Previsão de cheias com extensão de registros através de modelos determinísticos

Abstract

The costs, shapes and dimensions of the structures involved in any hydraulic project are strongly influenced by the selected "design flood" value. Thus, a reliable determination of the flood frequency at the project site is one of the most important requirements in its development. The well-known methodology called flood frequency analysis has the inconvenient of limiting the results precision, when applied to a short period of historical data. The main objective of this work is to analyze the use of deterministic mathematical models for the extension of the available observed values, in order to obtain a more precise evaluation of the magnitude of flows associated with several return periods. The flood frequency analysis was applied to three different types of data sets: samples of 30 years of observed records; samples composed by the first 10 years of theses records; and extended 30 year samples, obtained by the application of a deterministic model to the sets of the first 10 years of observed records. The comparison of the results obtained for the different types of data sets with the "real" flood values associated to several recurrence intervals indicates the validity of the proposed methodology.