Which value of NDVI indicates the possible presence of water or barren areas?

The correct value indicating the possible presence of water or barren areas is -1. NDVI, or the Normalized Difference Vegetation Index, is used to assess vegetation health, but it can also provide insights into areas with little to no vegetation. NDVI values range from -1 to +1, where higher values (typically above 0.3) indicate healthy vegetation, while lower values suggest less vegetation presence.

A value of -1 is indicative of very sparse or non-existent vegetation, such as water bodies or barren land. This negative value reflects the specific spectral characteristics of water or bare soil, which generally absorb more infrared light and reflect less red light compared to vegetation.

Other values like 0.5 and 1 generally correspond to healthy vegetation, while a value of 0.2 would indicate low vegetation presence but not to the extent of being barren or water. By differentiating these values, NDVI serves as a crucial tool in land cover classification and environmental monitoring.