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Arid Land Geography ›› 2025, Vol. 48 ›› Issue (2): 283-295.doi: 10.12118/j.issn.1000-6060.2024.324

• Ecology and Environment • Previous Articles     Next Articles

Driving mechanisms of vegetation change and ecological vulnerability in the Three-River Headwater Region

LI Kangning1,2,3(), LIN Yilin1,2,3(), ZHAO Junsan1,2,3, WANG Jian1,2,3, GE Feng4   

  1. 1. Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, China
    2. Key Laboratory of Geospatial Information Integration Innovation for Smart Mines, Kunming 650093, Yunnan, China
    3. Spatial Information Integration Technology of Natural Resources in Universities of Yunnan Province, Kunming 650211, Yunnan, China
    4. China National Petroleum Corporation Jilin Oilfield Branch Yingtai Oil Production Plant Ground Station, Jilin 138000, Jilin, China
  • Received:2024-05-26 Revised:2024-11-26 Online:2025-02-25 Published:2025-02-25
  • Contact: LIN Yilin E-mail:20222201075@stu.kust.edu.cn;20200111@kust.edu.cn

Abstract:

Investigating changes in vegetation cover, the driving mechanisms behind these changes, and the region’s ecological vulnerability in the Three-River Headwater Region (TRHR), Qinghai Province, China is essential for ensuring its ecological sustainability. Normalized difference vegetation index (NDVI) and kernel normalized difference vegetation index (kNDVI) were used, along with Theil-Sen Median trend analysis, Mann-Kendall significance test, and geographic detectors to explore the spatiotemporal changes in vegetation cover and driving forces. The sensitivity-resilience-pressure (SRP) model was used to assess ecological vulnerability. The results revealed the following trends: (1) From 2001 to 2020, both NDVI and kNDVI in the TRHR showed a fluctuating upward trend. Spatially, areas of improvement were mainly in the northeast and west, covering 73.70% and 79.79%, respectively, while areas of decline were primarily in the central and southern regions, covering 23.23% and 18.18%, respectively. (2) Precipitation, elevation, and temperature were the dominant factors influencing vegetation cover, with interactions among these factors led to bifactor or nonlinear enhancement effects. Precipitation between 573-675 mm and elevations of 3447-3850 m were most favorable for vegetation growth. (3) Ecological vulnerability increased from the southeast to the northwest, showing significant spatial variation. The region exhibited high ecological vulnerability, with areas of severe and extreme vulnerability, as indicated by NDVI and kNDVI, covering 35.38% and 36.85% of the total area, respectively.

Key words: NDVI, kNDVI, temporal and spatial changes of vegetation, ecological vulnerability assessment, geographic detector