The data which have been used here come from a Landsat image from 2015. Bands 4, 5 and 11 have been used to compute two variables. The Normalized Vegetation Index, from bands 4 (Red) and 5 (Near Infra-Red), according to the following equation : \(NDVI\ =\ \frac{NIR\ -\ Red}{NIR\ +\ Red}\) .
Thermal data from band 11 has been used as it was, and will be considered as an indicator about the ground surface temperature. We'll assume that high values imply high ground surface temperature and low values imply low ground surface temperature.