scholarly journals Development of a Practical Evaluation Method for Tsunami Debris and Its Accumulation

2022 ◽  
Vol 12 (2) ◽  
pp. 858
Author(s):  
Kentaro Imai ◽  
Takashi Hashimoto ◽  
Yuta Mitobe ◽  
Tatsuo Masuta ◽  
Narumi Takahashi ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Evaluation Method ◽  
Thickness Distribution ◽  
Empirical Evaluation ◽  
Practical Method ◽  
Tsunami Disaster ◽  
Fragility Function ◽  
Inundation Area ◽  
Inundation Depth ◽  
Accumulation Trend

Tsunami-related fires may occur in the inundation area during a huge tsunami disaster, and woody debris produced by the tsunami can cause the fires to spread. To establish a practical method for evaluating tsunami-related fire predictions, we previously developed a method for evaluating the tsunami debris thickness distribution that uses tsunami computation results and static parameters for tsunami numerical analysis. We then used this evaluation method to successfully reproduce the tsunami debris accumulation trend. We then developed an empirical building fragility function that relates the production of debris not only to inundation depth but also to the topographic gradient and the proportion of robust buildings. Using these empirical evaluation models, along with conventional tsunami numerical analysis data, we carried out a practical tsunami debris prediction for Owase City, Mie Prefecture, a potential disaster area for a Nankai Trough mega-earthquake. This prediction analysis method can reveal hazards which go undetected by a conventional tsunami inundation analysis. These results indicate that it is insufficient to characterize the tsunami hazard by inundation area and inundation depth alone when predicting the hazard of a huge tsunami; moreover, more practically, it is necessary to predict the hazard based on the effect of tsunami debris.

scholarly journals DEVELOPMENT OF TSUNAMI INUNDATION EVALUATION METHOD CONSIDERING DAMAGE LEVEL OF SEAWALL

2018 ◽  
pp. 77
Author(s):  
Katsumi Seki ◽  
Taro Arikawa ◽  
Kenichiro Shimosako ◽  
Tomohiro Takagawa ◽  
Yu Chida
Keyword(s):  
Numerical Simulation ◽  
Monte Carlo ◽  
Evaluation Method ◽  
Numerical Models ◽  
Destruction Process ◽  
Tsunami Inundation ◽  
Damage Level ◽  
Inundation Area ◽  
Inundation Depth ◽  
Subduction Zone Earthquake

Against the huge tsunami with the subduction-zone earthquake, structures such as breakwater and seawall are constructed. The expected effects of these structures are to reduce the inundation depth and inundation area. In other words, if we estimate tsunami inundation using numerical simulation accurately, it is necessary to reflect the situation of these structures in the numerical models. However in the present technology, it is difficult to predict while to estimate and reflect the destruction process by earthquake and tsunami attack. In this study, we assume that the damage level of structures are uncertain phenomenon and we develop that evaluated the tsunami inundation stochastically using Monte Carlo method.

scholarly journals Flood Inundation Assessment in the Low-Lying River Basin Considering Extreme Rainfall Impacts and Topographic Vulnerability

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 896
Author(s):  
Thanh Thu Nguyen ◽  
Makoto Nakatsugawa ◽  
Tomohito J. Yamada ◽  
Tsuyoshi Hoshino
Keyword(s):  
River Basin ◽  
Extreme Rainfall ◽  
Flood Damage ◽  
Water Levels ◽  
Flood Inundation ◽  
Inundation Area ◽  
Inundation Depth ◽  
Study Results ◽  
Inundation Duration ◽  
Short Time

This study aims to evaluate the change in flood inundation in the Chitose River basin (CRB), a tributary of the Ishikari River, considering the extreme rainfall impacts and topographic vulnerability. The changing impacts were assessed using a large-ensemble rainfall dataset with a high resolution of 5 km (d4PDF) as input data for the rainfall–runoff–inundation (RRI) model. Additionally, the prediction of time differences between the peak discharge in the Chitose River and peak water levels at the confluence point intersecting the Ishikari River were improved compared to the previous study. Results indicate that due to climatic changes, extreme river floods are expected to increase by 21–24% in the Ishikari River basin (IRB), while flood inundation is expected to be severe and higher in the CRB, with increases of 24.5, 46.5, and 13.8% for the inundation area, inundation volume, and peak inundation depth, respectively. Flood inundation is likely to occur in the CRB downstream area with a frequency of 90–100%. Additionally, the inundation duration is expected to increase by 5–10 h here. Moreover, the short time difference (0–10 h) is predicted to increase significantly in the CRB. This study provides useful information for policymakers to mitigate flood damage in vulnerable areas.

Numerical analysis of an electromagnetic nondestructive evaluation method for rotating machinery

2010 ◽  
Vol 33 (3-4) ◽  
pp. 1101-1107
Author(s):  
Haoyu Huang ◽  
Ryo Kayata ◽  
Stephane Perrin ◽  
Noritaka Yusa ◽  
Kenzo Miya
Keyword(s):  
Numerical Analysis ◽  
Nondestructive Evaluation ◽  
Evaluation Method ◽  
Rotating Machinery

scholarly journals Developing Tsunami fragility curves using remote sensing and survey data of the 2010 Chilean Tsunami in Dichato

2012 ◽  
Vol 12 (8) ◽  
pp. 2689-2697 ◽  
Author(s):  
E. Mas ◽  
S. Koshimura ◽  
A. Suppasri ◽  
M. Matsuoka ◽  
M. Matsuyama ◽  
...  
Keyword(s):  
Pacific Coast ◽  
Fragility Curves ◽  
Practical Method ◽  
South American ◽  
Survey Team ◽  
Inundation Depth ◽  
Structural Fragility ◽  
Tsunami Fragility ◽  
Chilean Tsunami ◽  
The Town

Abstract. On 27 February 2010, a megathrust earthquake of Mw = 8.8 generated a destructive tsunami in Chile. It struck not only Chilean coast but propagated all the way to Japan. After the event occurred, the post-tsunami survey team was assembled, funded by the Japan Science and Technology Agency (JST), to survey the area severely affected by the tsunami. The tsunami damaged and destroyed numerous houses, especially in the town of Dichato. In order to estimate the structural fragility against tsunami hazard in this area, tsunami fragility curves were developed. Surveyed data of inundation depth and visual inspection of satellite images of Dichato were used to classify the damage to housing. A practical method suitable when there are limitations on available data for numerical simulation or damage evaluation from surveys is presented here. This study is the first application of tsunami fragility curves on the South American Pacific coast and it might be of practical use for communities with similar characteristics along the west Pacific coast. The proposed curve suggests that structures in Dichato will be severely damaged – with a 68% probability – already at 2 m tsunami inundation depth.

EVALUATION OF THE WINDALIA SAND, BARROW ISLAND AN EMPIRICAL APPROACH

1970 ◽  
Vol 10 (1) ◽  
pp. 91 ◽  
Author(s):  
J. W. Burdett ◽  
J. C. Parry ◽  
S. P. Willmott
Keyword(s):  
Bulk Density ◽  
Transit Time ◽  
Evaluation Method ◽  
Water Saturation ◽  
Drilling Fluid ◽  
Empirical Evaluation ◽  
High Porosity ◽  
Fluid Density ◽  
Injection Wells ◽  
Standard Format

The Barrow Island oilfield derives 97 percent of its 46,000 barrels per day production from the Lower Cretaceous Windalia Sand. The lithology of the sand, which is 110' + 20' thick across the field, is very finegrained, glauconitic sandstone, shaly and silty in parts and varying from moderately unconsolidated to firm. Thin, hard beds of dolomitic and calcareous, sandstone occur throughout. The sand has high porosity and low permeability.The argillaceous and unconsolidated nature of the formation precludes the use of log interpretation methods based on standard parameters, and it was decided to develop an empirical log evaluation method. In order to calibrate the logs, sixteen of the early wells were fully cored and logged, and the data compared using the Holgate method, which allows two parameters to be correlated to determine their relationship. In the example which is the subjert of this paper, core porosity was correlated against both sonic transit time and bulk density and hence calibration of these log parameters was obtained.The best fit straight line relating porosity and sonic transit time has its origin at 76 microseconds per foot and extrapolates to 246 microseconds per foot at 100 percent porosity. The bulk density — porosity cross plot gives a grain density of 2.71 grams per cubic centimetre and fluid density of 1.16 grans/ cc. The deviations from the standard parameters of delta-t matrix = 56. delta-t fluid = 189, grain density = 1.65, fluid density = 1.0 are explained by the shaliness and lack of compaction of the formation. Using charts for the calculation of water saturation and porosity from induction conductivity and sonic transit time (or bulk density) at 2' intervals through the sand, backed up with traced SP and caliper curves, an evaluation plot of standard format is developed. Intervals of nett effective pay are then chosen.Other evaluation techniques used during the development of the Windalia Poo! include a modified movable oil plot, used in the water injection wells where a saturated saline drilling fluid was employed, and a Sonic-Neutron log comparison for the identification of suspected gas columns in the Windalia.440 wells have now been drilled at Barrow Island, and the empirical evaluation methods evolved have enabled the definition of beds of producible hydrocarbons in all cases.

scholarly journals Numerical Analysis of a Skew Rolling Process for Producing a Stepped Hollow Shaft Made of Titanium Alloy Ti6Al4V

2016 ◽  
Vol 61 (2) ◽  
pp. 677-682 ◽  
Author(s):  
Z. Pater ◽  
T. Bulzak ◽  
J. Tomczak
Keyword(s):  
Numerical Analysis ◽  
Thickness Distribution ◽  
Effective Strain ◽  
Rolling Process ◽  
Forming Process ◽  
Hollow Shaft ◽  
Wall Thickness Distribution ◽  
Light Trucks ◽  
Titanium Alloy Ti6al4v ◽  
Skew Rolling

Abstract The paper describes a rolling process for a hollow Ti6Al4V alloy shaft used in driving systems of light trucks. The shaft is formed by skew rolling using three tapered rolls. The principle of this forming process was discussed stressing its universality due to the potential of applying it for forming various products by one set of rolls. The numerical analysis results (product shape progression in rolling, wall thickness distribution, effective strain, temperature and variations in loads and torques) confirm that the proposed technique can be used for producing hollow long shafts.

Practical Method for Estimating Time-Dependent Corrosion Depth of Uncoated Carbon Steel Plates under Various Atmospheric Environmental Conditions Using Fe/Ag Galvanic Couple Corrosion Sensor

2016 ◽  
Vol 713 ◽  
pp. 187-190 ◽  
Author(s):  
Shigenobu Kainuma ◽  
Yuya Yamamoto ◽  
Young Soo Jeong
Keyword(s):  
Carbon Steel ◽  
Evaluation Method ◽  
Practical Method ◽  
Sea Salt ◽  
Steel Plates ◽  
Time Dependent ◽  
Corrosion Monitoring ◽  
Corrosion Depth ◽  
Galvanic Couple ◽  
Corrosion Sensor

In this research, an evaluation method for the time-dependent corrosion depth of uncoated structural steel plates using an Fe/Ag galvanic couple atmospheric corrosion monitoring (ACM)-type sensor was proposed. This method was focused on environments with and without effects of rainfall and airborne sea salt. Atmospheric exposure tests were carried out on the uncoated carbon steel plates in four sites in which the environments varied widely as a function of rainfall and airborne sea salt. In addition to this, the corrosive environments of the skyward-and groundward-facing surfaces of the plates were monitored using the ACM sensors.

scholarly journals On-line multistep-ahead inundation depth forecasts by recurrent NARX networks

2012 ◽  
Vol 9 (10) ◽  
pp. 11999-12028 ◽  
Author(s):  
H.-Y. Shen ◽  
L.-C. Chang
Keyword(s):  
Nonlinear Dynamical Systems ◽  
Flood Inundation ◽  
Forecast Period ◽  
Nonlinear Dynamical ◽  
Inundation Area ◽  
Inundation Depth ◽  
On Line ◽  
Dimensional Simulation ◽  
Hydrological Fields ◽  
Nonlinear Autoregressive

Abstract. Various types of artificial neural networks (ANNs) have been successfully applied in hydrological fields, but relatively scant on flood inundation forecast. This study proposes a recurrent configuration of nonlinear autoregressive with exogenous inputs (NARX) network, called R-NARX, to forecast multistep-ahead inundation depths in an inundation area. The proposed R-NARX is constructed based on the recurrent neural network (RNN), which is commonly used for modeling nonlinear dynamical systems. The models were trained and tested based on a large number of inundation data generated by a well validated two-dimensional simulation model at thirteen inundation-prone sites in Yilan County, Taiwan. We demonstrate that the R-NARX model can effectively inhibit error growth and accumulation when being applied to on-line multistep-ahead inundation forecasts over a long lasting forecast period. For comparison, a feedforward time-delay and an on-line feedback configuration of NARX networks (T-NARX and O-NARX) were performed. The results show that (1) T-NARX networks cannot make on-line forecasts due to unavailable inputs in the constructed networks even though they provide the best performances for reference only; and (2) R-NARX networks consistently outperform O-NARX networks and can be adequately applied to on-line multistep-ahead forecasts of inundation depths in the study area during typhoon events.

scholarly journals Building Up a Common Recognition of City Development in the Southern Part of Kofu Basin under the Initiative of Knowledge Brokers with the Cooperation of Experts

2020 ◽  
Vol 12 (16) ◽  
pp. 6316
Author(s):  
Takeyasu Suzuki
Keyword(s):  
Urban Development ◽  
Flood Hazard ◽  
Heavy Rain ◽  
Study Group ◽  
City Development ◽  
Inundation Area ◽  
Inundation Depth ◽  
Hazard Area ◽  
Knowledge Brokers ◽  
Evacuation Plan

Extreme weather caused by global warming has caused an increase in the number and intensity of heavy rain disasters. Almost half the area of the Kofu Basin, Yamanashi Prefecture, Japan, is expected to be flooded by the largest expected rainfall in the basin. Approximately 310,000 people live in the inundation area, and the formulation of a wide-area evacuation plan in the event of a flood is an urgent issue. In the southern part of this area, where the estimated inundation depth is 5–10 m, a new station of the Linear Chuo Shinkansen Line, which will start operation in 2027, is planned, and urban development centered on the station is expected. In order to build a sustainable city that is resilient to floods in such a flood hazard area, the author established a study group on urban development consisting of knowledge brokers—professors at University of Yamanashi—and experts with the participation of local government observers. The group has proposed a future image of sustainable Kofu Basin under the initiative of knowledge brokers with the cooperation of experts. The group attempted to put into practice the concept of sustainable cities presented by the author. As a result, by the unusual town development activities of the study group, perspective drawings that provide the participants a common recognition of the city development were successfully created.

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