSTRACT 
A study was made to develop a method for updating land use information in topographic maps by using satellite images together 
with old maps in the rapid developing area of Zhong Shan in southern China. The method consists of three main parts: region-based 
segmentation of a satellite image, preclassification of the segments based on their spectral properties and rule-based 
postclassification. In the rule-based postclassification, the preclassification result is combined with information derived from old 
maps by using the Dempster-Shafer theory of evidence for hierarchical cases. The method was tested in the Zhong Shan area by 
using a Landsat TM image and an old topographic map. In determining rules and belief values, field measurements were used in 
addition to the data itself. The rule-based postclassification improved the classification results and the information of the old map 
proved to be useful in interpretation of land use classes which are near each other in the spectral space. The biggest problem was the 
spatial resolution of the Landsat TM image, which was too low to detect some small but very important features of the study area. 
1. INTRODUCTION 
The need to update topographic and thematic maps increases as 
the frequency of changes in land use increases. These changes 
are relatively rapid especially in south-eastern Asia because of 
the rapid economic development. Traditionally satellite images 
are used for mapping as the only source of information and the 
results are only moderate even if visual interpretation or 
combined visual and mathematical interpretation is used 
(Ahokas et al., 1990). The main reasons for this are that the 
interpretation is mainly based on spectral information and the 
spatial resolution of the images is too low. New methods are 
needed to obtain better accuracy in the interpretation. 
Most of the mapping tasks consist today of updating of old 
maps, which offers the possibility to use maps and satellite data 
together in the interpretation. If useful mathematical methods 
can be found, the combined use of several data in interpretation 
can lead to more accurate results. The Dempster-Shafer theory 
of evidence and its modifications to hierarchical cases offer a 
good possibility to combine different types of data in the 
interpretation (Gordon and Shortliffe, 1985, Shafer and Logan, 
1987, Wilkinson and Mégier, 1990). 
The aim of this study was to apply the Dempster-Shafer theory 
of evidence in updating topographic maps in southern China 
where satellite images and old topographic maps are available. 
The method consists of the following parts: 
— Segmentation of the satellite image into spectrally 
homogeneous, connected regions using a region-based 
segmentation method, 
— Preclassification of the segments into spectral classes using 
the conventional Maximum Likelihood classification method 
(Duda and Hart, 1973), 
— Determination of attributes and rules for rule-based 
postclassification, 
995 
— Postclassification using the preclassification result, old maps 
and a rule-based interpretation method based on the 
Dempster-Shafer theory for hierarchical cases (Shafer and 
Logan, 1987). 
2. STUDY AREA AND DATA 
2.1 Study area 
The study was based on data from the Zhong Shan area of size 
20 km x 17 km. Zhong Shan is located in the Guangdong 
province in the southern part of China. It is an area that has 
developed economically very quickly in recent years. New 
office buildings, factories and private houses have been built, a 
lot of fishponds and roads have been constructed and a lot of 
gravel pits are used. Most of these changes have decreased the 
amount of cultivated land, especially rice fields. The land use 
has changed so much that there are large demands for up-to- 
date land use information for city planning and decision 
making. 
The area is relatively flat. The differences in elevation are less 
than 10 m for agricultural land, urban area and water, while 
forests are located in the hilly area ranging from 10 m to 250 m. 
Some rice fields had been harvested and burned at the time of 
the satellite image registration. 
2.2 Data 
A Landsat TM image from 24 December 1993, a digitised land 
use map in raster format and a digital elevation model (DEM), 
derived from the topographic map of 1983 on a scale of 
1:50,000, were used to produce an updated topographic map. 
The satellite image was rectified to the coordinate system of the 
topographic map. 
Field measurements were made in the Zhong Shan area in 
November 1994 and 1995 respectively. The aims of the 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996