Change Analysis of Vegetation Coverage Based on the NDVI used Gannan Tibetan Autonomous Prefecture as an Example
Clarifying the vegetation coverage status within a region can explain the trend of changes in landmark vegetation,laying a foundation for explaining regional environmental changes.This article uses the pixel dichotomy method to calculate the vegetation coverage in Gannan Tibetan Autonomous Prefecture from the year of 2000 to 2022,and analyzes the spatial and temporal changes features.The results show that:1)Low vegetation coverage is mainly distributed in the northern part of Gannan Prefecture,while high vegetation coverage is mainly distributed in the southeastern and southwestern parts of Gannan Tibetan Autonomous Prefecture;2)From 2000 to 2022,the area of high vegetation coverage decreased by 88 168.75 hm2,the area of low vegetation coverage increased by 3 268.75 hm2;3)The vegetation coverage increased from 2000 to 2005,and the area of vegetation coverage improvement was larger than the area of degradation.From 2005 to 2015,the degree of vegetation coverage showed a downward trend,and the area of vegetation coverage improvement was smaller than that of vegetation coverage degradation.From 2015 to 2022,the degree of vegetation coverage showed an upward trend,and the area of vegetation coverage improvement was larger than that of degradation.Overall,from 2000 to 2022,the vegetation corerage in cannan prefecfure shoured a fluctuating trend of"rising-falling-rising",the area of vegetation coverage improvement in Gannan Tibetan Autonomous Prefecture was 716 237.50 hm2,while the area of degradation was 857 193.75 hm2,and the degree of coverage showed a downward trend.
NETL
NSTL
万方数据
