GIS-based Spatial Analysis and NDVI Assessment of Vegetation Cover along Selected Sites of the Krishna River, Sangli District, Maharashtra, India

Abstract

Riparian vegetation along the Krishna River is spatially heterogeneous because of differences in land use, vegetation density, water availability, and local disturbance. This study assessed vegetation cover at selected sites in Sangli District, Maharashtra, using GIS-based spatial analysis, Landsat 8 OLI imagery, the Normalized Difference Vegetation Index (NDVI), and field observations. Landsat 8 data for Path/Row 147/048 and 147/049 were processed in ArcGIS 10.5. NDVI was used to distinguish water and non-vegetated surfaces from areas with low, moderate, and dense vegetation cover. Across the mapped study area, NDVI values ranged from −1 to 0.66, with the highest class (0.401–0.66) representing dense and comparatively healthy vegetation. GIS-based occurrence mapping at Brahmanal showed that Tamarindus indica was concentrated mainly within or near relatively green riparian zones, while the study appropriately notes that NDVI alone does not determine species distribution. Land-use/land-cover analysis for 1995–2026 showed that agriculture remained the dominant class, accounting for more than 73% of the mapped basin area throughout the period. Agricultural land increased from 188,645 km² (73.54%) in 1995 to 193,205 km² (75.28%) in 2015 and then declined slightly to 191,842 km² (74.74%) in 2026. Degraded land declined from 6,031 km² (2.35%) to 4,092 km² (1.59%). The integrated approach provides a spatial basis for vegetation monitoring and further ecological assessment along the Krishna River.