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Ecological Mapping and evaluation of Mongolian nature based on Remote Sensing Data

Dr. M. Saandar, Dr. D. Gunin
Remote Sensing and Geoinformation Center, Ulaanbaaatar, Mongolia


Summary
The growing negative tendencies changing the Mongolian nature has led to the undertaking of research works on ecological mapping and overall evaluation of the environmental situation as well as on the country's natural resources.

These studies were initially launched in 1988 and are the planned to be completed in 1992. This project is aimed at the mapping of the human-made degradation occurred in the Mongolian natural environment in scale 1:1 000 000 and 1:200 000 based on remote sensing data.

One the basis of the evaluations and results to be made under this project, we deem it necessary to elaborate in cooperation with all interested foreign and national institutions a scientifically well - sounded concept on national ecological programs which will enable us to foresee in time the ecologically critical situations in different regions of Mongolia and to put the resources management on an environmentally safe footing.

The remote sensing based Mongolian natural recourses information system assembles available data on features of the natural environment of Mongolia and was designed to assist decisions in policies on resource use at a central Asian continental scale.

Introduction
The map "Modern condition of ecosystems of Mongolia" on based remote sensing data represents the fundamental cartographic work that gives an information about ecological situation in the whole country and different regions. The analyses of the map may provide obtaining representative data regarding the degree of the anthropogenic pressure on the environment. The map show ecological relations in the system "man-industry-environment" of the different regions and may serve as a reliable cartographic source for developing regional ecological programms and plans for the separate branches of industry, for investigating of the large-scale building sites.

The map "Modern condition of ecosystems of Mongolia" is a mental protection and its execution. Also this map is a document, that is necessary for development of the anthropogenic influence, the reaction of nature, the transformation degree of natural ecosystems and distinguishes regions with dangerous ecological situations in 1990-1991 years.

Mongolia is a country with different contrast and mosaic lands capes. It is supercatena in which forest ecosystems of Siberian type are mixed with steppen and extraaring ecosystems of Central Asian type. As a result of marked degree of gypsometric height ( average altitude in Mongolia equals 1589 m), peculiar orographic estrangement from moist air streams, long season influence of formed here anticyclone and other factors, all developing ecosystems showed aired tendencies, which intensified their vulnerability, little adaptation, ecologic unstability during development.

There is world watershed between rivers of Arctic ocean and indranaged regions of Central Asia, which cover 2/3 of the country area, in Mongolian lands. Mongolia is one of a few countries, in which due to natural and historical peculiarities many ecosystems keep natural function. The main ecological damage in the conditions of the traditional pasturage is the vegetation violation, but there are the local areas of soils urbanic territories and mining industry zones with intensive anthropogenic influence. Increase of anthropogenic pressure and its duration is extended in areas of transformed ecosystems. Regions with bad ecological conditions influencing on human health arise. Space photo information was used for developing operative cartographic model being made up as inventory of ecosystems in their modern condition. Comparison of data obtained in different ranges increases the degree of correct interpretation of ecological data of the photographs. Selected control of obtained results was carried out in expeditions during route inspection of area.

The object of exploration was ecosystem , i.e. region with certain nature conditions of existing of complex part. The subjects of exploration were properties of ecosystems and its parts, previously vegetation and soil defining the basis of ecosystems.

The map of ecosystems of 1:1 000 000 scale means zonal and altitude state of nature complexes. More that 300 types of ecosystems were determined on the map. These ecosystems were classified according to distribution of soil, vegetation and forms of relief.

Ecosystems were evaluated according to pressure of various anthropogenic factors: forestry, agriculture, pasturage, settlement-industry, transport and other. After analysis of informatively of some characteristics and indexes of ecosystem condition about 10 main degradation process criteria was chose and was used for inspection. For example, the soil violation was characterized by erosion, deflation, mechanical changes of structure, increasing of salt content and others. Vegetation violation was characterized by decreasing of plant viability, phytocenotic reorganization of system and global changing of phytocenonis. Integral indexes of ecosystem transformation were laid in the foundation of the map "Anthropogenic violation degree".

Two problems were resolved during the developing of synthetic cartographic model "Modern conditions of Mongolia ecosystems".

to show the influence of geographic characteristics on space differentiation of ecosystems and to she depending of anthropogenic transformation degree on type of land use.

Increasing of map informatively demands combination of various cartographic methods. Colour reflects zonal and altitudinal type of the ecosystems. To show zonal and altitudinal situation of depicted objects several colour patterns were used. The background ( 25 types ) shows geomorphologic conditions of the ecosystems. Every selected contours has received integral anthropogenic violation degree estimation in a 5-point scale:

most violated ecosystems are coloured lighter, less violated ecosystems have more intensive colour. With the help of various indexes and colours many factors of anthropogenic violation were shown: pasturage, sloughing, transport, and others. The key to the map, having more that 300 types of ecosystems, consists, of tables, combined in three main parts:

" Natural and natural - anthropogenic ecosystems", "Anthropogenic ecosystems" and "Anthropogenic violation degree of ecosystems". In addition to that the tendencies of natural and anthropogenic stimulated processes, geographical state are also shown by extra-scale conventional signs.

All the maps are elaborated on 14 sheets of 1:1 000000 scale and matrix key, which is a result of 20 years work of Joint Soviet - Mongolian complex biological expedition of Academy of sciences of the USSR and Academy of Sciences of Mongolia. The position of Mongolia in the bounds of sub continental structures of Central Asia, South Siberia, Far East, at the interface between several sub regions allows to forecast the consequences of different anthropogenic influences in these regions and to consider fulfilled investigation as an example for the corresponding regions. The map "Modern condition of ecosystems of Mongolia" on based remote sensing data is the new type of work. The method of its developing may be used for monitoring of local, regional and global environment.