Temporal and Spatial Changes Monitoring of Vegetation Coverage in Qilian County Based on GF-1 Image

Qilian County demonstration area is an important ecological security barrier in the country. Based on the GF-1 image, the dimidiate pixel model was used to invert vegetation coverage in Qilian County demonstration area. The temporal and spatial variation characteristics of vegetation coverage were studied from 2017 to 2018. Results show that: 1) The vegetation coverage of Qilian County demonstration area was high. The vegetation coverage in Qilian demonstration area was generally high in the north and low in the south. The vegetation coverage in Qilian County is mainly medium vegetation coverage area, high vegetation coverage area and full vegetation coverage area. The monthly variations in vegetation coverage were basically the same in 2017 and 2018. The area of high vegetation coverage increased from June to August, and decreased from August to September. The overall vegetation coverage was increased. 2) The analysis of the annual variation of vegetation coverage showed that compared with 2017, the full vegetation coverage area decreased, while the medium vegetation coverage area and the low vegetation coverage area increased. (C) 2020 The Authors. Published by Elsevier B.V.