Abstract

Besides peakflow, a flood event is also characterized by other possibly mutually correlated variables. This study was aimed at exploring the statistical distribution of peakflow, flood duration and flood volume for Johor River in south of Peninsular Malaysia. Hourly data were recorded for 45 years from the Rantau Panjang gauging station. The annual peakflow was selected from the maximum flow in each water year (July-June). Five probability distributions, namely Gamma, Generalized Pareto, Beta, Pearson and Generalized Extreme Value (GEV) were used to model the distribution of peakflow events. Anderson-Darling and Chi-squared goodness-of-fit tests were used to evaluate the best fit. Goodness-of-fit tests at 5% level of significance indicate that all the models can be used to model the distribution of peakflow, flood duration and flood volume. However, Generalized Pareto distribution was found to be the most suitable model when tested with the Anderson-Darling-Smirnov test and the Chi-squared test suggested that Generalized Extreme Value was the best for peakflow. The result of this research can be used to improve flood frequency analysis.

Keywords:

Flood frequency characteristic, goodness-of-fit test, probability distribution,

References

Competing interests

The authors have no competing interests.

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Copyright

The authors have no competing interests.