An Assessment of Water Color for Inland Water in China Using a Landsat 8-Derived Forel-Ule Index and the Google Earth Engine Platform

• Published in: IEEE journal of selected topics in applied earth observations and remote sensing 2021, Vol.14, p.5773-5785
• Main Authors: Chen, Xidong, Liu, Liangyun, Zhang, Xiao, Li, Junsheng, Wang, Shenglei, Liu, Dong, Duan, Hongtao, Song, Kaishan
• Format: Article
• Language: English
• Subjects: Algorithms; Artificial satellites; China; Cloud computing; Color; Consistency; Earth; Forel–Ule index (FUI); Google earth engine; Image color analysis; Imagery; inland water color; Inland waters; lake; Lakes; Landsat; Landsat 8; Landsat satellites; Quality assessment; Quality control; Reflectance; Remote sensing; Satellite imagery; Trophic levels; Water color; Water colour; Water pollution; Water quality; Water quality assessments; Water resources
• ISSN: 1939-1404; 2151-1535
• DOI: 10.1109/JSTARS.2021.3085411

Water color is an important parameter in water quality assessment. However, the existing water color investigations have mostly focused on the lakes with areas greater 1 km 2 . In order to improve the understanding of the color of water bodies in China, a cloud-free composite image of China for the summer of 2015 was generated using time-series of Landsat-8 imagery and the best-available-pixel (BAP) compositing algorithm. Then, the first Forel-Ule index (FUI) water color product with a resolution of 30 m was produced for China using the generated BAP composite and the Google Earth Engine computing platform. Finally, the first national-scale assessment of the FUI of natural lakes with an area >0.01 km 2 ( N  = 60026) was conducted based on the generated FUI product. The generated FUI product was shown to have a high degree of consistency with in situ water surface reflectance-derived FUI (R 2  = 0.90, P