Title: An application of copulae in the analysis of sand transport phenomena
Authors: Franco Pellerey - Politecnico di Torino (Italy) [presenting]
Lorenzo Raffaele - Politecnico di Torino (Italy)
Luca Bruno - Politecnico di Torino (Italy)
Luigi Preziosi - Politecnico di Torino (Italy)
Abstract: The reliable prediction of the consequences of aeolian events related to sand transport phenomena is a key element for human activities in many arid regions of the word, and threshold shear velocity generating sand lifting is a key component of such a prediction. To this aim, a list of deterministic semi empirical models have been proposed in the specialized literature. Unfortunately, such models suffer from the effects of uncertainties of different origins, such as those related to physical phenomena or measurement procedures, and are often fitted to a small amount of data. Probabilistic models have been recently proposed as well, but they can be hardly applied since they require the knowledge of the distributions of a large number of random factors. The aim is to describe a purely statistical approach able to provide estimates of fluid threshold shear velocity for sand saltation based on a data set derived from published studies. In this approach, the relationship existing between threshold shear velocity and grain diameter of the sand is described through a suitable copula. Estimates of conditional probability distributions are shown and critically compared to those proposed in previous studies.