The chromophoric dissolved organic matter (CDOM) would affect bio-optical properties of inland water. The large-scale CDOM remote sensing research for inland waters is needed as a useful proxy for water quality assessment in complex aquatic systems.
The remote sensing application for different types of inland waters with complex absorption characteristics is always with low precision and complex parameterization of inland waters for past years. To overcome these limitations and expand the applicability of CDOM models, researchers have incorporated band ratios.
In a recent study published in Journal of Environmental Management, Dr. Liu Ge and Dr. Shang Yingxin from the Northeast Institute of Geography and Agroecology (IGA) of the Chinese Academy of Sciences proposed CDOM retrieval models using Sentinel-2 images and in-situ reflectance spectral data.
The researchers developed empirical algorithms for CDOM coefficient estimation between aCDOM(355) and reflectance band ratio (vegetation Red Edge/Blue) based on the trophic state of water reservoirs using field measurements and remotely-sensed images.
The Location of the sampled reservoirs for model calibration, validation and mapping across China.
The results showed that relationships are stronger (r2 > 0.7, p < 0.05) when analysis was conducted separately by the classification of trophic states. Validation models showed that it is possible to expand the geographical range of remote sensing-based models to determine CDOM.
This study provided a strategy for using local and remote sensing data to monitor the spatial variations of CDOM in reservoirs based on trophic states, and will contribute to water resources management.
Contact: SHANG Yingxin
Northeast Institute of Geography and Agroecology
E-mail: shangyinxgin@iga.ac.cn
Reference: Remote estimates of CDOM using Sentinel-2 remote sensing data in reservoirs with different trophic states across China
