Flood Frequency Analysis (FFA) in Spanish catchments

Abstract

Summary A frequency analysis of rainfall and flow from the available data and applications in Spain takes place. In the case of streamflow, various methods that can be grouped into two categories are used, (1) the gauged method which consist in the analysis of maximum flow rate annual series, and (2) the hydro-meteorological method which take into account processes with rainfall–runoff transformation models. The results are compared with observed data in historical series. Finally, six episodes with actual rainfall and flow record are analyzed. These episodes are also classified according to their frequency domain and results obtained from models are contrasted. To make this work we have used two applications launched in the University of Zaragoza: the SHEE program, which provides a simple and flexible working environment which allows the simultaneous management of the most actual and important databases from a hydrological point of view, highlighting the digital terrain models, the rainfall coverage and the curve number coverage, and that is suitable for the application of hydro-meteorological models; and the EHVE software, which is a hydrological statistical program for analysis of time series of extreme values, suitable for application in models of gauged data.