Fig. 1. Normalized mean spectral curves for different types of substrates and schematic of BRN index for other water

Fig. 2. Frequency distributions of normalized apparent reflectance in different bands for pixels of different types of substrates. (a) Blue band; (b) green band; (c) red band; (d) NIR band

Fig. 3. Frequency distributions of BRN index and NDVI for seagrass water and other water. (a) BRN index; (b) NDVI

Fig. 4. Normalized mean spectral curves for seagrass water and other water in overlapping intervals, and schematic of Δz index for other water

Fig. 5. Frequency distribution of Δz index for seagrass water and other water

Fig. 6. Flowchart of seagrass satellite remote sensing detection model

Fig. 7. Accuracy evaluation of seagrass satellite remote sensing detection model. (a)(d) False-color images of Swan Lake; (b)(e) seagrass distribution results extracted by seagrass satellite remote sensing detection model; (c)(f) distributions of BRN index for seagrass water extracted by seagrass satellite remote sensing detection model

Fig. 8. Changes of CPA and AA of seagrass in Swan Lake, 2023

Fig. 9. Changes of AD of seagrass in Swan Lake, 2023

Fig. 10. Variation of CPA of seagrass of Swan Lake from 2018 to 2023

Fig. 11. Mean spectral curves for pixels of different types of substrates before normalization

Fig. 12. Frequency distributions of BRN index and Δz index for seagrass water, other water and turbidity water. (a) BRN index; (b) Δz index