Question

Three pixels P, Q, and R in an image are characterized by the NDVI values of +0.84, +0.01, and -0.89, respectively. Which of the following options is/are correct?

• A. P is from vegetation area and Q is from barren land
• B. Q is from water body and R is from barren land
• C. Q is from barren land and R is from water body
• D. P is from vegetation area and Q is from water body

Hint:

NDVI values close to +1 indicate healthy vegetation, values close to 0 indicate barren land, and negative values suggest the presence of water bodies.

Answer 1

The Correct Option is A, C

Step 1: Understanding NDVI Values
The NDVI (Normalized Difference Vegetation Index) values are commonly used to assess the presence of vegetation in a given area:
NDVI value for vegetation: Typically ranges from +0.2 to +1.0, with higher values indicating more dense and healthy vegetation.
NDVI value for barren land: Close to 0, indicating the absence of vegetation.
NDVI value for water body: Usually negative, generally ranging from -0.2 to -0.8.

Step 2: Analyzing Given Values
P (+0.84): This value is close to 1, indicating dense vegetation, so P is from a vegetation area.
Q (+0.01): This value is very close to 0, indicating barren land, so Q is from barren land.
R (-0.89): This value is negative, indicating a water body, so R is from a water body.

Step 3: Conclusion
Option (A) is correct because P represents vegetation, and Q represents barren land.
Option (C) is correct because Q represents barren land, and R represents a water body.