Land Use and Land Cover Change Detection Over Three Decades (1995 To 2025) Using Remote Sensing and GIS In the Kushavathi Eru Catchment, Annamayya District, Andhra Pradesh, India

Land use and land cover (LULC) change in semi-arid hard rock catchments alters infiltration, runoff and groundwater recharge, yet decadal evidence at the scale of small watersheds in Rayalaseema remains scarce. This study quantified LULC dynamics in the Kushavathi Eru catchment (257.74 km²), Annamayya District, Andhra Pradesh, for 1995, 2005, 2015 and 2025. Landsat imagery was processed in Google Earth Engine and classified at 30 m into five classes: agriculture, forest, rangeland, built-up land and water bodies. Classification accuracy was assessed against 1,539 independent validation samples, and change was analysed through cross-tabulation, gain and loss components, intensity analysis, trend tests and landscape metrics. Overall accuracy ranged from 88.50% to 90.64% (Kappa 0.850 to 0.878). Agriculture remained the dominant class but contracted from 201.43 km² (78.15%) in 1995 to 188.83 km² (73.26%) in 2025, a net loss of 12.60 km². Built-up land more than doubled, from 5.26 km² to 11.27 km² (+114.27%; 2.54% yr⁻¹), and forest increased by 5.89 km², most of it after 2015. Over the full period 25.53 km² (9.90%) of the catchment changed category; agriculture to forest (8.21 km²) and agriculture to built-up (6.36 km²) were the largest transitions. Annual change intensity rose from 0.623% in 1995 to 2005 to 0.797% in 2015 to 2025, exceeding the uniform rate (0.734% yr⁻¹) in the last two intervals. Agricultural patches fragmented, with mean patch size falling from 112.53 ha to 69.42 ha, while Shannon’s diversity rose from 0.701 to 0.819. The results provide a quantified baseline of land transformation for groundwater potential mapping and watershed planning in the catchment.