Best practice for the estimation of extremes:: A review

Task 2: Estimation of Extremes of the European Union research project FLOODsite was dedicated to analysing single and joint probability extremes in river, coastal and estuarine environments. It considers the sources of risk, such as river flow and level, wave height, period and direction, and sea level. Herein the work done within Task 2 is reviewed. Several statistical models and various fitting techniques are described. Planning an appropriate extremes analysis involves an understanding of the problem to be addressed, selection and preparation of source data, selection of methods for analysis and parameter fitting, and use of the derived extremes to address the problem. The applications described illustrate some of the pitfalls and difficulties associated with extreme predictions, particularly for the case of more than one variable. Understanding the assumptions and interpreting the obtained results are important for extreme analysis.