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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B7, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
FOREST RESOURCES STUDY IN MONGOLIA USING
ADVANCED SPATIAL TECHNOLOGIES
D. Amarsaikhan * *, M. Saandar ", V. Battsengel ©, Sh. Amarjargal “
? Institute of Informatics and RS, MAS, Ulaanbaatar-51, Mongolia - amar64(@arvis.ac.mn
® MonMap Engineering Services Co., Ulaanbaatar, Mongolia - msaandar@mongol.net
* School of Geography and Geology, NUM, Ulaanbaatar, Mongolia - battsengel@num.edu.mn
4 Research Centre of Astronomy and Geophysics, MAS, Ulaanbaatar, Mongolia - amarshrgl@yahoo.com
Commission VII, WG VII/5
KEY WORDS: Optical, Microwave, Forest mapping, Refined maximum likelihood classification
ABSTRACT:
The aim of this study is to conduct a forest resources study using optical and synthetic aperture radar (SAR) satellite images. For
this purpose, a forest-dominated site around the Lake Khuvsgul located in northern Mongolia is selected. As remote sensing (RS)
data sources, panchromatic and multispectral Landsat 7 images as well as ALOS PALSAR L-band HH polarization data are used. To
produce a reliable land cover map from the multisensor images, a novel refined maximum likelihood classification based on the
spectral and spatial thresholds are applied and for the accuracy assessment an overall accuracy is used. Overall, the research
demonstrates that advanced spatial technologies based on optical and microwave RS are reliable tools for different forest studies.
1. INTRODUCTION
Forest is a very important natural resource that plays a
significant role in keeping an environmental stability,
ecological balance, environmental conservation, food security
and sustainable development in both developed and developing
countries. In recent years, deforestation and forest land
degradation have become the main concern for forest
specialists and ecologists as well as policy and decision-makers
dealing with the environment. It has been found that much of
the existing forests have been destroyed, mainly by shifting
cultivation, timber preparation, legal and illegal logging, forest
fires and increased number of people involved in agricultural
activities Amarsaikhan ef al. 2011). To protect and conserve
the deteriorating forest, it is very important to introduce a
sustainable forest management policy.
The concept of sustainable forest management should involve
clear definition of the desired future condition of a forest,
evaluation of the current management practices and thoroughly
defined objectives to achieve a desired future condition.
Achieving sustainable forest management should require
effective measuring and monitoring activities which can
provide reliable forest information to support policy and
decision-making related to sustainable development (Haase
and Camphausen, 2007). It is unambiguous that accurate and
real-time forest related spatial information along with its
attributes is the key for successful planning and management.
In spatial context, such information might be collected from
many different sources. However, the most reliable source that
could provide real-time information for the accurate analysis
could be RS (Amarsaikhan, 2011).
* Corresponding author
Traditionally, multispectral RS images have been widely used
for forest monitoring and management. Since the end of the
last century, single polarization SAR data sets have been
increasingly accessible for the forest specialists. As the present
space science and technology are so advanced, very high
resolution multichannel optical and polarimetric SAR images
are available for different forest studies. The combined
application of optical and radar data sets can provide unique
information for forest planning and management, because
passive sensor images will represent spectral variations of the
top layer of the forest classes, whereas microwave data with its
penetrating capabilities can provide some additional
information about forest canopy (Amarsaikhan ef al. 2004,
Amarsaikhan et al. 2011). Moreover, it is clear that the
integrated use of the optical and microwave data sets should
improve an accuracy in a forest mapping, because as the
images are acquired in different portions of electro-magnetic
spectrum, could positively influence a decision-making in
overlapping boundaries (Amarsaikhan et al. 2009).
The aim of this research is to conduct a forest resources study
using optical and microwave RS along with a geographical
information system (GIS). For this purpose, a test site located in
northern Mongolia has been selected. As RS data sources,
multitemporal Landsat ETM+ images and ALOS PALSAR L-
band HH polarization data were used. To produce a land cover
map from the multisensor images, a novel refined maximum
likelihood classification based on the spectral and spatial
thresholds has been applied and for the accuracy assessment an
overall accuracy was used. The analysis was carried out using
Erdas Imagine and ArcGIS systems installed in a PC
environment.