Quantifying lahar damage using numerical modelling
Stuart R. Mead1,2, Christina Magill1, Vincent Lemiale2, Jean-Claude Thouret3, and Mahesh Prakash21Risk Frontiers, Department of Environmental Science, Macquarie University, Sydney, Australia 2Commonwealth Scientific and Industrial Research Organisation, Clayton 3168, Victoria, Australia 3Laboratoire Magmas et Volcans UMR6524 CNRS, IRD and OPGC, University Blaise Pascal, Campus Les Cézeaux, 63178 Aubière, France
Received: 29 Aug 2016 – Accepted for review: 01 Sep 2016 – Discussion started: 02 Sep 2016
Abstract. Lahars are volcanic flows containing a mixture of fluid and sediment that have caused significant damage to buildings, critical infrastructure and human life. The extent of this damage is controlled by properties of the lahar, location of elements at risk and susceptibility of these elements to the lahar. Here we focus on understanding lahar-induced building damage. Quantification of building damage can be difficult due to the complexity of lahar behaviour (hazard), uncertainty in number and type of buildings exposed to the lahar (exposure) and the uncertain susceptibility of buildings to lahar induced damage (vulnerability). In this paper, we quantify and examine the relative importance of lahar hazard, exposure and vulnerability in determining building damage with reference to a case study in the city of Arequipa, Peru. Numerical modelling is used to investigate lahar properties important in determining the inundation area and forces applied to buildings. Building vulnerability is quantified through the development of critical depth–pressure curves based on the ultimate bending moment of masonry structures. In the case study area, results suggest that building strength plays a minor role in determining overall building losses in comparison to the effects of building exposure and lahar hazard properties such as hydraulic characteristics of the flow.
Mead, S. R., Magill, C., Lemiale, V., Thouret, J.-C., and Prakash, M.: Quantifying lahar damage using numerical modelling, Nat. Hazards Earth Syst. Sci. Discuss., doi:10.5194/nhess-2016-282, in review, 2016.