Permafrost

We have the map of seasonally frozen ground and permafrost distribution at a scale of
1:1500000. This map was compiled by the results of Soviet – Mongolian geocryological
expedition in 1967 – 1971. After this period our senior researchers, doctor D.Tumurbaatar,
N.Sharkhuu, compiled the series of permafrost distribution map at a different scale. The main
methodology of these maps is the geographical elevation belts.
Two thirds of the population of Mongolia lives in the region with permafrost distribution.
With the increasing activity of infrastructure networks, knowledge about the distribution
patterns of mountain permafrost helps reducing installation costs, and improves life safety of
people in such area.
At the present, we concentrate on the modelling and mapping of mountain permafrost
distribution patterns using GIS applications and Remote Sensing.
The occurrence of mountain permafrost depends on many parameters, which have direct
and indirect relationships between each other, such as solar radiation, elevation, sloppiness,
aspect, mean annual temperature on permafrost table.
The modelling is based on the mean annual temperature on permafrost table. The mean
annual temperature on permafrost table depends on energy flux in an active layer and the
ground parameters (ground moisture, heat capacity, and etc).
The energy flux in an active layer depends on a solar radiation and landscape conditions.
The rate of solar radiation varies in mountainous area. The minimum mean annual
temperature on permafrost table is one of the criteria of permafrost occurrence.
In valleys and depressions with same solar radiation rate, the permafrost occurrence
depends on ground moisture. The permafrost distributes in an area with more moisture along
the valley and in the depression.
Based on the modelling results, we compiled the map of permafrost distribution in
Ulaanbaatar area using GIS applications and Remote Sensing.
Key words: permafrost, GIS, Remote Sensing, modelling, mapping, mountain
Land surface condition on warm-permafrost region in Mongolia and its
impact to evapotranspiration processes
Yinsheng Zhang 1 , Gombo Davaa 2 , Mamoru Ishikawa 1 , Tsutomu Kadota 1 , Tetsuo Ohata 1
(1. Institute of Observational Research for Global Change, JAMSTEC, Yokosuka, Japan
2. Institute of Meteorology and Hydrology, MAS. Ulaanbaatar. Mongolia)
Abstract: Mongolia is located at the periphery of the sub-Arctic permafrost region. Permafrost
covers about 63% of Mongolia, at the southern fringe of Siberian permafrost. Relating to
climatic condition, a thick active layer and higher ground surface temperatures characterize this
permafrost region. This situation can be classified as “warm permafrost”. Observations of
ground temperature from the surface to a depth of 3 m showed that the surface temperature was
continuously below 0 o C at the beginning of October. The downward frost front moved from the
surface to 3 m in the following 85–90 days. After the snowcover disappeared at the beginning
of April, the surface started to melt. The downward-moving thawing front reached 3 m at the
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