Distinguishing surface cyanobacterial blooms and aquatic macrophytes using Landsat/TM and ETMÂ + shortwave infrared bands

The results showed that the spectral characteristics of cyanobacterial blooms were significantly different from those of aquatic macrophytes in the short-wave infrared (SWIR) region, indicating that the SWIR bands are important for distinguishing cyanobacterial blooms and aquatic macrophytes. The results also showed that the combination of FAI and NDWI4,5 was an effective method for classifying lake areas. We first used the FAI for extracting lake waters, and we then used the NDWI4,5 to classify the remaining areas as cyanobacterial blooms or aquatic macrophytes. The results also showed that the threshold of NDWI4,5 was less sensitive to the effects of both the atmosphere and mixed pixels compared to the other indices. Our application of the FAI threshold of 0.05 and the NDWI4,5 threshold of 0.63 to six lakes in Japan and Indonesia showed that the proposed method could successfully distinguish lake water, cyanobacterial blooms, and aquatic macrophytes.