Fig. 1. The geographical location and surrounding environment of the study area

Fig. 2. Example of sampling point collection

Fig. 3. Spectral characteristics of non-shadow water, shadow and vegetation on water surface

Fig. 4. The scatter diagram of reflectance at 666 nm/791 nm and 492 nm

Fig. 5. Umbra, penumbra, non-shadow water image and reflectance spectral comparison

Fig. 6. The process of surface shadow detection

Fig. 7. The shadow detection result of test scenario 1

Fig. 8. The shadow detection result of test scenario 2

Fig. 9. The shadow detection result of test scenario 3

Fig. 10. The shadow detection result of test scenario 4

Fig. 11. Building shadow and tree shadow recognition effect

Fig. 12. Analysis on the effect of floating objects on water shadow detection

Fig. 13. The results of shadow detection when divided into 2 and 3 categories

Fig. 14. Black and odor water recognition result in test scenario 3 before and after shadow mask