Simulating the area covered by lava flows by using the DOWNFLOW code (Invited)
Abstract
DOWNFLOW determinates the area inundated by a lava flow in a probabilistic way. After the emission from the vent, if lava emplacement evolves on a slope, the main control on the path followed is constituted by the local topography. The basic idea of DOWNFLOW is that the topography itself is continuously perturbed by the morphological complexities created by the emplacement dynamics of the lava flow. As a result, the path of the flowing lava does not coincide with the simple steepest descent path univocally determined on the initial topography, but it is better described by a bundle of steepest descent paths (SDPs), each path being determined over a topography whose elevation has been perturbed, randomly, within a given elevation interval × Δh. Two parameters are then introduced: the number N of SDPs and the dimension of the perturbation Δh. The envelope of the N SDPs is the result of a DOWNFLOW simulation, and represent the area susceptible of being inundated by the lava emitted from the given vent. DOWNFLOW does not constrain, per se, the length of the flow. For this reason the length parameter is an external probabilistic input which is applied after, on the simulation output. N and Δh are instead tuned before the simulation run through a best-fit session over meaningful past events for the approached scenario.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.V44A..02T
- Keywords:
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- 8488 VOLCANOLOGY Volcanic hazards and risks;
- 8425 VOLCANOLOGY Effusive volcanism;
- 8488 VOLCANOLOGY Volcanic hazards and risks