Study on the Characteristics and Driving Factors of Vegetation Cover in Shiyang River Basin from 1990 to 2015

Abstract

The earth is the home of human survival, and vegetation, as an important natural resource on the land surface, has the functions of sand sealing and soil consolidation, water conservation and so on. Change of vegetation can reflect the change of ecological environment. It is also an important role in the energy cycle and water cycle of the earth's surface and atmosphere. By studying the change of vegetation coverage, we can get the information of ecology and water source. Then, we need to take effective measures to improve our ecological environment. It is also of great significance for us to understand the ecological environment. In this paper, the clear images of 1990, 1998, 2015and 2018in June and July are downloaded from Landsat 8 satellite image data. The vegetation index NDVI of each year is calculated by ArcMap software, and the vegetation coverage is calculated by NDVI. The changes of NDVI and vegetation coverage are analysed. The influencing factors of vegetation coverage and the objective control methods are put forward. Based on the change of vegetation coverage from 1990to 2018, it is concluded that the area of vegetation restoration in the upper reaches of Shiyang River Basin is larger than that of degradation, that in the middle reaches of the basin is larger than that of degradation that in the lower reaches of the basin is larger than that of vegetation restoration, and that in Minqin Basin is larger than that of vegetation restoration Product. Generally speaking, the area of vegetation restoration in Shiyang River Basin is slightly larger than that of vegetation degradation. Based on the statistical analysis of the vegetation coverage in the basin, we should focus on the control of the vegetation in the extremely low vegetation coverage area and the medium vegetation coverage area.