Sensitivity Analysis and Uncertainty Estimation for Tephra Dispersal Models

Sensitivity analysis and uncertainty estimation are crucial to the validation and calibration of numerical models. In this paper we present the application of sensitivity analyses, parameter estimations and Monte-Carlo uncertainty analyses on TEPHRA, an advection-diffusion model for the description of particle dispersion and sedimentation from volcanic plumes. The model and the related sensitivity analysis are tested on two sub-plinian eruptions: the 22 July 1998 eruption of Etna volcano (Italy) and the 17 June 1996 eruption of Ruapehu volcano (New Zealand). Sensitivity analyses are key to (i) constrain crucial eruption parameters (e.g. total erupted mass) (ii) reduce the number of variables by eliminating non-influential parameters (e.g. particle density) and (iii) investigate the interactions among all input parameters (plume height, total grain-size distribution, diffusion coefficient, fall-time threshold and mass-distribution parameter). In addition, the uncertainty of predicted tephra accumulation can also be evaluated, with important implications for hazard assessment of a given volcano.

SCOLLO Simona;  TARANTOLA Stefano;  BONADONNA Costanza;  COLTELLI Mauro;  SALTELLI Andrea; 

2008-09-23

AMER GEOPHYSICAL UNION

JRC35449

0148-0227,   

http://www.agu.org/pubs/crossref/2008/2006JB004864.shtml,    https://publications.jrc.ec.europa.eu/repository/handle/JRC35449,   

10.1029/2006JB004864,