1. Department of Civil Engineering, Federal University of Technology, Akure, Nigeria
2. Formerly of Department of Water Resources and Environmental Engineering, Ahmadu Bello University, Zaria, Nigeria
3. Department of Civil Engineering, Obafemi Awolowo University, Ile–Ife, Nigeria. E-mail: okeia@oauife.edu.ng
4. Department of Civil Engineering, Obafemi Awolowo University, Ile–Ife, Nigeria.