1,632 research outputs found

    Numerical tool for tsunami risk assessment in the southern coast of Dominican Republic

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    The southern coast of Dominican Republic is a very populated region, with several important cities including Santo Domingo, its capital. Important activities are rooted in the southern coast including tourism, industry, commercial ports, and, energy facilities, among others. According to historical reports, it has been impacted by big earthquakes accompanied by tsunamis as in Azua in 1751 and recently Pedernales in 2010, but their sources are not clearly identified. The aim of the present work is to develop a numerical tool to simulate the impact in the southern coast of the Dominican Republic of tsunamis generated in the Caribbean Sea. This tool, based on the Tsunami-HySEA model from EDANYA group (University of Malaga, Spain), could be used in the framework of a Tsunami Early Warning Systems due the very short computing times when only propagation is computed or it could be used to assess inundation impact, computing inundation with a initial 5 meter resolution. Numerical results corresponding to three theoretical sources are used to test the numerical tool.This research has been partially supported by the Spanish Government Research project SIMURISK (MTM2015-70490-C2-1-R), the Junta de Andalucía research project TESELA (P11-RNM7069), and Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech. The GPU and multi-GPU computations were performed at the Unit of Numerical Methods (UNM) of the Research Support Central Services (SCAI) of the University of Malaga

    Non-linear shallow water models for coastal run-up simulations

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    Shallow water models are frequently used to simulate ocean or coastal circulation or tsunami wave propagation. But these models are seldom used to explicitely reproduce for example tsunami wave run-up into coast. In this work we porpose an implementation of dry/wet areas for shallow water models that allow to reproduce coastal inundation and water retrainment once the impact wave passes over. The run-up model has been tested for simple test cases and geometries as in complex, real cases, as the Lituya Bay 1958 megatsunami.Proyecto DAIFLUID - Plan Nacional de I+D (MEC/FEDER) Referencia MTM2012 / TESELA - Proyecto de Excelencia de la Junta de Andalucía (convocatoria 2011) Referencia P11 - RNM7069 / Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Un modelo 1D NPZ de acoplamiento entre la hidrodinámica y los flujos biogeoquímicos en estrechos bicapa. Aplicación a la dinámica mareal en el Estrecho de Gibraltar

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    Los modelos NPZ (siglas para Nutrientes-Fitoplancton-Zooplancton en inglés) son comúnmente utilizados en estudios de biología marina. Este tipo de modelos utiliza un conjunto de ecuaciones diferenciales muy sencillo para definir la dinámica del plancton marino. Las variables de estado de las cuales se modeliza su evolución son los nutrientes, el fitoplancton y el zooplankton, esto se hace en términos de su contenido de nitrógeno, ya que este compuesto el que normalmente limita la producción primaria en el océano. En este trabajo se implementa el acoplado de un modelo NPZ para el modelado de los flujos biogeoquímicos con un modelo de aguas poco profundas bicapa para la hidrodinámica. El objetivo es aplicar este modelo a la simulación de flujos biogeoquímicos en el Estrecho de Gibraltar con imposición de la dinámica mareal.1) Proyecto DAIFLUID. Plan Nacional MTM2012-38383-C02-01. 2) Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    HySEA model verification for Tohoku 2011 Tsunami. Application for mitigation tsunami assessment

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    In many aspects Tohoku-Oki 2011 mega tsunami has changed our perception of tsunami risk. The tsunami-HySEA model is used to numerically simulate this event and observed data will we used to verify the model results. Three nested meshes of enhanced resolution (4 arc-min, 32 arc-sec and 2 arc-sec) will be used by the numerical model. The propagation mesh covers all Pacific Ocean with more of 7 million cells. An intermediate mesh with 5 millions cells contains the Japanese archipelago and, finally, two finer meshes, with nearly 8 and 6 millions cells, cover Iwate and Miyagi Prefectures at Tohoku region, the most devastated areas hit by the tsunami. The presentation will focus on the impact of the tsunami wave in these two areas and comparisons with observed data will be performed. DART buoys time series, inundation area and observed runup is used to assess model performance. The arrival time of the leading flooding wave at the vicinity of the Senday airport, as recorded by video cameras, is also used as verification data for the model. After this tsunami, control forests as well as breakwaters has been discussed as suitable mitigation infrastructures. As particular case, we will analyse the evolution of the tsunami in the area around the Sendai airport (Miyagi Prefecture) and its impact on the airport. A second simulation has been performed, assuming the existence of a coastal barrier protecting the area. The role of this barrier in modifying tsunami wave evolution and mitigating flooding effects on the airport area are discussed. The protection effect of the breakwaters near Kamaishi (Iwate Prefecture) is also assessed. The numerical model shows how these structures, although did not provide a full protection to tsunami waves, they helped to largely mitigate its effects in the area.Acknowledgements. This research has been partially supported by the Junta de Andalucía research project TESELA (P11-RNM7069), the Spanish Government Research project DAIFLUID (MTM2012-38383-C02-01) and Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech. The multi-GPU computations were performed at the Laboratory of Numerical Methods (University of Malaga)

    HySEA: An operational GPU-based model for Tsunami Early Warning Systems

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    HySEA numerical model for the simulation of earthquake generated tsunamis is presented. The initial sea surface deformation is computed using Okada model. Wave propagation is computed using nonlinear shallow water equations in spherical coordinates, where coastal inundation and run-up are suitable treated in the numerical algorithm. Generation, propagation and inundation phases are all integrated in a single code and computed coupled and synchronously when they occur at the same time. Inundation is modelled by allowing cells to dynamically change from dry to wet and reciprocally when water retreats from wetted areas. Special effort is made in preserving model well-balanced (i.e. capturing small perturbations to the steady state of the ocean at rest). The GPU model implementation allows faster than real time (FTRT) simulation for real large-scale problems. The large speed-ups obtained make HySEA code suitable for its use in Tsunami Early Warning Systems. The Italian TEWS at INGV (Rome) has adopted HySEA GPU code for its National System. The model is verified by hindcasting the wave behaviour in several benchmark problems. Numerical results for an earthquake-generated tsunami in the Mediterranean Sea is presented and computing time analysed. The interest of using higher order methods, analysing numerical schemes from first order up to order five, in the context of TEWS, is also addressed. Tsunami codes do not usually use higher than second order methods. It is demonstrated that this should idea should be revised.This research has been partially supported by the Junta de Andalucía research project TESELA (P11-RNM7069), the Spanish Government Research project HySEA2 (MTM2009-11923) and Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech. The multi-GPU computations were performed at the Laboratory of Numerical Methods (University of Malaga)

    A general vertical decomposition of Euler equations: Multilayer-moment models

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    In this work, we present a general framework for vertical discretizations of Euler equations. It generalizes the usual moment and multilayer models and allows to obtain a family of multilayer-moment models. It considers a multilayer-type discretization where the layerwise velocity is a polynomial of arbitrary degree N on the vertical variable. The contribution of this work is twofold. First, we compare the multilayer and moment models in their usual formulation, pointing out some advantages/disadvantages of each approach. Second, a family of multilayer-moment models is proposed. As particular interesting case we shall consider a multilayer-moment model with layerwise linear horizontal velocity. Several numerical tests are presented, devoted to the comparison of multilayer and moment methods, and also showing that the proposed method with layerwise linear velocity allows us to obtain second order accuracy in the vertical direction. We show as well that the proposed approach allows to correctly represent the vertical structure of the solutions of the hydrostatic Euler equations. Moreover, the measured efficiency shows that in many situations, the proposed multilayer-moment model needs just a few layers to improve the results of the usual multilayer model with a high number of vertical layers.This research has been partially supported by the Spanish Government and FEDER through the research projects RTI2018-096064-B-C2(1/2) and PID2020-114688RB-I00, the Junta de Andalucía research project P18-RT-3163, the Junta de Andalucia-FEDER-University of Málaga research project UMA18-FEDERJA-16. Funding for open access charge: Universidad de Málaga / CBUA

    Use of Neural Networks for Tsunami Maximum Height and Arrival Time Predictions

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    Operational TEWS play a key role in reducing tsunami impact on populated coastal areas around the world in the event of an earthquake-generated tsunami. Traditionally, these systems in the NEAM region have relied on the implementation of decision matrices. The very short arrival times of the tsunami waves from generation to impact in this region have made it not possible to use real-time on-the-fly simulations to produce more accurate alert levels. In these cases, when time restriction is so demanding, an alternative to the use of decision matrices is the use of datasets of precomputed tsunami scenarios. In this paper we propose the use of neural networks to predict the tsunami maximum height and arrival time in the context of TEWS. Different neural networks were trained to solve these problems. Additionally, ensemble techniques were used to obtain better results.This work was funded by “Innovative ecosystem with artificial intelligence for Andalusia 20205” project of CEI Andalucía Tech and University of Málaga, UMA-CEIATECH-05. The numerical results presented in this work were performed with the computational resources provided by the Spanish Network for Supercomputing (RES) grants AECT-2020-1-0009 and AECT-2020-2-0001. Finally, this research has been partially supported by the Spanish Government research project MEGAFLOW (RTI2018-096064-B-C21), ChEESE project (EU Horizon 2020, grant agreement N. 823844), and eFlows4HPC project (funded by the EuroHPC JU under contract 955558 and the Ministerio de Ciencia e Innovación, Spain). Partial funding for open access charge: Universidad de Málag

    An Arbitrary High Order Well-Balanced ADER-DG Numerical Scheme for the Multilayer Shallow-Water Model with Variable Density

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    In this work, we present a novel numerical discretization of a variable pressure multilayer shallow water model. The model can be written as a hyperbolic PDE system and allows the simulation of density driven gravity currents in a shallow water framework. The proposed discretization consists in an unlimited arbitrary high order accurate (ADER) Discontinuous Galerkin (DG) method, which is then limited with the MOOD paradigm using an a posteriori subcell finite volume limiter. The resulting numerical scheme is arbitrary high order accurate in space and time for smooth solutions and does not destroy the natural subcell resolution inherent in the DG methods in the presence of strong gradients or discontinuities. A numerical strategy to preserve non-trivial stationary solutions is also discussed. The final method is very accurate in smooth regions even using coarse or very coarse meshes, as shown in the numerical simulations presented here. Finally, a comparison with a laboratory test, where empirical data are available, is also performed.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Funding for open access charge: Universidad de Málaga / CBU

    Clinical and Functional Outcome of Meniscal Injuries Treated with Platelet-Rich Plasma: A Single-Center Case Series

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    Meniscal injuries are among the most frequently encountered conditions in the knee joint. Therapeutic approaches are diverse and are largely dependent on the extent and location of the injury. The purpose of this study was to describe the clinical and functional outcomes of an intraarticular and percutaneous platelet-rich plasma (PRP) injection regime in patients with stable meniscal injuries. Demographics, the type of tear, affected knee, surgical procedure, type of intervention, follow-up period, and outcomes were recorded in all cases. Patient-reported outcome measures included the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Tegner activity level scale. Overall patient satisfaction, quality of life, and pain intensity were also assessed. A total of 38 cases (8 females) had sustained a stable meniscal lesion (32 medial, 6 lateral) and met the inclusion criteria. All of them received three intraarticular and percutaneous PRP injections. Patients receiving the PRP injection regime reported clinically (p = 0.000) and functionally (p = 0.000 and p = 0.001) significant improvement in all outcome measures during this interval. All patients reported they were very satisfied or satisfied with the outcome. The results of this study suggest that the treatment of stable meniscal injuries with percutaneous–intraarticular PRP injections can achieve a significant clinical and functional improvement.This research received no external funding. Partial funding for open access charge: Universidad de Málag

    2D GPU-based HySEA model for tsunami simulation. Some practical examples.

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    A two-waves TVD-WAF type scheme for solving 2D shallow-water equation is considered together with a first and second order HLL scheme. Comparison among the different schemes will be performed to check the performance for the proposed one. A description of the GPU implementation will be presented as well as some applications to tsunami simulation in real topo-bathymetries.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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