Tsunami Evacuation Building Research Articles

Establishment of a system to accept evacuees in condominiums designated as tsunami evacuation buildings by focusing on cooperation with local organizations

Establishment of a system to accept evacuees in condominiums designated as tsunami evacuation buildings by focusing on cooperation with local organizations

Determination of closest facility tsunami evacuation building using GIS Heuristic Method: A Case Study of Meuraxa District, Banda Aceh City

Determination of closest facility tsunami evacuation building using GIS Heuristic Method: A Case Study of Meuraxa District, Banda Aceh City

Analisis Jalur Terdekat Menuju Bangunan Shelter Evakuasi Tsunami di Kota Padang Menggunakan Network Analyst

West Sumatra is one of the provinces in Indonesia that is prone to earthquakes due to the Great Sumatran Fault and the convergence of the Indo-Australian Plate and the Eurasian Plate beneath the sea to the west of the island of Sumatra. Padang is a city with earthquake potential due to the Semangko Fault, and one of the potential consequences is the occurrence of tsunamis. To minimize these impacts in Padang, tsunami evacuation buildings, known as shelters, have been established. Therefore, it is crucial for the community to be aware of the nearest routes to these evacuation shelters in Padang. One method employed is using Network Analyst. Network Analyst is a tool within the ArcGIS software, which is a Geographic Information System (GIS) developed by ESRI to manage, analyze, and visualize geographical data. By utilizing Network Analyst, the closest routes to the researched areas are generated. Network Analyst employs the Dijkstra's algorithm to solve routing problems and can be generated based on two criteria: distance and time. The result of the nearest route to the tsunami evacuation shelter in Batang Arau Subdistrict, South Padang District, is from SDN 29 Pebayan Penggalangan to Nurul Iman Mosque Padang, spanning a distance of 1585 meters. The analysis of the nearest route using Network Analyst is then compared with manually calculated results using the Dijkstra's algorithm. The difference between manual calculations and Network Analyst results ranges from 1 to 4 meters, approaching reality. This information can serve as a reference for determining the nearest routes to evacuation shelters in the event of a tsunami in Padang.

Tsunami fragility based characterisation of mosques as alternatives tsunami evacuation buildings: Reconstructing evidence from the 2004 Indian ocean tsunami

Buildings located in coastal areas can also function as protection or shelter during a tsunami wave event. High buildings on the coast such as mosques can be used as vertical evacuation buildings when a tsunami occurs. During the 2004 Indian Ocean Tsunami (IOT), there were many people evacuated and saved at mosques. The community in this region evacuated themselves to some mosques during a tsunami evacuation order on April 11, 2012. However, there is no study has been conducted to prove the fragility of mosques against tsunamis and how the mosques can function as alternative tsunami evacuation buildings. This study is aimed at reconstructing evidence of the impacts of tsunamis on mosques and at assessing the opportunities to use mosques as alternative evacuation buildings. The research was conducted in two modes: (1) a series of numerical modelling were performed to reconstruct tsunami flow depths based on the 2004 Indian Ocean Tsunami (IOT), and (2) impacts of tsunami on mosques were collected based on survivor's eyewitness accounts or photos were taken immediately after the event. The impacts were later used to compose a set of tsunami fragility curves to see the influence of flow depth on the level of mosque damage. Field surveys were at four districts that were severely affected by the 2004 IOT, namely Banda Aceh, Aceh Jaya, West Aceh, and Aceh Besar. Tsunami wave simulations were performed using the Cornell Multigrid Coupled Tsunami Model (COMCOT) to obtain flow depths at mosque locations. Validations of the numerical simulation results were done using secondary flow depth data reported previously. A total of 210 mosque buildings were assessed at the study sites, where 98 % of them were constructed using reinforced concrete with varying building heights ranging from 5 to 11 m (from floor to ceiling). The probability of absolute damage was caused when flow depths exceeded 10 m. The mosque buildings has a lower probability of collapse compared the other building such as house and other building in general. At 3.0 m of flow depth, the mosque would only be totally destroyed by around 12 %. The lower damage probability for mosque buildings can be attributed to mosques being constructed with stronger structures than typical residential buildings.

Enhancement of disaster preparedness: Approaches of place attachment and behavior to “build back better” mosque as tsunami evacuation building in Banda Aceh City, Indonesia

The Sendai Framework for Disaster Risk Reduction 2015–2030 emphasizes the importance of learning from experiences to strengthen preparedness and “Build Back Better” through risk reduction in the phases of recovery, rehabilitation, and reconstruction. On December 26, 2004, Aceh Province in Indonesia was affected by an earthquake and tsunami that caused infrastructure damage and resulted in the death of 160,000–200,000 people. Mc. Caughey simulation (2017) showed that 50% of respondents in Banda Aceh, preferred mosques as tsunami evacuation sites in the future. Therefore, this study aimed to examine the function of mosques as tsunami evacuation buildings through a community-based approach. The method involved participatory observation and in-depth interviews, guided by the principles of Sense of Place Attachment and Behavior Theory. The results showed that the Baitul Musyahadah Mosque satisfied the criteria for serving as a tsunami evacuation facility. A significant proportion of the community (38%) selected mosques as their preferred evacuation sites, considering factors such as ease of horizontal access (22%), ease of vertical access (22%), the call to prayer (12%), and the available space (4%). The analysis of sociodemographic factors indicated that individuals aged 20–30 expressed attachment towards the physical aesthetics of the mosques, while those aged 31–50 exhibited attachment towards the symbolic significance. This study recommended integrating the design concept of mosques to accommodate worship activities and emergency evacuation, thereby contributing to national and international endeavors aimed at mitigating tsunami risks.

Fragility based characterization of alternative tsunami evacuation buildings in Banda Aceh, Indonesia

Providing sufficient structures suitable for vertical evacuation from tsunamis is critically important for a tsunami-prone city like Banda Aceh, the city most severely affected by the 2004 Indian Ocean tsunami. However, lack of sufficient financial capacity along with difficulties to find affordable land to be acquired have prevented some tsunami-prone cities to do so. This research is aimed at investigating potential structures to serve as alternative tsunami vertical evacuation buildings. The research was performed by mapping modified Building Tsunami Vulnerability (BTV) based on numerical simulations and types of the buildings. In 2018, all 79,420 structures in Banda Aceh were surveyed and classified into five building categories. Numerical simulations were performed using the Cornell Multi Grid Coupled Tsunami Model (COMCOT). Five scenarios of earthquake-triggered tsunamis were incorporated in the simulations, namely magnitude 9.2 Mw, 9.0 Mw, 8.8 Mw, 8.6 Mw, and 8.4 Mw events. Results of this research revealed that some 96 to 134 buildings could be used as alternative tsunami vertical evacuation buildings. None of the surveyed buildings could be classified as very low BTV condition. The buildings were schools, hotels, an assembly hall, government offices, and houses. The capacity of the alternatives evacuation buildings to accommodate tsunami evacuees were later calculated. The alternative tsunami evacuation buildings are expected to facilitate about 4 times the present capacity of six official tsunami escape buildings in Banda Aceh, Indonesia.

A Simulation Model of Escapable and Non-Escapable Areas from Which Pregnant Women Can Reach Tsunami Evacuation Buildings: The Case in 110 Elementary School Districts in Nagoya City, Aichi, Japan.

The objective of this study was to establish a method for evaluating the possibility of pregnant women evacuating to tsunami evacuation buildings in coastal areas affected by tsunami. We used data published by the Japanese government and a general-purpose geographic information system to develop a simulation method for evaluating the possibility of evacuation. The data included the number of pregnant women in each elementary school district, tsunami inundation forecast maps, location information of tsunami evacuation buildings, and the number of ordinary buildings. We used our method to conduct a tsunami evacuation possibility simulation for pregnant women in each elementary school district in 7 wards of Nagoya, Japan. Dense population areas at low elevations are high-risk areas from which many pregnant women may not be able to evacuate. Districts with evenly distributed tsunami evacuation buildings tend to have a lower risk. The proposed simulation method was able to determine the risk in elementary school districts in densely populated low-lying areas. However, it is suggested that the risk tends to be estimated higher in school districts where there are differences in elevation and the building distribution is not uniform.

Tsunami evacution building model (TEBM) in Teluk Palu (Palu Bay) area

The research was conducted in the coastal area of Palu Bay, Lere Village. Data were collected using observation, interviews, and literature study techniques. The data were analyzed using qualitative descriptive methods and focused on the concept of the design of the tsunami evacuation building on the coast of Palu Bay. Data analysis was carried out to obtain an overview of the problems that occurred at the planning location which was analyzed with the concept of architectural design by considering the existing conditions of the site and the surrounding environment, as well as utilizing the potential of the site so that it has the potential for building functions. The conclusion obtained is based on the results of data analysis, it is necessary to have a building that can function as an evacuation container for the community when a disaster occurs in the coastal area of Palu Bay, thereby reducing the number of casualties. The benefit of this research is that it is a solution for local people to save themselves when the tsunami disaster.

KELAIKAN BANGUNAN FASILITAS UMUM UNTUK TEMPAT EVAKUASI TSUNAMI DI KECAMATAN BAITUSSALAM

Tsunami evacuation buildings in the tsunami-prone zone area are essential to minimize the number of fatalities. The purpose of this study is to analyze the behavior of the existing building structures caused by earthquake and tsunami loads in the Baitussalam District. The existing buildings that were reviewed were the SD 1 Lambada Klieng Building and the Syahamah Aceh Putra Foundation Building. The methodology in determining the capacity of the existing structures by conducting a field assessment to obtain data on existing buildings which will then be modeled, both existing buildings and a potential design of buildings using structural analysis software. for analysis. The results of the analysis show that the existing buildings need to be strengthened and redesigned to be able to withstand the effects of earthquake and tsunami loads. The remodeled of the buildings included modifying the column dimensions and also additional building stories. The remodeled of the existing building structures to become the tsunami evacuation structures is safe enough against earthquake loads and tsunami loads that occur.

Issues in Tsunami Countermeasures from the Viewpoint of Geotechnical Engineering

The 2011 off the Pacific coast of Tohoku Earthquake, with its epicenter off the Sanriku coast, measured the moment magnitude of 9.0, had a maximum seismic intensity of 7 in the northern part of Miyagi Prefecture, and impacted an area of 450 km. Consequently, a variety of unprecedented problems were made apparent. In particular, the human and property damage wrecked by the ensuing tsunami triggered our response for earthquake and tsunami resistance. In addition to conventional issues, such as earthquake resistance of buildings, disruption of lifelines, liquefaction of residential land and soil structures, and tsunami damage in coastal areas, there were new challenges, such as prolongation of earthquake disaster waste treatment. During the 10 years since the 2011 earthquake, tsunami countermeasures have been reexamined, and based on the concept of multiple protections, both tangible and intangible countermeasures have been advanced. This article addresses technical problems related to complex disasters, and includes the example of actual damage to a river levee in the Iwate Prefecture and the case of a building overturned by tsunami in Onagawa City, Miyagi Prefecture. It also discusses liquefaction caused by earthquakes and lists the points to be considered when selecting tsunami evacuation buildings to tackle future tsunami disasters.

Sequential Simulations of Steel Frame Buildings Under Multi-Phase Hazardous Loads During Earthquake and Tsunami

Based on the experience of the 2011 Great East Japan Earthquake and the following tsunami, this study aims to develop effective analytical tools that can comprehensively be applied to buildings under multi-phase hazardous loads such as seismic motion, fluid force, and debris impact. Simulations by two kinds of analytical tools were conducted. First, a structural collapse analysis of a steel frame building under successive applications of varying loads was performed using the ASI (Adaptively Shifted Integration)-Gauss code, which simulates behaviors of structures by simple modeling. The steel frame building model was first excited under an acceleration record observed in Kesennuma-shi during the earthquake, and fluid forces due to a tsunami wave were applied. Then, the collapse behavior of the building was investigated by implementing a sophisticated contact algorithm in the numerical code to express a collision between debris and a building. It became evident that the damage to the building intensifies if a head-on collision occurs under a tsunami flow with a lower inundation height, and the damage to the building becomes larger if sideway collisions occur under a tsunami flow with a higher inundation height and higher velocity. The second simulation was conducted by using the stabilized finite element method based on the volume of fluid method, to estimate a drag coefficient of an actual tsunami evacuation building with openings. The practicability of an estimated wave force using the drag coefficient was confirmed by comparing with the wave force obtained from the fluid analysis. Finally, a sequential structural analysis, with a debris collision phase at the end, was conducted using the ASI-Gauss code to simulate the washout behavior of the building.

Challenges in increasing community preparedness against tsunami hazards in tsunami-prone small islands around Sumatra, Indonesia

Fifteen years since the 2004 Indian Ocean tsunami, which caused massive destruction around the Andaman Sea, people have participated in efforts to reduce tsunami risks in Indonesia. However, the most important question continues to be on whether such efforts are sufficient in dealing with tsunami risks. Among the most striking challenges here is bridging the gap in tsunami risk reduction between the Sumatra mainland and among communities in several small islands. Thus, this research aims to investigate the recent conditions of selected towns/cities in tsunami-prone small islands and identify the impediments to their tsunami hazard preparedness. It focuses on comparing efforts in terms of available facilities for tsunami evacuation plans and the tsunami estimated time of arrival (ETA), which is computed based on deterministic tsunami propagation models. In this regard, five of the observed locations are classified as being in a critical tsunami preparedness condition, namely Balai island, Lahewa of Nias Island, Sabeugunggung of North pagai Island, Surat Aban of South Pagai island, and Enggano Island. Most of them have limited space for tsunami evacuation and a short tsunami ETA, which constitutes an extreme condition requiring immediate tsunami mitigation measures. One possible approach is to construct a vertical tsunami evacuation building or modify existing buildings that can be used for tsunami evacuation on the islands. This article also highlights societal aspects related to tsunami preparedness.

Study of alternative building for tsunami evacuation in Kuta Alam sub-district Banda Aceh

Kuta Alam Sub District has many potential hazards, especially from the sea. The location of the area that is directly adjacent to the sea causes it to be very vulnerable to tsunami. Its topography is lowland less than 1 meter above the sea-level. Tsunami in 2004 had taken a great number of people lives in the area about 14.95 % of the total number of inhabitants which is 55,030 people that time. However, there is still no any evacuation building available in Kuta Alam to escape from Tsunami. We know tsunami which might be occurred anytime unpredictable. In order to save people’s lives, it is needed to conduct a study to find alternatives buildings to be used for evacuation and rescue in the area. The aim of this study to identify the locations and number of alternative buildings that are potential as the tsunami evacuation building in Kuta Alam Sub-district. The study used the survey system toward the buildings with qualitative and quantitative approaches. Data analyzing is conducted spatially through geographic information systems. Based on observation results toward evacuation building in Kuta Alam Sub-district, there are some buildings renovated in order to be functioned as tsunami evacuation buildings. The renovation should be done on roof, school, and ladder evacuation of the mosque that are selected as evacuation buildings. Until today, those buildings have not been renovated to be eligible as evacuation places. The result found that there are 45 public buildings that can be used for alternative evacuation buildings in Kuta Alam Sub-district. That can accommodate 94.06 % of the total number of people this time which is 49,011 people.

Mapping of Geospatial Information on Disasters Predicted to Occur in Wetland Areas of the Shonan Region

Abstract. Ground damage, such as liquefaction events, occurred in the Kanto region during the Great East Japan Earthquake on March 11, 2011. Similar disasters can be expected to occur in the future. Disaster prevention and preparedness plans have been developed by municipal governments based on the principle of Jijo (self-aid), Kyojo (community assistance), and Kojo (government assistance). With national land information, including the latest satellite images and Jinsokusokuzu (QuickMap) prepared during the Meiji period, being compiled, consolidated and analysed, it is now expected that such national land information can be utilized in the field of disaster mitigation.According to an old map, the old Kugenuma Lake used to be spread in the southeast of the city of Fujisawa, which is currently located in the dune lands in the Shonan region. This area is composed of sandbanks formed by the Hikichi River and the Sakai River. From the synthetic images based on satellite images and QuickMap, among other things, it is expected that a disaster may cause serious damage in areas of weak ground conditions along the old river ways and the brinks (cliffs) of the old Kugenuma Lake as they have been rapidly converted into residential areas (Figure 1). The evacuation map prepared based on this assumption indicates that nearby tsunami evacuation buildings should serve as an emergency evacuation centre for evacuees (Figure 2). In the vicinity of these emergency evacuation centres, however, there are various areas that may become impassable for evacuees and emergency vehicles due to the potential collapse of stone walls and utility poles, among other things.From the synthetic images based on geospatial information, it is possible to identify areas prone to liquefaction in regions whose past land cover is related to water (Figure 1). The evacuation map, which has been prepared based on the reading of hazard maps and the results of our field investigation, has exposed a number of issues facing disaster-predicted areas (Figure 2). As a result, it is recommended that 1) a community association ensure to always keep evacuation routes operable and clear of any obstructions that may impede evacuation and 2) to conduct an emergency evacuation drill in different seasons and time zones. It is also essential to ensure that a community will develop its own technical capability and autonomous community-based capability to provide relief to its own community members through Kyojo.

Using GIS to simulate tsunami evacuation guidance signs for the hearing impaired.

The Nankai Trough in Japan has been identified as a geological feature that could cause extensive damage in the event of a major earthquake. In this study, we investigated the impact of effective guidance signs for hearing-impaired individuals requiring special care when escaping to a tsunami evacuation building (emergency evacuation location) using geographical information system (GIS) and viewshed analysis. We selected an area we considered would suffer severe damage following a major earthquake and tsunami; we identified difficulties in the provision of escape routes. Using GIS, we determined the time required for escape and tsunami arrival time if effective signs were installed; we undertook such analysis using the height data of buildings in the target area. With effectively installed guidance signs, the average required evacuation time was 36.88 minutes; without such signs (which is currently the case in the target area), the average time was 47.10 minutes: that would result in citizens getting caught by the tsunami. Installing effective guidance signs would allow hearing-impaired individuals to escape to an evacuation building before being hit by the tsunami.

A review of vertical evacuation on tsunami mitigation case

Banda Aceh City was hit by a tsunami at the end of 2004. The experience of this great disaster directly or indirectly has led to many problems that are a must in finding the right solution. It is very important to do in order to minimize the disaster victims of the tsunami in the future. During the rehabilitation and reconstruction period after the 2004 earthquake and tsunami, between 2005 until now, various mitigation efforts have been carried out. One of the tsunami mitigation efforts is to build tsunami evacuation buildings. The city of Banda Aceh is one of the cities in Indonesia that has vertical tsunami evacuation facilities such as escape building. Although it still does not meet the expected availability standards, it can be called the right initial step for Banda Aceh City in the face of the tsunami disaster in the future. However, its existence will be in vain if the community does not use it to its full potential in their daily activities. This study evaluates the effectiveness of the escape building for vertical evacuation based on some supporting literature reviews.

Tsunami evacuation buildings designated by local community

Tsunami evacuation buildings designated by local community

Engineering Applications Using Probabilistic Aftershock Hazard Analyses: Aftershock Hazard Map and Load Combination of Aftershocks and Tsunamis

After the Tohoku earthquake in 2011, we observed that aftershocks tended to occur in a wide region after such a large earthquake. These aftershocks resulted in secondary damage or delayed rescue and recovery activities. In addition, it has been reported that there are regions where the intensity of the vibrations owing to the aftershocks was much stronger than those associated with the main shock. Therefore, it is necessary to consider the seismic risk associated with aftershocks. We used the data regarding aftershocks that was obtained from the Tohoku earthquake and various other historically large earthquakes. We investigated the spatial and temporal distribution of the aftershocks using the Gutenberg–Richter law and the modified Omori law. Subsequently, we previously proposed a probabilistic aftershock occurrence model that is expected to be useful to develop plans for recovery activities after future large earthquakes. In this study, the probabilistic aftershock hazard analysis is used to create aftershock hazard maps. We propose a hazard map focusing on the probability of aftershocks on the scale of the main shock for use with a recovery activity plan. Following the lessons learned from the 2011 Tohoku earthquake, we focus on the simultaneous occurrence of tsunamis and aftershocks just after a great subduction earthquake. The probabilistic aftershock hazard analysis is used to derive load combination equations of the load and resistance factor design. This design is intended to simultaneously consider tsunamis and aftershocks for tsunami-resistant designs of tsunami evacuation buildings.

A GIS-BASED TSUNAMI EVACUATION MODEL CONSIDERING LAND COVER AND SPATIAL CONFIGURATION (CASE OF PURWOREJO REGENCY, INDONESIA)

In Indonesia, several programs have dealt with tsunami mitigation, such as The German-Indonesian Tsunami Early Warning System (GITEWS) project (2005-2011). Despite the success of these projects, many coastal areas in Indonesia are still vulnerable to tsunamis, due to the variety of land cover and spatial configuration characteristics. One of such vulnerable areas includes Purworejo Regency. This paper evaluated the degree to which land cover and spatial configuration characteristics influence the tsunami evacuation process, and thus influence tsunami hazard mitigation. The evaluation drawn on data from a low to medium density populated coastal area of Purworejo Regency. The analysis relied on a quantitative approach, using a cross-sectional field survey, followed by a GIS-based analysis. This is complemented by a raster-based analysis to incorporate the land cover and spatial configuration aspects. The combined analysis derived which buildings could act as evacuation buildings in case of a tsunami. The associated tsunami evacuation routes were calculated using a Least Cost Path (LCP) analysis method. The results suggested that several public facility buildings are likely to be used as tsunami evacuation buildings. Yet, even though the overall capacity of these buildings is adequate to accommodate the estimated number of evacuees in a larger area, the specific demand at certain locations in the study area is much higher than these localities can handle. This disproportionate spatial variation in required capacity needs further attention. Moreover, the survey responses indicated that the majority of the respondents was not well informed regarding the tsunami evacuation procedures

Fragility assessment of a RC structure under tsunami actions via nonlinear static and dynamic analyses

Current guidelines for design and assessment of buildings under tsunami actions do not explicitly state how to apply tsunami loads to buildings and which analysis methods to use in order to assess the structural response to the tsunami loads. In this paper, a reinforced concrete (RC) moment-resisting frame, which is designed as a tsunami evacuation building, is selected as a case study and subjected to simulated 2011 Tohoku tsunami waves. To assess tsunami impact on the model building, different nonlinear static analyses, i.e. constant-height pushover (CHPO) and variable-height pushover (VHPO), are compared with nonlinear dynamic analysis. The results of VHPO provide a good prediction of engineering demand parameters and collapse fragility curves obtained from the dynamic analysis under a wide range of tsunami loading. On the other hand, CHPO tends to overestimate interstorey drift ratio (IDR) and underestimate column shear by about 5–20%. It provides a larger fragility, i.e. about 10% in median value, for global failure and a smaller fragility for local shear failure. On the basis of these results, it is recommended that VHPO be used in future fragility analysis of buildings subjected to tsunami. However, pushover methods might not be adequate in cases where the tsunami inundation force time-histories are characterised by a “double-peak”, which subjects the structure to a two-cycle load. Finally, it is found that tsunami peak force is better correlated to IDR than flow velocity and inundation depth for the considered structure. This suggests that the peak force would be a more efficient intensity measure than the other two in the development of tsunami fragility curves.