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

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.

2012 ◽  
Vol 12 (1) ◽  
pp. 151-163 ◽  
Author(s):  
A. Grezio ◽  
P. Gasparini ◽  
W. Marzocchi ◽  
A. Patera ◽  
S. Tinti

Abstract. We present a first detailed tsunami risk assessment for the city of Messina where one of the most destructive tsunami inundations of the last centuries occurred in 1908. In the tsunami hazard evaluation, probabilities are calculated through a new general modular Bayesian tool for Probability Tsunami Hazard Assessment. The estimation of losses of persons and buildings takes into account data collected directly or supplied by: (i) the Italian National Institute of Statistics that provides information on the population, on buildings and on many relevant social aspects; (ii) the Italian National Territory Agency that provides updated economic values of the buildings on the basis of their typology (residential, commercial, industrial) and location (streets); and (iii) the Train and Port Authorities. For human beings, a factor of time exposition is introduced and calculated in terms of hours per day in different places (private and public) and in terms of seasons, considering that some factors like the number of tourists can vary by one order of magnitude from January to August. Since the tsunami risk is a function of the run-up levels along the coast, a variable tsunami risk zone is defined as the area along the Messina coast where tsunami inundations may occur.


2019 ◽  
Vol 13 (05n06) ◽  
pp. 1941001
Author(s):  
Su Yean Teh ◽  
Hock Lye Koh ◽  
Yong Hui Lim

Many beaches in Penang island were severely inundated by the 26 December 2004 Indian Ocean mega tsunami with 57 deaths recorded. It is anticipated that the next big tsunami will cause even more damages to beaches in Penang. Hence, developing community resilience against the risks of the next tsunami is essential. Resilience entails many interlinked components, beginning with a good understanding of the inundation scenarios critical to community evacuation and resilience preparation. Inundation scenarios are developed from tsunami simulations involving all three phases of tsunami generation, propagation and run-up. Accurate and high-resolution bathymetric–topographic maps are essential for simulations of tsunami wave inundation along beaches. Bathymetric maps contain information on the depths of landforms below sea level while topographic maps reveal the elevation of landforms above sea level. Bathymetric and topographic datasets for Malaysia are, however, currently not integrated and are available separately and in different formats, not suitable for inundation simulations. Bathymetric data are controlled by the National Hydrographic Centre (NHC) of the Royal Malaysian Navy while topographic data are serviced by the Department of Survey and Mapping Malaysia (JUPEM). It is highly desirable to have seamless integration of high-resolution bathymetric and topographic data for tsunami simulations and for other scientific studies. In this paper, we develop a robust method for integrating the NHC bathymetric and JUPEM topographic data into a regularly-spaced grid system essential for tsunami simulation. A primary objective of this paper is to develop the best Digital Elevation and Bathymetry Model (DEBM) for Penang based upon the most suitable and accurate interpolation method for integrating bathymetric and topographic data with minimal interpolation errors. We analyze four commonly used interpolation methods for generating gridded topographic and bathymetric surfaces, namely (i) Kriging, (ii) Multiquadric (MQ), (iii) Thin Plate Spline (TPS) and (iv) Inverse Distance to Power (IDP). The study illustrated that the Kriging interpolation method produces an integrated bathymetric and topographic surface that best approximates the admiralty nautical chart of Penang essential for tsunami run-up and inundation simulations. Tsunami inundation scenarios critical to risk analysis and mitigation could then be developed using this DEBM for various earthquake scenarios, as presented in this paper for the 2004 Indian Ocean Tsunami.


2019 ◽  
Vol 15 (1) ◽  
pp. 1-10
Author(s):  
Andi Syukri

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.


2021 ◽  
Vol 16 (7) ◽  
pp. 1015-1029
Author(s):  
Ako Yamamoto ◽  
Yuki Kajikawa ◽  
Kei Yamashita ◽  
Ryota Masaya ◽  
Ryo Watanabe ◽  
...  

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.


Author(s):  
Anastasios Kitsos ◽  
Antonios Proestakis

AbstractWe examine the role of political alignment and the electoral business cycle on municipality revenues in Greece for the period 2003–2010. The misallocation of resources for political gain represents a waste of resources with significant negative effects on local growth and effective decentralization. The focus of our analysis is municipality mayors since they mediate the relationship between central government and voters and hence can influence the effectiveness of any potential pork-barrelling activity. A novel panel data set combining the results of two local and three national elections with annual municipality budgets is used to run a fixed-effects econometric model. This allows us to identify whether the political alignment between mayors and central government affects municipality financing. We examine this at different stages of local and national electoral cycles, investigating both direct intergovernmental transfers (grants) and the remaining sources of local revenues (own revenues, loans). We find that total revenues are significantly higher for aligned municipalities in the run-up to elections due to higher intergovernmental transfers. We also find evidence that the 2008 crisis has reduced such pork-barrelling activity. This significant resource misallocation increases vertical networking dependency and calls for policy changes promoting greater decentralization and encouraging innovation in local revenue raising.


2021 ◽  
Vol 13 (7) ◽  
pp. 1399
Author(s):  
Quang Nguyen Hao ◽  
Satoshi Takewaka

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.


1983 ◽  
Vol 4 ◽  
pp. 14-18 ◽  
Author(s):  
Raymond A. Assel

A digital ice-concentration database spanning 20 years (1960 to 1979) was established for the Great Lakes of North America. Data on ice concentration, i.e. the percentage of a unit surface area of the lake that is ice-covered, were abstracted from over 2 800 historic ice charts produced by United States and Canadian government agencies. The database consists of ice concentrations ranging from zero to 100% in 10% increments for individual grid cells of size 5 × 5 km constituting the surface area of each Great Lake. The data set for each of the Great Lakes was divided into half-month periods for statistical analysis. Maxinium, minimum, median, mode, and average ice-concentrations statistics were calculated for each grid cell and half-month period. A lakewide average value was then calculated for each of the half-month ice-concentration statistics for all grid cells for a given lake. Ice-cover variability and the normal extent and progression of the ice cover is discussed within the context of the lakewide averaged value of the minimum and maximum ice concentrations and the lakewide averaged value of the median ice concentrations, respectively. Differences in ice-cover variability among the five Great Lakes are related to mean lake depth and accumulated freezing degree-days. A Great Lakes ice atlas presenting a series of ice charts which depict the maximum, minimum, and median icecover concentrations for each of the Great Lakes for nine half-monthly periods, starting the last half of December and continuing through the last half of April will be published in 1983 by the National Oceanic and Atmospheric Administration (NOAA). The database will be archived at the National Snow and Ice Data Center of the National Environmental Satellite Data and Information Service (NESDIS) in Boulder, Colorado, USA, also in 1983.


Author(s):  
Juh-Whan Lee ◽  
Jennifer L. Irish ◽  
Robert Weiss

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


Sign in / Sign up

Export Citation Format

Share Document