Remote Sensing (Oct 2024)

Advancing Forest Degradation and Regeneration Assessment Through Light Detection and Ranging and Hyperspectral Imaging Integration

  • Catherine Torres de Almeida,
  • Lênio Soares Galvão,
  • Jean Pierre H. B. Ometto,
  • Aline Daniele Jacon,
  • Francisca Rocha de Souza Pereira,
  • Luciane Yumie Sato,
  • Celso Henrique Leite Silva-Junior,
  • Pedro H. S. Brancalion,
  • Luiz Eduardo Oliveira e Cruz de Aragão

DOI
https://doi.org/10.3390/rs16213935
Journal volume & issue
Vol. 16, no. 21
p. 3935

Abstract

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Integrating Light Detection And Ranging (LiDAR) and Hyperspectral Imaging (HSI) enhances the assessment of tropical forest degradation and regeneration, which is crucial for conservation and climate mitigation strategies. This study optimized procedures using combined airborne LiDAR, HSI data, and machine learning algorithms across 12 sites in the Brazilian Amazon, covering various environmental and anthropogenic conditions. Four forest classes (undisturbed, degraded, and two stages of second-growth) were identified using Landsat time series (1984–2017) and auxiliary data. Metrics from 600 samples were analyzed with three classifiers: Random Forest, Stochastic Gradient Boosting, and Support Vector Machine. The combination of LiDAR and HSI data improved classification accuracy by up to 12% compared with single data sources. The most decisive metrics were LiDAR-based upper canopy cover and HSI-based absorption bands in the near-infrared and shortwave infrared. LiDAR produced significantly fewer errors for discriminating second-growth from old-growth forests, while HSI had better performance to discriminate degraded from undisturbed forests. HSI-only models performed similarly to LiDAR-only models (mean F1 of about 75% for both data sources). The results highlight the potential of integrating LiDAR and HSI data to improve our understanding of forest dynamics in the context of nature-based solutions to mitigate climate change impacts.

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