Estimating return values of environmental parameters

Abstract

Abstract Return values of an environmental parameter, such as wind speed or wave height, are frequently estimated from an extreme value analysis of observed annual maxima assuming that the parameter is identically distributed throughout the year. Environmental data generally have considerable within‐year variation. an indication of the error in return values resulting from this assumption is obtained by analysing monthly maxima of wave height and wind speed data. It appears that the assumption leads to an underestimation of return values.