Modelling Rainfall Intensity by Optimization Technique in Abeokuta, South-West, Nigeria

Main Article Content

A. O. David
Ify L. Nwaogazie
J. C. Agunwamba


The design of water resources engineering control structures is best achieved with adequate estimation of rainfall intensity over a particular catchment. To develop the rainfall intensity, duration and frequency (IDF) models, 25 year daily rainfall data were collected from Nigerian Meteorological Agency (NIMET) Abuja for Abeokuta. The annual maximum rainfall amounts with durations of 5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240, 300 and 420 minutes were extracted and subjected to frequency analysis using the Excel Optimization Solver wizard. Specific and general IDF models were developed for return periods of 2, 5, 10, 25, 50 and 100 years using the Gumbel Extreme Value Type -1 and Log Pearson Type -3 distributions. The Anderson-Darling goodness of fit test was used to ascertain the best fit probability distribution. The R2 values range from 0.973 – 0.993 and the Mean Squared Error, MSE from 84.49 – 134.56 for the Gumbel and 0.964 – 0.997 with MSE of 42.88 – 118.68 for Log Pearson Type -3 distribution, respectively. The probability distribution models are recommended for the prediction of rainfall intensities for Abeokuta metropolis.

Abeokuta, excel optimization solver, Gumbel extreme value type -1, IDF models, Log Pearson type -3 distributions

Article Details

How to Cite
David, A. O., L. Nwaogazie, I., & Agunwamba, J. C. (2019). Modelling Rainfall Intensity by Optimization Technique in Abeokuta, South-West, Nigeria. Journal of Engineering Research and Reports, 6(4), 1-10.
Original Research Article


Bernard MM. Formulas for rainfall intensities of long duration, Transactions, ASCE, 96 (Paper No.1801). 1932;592624.

Hosking JRM, Wallis JR. Regional frequency analysis: an approach based on L-moments. Cambridge University Press, Cambridge, U.K; 1997.

Ologhadien Itolima, Nwaogazie IL. Comparative analysis of rainfall IDF equation types for predicting rainfall intensity in Southern Nigeria. Nigerian Journal of Technology. 2016;36(4):1296 – 1302.

Nwaogazie IL. Sam-Masi G. Probability and non-probability rainfall intensity duration-frequency modeling for Port-Harcourt metropolis, Nigeria. Int J Hydro. 2019;3(1):66‒75.

Chow VT, Maidment DR, Mays LW. Applied hydrology McGraw-Hill International editions, New York, USA; 1988.

Bell FC. Generalised rainfall duration frequency relationships. Journal of Hydraulic Engineering, ASCE. 1969;95(1):311-327.

Chen CL. Rainfall intensity-duration – Frequency formulas. Journal of Hydraulic Engineering. ASCE. 1983;109(12):1603-1621.

Ekeng BE. Effective implementation of urban storm water drains: A case study of Calabar, in tropical environmental forum, conference proceeding in the polytechnic Calabar, Calabar; 1998.

El-Syed EA. Generation of rainfall intensity duration frequency curves for ungauged sites. Nile Basin Water Science & Engineering Journal. 1961;4(1):112-124.

Hershfield DM. Estimating the probable maximum precipitation. Journal of the Hydraulic Division, Proceeding of the ASCE, HY5. 1961;99–116.

Kothyari UC, Garde RJ. Rainfall intensity duration frequency formula for India. J. Hydr. Engrg. ASCE. 1992;118(2):323-336.

Mohammad Zakwan. Application of optimization technique to estimate IDF parameters. Water And Energy International; 2016.

Nwaogazie Ify L, Duru E. Developing rainfall intensity-frequency model for Port Harcourt. NSE Technical Transaction. 2002;37(2):19-32.

Nwaogazie IL, Uba LO. Urban drainage failures and incidenceof flooding in Southern Nigeria. NSE Technical Transactions. 2001;36(3):43–53.

Nwaogazie IL, Ekwueme MC. Rainfall Intensity-Duration-Frequency (IDF) models for Uyo city, Nigeria. Medcrave International Journal of Hydrology. 2017;1(3):63-66.

Nwaogazie IL, Okonkwo SC. Rainfall- intensity-duration-frequency modelling and comparative analysis of developed models for Abakaliki, Ebonyi State, Nigeria. International Journal of Trend in Research and Development. 2017;4(2).

Motes JE, Criswell JT. Sweet potato production. Oklahoma cooperative extension service. Division of Agricultural Sciences and Natural Resources, Oklahoma State University, HLA-6022, 2012; 2010.

Opafola OT, David AO, Lawal NS, Babalola AA. Estimation of water needs of sweet potato (Ipomoea batatas) using the Penman-Monteith model in Abeokuta, South Western Nigeria, Arid Zone Journal of Engineering, Technology and Environment. 2018;14(1):143–152.

Morton J. The impact of climate change on smallholder and subsistence agricultural. Proceedings of the National Academy of Sciences of the United States of America. 2007;104(50):19680–19685.

FAO, Phoebe L, Mohamed AM. Impacts of climate change on farming systems and livelihoods in the Near East and North Africa; 2018.

Sherma CW. Frequency and intensity of excessive rainfalls at Boston Massachusetts, Am Soc, of civil Engrs. 1931;95:951–960.