Quantifying how topography impacts vegetation indices at various spatial and temporal scales

Remote Sensing of Environment, Journal Year: 2024, Volume and Issue: 312, P. 114311 - 114311

Published: Aug. 3, 2024

Satellite-derived vegetation indices (VIs) have been extensively used in monitoring dynamics at local, regional, and global scales. While numerous studies explored various factors influencing VIs, a remarkable knowledge gap persists concerning their applicability mountain areas with complex topographic variations. Here we bridge this by conducting comprehensive evaluation of the effects on ten widely VIs. We three strategies, including: (i) an analytic radiative transfer model; (ii) 3D ray-tracing (iii) Moderate Resolution Imaging Spectroradiometer (MODIS) products. The two models provided theoretical results under specific terrain conditions, aiding first exploration interactions both shadow spatial scale MODIS-based quantified discrepancies VIs between MODIS-Terra MODIS-Aqua over flat rugged terrains, providing new insights into real satellite data across different temporal scales (i.e., from daily to multiple years). Our were consistent these revealing key findings. normalized difference index (NDVI) generally outperformed other yet all did not perform well (e.g., mean relative error (MRE) 14.7% for NDVI non-shadow 26.1% areas). impacts exist spatiotemporal For example, MREs reached 28.5% 11.1% 30 m 3 km resolutions, respectively. quarterly annual deviations also increased slope. found topography-induced interannual variations simulated MODIS data. trend Tibetan Plateau 2003 2020 as slope steepened enhanced (EVI) doubled). Overall, sun-target-sensor geometry changes induced topography, causing shadows mountains along obstructions sensor observations, compromised reliability terrains. study underscores considerable particularly effects, scales, highlighting imperative cautious application VIs-based calculation mountains.

Language: Английский

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Evaluation of similarity-checking methods for reference samples migration to monitor land cover changes in the complex terrain of the Alborz Mountains, Iran

Earth Science Informatics, Journal Year: 2025, Volume and Issue: 18(3)

Published: March 1, 2025

Language: Английский

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A satellite perspective of interannual and seasonal variations in greenspace and human exposure over urban and peri-urban areas in Chinese cities from 2000 to 2020

Landscape and Urban Planning, Journal Year: 2025, Volume and Issue: 259, P. 105354 - 105354

Published: March 30, 2025

Language: Английский

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The High-Resolution Global Land Surface Satellite (Hi-Glass) Products Suite

Published: Jan. 1, 2024

Language: Английский

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