Investigation of the Urban Gully Erosion in some Indigenous Communities of Ibadan, Southwestern Nigeria.

Abstract

The interaction between environmental change and land degradation is of importance in geomorphology. Gully erosion, influenced by soil characteristics, geomorphic dynamics, and human activities, remains a notable environmental threat to infrastructure and community well-being in urban areas. This study examines the interaction between gully morphology and soil properties in the densely populated indigenous communities of Ibadan, southwestern Nigeria, to better understand urban gully erosion dynamics. Three gully sites (Komoboje-Omiyale, Kombomoje-Oosa-diya, and Idiikan-Olokun) were investigated through field measurements of gully dimensions and topsoil sampling at 0-15 cm and 15-30 cm depths. Correlation analysis was used to examine the degree of association between gully morphology (width, depth and volume) and soil properties (textural composition, exchangeable acidity, pH, electrical conductivity, organic matter and base cations). Maximum gully length, width and depth of 80.23 m, 30.10 m and 3.75 m, respectively were identified. Total sediment loss was estimated at 1755.81 tons. Gullies are predominantly wide and shallow with active vertical corrosion. Soil textural composition is largely sandy (>70%), while the presence of sodium (18-20 mg/kg) and potassium (2-7 mg/kg) in varying concentrations encourages soil dispersion. A significant positive correlation exists between gully depth and sodium concentration (r = 0.69, p < 0.05). Anthropogenic activities, including the use of gullies for waste disposal, contributed significantly to gully expansion. This study highlights the importance of integrating geomorphic processes and socio-environmental factors in sustainable urban landscape management, with a need for further research on the role of pedological variability and human activities in gully formation.

Publication Info:

Author: Obateru, R.O. and Fashae, O.A

Volume: 60

Issue: September

Published By: Journal of Mining and Geology , 2024-01-09