FLOOD FREQUENCY ANALYSIS CONSIDERING THE OUTLIER EFFECT

Abstract

Estimation of a flood of desired frequency has an important role in the hydraulic design of water resources project and engineering structures. While designing these, proper safeguards must be made for the safe passage of the maximum flood expected. The designer has to take greater care in the estimation of the design flood in such cases. The estimation of design flood is generally done by frequency analysis of available historical data. However, uncertainly still prevails in the estimation of peak discharge of floods because of the existence of one or more observations which lie far above the other values. These extreme events are termed as 'outliers'. In the present study flood frequency analysis has been made considering the effect of outlier on the flood series.