Application of Geospatial Technology for Land Use Land Cover Changes during 1994-2024 in the Lower Dikhow River Basin, Assam, India

Abstract

Monitoring land use and land cover (LULC) change is essential for sustainable land management in dynamic river basins. This study applied geospatial techniques to assess LULC changes in the Lower Dikhow River Basin, Assam, India, over 30 years (1994–2024). Landsat 5 TM imagery was used for 1994 and 2004, while Landsat 8 OLI imagery was used for 2014 and 2024. Images acquired in December were processed in ArcMap 10.8 and classified using a supervised maximum-likelihood approach into nine LULC classes: river, ponds, built-up area, cropland, tree-clad area, plantation, forest, marshes and swamps, and sandy area. Change detection and accuracy assessment were performed using confusion matrices, overall accuracy, and Kappa coefficients. Cropland remained the dominant class, accounting for 42.6% in 1994 and 43.5% in 2024. Over the full study period, built-up area increased by 68.32 km² and marshes and swamps by 17.46 km², whereas tree-clad area and forest decreased by 53.91 km² and 22.00 km², respectively. Plantation declined by 14.94 km², while river and sandy areas showed relatively small net decreases. Overall classification accuracy ranged from 83.61% to 92.50%, with Kappa coefficients from 0.82 to 0.92, indicating almost perfect agreement. The observed changes demonstrate substantial spatial reorganisation of land cover, particularly expansion of built-up areas and reduction of wooded cover. The results provide a geospatial basis for land-use planning and continued LULC monitoring in the basin.