Towards operational guidelines for over-threshold modeling

Annual maximum flood (AMF) sampling remains the most popular approach to fl ood frequency analysis. An alternative, the "peaks over threshold" (POT) ap proach, deals with the selection of over-threshold values. However, the POT approach remains under-employed mainly because of the complexities associa ted with its use. Among the difficulties are the choice of threshold and th e selection of criteria for retaining flood peaks. The literature remains s parse and incoherent concerning the various elements and complexities of th e POT model. The purpose of the present paper is to shed some light on some of the recurrent and most important questions with regard to the practice of POT modeling, and to make a first step in establishing a set of coherent practice-oriented guidelines for the use of the POT model. This paper revi ews tests and methods useful for modeling the process of over-threshold val ues, the choice of the threshold level, the verification of the independenc e of the values and the stationarity of the process, and also presents an a pplication. (C) 1994 Elsevier Science B.V. All rights reserved.