Spatial relationship between NDVI, EVI, SAVI and land cover change in the Lake Chad area from 1987 to 2017

Abstract

The interpretation and analysis of remotely sensed data for land cover change detection can be enhanced with the use of vegetation indices. This study used Landsat imageries to assess the relationship between the normalized difference vegetation index (NDVI), the enhanced vegetation index (EVI) the soil adjusted vegetation index (SAVI), and land cover changes in the Lake Chad area with a view to providing an informed perspective on changes within the lake’s environment. The Landsat imageries were subjected to maximum likelihood classification to extract land cover and the VIs were calculated. The interim results show that between 1987 and 2017, built-up areas and bare lands increased by 174.69km2 and 349.90km2 respectively while vegetation increased by 2,290.10km2. The water bodies reduced by 937.54km2 during the period. The correlation coefficient between NDVI, EVI, and SAVI in 1987 and 2017 is strongly positive. These are interim results presented from an ongoing study. Further research can determine the pattern and trajectory of the observed changes in the Lake Chad area.