Abstract
Impact of Change Point Presence in Extreme Rainfall Series on Hydrological Design
The study was conducted on analyzing variation of maximum rainfall data sequences and on impact of change in these datasets on their frequency analysis. This goal was achieved with pettitt test considered in detection of change-point and, with Generalized Extreme Value (GEV) distribution for frequency analysis. Based on the GEV distribution, quantile values at different return periods were estimated for two data sets before and after change-point for each site. The couple of quantile at each return period had significant different. It was emphasized that it is imperative to eliminate the change in data in obtaining reliable data required in the design of hydraulic projects. When double-mass curve method is applied to a data with a change point, it is confirmed that a reliable data would be able to be reached.
Keywords
Maximum rainfall, change-point, Pettitt test, GEV distribution
