Analysis of Oyan River Channel Changes Using Remote Sensing Technology

Abstract

This study employs remote sensing technology to analyze river channel changes in Oyan River, Abeokuta North, Ogun State, Nigeria. Understanding and monitoring river dynamics are essential for ecological sustainability and effective water resource management. Remote sensing and GIS techniques provide a cost-effective and efficient approach to assessing these changes. Landsat satellite images (30m resolution) from 2002 to 2023 at three-year intervals were compared and analyzed.  Land use land cover, river channel, and river bank erosion maps were produced. The quantity of accretion and erosion was assessed using the geoprocessing tool in a GIS system. The results of this study revealed significant morphological changes in the Oyan River channel. Between 2002 and 2011, erosion and accretion affected 95 and 104 hectares, respectively, while 2403 hectares remained unchanged. From 2011 to 2023, erosion and accretion increased to 213 hectares each, with 2294 hectares unchanged. Over the entire study period (2002–2023), 147 hectares underwent erosion, 156 hectares experienced accretion, and 2351 hectares remained stable. A critical period of accelerated erosion occurred between 2011 and 2023, largely influenced by the 2014 flood event, which significantly altered the river's course. These findings highlight the urgent need for effective management strategies to mitigate flood risks and protect surrounding communities and infrastructure, ensuring the sustainable use of river resources.