Analyzing urban sprawl in response to land use land cover change dynamics in Areka town and surrounding area: Wolaita Zone, Ethiopia

Abstract

Urban sprawl, the uncoordinated and spatially dispersed expansion of urban areas into surrounding rural lands, poses significant challenges to sustainable development, resulting in the loss of agricultural and forest land, habitat degradation, and a weakening of ecosystem services. Using Landsat data for 1995 and 2025, LULC was analyzed for spatiotemporal change in Areka Town and its surrounding area, employing GIS and remote sensing techniques. Training samples were generated by combining multiple bands, and supervised classification was performed using the Support Vector Machine (SVM) algorithm. The resulting classification map was validated using a confusion matrix and the Kappa statistic. The Kappa coefficients of the LULC maps for 1995 and 2025 were 0.8942 and 0.9428, respectively. The findings demonstrate that substantial landscape transformation occurred between 1995 and 2025. Built-up areas and vegetation cover increased by 1,188.83 ha (+492.98%) and 1,291.49 ha (+40.09%), with annual rates of increase of 39.63 ha/year (16.43%) and 43.05 ha/year (1.34%), respectively. However, agricultural and bare land decreased by -1875.8 ha (−47.16%) and -604.9 ha (−23.24%), respectively. Population density analysis revealed that, in 2000, it ranged from 244 to 3264 people/km 2 , whereas in 2020 these values rose to 478 to 4,644 people/km 2 , indicating substantial spatial and temporal intensification accompanied by the outward expansion of the built-up area. Spectral indicators (NDVI and NDBI) provide a quantitative assessment of vegetation dynamics and urban expansion. In 1995, NDVI values ranged from 0.06 to 0.39, whereas in 2025, values had shifted slightly to −0.04 to 0.39, indicating a reduction in vegetation vigor and an increase in impervious surfaces (concrete, asphalt, and buildings). Likewise, the NDBI values, which ranged from −0.24 to 0.19 in 1995 and −0.27 to 0.21 in 2025, reveal a consistent increase in built-up intensity. The gradient directional analysis also demonstrated an asymmetric growth pattern radiating outward from the CBD, along the northern (N), northeastern (NE), and southern (S to SSE) axes, associated with infrastructure development and major roads linking the town with emerging peri-urban settlements. The findings would provide critical insights into the spatial extent and pattern of urban sprawl, helping in sustainable urban planning and land resource management. • GIS and remote sensing analysis using Landsat imagery revealed pronounced urban sprawl • LULC supervised classification using the SVM algorithm achieved plausible accuracy • Built-up expanded (+492.98%), at the expense of agricultural (−47.16%) and bare land (−23.24%) • NDVI and NDBI analysis confirmed declining vegetation vigor and increasing urban sprawl • Directional sprawl analysis showed asymmetric outward expansion along major infrastructure development