7. Conclusions
The idea of the research was to analyze urban land use
changes occurred in central part of Ulaanbaatar city from
1930 to 2008 with a 10-year interval using GIS and very highresolution
optical and SAR data sets. As data sources, 1 : 5000
scale topographic map, panchromatic and multispectral
Quickbird images, and TerraSAR data were used. The
primary urban land use database was developed using the
topographic map of the study area and historical data about
buildings. To extract updated land use information from the
RS images, Quickbird and TerraSAR images were fused. For
the data fusion, multiplicative method, Brovey transform,
modified IHS, PCA, Ehlers fusion, and wavelet-based fusion
were compared. Of these methods, the image obtained by
the wavelet-based fusion gave a superior image in terms of
the differentiation between the buildings and other urban
classes. To extract reliable land use information from the
fused image, a visual interpretation was applied. As could
be seen from the analysis, in the study area, there were built
571 buildings having 689952.6 sq.m until 1990. However,
since Mongolia entered the market economy in 1990, the
interests of people to own land parcels and build houses
have greatly increased, and there were built 792 buildings
having 645892.9 sq.m. Overall, the study demonstrated that
within the last few decades the central part of Ulaanbaatar
was urbanized very rapidly and became very dense.