Spatiotemporal variation characteristics of vegetation coverage in Ulagai management area from 2001 to 2023

The vegetation change analysis was conducted using imagery data from 2001 to 2023. The Fractional Vegetation Cover (FVC) was calculated using the pixel-based binary method, and the area occupied by different coverage pixels was statistically analyzed. Additionally, a simple regression method was applied to analyze the trend of changes in order to understand the vegetation change characteristics of the region. The results show that: 1) Over the past 23 years, the vegetation coverage in the Ulagai management area has generally shown an upward trend and undergone structural changes. In 2001, medium-high and high vegetation coverage dominated, accounting for 25.88% and 67.28% of the total area, respectively. By 2022, high-coverage vegetation had become dominant, with its area ratio increasing to 95.99%. 2) From 2001 to 2007 and 2013 to 2016, the annual average vegetation coverage decreased slowly in both periods. 3) The vegetation coverage in the Ulagai management area has significantly increased, with the area of significant increase being larger than the area of significant decrease. Among them, the area with no significant decrease accounted for 11.34%, the area with significant decrease accounted for 1.17%, the area with no significant increase accounted for 35.20%, and the area with significant increase accounted for 52.28%. Conclusion: Over the past 23 years, the vegetation coverage in the Ulagai management area has shown fluctuating changes, with an overall increasing trend and a noticeable growth trend.