WV2 (2 m)

[73] [74]

Larsemann Hills, Antarctica

NDWI-based indices approach offers several advantages as it is consistent in extracting water bodies against noise, flexible as the threshold values can be adjusted to remove background noise by not affecting the target extraction, time efficient in processing and producing the output and comparatively easier to implement.

Landsat ETM+ (15 m and 30 m)


Lake Merzbacher, border of China

Threshold 0.35 to 0.55

To accurately extract area of floating ice, ratio is used:

Results show that the index can predict the outburst process of the lake and determine the outburst period of the lake after its drainage had occurred.

The automatic program is not so perfect due to the Interferential factors such as snow or spissatus in images (accuracy= 92.0%).

Landsat TM and SPOT

(Fused 10 m)


Swiss Alps

Simple channel ratio:

TM4 and TM1 bands can be replaced by TM5 and TM7, but TM4 and TM1 are capable of discriminating water from snow and ice more accurately. The simple channel ratio works well, but NDWI showed an enhanced contrast between water and surrounding environment.