Babak Mohammadi
Doctoral student
Credibility of design rainfall estimates for drainage infrastructures : extent of disregard in Nigeria and proposed framework for practice
Author
Summary, in English
Rainfall intensity or depth estimates are vital input for hydrologic and hydraulic models used in designing drainage infrastructures. Unfortunately, these estimates are susceptible to different sources of uncertainties including climate change, which could have high implications on the cost and design of hydraulic structures. This study adopts a systematic literature review to ascertain the disregard of credibility assessment of rainfall estimates in Nigeria. Thereafter, a simple framework for informing the practice of reliability check of rainfall estimates was proposed using freely available open-source tools and applied to the north central region of Nigeria. The study revealed through a synthesis matrix that in the last decade, both empirical and theoretical methods have been applied in predicting design rainfall intensities or depths for different frequencies across Nigeria, but none of the selected studies assessed the credibility of the design estimates. This study has established through the application of the proposed framework that drainage infrastructure designed in the study area using 100–1000-year return periods are more susceptible to error. And that the extent of the credibility of quantitative estimates of extreme rains leading to flooding is not equal for each variability indicator across a large spatial region. Hence, to optimize informed decision-making regarding flood risk reduction by risk assessor, variability and uncertainty of rainfall estimates should be assessed spatially to minimize erroneous deductions.
Department/s
- Dept of Physical Geography and Ecosystem Science
Publishing year
2021-07-19
Language
English
Pages
1557-1588
Publication/Series
Natural Hazards
Volume
109
Issue
2
Document type
Journal article
Publisher
Springer
Topic
- Physical Geography
- Water Engineering
Keywords
- Design rainfall estimates
- Parametric bootstrap
- Stochastic simulation
- Two-dimensional Monte Carlo framework
- Variability and uncertainty analysis
Status
Published
ISBN/ISSN/Other
- ISSN: 0921-030X