Choose the correct statements about Normalized Difference Water Index (NDWI).
1. It is a satellite-derived index from the Near-Infrared (NIR) and Short Wave Infrared (SWIR) channels
2. It's very useful for drought monitoring and early warning
3. It is a normalized index for estimating the leaf water content at the canopy level.
4. It is associated with vegetation canopy characteristics such as biomass, leaf area index, and percentage of vegetation cover.
1
1 and 2 only
2
1, 2 and 3 only
3
2 and 3 only
4
1, 3 and 4 only