Parametric modelling of rainfall return periods in south-western Nigeria: Survival analysis approach

Background: Rainfall is the main source of water on earth’s surface. It infiltrates and percolates deep into soil for groundwater recharge. Rainfall patterns, amounts, durations, intensities can vary daily, monthly, annually, spatially. therefore important to accurately estimate rainfall return periods, which be employed in hydraulic design flood control measures. Methods: This research considered survival analysis approach prediction periods including intensity, months during these would occur south-western Nigeria. Twenty years’ annual data were obtained from three metrological stations subjected nine different probability plotting position methods. Results positions was further four models using five years censor time. The Akaike Information Criterion (AIC) used determine best-fitting model dataset. Results: The Laplace conjunction with log-logistic distribution best describes datasets, since it gave lowest AIC value 22.53. also suitable period Weibull values 6.934 -4.332 respectively. Hirsh description Conclusion: established parametric are accurate peak events any month year.