scholarly journals The Implementation of Combined Roughness and Reflected Model (CRRM) in Tsunami Run-up Simulation through Coastal Vegetation

2018 ◽  
Vol 4 (3) ◽  
pp. 201
Author(s):  
Benazir B. Iska ◽  
Radianta Triatmadja ◽  
Adam Pamudji Rahardjo ◽  
Nur Yuwono
Keyword(s):  
Numerical Model ◽  
Numerical Method ◽  
Physical Model ◽  
Physical Process ◽  
Experimental Work ◽  
Coastal Vegetation ◽  
Vegetation Models ◽  
Run Up ◽  
Tsunami Run Up ◽  
Inertia Forces

Hydraulics resistance is commonly used to simulate or replace drag and inertia forces due to vegetation when modeling tsunami run-up. A new numerical method was proposed which was named Combined Roughness and Reflected Model (CRRM). This method accommodates the reflection process of tsunami flow by tree surfaces. A series of experimental work was performed in laboratory to verify the numerical results. The physical process of laboratory work was discussed to explain the interaction between tsunami and vegetation models. The relation of some notable parameters was reviewed for both models. The physical model verified that the deviations between the physical and the numerical model were below 20%. With such numerical method, more challenging forest layout such as zigzag arrangement can be studied more accurately. It is concluded that the zigzag arrangement of trees layout and higher density of trees were capable of reducing tsunami run-up on land significantly. 

scholarly journals Numerical Investigations of Tsunami Run-Up and Flow Structure on Coastal Vegetated Beaches

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1776 ◽  
Author(s):  
Hongxing Zhang ◽  
Mingliang Zhang ◽  
Tianping Xu ◽  
Jun Tang
Keyword(s):  
Wave Propagation ◽  
Numerical Model ◽  
Peak Flow ◽  
Tsunami Wave ◽  
Coastal Vegetation ◽  
Coastal Forest ◽  
Governing Equations ◽  
Tsunami Waves ◽  
Run Up ◽  
Sloping Beach

Tsunami waves become hazardous when they reach the coast. In South and Southeast Asian countries, coastal forest is widely utilized as a natural approach to mitigate tsunami damage. In this study, a depth-integrated numerical model was established to simulate wave propagation in a coastal region with and without forest cover. This numerical model was based on a finite volume Roe-type scheme, and was developed to solve the governing equations with the option of treating either a wet or dry wave front boundary. The governing equations were modified by adding a drag force term caused by vegetation. First, the model was validated for the case of solitary wave (breaking and non-breaking) run-up and run-down on a sloping beach, and long periodic wave propagation was investigated on a partially vegetated beach. The simulated results agree well with the measured data. Further, tsunami wave propagation on an actual-scale slope covered by coastal forest Pandanus odoratissimus (P. odoratissimus) and Casuarina equisetifolia (C. equisetifolia) was simulated to elucidate the influence of vegetation on tsunami mitigation with a different forest open gap. The numerical results revealed that coastal vegetation on sloping beach has significant potential to mitigate the impacts from tsunami waves by acting as a buffer zone. Coastal vegetation with open gaps causes the peak flow velocity at the exit of the gap to increase, and reduces the peak flow velocity behind the forest. Compared to a forest with open gaps in a linear arrangement, specific arrangements of gaps in the forest can increase the energy attenuation from tsunami wave. The results also showed that different cost-effective natural strategies in varying forest parameters including vegetation collocations, densities, and growth stages had significant impacts in reducing the severity of tsunami damage.

scholarly journals Physical and Numerical Modelling of Tsunami Run-up on Seawall at Sloping Beach

2019 ◽  
Vol 5 (2) ◽  
pp. 139
Author(s):  
Ma'ruf Hadi Sutanto
Keyword(s):  
Numerical Model ◽  
Water Depth ◽  
Tsunami Wave ◽  
Peak Height ◽  
Initial Water ◽  
Tsunami Mitigation ◽  
Run Up ◽  
Tsunami Run Up ◽  
Sloping Beach ◽  
Reduction Percentage

Tsunami run-up on land has a large destructive power. Further studies are deemed necessary to understand the process and characteristics of tsunami run-up in coastal areas. Seawall structures can reduce the run-up of a tsunami depending on the height of the seawall crest. Physical modeling shows that seawall may significantly reduce run-up (𝑅) and inundation (𝑋𝑖). The highest reduction up to 55% where the seawall peak height is 7 cm and the water depth is 15 cm. With the same scenario in numerical modeling, the percentage reduction is 67.53%. The highest inundation (Xi) in the scenario without seawall structure is 6.081 m when the initial water depth (d0) equals to 30 cm. The result of the numerical model for the same scenario is 6.970 m. Seawall as tsunami mitigation structure is only effective when the tsunami wave is relatively low compared to the seawall height (H/ sw). Reduction percentage > 25%, with conditions that H/ sw is < 0.856 (physical model) and < 0.802 (numerical model).

Numerical Model for Tsunami Run-Up

1970 ◽  
Vol 96 (3) ◽  
pp. 701-719
Author(s):  
Kenneth L. Heitner ◽  
George W. Housner
Keyword(s):  
Numerical Model ◽  
Run Up ◽  
Tsunami Run Up

scholarly journals Erratum for “Numerical Model for Tsunami Run-Up”

1971 ◽  
Vol 97 (4) ◽  
pp. 766-766
Author(s):  
Kenneth L. Heitner ◽  
George W. Housner
Keyword(s):  
Numerical Model ◽  
Run Up ◽  
Tsunami Run Up

scholarly journals Shoreline Changes along Northern Ibaraki Coast after the Great East Japan Earthquake of 2011

2021 ◽  
Vol 13 (7) ◽  
pp. 1399
Author(s):  
Quang Nguyen Hao ◽  
Satoshi Takewaka
Keyword(s):  
Near Infrared ◽  
Thermal Emission ◽  
Sandy Beaches ◽  
Great East Japan Earthquake ◽  
Shoreline Changes ◽  
Run Up ◽  
Tsunami Run Up ◽  
Sentinel 2 ◽  
Infrared Radiometer

In this study, we analyze the influence of the Great East Japan Earthquake, which occurred on 11 March 2011, on the shoreline of the northern Ibaraki Coast. After the earthquake, the area experienced subsidence of approximately 0.4 m. Shoreline changes at eight sandy beaches along the coast are estimated using various satellite images, including the ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer), ALOS AVNIR-2 (Advanced Land Observing Satellite, Advanced Visible and Near-infrared Radiometer type 2), and Sentinel-2 (a multispectral sensor). Before the earthquake (for the period March 2001–January 2011), even though fluctuations in the shoreline position were observed, shorelines were quite stable, with the averaged change rates in the range of ±1.5 m/year. The shoreline suddenly retreated due to the earthquake by 20–40 m. Generally, the amount of retreat shows a strong correlation with the amount of land subsidence caused by the earthquake, and a moderate correlation with tsunami run-up height. The ground started to uplift gradually after the sudden subsidence, and shoreline positions advanced accordingly. The recovery speed of the beaches varied from +2.6 m/year to +6.6 m/year, depending on the beach conditions.

Numerical Investigation of Wave Period Influence on Long Wave Run-Up on Slope With Rigid Vegetation

2016 ◽  
Author(s):  
Jun Tang ◽  
Yongming Shen
Keyword(s):  
Shallow Water Equations ◽  
Water Wave ◽  
Wave Period ◽  
Coastal Vegetation ◽  
Coastal Structures ◽  
Rigid Vegetation ◽  
Comparison With Experiment ◽  
Long Wave ◽  
Nonlinear Shallow Water Equations ◽  
Run Up

Coastal vegetation can not only provide shade to coastal structures but also reduce wave run-up. Study of long water wave climb on vegetation beach is fundamental to understanding that how wave run-up may be reduced by planted vegetation along coastline. The present study investigates wave period influence on long wave run-up on a partially-vegetated plane slope via numerical simulation. The numerical model is based on an implementation of Morison’s formulation for rigid structures induced inertia and drag stresses in the nonlinear shallow water equations. The numerical scheme is validated by comparison with experiment results. The model is then applied to investigate long wave with diverse periods propagating and run-up on a partially-vegetated 1:20 plane slope, and the sensitivity of run-up to wave period is investigated based on the numerical results.

scholarly journals NEAR-FIELD TSUNAMI FORECASTING BASED ON A TSUNAMI RUN-UP RESPONSE FUNCTION

2020 ◽  
pp. 5
Author(s):  
Juh-Whan Lee ◽  
Jennifer L. Irish ◽  
Robert Weiss
Keyword(s):  
Real Time ◽  
Response Function ◽  
Near Field ◽  
Coastal Communities ◽  
Tsunami Forecast ◽  
Earthquake Fault ◽  
Tsunami Forecasting ◽  
Fault Parameters ◽  
Run Up ◽  
Tsunami Run Up

Since near-field-generated tsunamis can arrive within a few minutes to coastal communities and cause immense damage to life and property, tsunami forecasting systems should provide not only accurate but also rapid tsunami run-up estimates. For this reason, most of the tsunami forecasting systems rely on pre-computed databases, which can forecast tsunamis rapidly by selecting the most closely matched scenario from the databases. However, earthquakes not included in the database can occur, and the resulting error in the tsunami forecast may be large for these earthquakes. In this study, we present a new method that can forecast near-field tsunami run-up estimates for any combination of earthquake fault parameters on a real topography in near real-time, hereafter called the Tsunami Run-up Response Function (TRRF).Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/tw1D29dDxmY

scholarly journals Effects of Water Intake Layout along the Wharf Shoreline on Ships

2019 ◽  
Vol 26 (4) ◽  
pp. 165-171
Author(s):  
Xian-wei Kong ◽  
Lei Ding ◽  
Hai-cheng Liu ◽  
Jing Qu ◽  
Xiao-song Li
Keyword(s):  
Numerical Model ◽  
Water Level ◽  
Physical Model ◽  
Water Intake ◽  
Hydrodynamic Forces ◽  
Lateral Flow ◽  
Real Situation ◽  
The Real ◽  
Level Difference ◽  
Two Sides

Abstract The construction of a water intake along the wharf shoreline can realise the intensive and comprehensive utilisation of the shoreline. However, since the water intake will increase the lateral flow at the wharf and also the hydrodynamic forces on ships, it will bring risks to ships mooring and leaving. The effects of the water intake on ships are studied using a physical model, numerical model and standard formulas. The results show that it leads to an increase of the hydrodynamic forces acting on the ship when the standard formulas are used to calculate the forces without considering the water level difference between the two sides of the ship. The results of the physical model are closer to the real situation. Measures that can effectively reduce the influence of the water intake on ships are proposed by increasing the distance between the wharf front and the front of the water intake as well as the depth of the water inlet windows.

scholarly journals PHYSICAL MODEL TESTS ON WAVE OVERTOPPING AND FLOW PROCESSES ON DIKE CRESTS INFLUENCED BY WAVE-CURRENT INTERACTION

2012 ◽  
Vol 1 (33) ◽  
pp. 34 ◽  
Author(s):  
Stefanie Lorke ◽  
Babette Scheres ◽  
Holger Schüttrumpf ◽  
Antje Bornschein ◽  
Reinhard Pohl
Keyword(s):  
Physical Model ◽  
Model Tests ◽  
Longshore Current ◽  
Wind Fields ◽  
Incoming Wave ◽  
Wave Overtopping ◽  
Improve Design ◽  
Physical Model Tests ◽  
Flow Processes ◽  
Run Up

Flow processes like flow depths and flow velocities give important information about erosion and infiltration processes, which can lead to an unstable dike structure and consequently to dike failure. Up to now several physical model tests on wave run-up and wave overtopping are available to adjust and improve design formula for different dike structures. This kind of physical model tests have been performed in the here presented project FlowDike. Its main purpose is to consider two new aspects that could influence the assessment of wave run-up and wave overtopping as well as the flow processes on dikes which have not been investigated yet: longshore current and wind. Especially in estuaries and along coasts, the effect of tidal and storm induced currents combined with local wind fields can influence the incoming wave parameters at the dike toe as well as the wave run-up height, the wave overtopping rate and the flow processes on dikes. This paper will focus on these flow processes on dike slopes and dike crests on an 1:6 sloped dike influenced by oblique wave attack and longshore current.

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