Estimation of risk measures for extreme pluviometrical measurements
Abstract
Many risk measures can be found in the literature such as the Value-at-Risk and the Conditional Tail Expectation. In statistical terms, the Value-at-Risk is aquantile of the distribution of the variable of interest. In hydrology, the Value-at-Risk of the rainfall distribution is the return level. The Conditional Tail Expectation is the mean of the rainfalls larger than the Value-at-Risk. Here, we focus on the properties of these risk measures in case of extreme rainfall modeled by heavy-tailed distributions. In order to take into account the geographical factors, we also assume that these risk measures depend on a covariate. We present the theoretical properties of our estimators and we illustrate their behaviour on a real data set of daily rainfalls in the Cévennes-Vivarais region.