Frequency Analysis of Extreme Mean Annual Rainfall Events
Loading...
Date
2016
Journal Title
Journal ISSN
Volume Title
Publisher
Organising Committee, CIGR 2016
Abstract
Frequency analysis of extreme mean annual rainfall events is important to water resource planners at catchment level because mean annual rainfall is an important parameter in determining mean annual runoff. Mean annual runoff is an important input in determining surface water available for water resource infrastructure development. The objective of this study was to carry out frequency analysis of extreme low mean annual rainfall events in 8 rainfall zones in the Sabie River catchment in South Africa.
Peaks Below Threshold (PBT) method was applied to extract extreme low mean annual rainfall events from 85 year
record. Candidate Model Identification Criterion (CMIC) and Least Sum of Statistic Model Selection Criterion
(LSSMSC) were applied to identify the best fit models for the frequency analysis. Parameters were estimated by
maximum likelihood method. Quantile-Quantile (Q-Q) and Probability-Probability (P-P) plots were applied to evaluate
the performance of the model selection criteria. From the study, the quantiles at return periods of 5, 10, 25, 50, 100 and 200 years for each of 8 rainfall zones in Sabie River catchment were obtained. Based on the results of the study, no single probability distribution function or model is the best fit for frequency analysis of extreme low mean annual rainfall events in all 8 rainfall zones Sabie River catchment.
Description
Keywords
least sum of statistics model selection criterion, Best fit probability distribution function, Candidate model identification criterion
Citation
Masereka, E. M., Otieno, F. A. O., Ochieng, G. M., & Snyman, J. (2016). Frequency analysis of extreme mean annual rainfall events. In CIGR-AgEng Conference, 26-29 June 2016, Aarhus, Denmark. Abstracts and Full papers (pp. 1-7). Organising Committee, CIGR 2016.