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Vegetation coverage change in Miyun County and its affecting factors based on 3S 
Gai Yongqin , Li Xiaobing , Xi Bin, Hu Ying 
College of Resources Science and Technology, Beijing Normal University 
State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing; China, 100875 
KEY WORDS GIS; land cover; land use; vegetation; detection 
ABSTRACT 
Vegetation index is one of the important parameters describing the land cover characters while remote sensing is generally used in 
getting regional vegetation index. In this article TM remote sensing data is used to acquire vegetation coverage of Miyun County 
with NDV1 as one parameter in 1991 and 1997 respectively. It indicates that the average vegetation fractional coverage in Miyun 
County decreases in 1970s, from 53.46% to 51.59%, the effective vegetation coverage decreases from 23.89% to 15.54%. Besides 
the effect of natural factors such as temperature and precipitation, the effect of human activities on the change of land use structure is 
the main reason. As a result, the area of grassland and farmland decreases and the area of unused land increases while the former 
decreases by 15.80% and 2.87% respectively the latter increases by 5.35%. It is very important to keep and make full use of 
grassland and strengthening the management of unused land. 
1 INTRODUCTION 
coverage with remote sensing data. Analysis of dynamic 
change of vegetation fractional coverage in Miyun County in 
1990s to utilize land use structure in study area and protect soil 
from being taken away and protect water. 
Land use/cover change (LUCC) is the change of land surface 
caused by human activity on land use. Land use/cover change 
(LUCC) is one of the main ideas in global change research and 
important in regional ecology construction (Zhang Y.X., 2003; 
Li X.B., 1999). Vegetation fractional coverage is a sign for 
justifying regional ecological environment and increased 
vegetation fractional coverage plays an important part in 
ecology recovery and environmental construction (Li X.B. 
1996). Change of land use types and land use structure is a 
main direct reason for that change and it is guidable for 
regional land plan to analyze this change. Miyun County, sit in 
north-east Beijing, is an important natural ecological area and 
water supply protection area. Sited in the middle of Beijing, 
Miyun reservoir is the only drinking water source in Beijing. 
As a result, the dynamic change of vegetation fractional cover 
and analysis of its driven reason become the important reason 
for making land use plan and ecological environmental 
utilization. Vegetation index is the important parameter for 
Miyun County seats in north-east Beijing, longitude between 
116°41 ' and 117°30', latitude between 40° 14' and 40°48'. Its 
border is around with Xinglong, Chengde, Luanping of Hebei 
province in eastern and northern Beijing, Huairou in west and 
Shunyi and Pinggu in south (Figure 1.). The area of Miyun 
114°0‘0 "E 
114WE 
Figure 1. Study area 
2 STUDY AREA 
116WE 
116WE 
118°0'0 "E 
118WE 
describing regional vegetation fractional coverage and can be 
acquired by remote sensing technology. We choose Normalized 
difference vegetation index (NDVI) to get vegetation fractional