Natural breaks ndvi mean
IntroductionVegetation in cities is generally very appreciated but not always considered as a priority by the land use planning services. Should one now define green areas installations in cities as priority need ? Indeed this interesting question needs to be approached from different viewpoints. Vegetation in urban zones is important for the population comfort as it can provides relaxation and recreational areas and also a scenic beauty. But according to several recent studies, urban vegetation could also have real benefits on several Environmental health criteria1. For example, the Urban Heat Island as an urban area that is significantly warmer than its rural surrounding (due tu human activities) could possibly aggravate the situation about global warming. This phenomenon could eventually be better controled thanks to green roofs or gardens. This study aim to caracterize the relation between a vegetation index and thermal data in the city of Geneva, Swtizerland, in order to see if vegetation can be an efficient answer to overheating in cities.DataThe data 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 (NDVI), 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 considered as an indicator about the ground surface temperature. We'll assume that high values imply high ground surface temperatures and low values imply low ground surface temperatures.