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УДК 528.926:004
Г. Удвалцецег
Институт геоэкологии Академии наук Монголии, Монголия БАЗА ГЕОДАННЫХ ДЛЯ БАССЕЙНА РЕКИ ТУУЛ
G. Udvaltsetseg
Mongolian Academy of Sciences Institute of Geoecology Mongolia
E-mail: udvaltsetseg@ecology.mas.ac.mn
GEO-INFORMATION DATABASE FOR THE TUUL RIVER BASIN
Abstract
The Tuul River is one of the biggest rivers in Mongolia and it originates from Khan Khentii wilderness and runs through the city of Ulaanbaatar and flows into the Orkhon River, which is the biggest tributary of Selenga River basin.
Domestic and international scientists concerning the ecosystem of the Tuul River basin have become highly vulnerable to climate change impact. We have developed a geodata base for the first time in Mongolia by digitizing the topographic map at scale of 1:100000, using ArcView software. The database will further become the base information for any research work relevance to make spatial-time analyzes within the river basin.
Key words: topographic map, geoinformation system, space, vector data, attribute information
Introduction
Creation of computer and high technology made the bigger step forward to the development of science such as appropriate and organized way of collecting massive size of information on nature and efficient use of such information in place. Moreover, a possibility of making spatial-time analysis and quality assessment on the information and ways to create a new information and data on the software have been facilitating scientists to enhance their work efficiency in the development and creation of science. The organized and collated data and information help decision makers to make appropriate solution in regard with the governing the country.
Nowadays, there are a large choice of software and systems to be used for various purposes, research and study and they are based on computerized technologies with high capacity. A geoinformation system is the best example [1].
A geoinformation system is the complex of computer, software and geographical data that captures, stores, analyzes, manages, and presents data that is linked to location [2].
A geoinformation system is the most appropriate method for analyzing spatial information on all nature objects [3].
The main key for effective use of geo-information data is high qualitative technology, system and software. Another one of the important things for geoinformation data is to have well organized and logically orderliness and standardized sources of information which also have to be accurate and realistic.
The Institute of Geo-ecology of MAS has been carrying out the basic research work called “Modeling the integrated water management of the Tuul River and ecological study of the area”. Within the framework of the research work, we have developing complete vector data associated attribute information by digitizing main elements of topographic maps. As a result, the geo-information database for the Tuul River has been done by using ArcView software.
Reference information, data and study
The basic geo reference materials for this research work will be the 1:100 000 scale 65 topographic maps developed in between 1980-1986. The maps were developed based on aerial photographs which were taken in between 1942-1945, using stereo-photogram method.
There were no investigations done for the Tuul River basin. The Tuul River basin mapping was a part of the “National project for utilization and protection of integrated water resources in Sele nga River basin” developed by the Institute of Water Survey and Research /old name/ in 1984. The scale of mapping in the scheme is 1:1 500 000 - 1:3 000 000.
In the past few years, the scientists from the Institute of Geo-ecology have developed series of electronic maps on geomorphology, land shaft and soil in medium scales.
Methodology
Methodological technology for processing geo-information database for the Tuul River basin is shown in Fig. 1.
It was decided that the projected coordinate system „Universal Transverse Mercator „(UTM) and geographic coordinate system „World Geodetic System 84’ (WGS 84) should be used for georeferencing the maps and displaying subsequent vector data. This coordinate system was approved by the Mongolian Government regulation 25 on the 28th January 2009.
The Tuul River Basin georeferencing was done using GPS-derived tic points, to give an accurate representation in the WGS 84 geographic coordinate system. The original topographic maps were published in the Krasovsky 1940 geographic coordinate system.
Figure 1. Methodological technology for processing geo-information database
Results
The most common method for illustrating spatial data by graph is the map and it shows the object by point, line and area [4].
Table 1 shows that which element of spatial base shall be chosen for digitizing main elements of the map into the vector data. By using this sample, the spatial base of main elements will be created.
Table 1. Sample for digitizing elements of main map into vector data
Structure of sample Base data Type of spatial base
I II III
1 2 3 4 5
1. Digital map-base map 1.1. Relief /Digital sample of altitude/ 1.2. Urban area /status of administration and 1:100000 scale topographic map will be used *
number of population/ 1.3. Road network * *
/by type of road/ 1.4.Administration and territory distribution *
/various type of boundaries/
2. Data relevant to water object Location map will be
2.1. River /with permanent and temporary flow/ used *
2.2. Lake /volatile and perennial, salty and unsalted/ *
2.3. Springs 2.4. Well * *
2.5. Saline, salt-marsh and sludge * *
Note: I- Point,II-Line, III-Area
Sample for created attribute data base of base topographic map details For the Tuul River Basin all features have been digitized and all attribute information completed. For instance, all objects which are illustrated by points have been added to the database such are data of altitude and all socio-economic related data such as number of population, wells, springs and other objects and their location in urban area (Fig. 2).
a UULJ lana a bibb lj mo □□ m
Figure 2. A database for water points in the Tuul River basin
All objects which are illustrated by lines have been added to the database such are length of the objects and other related necessary information (Fig. 3).
Figure 3. A database for rivers in the Tuul River basin
All objects which are illustrated by area have been added to the database such are sub-data related to squire and distribution of the objects (Fig. 4).
Figure 4. A database for administration unit in the Tuul River basin
The following data will be used for sub-database for geo-information database
as:
Rivers - their name, length /this data will be created as polygon/ and other necessary information have been included into the sub-data base. For the rivers data relating to rivers' width, run-off, chemical characteristics, name of province (aima) and sub-province (soum) are added.
Lakes - their name, squire and perimeter (those data will be created as polygon) and other necessary information have been added in the sub-data base. For the lakes, the data related to lakes’ width, chemical characteristics, name of province and sub-province, where the lakes are located, can be added.
Relief - horizontal and altitude points
Center of province (aimag) and sub-province (soum) - name
Boundary squire of aimags and soums.
Using above mentioned geo-information database, we have developed an electronic physiographic map (Fig. 5).
Figure 5. The physiographic map of the Tuul River basin
Conclusion
1. The developed geo-information database for the Tuul River by digitizing scale 1:100000 topographic map using ArcView will be crucial for further cartographic work.
2. Since the ecosystem of the Tuul River basin have become highly vulnerable to climate change impact and it has been concerned by domestic and International scientists, the geo-information database developed by us will be used as a base reference for further spatial and time analysis and qualitative and quantitative assessment on space and time.
References
1. Amarsaikhan D. “Geoinformation system and modeling spatial features”. “Erdem” newspaper, printed by MAS, N: 04/58/. UB. 2002. Page 4-6.
2. Amarsaikhan D. “Principles for using geoinfoprmation database system in nature resources management” UB. 2007
3. Konavalova N.B, Kapralov E.G. “Introduction into GIS”. Petrazavodsk, 1995. 160p.
4. Udvaltsetseg G. “Developing necessary geo-information database for water resources mapping”. “Aspects of Mongolian Geo-ecology” N: 3. Institute of Geo-ecology of MAS. UB. 2000. Page 102-112
Contacts
Gendavaa UDVALTSETSEG, PhD
Scientific Secretary of the Subassembly of Geology and Geography
Institute of Geoecology
Mongolian Academy of Sciences
A.Amar street 1, Sukhbaatar Sq.3
Ulaanbaatar 210620A
Mongolia
Tel: (976-11) 265001
Fax:(976-11) 262247
E-mail: udvaltsetseg@ecology.mas.ac.mn
gendvaa_u@yahoo.com
www.mas.ac.mn/mn/index.php
© r. Удeаnцецег, 2010
