Study On Vegetation Coverage And Its Dynamic Change Of Hunyuan County In Shanxi Province By Remote Sensing

Vegetation is an important part of both the ecosystem and the ground cover. And vegetation is an important character of reflecting the earth’s surface. Vegetation plays a vital role in global change. It’s also an important parameter that can characterize and evaluate the ecosystem. The change of vegetation coverage indicates the changes of global and regional environment. It’s important to study on the vegetation changes for the environmental changes and global change.This paper introduced the basic theory of the vegetation coverage and its research status. Then it’s time to summarize the basic methods of measuring the vegetation coverage. This paper indicated the basic concept, application limits and the strengths and weaknesses of measuring methods. This paper emphasized NDVI index and the dimidiate pixel model. And established an improved model to estimate the vegetation coverage by NDVI based on the dimidiate pixel model.The introduced the process of parameters determination. The improved model became easier and practical. And it’s independent of actual measuring data. Various type of vegetation and different resolutions remote sensing images can be applied to the improve model. This paper selected this model to estimate the vegetation coverage.This paper chose Hunyuan County in Shanxi province as the study area. The county is located in the northern part of Shanxi Province, the eastern edge of the Loess Plateau region. It has the complex geomorphic types, mainly hilly area. There is Loess Hilly Region in northern area, the middle flat, and the southern mountain. The northern Mt. Hengshan is located in the study area. This area is rich in mineral resources and tourism resources. Reasonable utilization of resources is important to economic construction, and improving the people’s living level is an important way to protect the existing ecosystem. At the same time, the ecological environment is also very important. Therefore, study on the vegetation coverage of this county has very practical significance.This paper obtained TM, ETM+Remote Sensing images on1987,1999and2007of Hunyuan County. This paper estimated the vegetation coverage of the3periods, and analyzed the land use status of three periods, in order to analyze driving force factors of vegetation cover change. Based on the result of vegetation coverage estimation, this paper analyzed the vegetation coverage change on1987a,1999a and2007a, and made an area statistics about different grade of the vegetation coverage, combined with the township administrative area and estimated different region’s vegetation coverage. The results show that vegetation coverage is higher in the southeast of the county and lower in the central area and the northwest area. The average degree of the vegetation coverage increased. And the vegetation coverage of southern region has been to maintain a high level, due to vegetation protection. The vegetation coverage of the central area decreases somewhat, basically owning to the social and economic development and urban construction. Human activities have a direct impact on land use and vegetation cover change.It has certain guiding significance on social, economic construction to study on land use and vegetation cover change.