Distribution of Floods Frequency of Manafwa River, Uganda

  • Joseph Micheal Okoth Busitema University
  • Daniel Otim, PhD Busitema University
  • Edwin Kamalha, PhD Busitema University
Keywords: Flood Frequency, River Flows, Manafwa River, Floodplains, Distribution Analysis
Share Article:


The objective of this study was to analyse Manafwa River flood frequency in Eastern Uganda. Analysis of Manafwa River maximum annual flows from 1949-2015 was undertaken using Log Pearson 3 distribution in comparison with Gumbel, Normal and Log Normal distributions to determine frequency of occurrence and magnitude of extreme floods. Statistical analysis including goodness of fit tests of chi-square, Kolmogorov-Smirnov and Anderson-Darling tests were used to generate the most suitable probability distribution model. The results show quantile magnitudes lowest for Log Normal distribution at 43.59 m3/s and highest for Log Pearson 3 distribution at 51.67 m3/s. The 5-year quantile estimates are highest for Normal and Log Pearson at 70.37 m3/s and 63.99 m3/s respectively. The 10-year quantile estimates are highest for Log Normal and lowest for Log Pearson 3 distributions at 87.57 m3/s and 75.13 m3/s respectively. The 100-year quantile estimates are lowest for Normal and highest for Log Normal distributions at 108.57 m3/s and 154.66 m3/s respectively. The 200-year quantile estimates are lowest for Normal and highest for Log Normal distributions respectively at 114.980 m3/s and 177.16 m3/s respectively. Log Pearson 3 distribution emerged as best fit for data. From the statistical analysis, LP 3 probability distribution presents the most accurate regression coefficient at 0.8486 and the most suitable distribution of goodness of best fit using A-D, K-S and Chi square tests followed by the Gumbel distribution. The tests yield 0.15666, 0.04855 and 0.88502 for A-D, K-S and Chi square tests respectively for the LP 3 distribution. There is an increasing upward trend of the discharges at Manafwa River floodplains at higher probabilities of exceedance across all the probability distributions due to varrying climatic changes and rapid landuse changes in the Manafwa catchment. Manafwa river floodplains have the capacity to accommodate and boost crop production and productivity. Any nutrients lost to leaching could be gained from subsequent fallowing and sustainable soil fertility management including; proper drainage, crop rotation, adding organic manure, cover cropping and among others


Download data is not yet available.


Agrawal, S., Gopalakrishnan, T., Gorokhovich, Y., & Doocy, S. (2013). Risk factors for injuries in landslide- and flood-affected populations in Uganda. Prehospital and Disaster Medicine, 28(4), 314–321. https://doi.org/10.1017/S1049023X13000356

Alghazali, N. O., & Alawadi, D. A. (2014). Fitting statistical distributions of monthly rainfall for some Iraqi stations. Civil and Environmental Research, 6(6), 40–46.

Aslam, M. (2019). Introducing Kolmogorov–Smirnov tests under uncertainty: an application to radioactive data. ACS Omega, 5(1), 914–917.

Bai, Y., Zhang, Z., & Zhao, W. (2019). Assessing the impact of climate change on flood events using HEC-HMS and CMIP5. Water, Air, & Soil Pollution, 230(6), 1–13.

Bhat, M. S., Alam, A., Ahmad, B., Kotlia, B. S., Farooq, H., Taloor, A. K., & Ahmad, S. (2019). Flood frequency analysis of river Jhelum in Kashmir basin. Quaternary International, 507, 288–294. https://doi.org/10.1016/j.quaint.2018.09.039

Bingwa, F. (2013). A quantitative analysis of the impact of land use changes on floods in the Manafwa River Basin. Massachusetts Institute of Technology.

Cecinati, F. (2013). Precipitation analysis for a flood early warning system in the Manafwa River Basin, Uganda. Massachusetts Institute of Technology.

Châu, V. N. (2014). Assessing the Impacts of Extreme Floods on Agriculture in Vietnam : Quang Nam Case Study. 214.

Chow, V. Te, Maidment, D. R., & Mays, L. W. (1988). Applied_Hydrology_Chow_1988. McGraw-Hill.

Dis, M. O., Anagnostou, E., & Mei, Y. (2018). Using high-resolution satellite precipitation for flood frequency analysis: case study over the Connecticut River Basin. Journal of Flood Risk Management, 11, S514–S526. https://doi.org/10.1111/jfr3.12250

Ehiorobo, J. O., & Izinyon, O. C. (2013b). Flood Frequency Analysis at Oshun River in Asejire Dam Site, Nigeria. In Journal of Earth Science and Engineering (Vol. 3).

Ehiorobo, J. O., & Uso, N. O. (2014). Flood Frequency Analysis in the Lower River Niger Basin at Onitsha. Journal of Engineering Research, 19(1). www.waado.org/nigerdelta/nigeria_facts/nigerianmaps/nigeria_cities.html

Farooq, M., Shafique, M., & Khattak, M. S. (2018). Flood frequency analysis of river swat using Log Pearson type 3, Generalized Extreme Value, Normal, and Gumbel Max distribution methods. Arabian Journal of Geosciences, 11(9). https://doi.org/10.1007/s12517-018-3553-z

Franks, S. W., & Kuczera, G. (2002). Flood frequency analysis: Evidence and implications of secular climate variability, New South Wales. Water Resources Research, 38(5), 20-1-20–27. https://doi.org/10.1029/2001wr000232

Ibrahim, U. A., Yadima, S. G., & Nur Alkali, A. (2016). Flood Frequency Analysis at Hadejia River in Hadejia–Jama’are River Basin, Nigeria. Civil and Engineering Research, 8(9), 514–2225.

Kamal, V., Mukherjee, S., Singh, P., Sen, R., Vishwakarma, C. A., Sajadi, P., Asthana, H., & Rena, V. (2017a). Flood frequency analysis of Ganga river at Haridwar and Garhmukteshwar. Applied Water Science, 7(4), 1979–1986.

Kundu, P. M., Singo, R. L., Odiyo, J. O., & Nkuna, R. N. (2014). An evaluation of the effects of climate change on flood frequency in the luvuvhu river catchment, limpopo province, south africa. WIT Transactions on Ecology and the Environment, 185, 157–168. https://doi.org/10.2495/SI140151

Malik, S., & Pal, S. C. (2021). Potential flood frequency analysis and susceptibility mapping using CMIP5 of MIROC5 and HEC-RAS model: a case study of lower Dwarkeswar River, Eastern India. SN Applied Sciences, 3(1). https://doi.org/10.1007/s42452-020-04104-z

Manta, H., & Ahaneku, E. (2009). Flood frequency analysis of Gurara River catchment at Jere, Kaduna State, Nigeria. Scientific Research and Essay, 4(6), 636–646. http://www.academicjournals.org/SRE

Masood, M., & Takeuchi, K. (2012). Assessment of flood hazard, vulnerability and risk of mid-eastern Dhaka using DEM and 1D hydrodynamic model. Natural Hazards, 61(2), 757–770.

Mayega, R. W., Tumuhamye, N., Atuyambe, L., Okello, D., Bua, G., Ssentongo, J., & Bazeyo, W. (2015). Qualitative assessment of resilience to the effects of climate variability in the three communities in Uganda. In RAN Secretariat and East African Resilience Innovation Lab (EA RILab), Kampala.

Mehmood, A., Jia, S., Mahmood, R., Yan, J., & Ahsan, M. (2019). Non-stationary Bayesian modeling of annual maximum floods in a changing environment and implications for flood management in the Kabul River Basin, Pakistan. Water, 11(6), 1246.

Njoku, C., Njoku, C., & Okoro, G. C. (2015). Effect of flooding on soil properties in Abakaliki South-Eastern Nigeria Physico-chemical analysis of water from some selected automobile repairing area in Abakaliki Southeastern Nigeria View project Soil Properties View project Effect of flooding on soil. Scholarly Journal of Agricultural Science, 5(5), 165–168. https://doi.org/10.13140/RG.13314.12489

Njoku, C., & Okoro, G. C. (2015). Effect of flooding on soil properties in Abakaliki South-Eastern Nigeria. Scholarly Journal of Agricultural Science, 5(5), 165–168. http://www.scholarly-journals.com/SJAS

Obubu, J. P., Mengistou, S., Fetahi, T., Alamirew, T., Odong, R., & Ekwacu, S. (2021). Recent climate change in the lake kyoga basin, Uganda: An analysis using short-term and long-term data with standardized precipitation and anomaly indexes. Climate, 9(12). https://doi.org/10.3390/cli9120179

Odunuga, S., & Raji, S. A. (2014). Flood Frequency Analysis and Inundation Mapping of Lower Ogun River Basin. In Journal of Water Resource and Hydraulic Engineering Sept (Vol. 3, Issue 3).

Ogbodo, E. N. (2011). Assessment of Some Soil Fertility Characteristics of Abakaliki Urban Flood Plains of South-East Nigeria, for Sustainable Crop Production. World Journal of Agricultural Sciences, 7(4), 489–495.

Ogwang, B. A., Guirong, T., & Haishan, C. (2012). (droughts) experienced in the years. In Pakistan Journal of Meteorology (Vol. 9).

Olofintoye, O. O., Sule, B. F., & Salami, A. W. (2009). Best–fit Probability distribution model for peak daily rainfall of selected Cities in Nigeria. New York Science Journal, 2(3), 1–1

Pamuttu, D. L., Lasminto, U., Pasalli, D. A., Rada, Y. H. M., & Doloksaribu, A. (2018). The Selection of Rain Distribution Analysis Method in (Bengawan Solo Watershed) Downstream Sub-Watershed. International Conference on Science and Technology (ICST 2018), 416–420.

Roy, P. K., Roy, P., & Kumar De, S. (2015). A comparative approach to flood frequency analysis of the Puthimari river in Assam, India. In asian journal of spatial science (vol. 3).

Singo, L. R., Kundu, P. M., Mathivha, F. I., & Odiyo, J. O. (2016). Evaluation of flood risks using flood frequency models: a case study of Luvuvhu River Catchment in Limpopo Province, South Africa. Urban Water III, 1, 215–226. https://doi.org/10.2495/uw160191

Sinshaw, B. G., Moges, M. A., Kinde Tefera, A., Birhan Atanaw, S., Fenta, H. M., Bazezew, H. A., Geletaw Eshete, D., & Legese, K. G. (2018). Analysis of regional flood frequency and its socio-economic impact in Ethiopia. 12(12). https://doi.org/10.5897/AJEST2018.xxxx

Suhartanto, E., Montarcih Limantara, L., Noviadriana, D., Iman Harta, F., & Aryani, D. K. (2018). Estimation of Design Flood with Four Frequency Analysis Distributions. In Asian Journal of Applied Science and Technology (AJAST) (Open Access Quarterly International Journal (Vol. 2, Issue 1). www.ajast.net

Thomopoulos, N. T., Thomopoulos, N. T., & Philipson. (2018). Probability Distributions. Springer.

Wan Deraman, W. H. A., Abd Mutalib, N. J., & Mukhtar, N. Z. (2017). Determination of return period for flood frequency analysis using normal and related distributions. Journal of Physics: Conference Series, 890(1). https://doi.org/10.1088/1742-6596/890/1/012162

24 January, 2024
How to Cite
Okoth, J., Otim, D., & Kamalha, E. (2024). Distribution of Floods Frequency of Manafwa River, Uganda. East African Journal of Engineering, 7(1), 1-20. https://doi.org/10.37284/eaje.7.1.1670