Spatiotemporal Dynamics of Land Use and Land Cover Change in the Surha Tal Wetland, Uttar Pradesh, India

Abstract

Wetland ecosystems are highly responsive to changes in land use and land cover (LU/LC), profoundly affecting hydrological processes, biodiversity, and ecosystem health. The current research examines the spatio-temporal land-use/land-cover (LU/LC) transitions in a 1.5-kilometre buffer zone surrounding Surha Tal, a prominent wetland in Ballia, Uttar Pradesh, over 20 years (2005–2025). Utilizing Landsat 5 and Landsat 8 satellite imagery, and supported by background data from Google Earth, this study employs the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) to examine changes in vegetation cover and the conditions of water bodie. The supervised classification, using the maximum likelihood classification, generated LU/LC maps for the selected years. An accuracy evaluation was performed using a confusion matrix and ground truthing points, resulting in overall classification accuracy exceeding 85%, with Kappa statistics indicating high agreement. Agricultural land saw the largest expansion, increasing from 26.97 km² to 34.50 km², a growth of 27.92%. Similarly, built-up areas more than doubled, growing from 1.89 km² to 3.90 km², a substantial increase of 106.35%. Conversely, natural vegetation experienced a dramatic decline. It decreased from 13.91 km² in 2005 to 3.79 km² in 2025, representing a loss of 72.76%. The water body area showed a complex fluctuation. It initially decreased from 5.30 km² to 4.8 km² between 2005 and 2015, but then recovered to 5.32 km² by 2025. This resulted in a slight net increase of +0.02 km² (0.38%) over the entire period. Aquatic vegetation followed a similar fluctuating pattern, with a net increase of +0.57 km² (4.28%) over the twenty years. These findings correspond with the fact that urbanization and agricultural encroachment are the primary drivers of LU/LC change. The findings highlight an urgent need for action regarding sustainable land-use planning and efficient conservation policies to ensure the ecological integrity of Surha Tal.