Articles | Volume 371
12 Jun 2015
 | 12 Jun 2015

The evaluation of regional frequency analyses methods for nonstationary data

W. Nam, S. Kim, H. Kim, K. Joo, and J.-H. Heo

Abstract. Regional frequency analysis is widely used to estimate more reliable quantiles of extreme hydro-meteorological events. The stationarity of data is required for its application. This assumption tends to be violated due to climate change. In this paper, four nonstationary index flood models were used to analyze the nonstationary regional data. Monte Carlo simulation was used to evaluate the performances of these models for the generalized extreme value distribution with linearly time varying location parameter and constant scale and shape parameters. As a results, it was found that the index flood model with time-invariant index flood and time-variant growth curve could yield more statistically efficient quantile when record is long enough to show significant nonstationarity.

Short summary
Regional frequency analysis gives a quantity for the design of hydaulic structures. The stationarity of record shuld be assumed for its application. Climate change and anthropogenic factors can, however, violate this assumption. Nonstatonary regioanl frequency analysis, therefore, is required. There can be four types of index flood models as a representative technique for nonstationary regional frequency analysis. This research focused on the evaluation of their perfomances.