Question

Which of the following band is better for delineating water bodies?

• A. \( \text{Blue band} \)
• B. \( \text{Red band} \)
• C. \( \text{Green band} \)
• D. \( \text{Near-infrared band} \)

Hint:

Remember that water absorbs NIR energy like a sponge, making it stand out starkly from land in NIR images.

Answer 1

The Correct Option is D

The near-infrared (NIR) band is generally considered the best for delineating water bodies in satellite imagery. Water strongly absorbs NIR radiation, resulting in very low reflectance values and thus appearing very dark in NIR imagery. This strong contrast between water and land makes it easy to map and delineate water bodies. Blue and green bands have some penetration into water, and the red band is also absorbed by water, but the absorption is most pronounced in the NIR region.