Effect of digital elevation model on Mohr-Coulomb geophysical flow model output

Abstract. This paper presents the results of lahar modelling in the town of Villa La Angostura (Neuquén-Argentina) based on the Two-Phase-Titan modelling computer code. The purpose of this exercise is to provide decision makers with a useful tool to assess lahar hazard during the 2011 PuyehueCordón Caulle Volcanic Complex eruption. The possible occurrence of lahars mobilized from recent ash falls that could reach the city was analysed. The performance of the TwoPhase-Titan model using 15 m resolution digital elevation models (DEMs) developed from optical satellite images and from radar satellite images was evaluated. The output of these modellings showed inconsistencies that, based on field observations, were attributed to bad adjustment of the DEMs to real topography. Further testing of results using more accurate radar-based 10 m DEM, provided more realistic predictions. This procedure allowed us to simulate the path of flows from Florencia, Las Piedritas and Colorado creeks, which are the most hazardous streams for debris flows in Villa La Angostura. The output of the modelling is a valuable tool for city planning and risk management especially considering the glacial geomorphic features of the region, the strong urban development growth and the land occupation that has occurred in the last decade in Villa La Angostura and its surroundings.

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“…In addition, through our numerical experiment results, we support the work of Capra et al (2011) and Stefanescu et al (2012) …”

Section: Discussionsupporting

confidence: 84%

Secondary lahar hazard assessment for Villa la Angostura, Argentina, using Two-Phase-Titan modelling code during 2011 Cordón Caulle eruption

Córdoba

Villarosa

Sheridan

et al. 2015

Nat. Hazards Earth Syst. Sci.

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“…DEM resolution can have a strong impact on the TITAN2D outputs as has been demonstrated in recent works (e.g., Capra et al, ; Stefanescu, Bursik, Cordoba, et al, ; Stefanescu, Bursik, & Patra, ). We use a DEM with 10 m of horizontal resolution and an associated altimetric error of about ±3.5 m (Tarquini et al, ).…”

Section: Methodsmentioning

confidence: 63%

Towards Quantitative Volcanic Risk of Pyroclastic Density Currents: Probabilistic Hazard Curves and Maps Around Somma‐Vesuvius (Italy)

et al. 2018

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Pyroclastic density currents (PDCs) are hot flowing mixtures of gas and pyroclasts that can cause widespread loss of life and structural damage around the erupting volcano. Hazard assessments that include quantification of aleatory and epistemic uncertainty are a necessary step toward calculating volcanic risk of PDCs in an accurate and complete manner. We develop a three‐stage procedure to quantify such uncertainties for dense PDCs. First, the TITAN2D model is parameterized to simulate the PDC phenomenology at the target volcano. Second, TITAN2D is coupled with Polynomial Chaos Quadrature to propagate aleatory uncertainty from model parameters to hazard intensity measures (flow depth and speed). Third, the TITAN2D‐PCQ analysis is merged with the Bayesian Event Tree for Volcanic Hazard to include other volcano‐specific aleatory uncertainty and estimates of epistemic uncertainty. A comprehensive collection of probabilistic hazard curves and maps for flow depth and speed around the volcano is obtained through this methodology and its application is illustrated at Somma‐Vesuvius (Italy). Our results indicate that, given an eruption from the current central crater, exceedance probabilities are around 30% (aleatory uncertainty only) and between 10% and 60% (aleatory and epistemic uncertainty), for flow depth = 1 m and flow speed = 2 m/s, over the first 2–3 km around the vent. Dense PDCs faster than 30 m/s may cover areas about 50 km2 around the vent, on average, 1 every 10 eruptions. This type of probabilistic hazard assessment represents a crucial step toward quantitative volcanic risk of dense PDCs at Somma‐Vesuvius and worldwide.

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“…Some sources of DEMs can be found in Table 1. The effect of DEM interpolation and sampling schemes on model outputs is discussed in Stefanescu et al (2009); (2) Defining dimensions of an initial ''pile'' of material or a flux source which adds mass over a specified time period and area at a specified rate, both including shape, footprint, height, volume, position and initial velocity (if required); (3) A variable that represents the angle of internal friction of the granular pile, which must be higher than the chosen bed friction angle. Analysis of input sensitivity and experience has shown that flows are relatively insensitive to the internal friction angle (Dalbey & Patra, 2008); (4) A variable that represents the angle of bed friction between the granular pile and the substrate.…”

Section: User Interactionmentioning

confidence: 99%

“…Applications of these models have been used for block-andash flows at several volcanoes including Colima, El Chichon and Nevado de Toluca volcanoes in Mexico Patra et al, 2005;Saucedo et al, 2005;Rupp et al, 2006;Macias et al, 2008;Sulpizio et al, 2010); Mount Taranaki, New Zealand (Procter et al, 2010); Tungurahua, Ecuador (Kelfoun et al, 2009); Galeras and El Chichon Volcano, Columbia (Stefanescu et al, 2009;Murcia et al, 2010); Arenal Volcano, Costa Rica (Berrocal & Malavassi, 2006); Soufrière Hills Volcano, Montserrat (Hidayat et al, 2007;Ogburn, 2008;Ogburn et al, in press); and Merapi Volcano, Indonesia (Itoh, 2000;Charbonnier & Gertisser, 2009, 2012.…”

Section: Introductionmentioning

confidence: 99%

Aplicación de modelos numéricos de "aguas someras" para el análisis de peligros de flujos volcánicos: El caso de Titan2D y volcán Turrialba (Costa Rica)

Charbonnier

Palma

Ogburn

2015

Rev. Geol. Amér. Central

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This paper introduces Titan2D, a depth averaged model of an incompressible Coulomb continuum for "shallow water" granular flows. Titan2D has been used successfully at many volcanoes to predict inundation by blockand-ash flows and debris avalanches. It can be run as a stand-alone program or through Vhub, a cyber-infrastructure platform. Practical considerations of choosing appropriate user inputs and the basics of running the model are discussed herein. Both synthetic and natural terrain examples are presented, including simulations of a block-and-ash flow generated from the gravitational collapse of a synthetic dome at Turrialba volcano (Costa Rica). These results suggest that the model should be limited to simulate cases of dense volcanic granular flows, like those produced by gravity-driven dome collapse events, but cannot be used to simulate dilute pyroclastic density currents. Finally, estimation of the Titan2D resistance terms by using empirical relationships provides a good method for reducing model input uncertainties.

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Effect of digital elevation model on Mohr-Coulomb geophysical flow model output

Cited by 28 publications

References 30 publications

Secondary lahar hazard assessment for Villa la Angostura, Argentina, using Two-Phase-Titan modelling code during 2011 Cordón Caulle eruption

Secondary lahar hazard assessment for Villa la Angostura, Argentina, using Two-Phase-Titan modelling code during 2011 Cordón Caulle eruption

Towards Quantitative Volcanic Risk of Pyroclastic Density Currents: Probabilistic Hazard Curves and Maps Around Somma‐Vesuvius (Italy)

Aplicación de modelos numéricos de "aguas someras" para el análisis de peligros de flujos volcánicos: El caso de Titan2D y volcán Turrialba (Costa Rica)

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