scholarly journals Comparisons of Numerical Models on Formation of Sediment Deposition Induced by Tsunami Run-Up

2021 ◽  
Vol 16 (7) ◽  
pp. 1015-1029
Author(s):  
Ako Yamamoto ◽  
Yuki Kajikawa ◽  
Kei Yamashita ◽  
Ryota Masaya ◽  
Ryo Watanabe ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Formation Process ◽  
Numerical Models ◽  
Bedload Transport ◽  
Tsunami Risk ◽  
Simulation Results ◽  
Run Up ◽  
Tsunami Run Up ◽  
Tsunami Sediment ◽  
Tsunami Sediments

Tsunami sediments provide direct evidence of tsunami arrival histories for tsunami risk assessments. Therefore, it is important to understand the formation process of tsunami sediment for tsunami risk assessment. Numerical simulations can be used to better understand the formation process. However, as the formation of tsunami sediments is affected by various conditions, such as the tsunami hydraulic conditions, topographic conditions, and sediment conditions, many problems remain in such simulations when attempting to accurately reproduce the tsunami sediment formation process. To solve these problems, various numerical models and methods have been proposed, but there have been few comparative studies among such models. In this study, inter-model comparisons of tsunami sediment transport models were performed to improve the reproducibility of tsunami sediment features in models. To verify the reproducibility of the simulations, the simulation results were compared with the results of sediment transport hydraulic experiments using a tsunami run-up to land. Two types of experiments were conducted: a sloping plane with and without coverage by silica sand (fixed and movable beds, respectively). The simulation results confirm that there are conditions and parameters affecting not only the amount of sediment transport, but also the distribution. In particular, the treatment of the sediment coverage ratio in a calculation grid, roughness coefficient, and bedload transport rate formula on the fixed bed within the sediment transport model are considered important.

scholarly journals EXPERIMENTS ON THE DENSITY OF TSUNAMI INUNDATION WATER AND ITS INFLUENCE ON THE TSUNAMI RUN-UP AND DEPOSIT

2018 ◽  
pp. 41
Author(s):  
Hideo Matsutomi ◽  
Fumiko Konno
Keyword(s):  
Small Scale ◽  
Distance Ratio ◽  
Sediment Grain Size ◽  
Tsunami Inundation ◽  
Deposit Thickness ◽  
Historical Tsunami ◽  
Run Up ◽  
Tsunami Run Up ◽  
Tsunami Sediment ◽  
Sediment Deposit

For the sophistication of the tsunami load, future and historical tsunami scale evaluations, the dependency of the density of tsunami inundation water with sediment on the hydraulic quantities, and then the dependencies of the tsunami run-up distance, sediment deposit distance, mean sediment deposit thickness on the density of the tsunami inundation water are examined through a devised small-scale hydraulic experiment. Within the experimental range of this study, it is verified that the density of the tsunami inundation water depends on the Froude number of the incident tsunami inundation flow and the sediment grain size, and the relative tsunami run-up distance (= the run-up distance of the inundation water with sediment/the run-up distance of the inundation water without sediment (= fresh water)), ratio of the tsunami sediment deposit distance to the tsunami run-up distance, ratio of the mean tsunami sediment deposit thickness to the tsunami sediment deposit distance depend on the density of the tsunami inundation water, and four empirical expressions for those dependencies are proposed.

scholarly journals TSUNAMI INUNDATION SIMULATIONS IN URBAN TOPOGRAPHY

2018 ◽  
pp. 62
Author(s):  
Takuya Miyashita ◽  
Nobuhito Mori
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Numerical Models ◽  
Tohoku Earthquake ◽  
The 2011 Tohoku Earthquake ◽  
Tsunami Inundation ◽  
Urban Topography ◽  
Run Up ◽  
Tsunami Run Up ◽  
Local Momentum

The inundation of the 2011 Tohoku Earthquake Tsunami showed complex behavior over the land. According to the surveys of the Tohoku Earthquake Tsunami in 2011, the behavior of tsunami in urban areas was different from that in rural areas and the damage was not only dependent on the inundation heights but also the local momentum. The buildings are commonly excluded and smoothed off in the topography in the conventional inundation simulation but it’s important to understand the local characteristics of tsunami run-up in urban areas. The purpose of this study is to understand and validate numerical models of tsunami in the urban area.

scholarly journals Examination of three practical run-up models for assessing tsunami impact on highly populated areas

2011 ◽  
Vol 11 (12) ◽  
pp. 3107-3123 ◽  
Author(s):  
A. Muhari ◽  
F. Imamura ◽  
S. Koshimura ◽  
J. Post
Keyword(s):  
Grid Cell ◽  
Roughness Coefficient ◽  
Human Beings ◽  
Data Set ◽  
Building Height ◽  
Topographic Data ◽  
Tsunami Risk ◽  
Run Up ◽  
Elevation Model ◽  
Tsunami Run Up

Abstract. This paper describes the examination of three practical tsunami run-up models that can be used to assess the tsunami impact on human beings in densely populated areas. The first of the examined models applies a uniform bottom roughness coefficient throughout the study area. The second uses a very detailed topographic data set that includes the building height information integrated on a Digital Elevation Model (DEM); and the third model utilizes different bottom roughness coefficients, depending on the type of land use and on the percentage of building occupancy on each grid cell. These models were compared with each other by taking the one with the most detailed topographic data (which is the second) as reference. The analysis was performed with the aim of identifying how specific features of high resolution topographic data can influence the tsunami run-up characteristics. Further, we promote a method to be used when very detailed topographic data is unavailable and discuss the related limitations. To this purpose we demonstrate that the effect of buildings on the tsunami flow can be well modeled by using an equivalent roughness coefficient if the topographic data has no information of building height. The results from the models have been utilized to quantify the tsunami impact by using the tsunami casualty algorithm. The models have been applied in Padang city, Indonesia, which is one of the areas with the highest potential of tsunami risk in the world.

scholarly journals Tsunami run-up estimation based on a hybrid numerical flume and a parameterization of real topobathymetric profiles

2017 ◽  
Author(s):  
Íñigo Aniel-Quiroga ◽  
Omar Quetzalcóatl ◽  
Mauricio González ◽  
Louise Guillou
Keyword(s):  
Numerical Models ◽  
Fluid Model ◽  
Coupled Model ◽  
Tsunami Hazard ◽  
Water Model ◽  
Tsunami Waves ◽  
Small Areas ◽  
Prone Area ◽  
Run Up ◽  
Tsunami Run Up

Abstract. Tsunami run-up is a key value to determine when calculating and assessing the tsunami hazard in a tsunami-prone area. Run-up is accurately calculated by means of numerical models, but these models require high-resolution topobathymetric data, which are not always available, and long computational times. These drawbacks restrict the application of these models to the assessment of small areas. As an alternative method, to address large areas, empirical formulae are commonly applied to estimate run-up. These formulae are based on numerical or physical experiments on idealized geometries. In this paper, a new methodology is presented to calculate tsunami hazard at large scales. This methodology determines the tsunami flooding by using a coupled model that combines a nonlinear shallow water model (2D-H) and a volume-of-fluid model (RANS 2D-V) and applies the optimal numerical scheme in each phase of the tsunami generation-propagation-inundation process. The hybrid model has been widely applied to build a tsunami run-up database (TRD). The aim of this database is to form an interpolation domain with which to estimate the tsunami run-up of new scenarios without running a numerical simulation. The TRD was generated by simulating the propagation of parameterized tsunami waves on real non-scaled profiles. A database and hybrid numerical model were validated using real and synthetic scenarios. The new methodology provides feasible estimations of the tsunami run-up; engineers and scientists can use this methodology to address tsunami hazard at large scales.

scholarly journals Rapid prediction of alongshore run-up distribution from near-field tsunamis

2021 ◽  
Author(s):  
Jun-Whan Lee ◽  
Jennifer Irish ◽  
Robert Weiss
Keyword(s):  
Numerical Models ◽  
Near Field ◽  
Northern Region ◽  
Computational Time ◽  
Hazard Characterization ◽  
Rapid Prediction ◽  
Computationally Intensive ◽  
Run Up ◽  
Rsm Model ◽  
Tsunami Run Up

Rapid prediction of the spatial distribution of the run-up from near- field tsunamis is critically important for tsunami hazard characterization. Even though significant advances have been made over the last decade, physics- based numerical models are still computationally intensive. Here, we present a response surface methodology (RSM)-based model called the tsunami run-up response function (TRRF). Derived from a discrete set of tsunami simulations, TRRF can produce a rapid prediction of a near-field tsunami run-up distribution that takes into account the influence of variable local topographic and bathymetric characteristics in a given region. This new method reduces the number of simulations required to build an RSM model by separately modeling the leading order contribution and the residual part of the tsunami run-up distribution. Using the northern region of Puerto Rico as a case study, we investigated the performance (accuracy, computational time) of the TRRF. The results reveal that the TRRF achieves reliable prediction while reducing the prediction time by six orders of magnitude (computational time: < 1 second per earthquake).

scholarly journals Study of Intersection Coverage Area for Pedestrian Overpasses as Vertical Evacuation from Tsunami in Padang, West Sumatra

2019 ◽  
Vol 15 (1) ◽  
pp. 1-10
Author(s):  
Andi Syukri
Keyword(s):  
Coastal Area ◽  
Large Space ◽  
Coverage Area ◽  
The Road ◽  
West Sumatra ◽  
Tsunami Risk ◽  
Vertical Evacuation ◽  
Run Up ◽  
Tsunami Run Up ◽  
Remaining Time

Padang City, as one of the highest vulnerable from earthquake and tsunami, has been transforming to become disaster smart city. However, the inadequacy of horizontal evacuation routes is caused by numerous tremors in 2007, 2009, 2010, and 2016 are indicating it is lack of occupancy for evacuee. Then, these condition is decreasing by traditional behavior evacuee are still using the vehicle and unwell planned evacuation as personally or in the community. The small number of vertical evacuation building and lack of awareness of community, and unmanaged the evacuation facilities make emergency response from earthquake and tsunami is uncontrolled in 0 – 20 minute for 30 minutes remaining time evacuate to inland in personally or community. Padang city has people density in the more than 1,317 people/km2 in the coastal area numerous potential for earthquake and tsunami risk. Pedestrian overpasses as primary facilities in many main roads in Padang City should be utilized for people to cross the road but it does not work properly but in fact, type of material, steel construction, was not durable with the climate in Padang that have coastal climate and a high number of behavior for crossing road in uncertain places. Regarding of the vulnerability in earthquake and tsunami risk, unmanaged construction and bad culture in crossing the road, pedestrian overpasses, especially in the intersection, will be redesigned to be a vertical evacuation. It will have a multifunction structure that is not simply for passing the pedestrian but also comprises remarkable facilities as a meeting point, commercial place and public facilities. Pedestrian overpasses for vertical evacuation from the tsunami will solve lack of area for construct vertical evacuation in the community. It can duplicate easily for any coastal cities that require vertical evacuation structures. Apparently, area availability will determine how vulnerable the site for vertical evacuation will suit for evacuee who living surrounding. Road intersection will be a good site for redesigning vertical evacuation Intersection of the road and have large space will be a good candidate for redesigning pedestrian overpasses as vertical evacuation structure. Road Intersection as vulnerable routes for horizontal evacuation is already happened in several occurrence of earthquake in Padang City. Based on google maps, every road will contribute a number of evacuee and mostly by using vehicle and fewer people who will evacuate by walking. The Study of coverage area intersection pedestrian overpasses as vertical evacuation from tsunami in Padang, West Sumatra will describe about how large the estimated capacity of pedestrian overpasses can be suit for vertical evacuation and how wide the area can be facilitated by this evacuation site. Remaining time of tsunami, walking space, readiness evacuation time, and time to reach upland. Those will be determined into how far the evacuee can reach the site. Based on the population density, it can observed the length of the radius can be serviced the evacuee to evacuation structure. People density will influence how large the coverage area for each site. According to this study, horizontal evacuation from tsunami in Padang city is still vulnerable for the people who living in coastal area. Bottleneck evacuation can be solved by build a vertical evacuation near by the bottleneck zone. Pedestrian overpasses for vertical evacuation is designing to accommodate the evacuee can save their life from the tsunami run up because incapability to reach inland.

Analytical and numerical models for tsunami run-up

2007 ◽  
pp. 209-236 ◽  
Author(s):  
Per A. Madsen ◽  
David R. Fuhrman
Keyword(s):  
Numerical Models ◽  
Run Up ◽  
Tsunami Run Up

STUDY ON THE INFLUENCE OF STRUCTURES ON THE SEDIMENT TRANSPORT DUE TO THE TSUNAMI RUN-UP TO RIVER

2021 ◽  
Vol 77 (2) ◽  
pp. I_277-I_282
Author(s):  
Takanobu KAMATAKI ◽  
Syunya KODACHI ◽  
Noritoshi SAITO ◽  
Kazuya WATANABE
Keyword(s):  
Sediment Transport ◽  
Run Up ◽  
Tsunami Run Up

scholarly journals Tsunami run-up estimation based on a hybrid numerical flume and a parameterization of real topobathymetric profiles

2018 ◽  
Vol 18 (5) ◽  
pp. 1469-1491 ◽  
Author(s):  
Íñigo Aniel-Quiroga ◽  
Omar Quetzalcóatl ◽  
Mauricio González ◽  
Louise Guillou
Keyword(s):  
Numerical Models ◽  
Fluid Model ◽  
Coupled Model ◽  
Tsunami Hazard ◽  
Water Model ◽  
Tsunami Waves ◽  
Small Areas ◽  
Prone Area ◽  
Run Up ◽  
Tsunami Run Up

Abstract. Tsunami run-up is a key value to determine when calculating and assessing the tsunami hazard in a tsunami-prone area. Run-up can be accurately calculated by means of numerical models, but these models require high-resolution topobathymetric data, which are not always available, and long computational times. These drawbacks restrict the application of these models to the assessment of small areas. As an alternative method, to address large areas empirical formulae are commonly applied to estimate run-up. These formulae are based on numerical or physical experiments on idealized geometries. In this paper, a new methodology is presented to calculate tsunami hazard at large scales. This methodology determines the tsunami flooding by using a coupled model that combines a nonlinear shallow water model (2D-H) and a volume-of-fluid model (RANS 2D-V) and applies the optimal numerical models in each phase of the tsunami generation–propagation–inundation process. The hybrid model has been widely applied to build a tsunami run-up database (TRD). The aim of this database is to form an interpolation domain with which to estimate the tsunami run-up of new scenarios without running a numerical simulation. The TRD was generated by simulating the propagation of parameterized tsunami waves on real non-scaled profiles. A database and hybrid numerical model were validated using real and synthetic scenarios. The new methodology provides feasible estimations of the tsunami run-up; engineers and scientists can use this methodology to address tsunami hazard at large scales.

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