1021 
LAND DEGRADATION ANALYSIS IN THE ONGI RIVER BASIN 
Tungalag.A 3 * , Tsolmon.R 3 , Bayartungalag.B 3 
a National University of Mongolia, School of Physics-Electronics, Laboratotay for Remote sensing/GIS 
NUM-ITC-UNESCO, Ulaanbaatar, Mongolia 
tungalag86@yahoo.com; tsolmon@num.edu.mn; b_tungalag_b@yahoo.com 
CommissionVII, WG VII/5 
KEY WORDS: Socio-economic, Mineral Resources, Degradation, Biodiversity, MSAVI2, NDVI, 
ABSTRACT: / 
During Mongolia’s transition to the free market, socio-economic factors such as poverty and profit-seeking have greatly increased 
small to large-scale mining, as well as illicit activity resulting in the exploitation of the country’s mineral resources. This has 
subsequently contributed to the deterioration and loss of regional biodiversity and increased levels land degradation. This study aims 
to monitor land degradation processes in the study area of the Ongi River Basin. This area is affected by mining activities and 
desertification processes. The vegetation indexes MSAVI2 and NDVI from SPOT data were applied in this area in order to determine 
vegetation cover change in the time period of 1998 to 2006.The result from both vegetation indexes described that there is a 
vegetation decrease due to mining activities in the study area. 
1 INTRODUCTION 
There are a limited research works in Mongolia particularly 
developing the necessary facilities and science for monitoring 
the socio-economic change and environmental impact derived 
from country’s mining sector. During Mongolia’s transition to 
the free market, socio-economic factors such as poverty and 
profit-seeking have greatly increased small to large-scale 
mining, as well as illicit activity resulting in exploitation of 
country’s mineral resources. Thus, the society and environment 
problems in Mongolia interact in such a way where poor 
environmental policy and regulation is linked to land 
degradation and environmental contamination, which therefore 
increases the society’s vulnerability. Lake, river and pond in 
Mongolia is dried up and lost ecological balance caused by 
human wrong activities and mineral extraction. Furthermore, it 
is caused damage on environment and people’s lifestyle in 
Mongolia. 
This study aims to determine vegetation condition in Ongi river 
basin. A great concern for the environmental officers Ongi river 
basin is mining. Mining is done legally by companies that have 
large concessions, but also illegally by so called "Ninjas", 
individuals and families that literally dig for gold without a 
license. The mining companies use heavy equipment to remove 
the top layer and vegetation. Vegetation and pasture land most 
important for the nomadic people living in the river basin. 
Therefore this study is analyzing vegetation change in the river 
basin in last years between 1998-2007. 
2.1 Study area 
The study are is, Ongi River basin is situated in the central part 
of Mongolia, is located on E101°44’24”-E104°30’00” and 
N44°22’48”-N46°41 ’24” (Figure 1). The Ongi river is one of 
the world bigger fresh watershed point and starts form Khangai 
Range then crossed 3 kinds of areas which are Mountain & 
Wooded area, steering plain area, gobi desert area. It is one of 
the important rivers in the area for the lifestock breeding for the 
local people (“Ongi” movement). Main environment concern is 
the river is drying up and starting to interrupt since 1998 (Figure 
2). 
The length of the river is 437km, site is 175 square km and 
1000-3000m above the sea level. The main reason of drying up 
Ongi river is to the mining of gold placer deposit and never 
making technical and biological reclamation (Mijiddorj.R, 
Bayasgalan.Sh, 2006). 
2.2 Data used 
VEGETATION SPOT 4 1km data from April to October 1998- 
2006, LANDS AT ETM+ data for 23 July, 1999 and 20 
September, 2000 were used in this research. Two kinds of 
vegetation indexes NDVI and MSAVI 2 were used for the 
monitoring vegetation change in the study area. 
Figure 1. Study area : Ongi river basin 
* 
corresponding author