Breakthrough in high-resolution vegetation mapping: China's leap towards advanced environmental monitoring

Fractional Vegetation Cover (FVC), key for ecological studies, has historically been mapped at coarse resolutions. Recent high-resolution satellite data have increased the demand for finer FVC products. However, combining fine spatial resolution with high temporal frequency remains challenging. Traditional estimation methods like the Vegetation Index (VI)-based mixture model struggle with accuracy due to difficulties in parameter determination.

For a study published in the Journal of Remote Sensing on 19 December 2023, a team of scientists led by Xihan Mu from Beijing Normal University has made a leap forward in environmental monitoring and ecological research. They have created seamless maps of Fractional Vegetation Cover (FVC) over China at 30-meter resolution and semimonthly intervals, covering the years 2010-2020.

The researchers adopted an adaptive time-series model for creating clear, seamless, and radiometrically consistent Normalized Difference Vegetation Index (NDVI) image composites using all available Landsat images in Google Earth Engine. They have developed a method that transforms Landsat NDVI datasets into a detailed Fractional Vegetation Cover (FVC) map using an improved VI-based mixture model. At the heart of this innovation is the MultiVI algorithm, which precisely calculates pixel-wise coefficients to transform NDVI into FVC. This method marks a major advancement over traditional VI-based mixture models, which typically depend on less accurate, statistically derived endmember VI values. MultiVI, on the other hand, employs multiangle data to generate pixel-wise endmember VI values, resulting in a more refined and accurate FVC calculation. The researchers validated this approach by comparing the generated FVC with ground measurements and existing global FVC products, demonstrating its good spatial and temporal consistency. The results underscored the method's superiority in capturing detailed vegetation patterns and dynamics with high accuracy, surpassing traditional models. This intricate mapping process fosters a more nuanced understanding of the Earth's vegetation cover and has potential applications in environmental monitoring, agricultural management, and climate change studies.

Dr. Xihan Mu, the lead researcher, emphasized, "This method not only refines the spatial resolution of FVC mapping with good accuracy but also captures the temporal changes in vegetation cover, marking a technological progress in remote sensing and ecological monitoring."

The 30-m/15-day FVC mapping carries profound implications for various applications, significantly enhancing ecological assessments, crop monitoring, and detailed vegetation analysis—all crucial for understanding and mitigating climate change effects. Additionally, it provides invaluable data for precision agriculture, urban ecosystem research, and soil erosion risk assessments, thereby boosting our capacity to monitor and respond effectively to environmental changes.

This research represents a new advancement in high-resolution vegetation mapping, offering a fresh perspective on Earth's terrestrial ecosystems. As this method continues to be adopted and refined, it promises to enhance environmental monitoring and management, unlocking new possibilities for a sustainable future.

###

References

DOI

10.34133/remotesensing.0101

Original Source URL

https://doi.org/10.34133/remotesensing.0101

Funding information

The National Natural Science Foundation of China (42090013, 42271338, and 41871230).

About Journal of Remote Sensing

The Journal of Remote Sensing, an online-only Open Access journal published in association with AIR-CAS, promotes the theory, science, and technology of remote sensing, as well as interdisciplinary research within earth and information science.