Copula-Based Simulation for the Estimation of Optimal Volume for a Detention Basin

Poisson rectangular pulses (PRPs) model describes the probabilistic nature of the average intensity and duration of storms. However, no consideration is given to the peak intensity or the relative position of the peak intensity of the storm. PRP model simplifies the procedure, and makes it attractive to hydrologists; however it can often produce inconsistencies and significant bias in flood estimates, which can lead to the under- or overdesign of engineering structures. This article proposes a model that overcomes the limitations of PRP model by treating the three storm rainfall components (i.e., storm duration, intensity, and the relative position of the peak intensity) as random variables. Their marginal distributions are modeled by using a heavy tailed law, namely, a generalized Pareto as well as Gumbel distributions. The statistical dependence between these three random variables is then modeled using 2-copulas. Finally, the model proposed in this article is applied to the predesign of a detention basin in the city of Granada (Spain).