**3.5 NDVI calculation**

Normalized Difference Vegetation Index (NDVI) was computed among several spectral indices. The relevant bands for NDVI are Red and NIR. NDVI is a simple but also undoubtedly effective and extensively implemented index for quantifying green vegetation. NDVI values range from −1 to +1. Negative values suggest the existence of water bodies. Values close to zero (−0.1–0.1) typically correspond to barren land. Values above 0.1 commonly indicate the existence of green vegetation [35]. NDVI of the study area is presented in **Figure 4**.

As shown in **Figure 4**, values from 0 to 0.2 clearly indicate the existence of mine areas, as it can be visually recognized from the natural color image. This

**Figure 4.** *NDVI of the imagery.*

*Delineation of Open-Pit Mining Boundaries on Multispectral Imagery DOI: http://dx.doi.org/10.5772/intechopen.94120*

observation lead to the exploitation of this specific feature to extract the boundaries of mine areas.
