Peng et al. (2025) Analysis of Spatiotemporal Changes in NDVI-Derived Vegetation Index and Its Influencing Factors in Kunming City (2000 to 2020)

Identification

• Journal: Forests
• Year: 2025
• Date: 2025-11-27
• Authors: Yanling Peng, Hede Gong
• DOI: 10.3390/f16121781

Research Groups

• College of Physics and Electronic Engineering, Qilu Normal University, Jinan, China
• School of Geography and Tourism, Qilu Normal University, Jinan, China

Short Summary

This study analyzed the spatiotemporal changes and driving factors of vegetation cover in Kunming City from 2000 to 2020 using MODIS NDVI and climate/socioeconomic data, finding an overall increase in vegetation cover primarily influenced by precipitation, with urbanized areas showing lower vegetation.

Objective

• To quantitatively identify the temporal trends and spatial patterns of NDVI-derived vegetation index in Kunming City over the past two decades.
• To reveal the relationships between vegetation dynamics and both climatic (temperature, precipitation) and socioeconomic (population, GDP) factors.
• To evaluate the relative contributions of natural and socioeconomic factors to vegetation changes within the context of Kunming’s rapid urban development.

Study Configuration

• Spatial Scale: Kunming City, China (102°23′–103°40′ E, 24°23′–26°33′ N), with MODIS data at 250 meter (m) spatial resolution.
• Temporal Scale: 2000 to 2020 (21 years).

Methodology and Data

• Models used:
  • Pixel dichotomy model (for Fractional Vegetation Coverage, FVC)
  • Linear regression (for temporal trend analysis of FVC)
  • Jenks natural breaks method (for classifying FVC trend slopes)
  • Pixel-wise Pearson correlation analysis (for relationships between FVC/NDVI and driving factors)
• Data sources:
  • Moderate Resolution Imaging Spectroradiometer (MODIS) MOD13Q1 data (Normalized Difference Vegetation Index, NDVI) from the Google Earth Engine (GEE) platform.
  • ERA5 Monthly Aggregates dataset (2 m air temperature, total precipitation) from the European Centre for Medium-Range Weather Forecasts (ECMWF) via GEE.
  • County-level Gross Domestic Product (GDP) data from the Resource and Environment Science and Data Center of the Chinese Academy of Sciences.

Main Results

• The NDVI-derived vegetation index in Kunming generally showed higher values in the west than in the east, and higher values in mountainous areas compared to plains and basins.
• From 2000 to 2020, the overall NDVI-derived vegetation index increased, with the mean NDVI rising from 0.48 to 0.545. Notable declines occurred in 2010 and 2012, likely due to drought conditions from reduced rainfall.
• During the study period, 37.21% of the area showed vegetation improvement (26.86% moderate, 10.35% significant), while 10.28% exhibited degradation. Improvements were concentrated in Xundian County, parts of Dongchuan District, northern Luquan County, and northern border areas adjoining Yiliang and Shilin Counties. Degradation was primarily in Kunming’s main urban area and along the corridor from the airport to Songming.
• 53.3% of areas exhibited a positive correlation between temperature and NDVI-derived vegetation index (18.6% significant positive), while 11.7% showed a significant negative correlation, mainly in the lower Pudu River basin, the Fumin–Luquan border, and the basin areas of Songming and Shilin Counties.
• 53% of areas showed a positive correlation between precipitation and FVC (19.7% significant positive), whereas 8.3% showed a significant negative correlation. Precipitation effects on NDVI-derived vegetation index typically lagged by about one year.
• Kunming’s GDP increased more than tenfold from 63.61 billion Chinese Yuan (CNY) in 2000 to 673.38 billion CNY in 2020. Areas with higher GDP were often associated with lower NDVI-derived vegetation index, reflecting a spatial mismatch due to rapid urbanization.

Contributions

• Provides an improved understanding of the long-term spatiotemporal vegetation dynamics in Kunming City from 2000 to 2020.
• Quantifies the relationships between vegetation changes and both climatic (temperature, precipitation) and socioeconomic (GDP) driving factors at a regional scale.
• Offers a scientific reference for strengthening ecological resilience and promoting sustainable urban development in rapidly urbanizing regions, particularly in the context of plateau mountain monsoon climates.

Funding

This research received no external funding. The Article Processing Charge (APC) was funded by Research start-up funds of Qilu Normal University.

Citation

@article{Peng2025Analysis,
  author = {Peng, Yanling and Gong, Hede},
  title = {Analysis of Spatiotemporal Changes in NDVI-Derived Vegetation Index and Its Influencing Factors in Kunming City (2000 to 2020)},
  journal = {Forests},
  year = {2025},
  doi = {10.3390/f16121781},
  url = {https://doi.org/10.3390/f16121781}
}

Generated by BiblioAssistant using gemini-2.5-flash (Google API)