Mapping NDVI – based Image Differencing (2014-2024) in Sheikan Locality – Sudan

NDVI image differencing stands out as a highly applicable spectral index for observing changes in the greenness of vegetation cover. The study area in Western Sudan has been highlighted in many reports, which indicate that its vegetation cover has faced severe to moderate changes since the mid-1980s. The main aim of this study is to depict changes in land surface greening using the NDVI index in Sheikan locality, Sudan, using three different periods (2014, 2018 and 2024). Landsat-8 OLI images of medium spatial resolution (30*30 m) were obtained from a USGS site (Earth explorer) to quantify NDVI values and pixel counts for the five NDVI maps reclassified classes. The pair periods analysis (2014 – 2018), (2014-2024) and (2018-2024) revealed significant variability in changes between these periods. The results concluded that a positive change occurred during 2014-2018 foe three classes and two classes showed negative changes. The same results applied for the periods 2014-2014 and 2018-2024, which presented three classes of positive NDVI changes and two classes of negative NDVI changes.