首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
A tsunami catalogue for Central America is compiledcontaining 49 tsunamis for the period 1539–1996,thirty seven of them are in the Pacific and twelve inthe Caribbean. The number of known tsunamis increaseddramatically after the middle of the nineteenth century,since 43 events occurred between 1850 and 1996. This isprobably a consequence of the lack of populationliving near the coast in earlier times.The preliminary regionalization of the earthquakessources related to reported tsunamis shows that, inthe Pacific, most events were generated by theCocos-Caribbean Subduction Zone (CO-CA). At theCaribbean side, 5 events are related with the NorthAmerican-Caribbean Plate Boundary (NA-CA) and 7 withthe North Panama Deformed Belt (NPDB).There are ten local tsunamis with a specific damagereport, seven in the Pacific and the rest in theCaribbean. The total number of casualties due to localtsunamis is less than 455 but this number could behigher. The damages reported range from coastal andship damage to destruction of small towns, and theredoes not exist a quantification of them.A preliminary empirical estimation of tsunami hazardindicates that 43% of the large earthquakes (Ms 7.0) along the Pacific Coast of Central America and100% along the Caribbean, generate tsunamis. On thePacific, the Guatemala–Nicaragua coastal segment hasa 32% probability of generating tsunamis after largeearthquakes while the probability is 67% for theCosta Rica–Panama segment. Sixty population centers onthe Pacific Coast and 44 on the Caribbean are exposedto the impact of tsunamis. This estimation alsosuggests that areas with higher tsunami potential inthe Pacific are the coasts from Nicaragua to Guatemalaand Central Costa Rica; on the Caribbean side, Golfode Honduras Zone and the coasts of Panama and CostaRica have major hazard. Earthquakes of magnitudelarger than 7 with epicenters offshore or onshore(close to the coastline) could trigger tsunamis thatwould impact those zones.  相似文献   

2.
Sugimoto  T.  Murakami  H.  Kozuki  Y.  Nishikawa  K.  Shimada  T. 《Natural Hazards》2003,29(3):587-602
This study presents a tsunami human damage prediction method employing numerical calculation and GIS (Geographical Information System) for Usa town, Tosa City, Shikoku Island, Japan. Sometime near the end of the first half of the twenty-first century, a huge earthquake is predicted to occur along the Nankai trough and costal areas facing the Pacific ocean of Shikoku Island. Much damage due to the resultant tsunamis will be caused, therefore, it is necessary to predict the extent of human damage for every town in high-risk areas.The number of tsunami victims was estimated by population in areas of maximum inundation. The number of deaths as a result of tsunami was estimated by a method which employed accumulated death toll of every area in terms of time and space, taking into account consideration of time necessary to begin to seek refuge after an earthquake, tsunami inundation depth on land, flow velocity and evacuation speed. As a result of this study a rapid decrease in death toll by early evacuation was shown quantitatively for the first time.Thus, with the method presented here, it is possible to estimate the extent of tsunami human damage on coastal regions, and may be useful as a tsunami human damage countermeasure.  相似文献   

3.
Natural hazards pose an increasing threat to society and, for this reason, it is necessary to develop models and methodologies for better understanding and forecasting extreme weather events. A new structure of the Greek Regional Administration (Kallikratis) was established in 2011, based on geographical criteria, in order to create an operational and capable administration. An Atmospheric Hazards Early Warning System (AHEWS) could be characterised as an ultimate tool for the local authorities (first and second tier level) in order to organise and implement efficient plans to mitigate the risk. New operation centres (related to regional and municipality administration level) are suggested to be staffed and equipped with the proposed Early Warning System (EWS). The AHEWS will link to extensive Geographical Information Systems (GIS) datasets and methodologies for safety plans by government agencies and services in order to mitigate the impacts caused by atmospheric extreme events. AHEWS involves high-resolution Numerical Weather Prediction (NWP) products, ground observation network, lightning detection network and satellite information in terms of early convective, initiation and Now-Casting. Storms, lightings, gale winds, snow, hail, tornadoes, low temperatures, heatwaves and several others extreme events are weather phenomena that AHEWS deals with in order to prevent and mitigate impacts on humans and constructions. An automated dissemination procedure is described here for individual and administrative users, followed by safety and action plans, respectively.  相似文献   

4.
Local Tsunami Warning in the Pacific Coastal United States   总被引：2，自引：1，他引：1  
Coastal areas are warned of a tsunami by natural phenomena and man-made warning systems. Earthquake shaking and/or unusual water conditions, such as rapid changes in water level, are natural phenomena that warn coastal areas of a local tsunami that will arrive in minutes. Unusual water conditions are the natural warning for a distant tsunami. Man-made warning systems include sirens, telephones, weather radios, and the Emergency Alert System. Man-made warning systems are normally used for distant tsunamis, but can be used to reinforce the natural phenomena if the systems can survive earthquake shaking. The tsunami warning bulletins provided by the West Coast/Alaska and Pacific Tsunami Warning Centers and the flow of tsunami warning from warning centers to the locals are critical steps in the warning process. Public knowledge of natural phenomena coupled with robust, redundant, and widespread man-made warning systems will ensure that all residents and tourists in the inundation zone are warned in an effective and timely manner.  相似文献   

5.
The 2014 Iyonada Earthquake, which occurred at 02:06 JST on 14 March, measured 6.2 on the Richter scale and originated in the Seto Inland Sea of Japan. To elucidate tsunami evacuation behavior, we examined two coastal communities in Kochi Prefecture, Okitsu and Mangyo, where residents evacuated to high ground in anticipation of a tsunami. In the event of a Nankai megathrust earthquake and tsunami, it is expected that a huge tsunami will be generated and these communities will be severely damaged. Before the Iyonada Earthquake, we had previously collected data about tsunami preparedness and evacuation plans from the residents of these communities, and after the earthquake, we conducted in-depth interviews and questionnaire surveys with the residents regarding the actual evacuation behaviors that they took. This enabled us to compare evacuation plans with evacuation behaviors. Results indicate that many residents responded quickly to the earthquake, either by immediately evacuating to emergency shelters on high ground or by preparing themselves for evacuation. Additionally, the earthquake revealed great differences between the prior evacuation plans and the actual situation of residents’ evacuation, such as specific triggers that significantly led residents to evacuate and the use of vehicles in evacuation.  相似文献   

6.
Classification of Tsunami and Evacuation Areas   总被引：3，自引：2，他引：1  
On March 11, 2011, a large earthquake that occurred offshore the north-east coast of Japan generated a large tsunami which devastated extensive areas of the Tohoku coastline. Despite Japan being considered a country well prepared for these types of disasters, large casualties were recorded, with numerous discussions amongst the Japanese coastal engineering community ensuing. As a result, two different levels of tsunamis have been proposed and now recognized in Japan, depending on the frequency of such extreme events. The idea that hard measures can protect the lives of inhabitants of coastal areas has been abandoned, and these measures are only considered to be effective in protecting properties against the more frequent but lower magnitude events. Soft measures should always be used to protect against the loss of lives, and to this respect, the authors of the paper propose the introduction of a Classification of Evacuation Areas, to show which of these should be prioritized by residents as they seek to evacuate.  相似文献   

7.
Inland flooding remains one of the greatest threats to the safety of human population in the United States (US). While few large-scale studies exist, the potential role of naturally occurring wetlands in mitigating flood duration and intensity has been widely discussed. This study examines the relationship between wetland alteration and coastal watershed flooding in Texas and Florida over a 12-year period. Specifically, we geo-reference wetland alteration permits required under Section 404 of the US Clean Water Act and correlate the number of granted permits with the degree of flooding measured by stream gauge data. Results indicate that specific types of federal permits exacerbate flooding events in coastal watersheds while controlling for various environmental and socioeconomic characteristics.  相似文献   

8.
Tsunamis have occurred in Canada due to earthquakes, landslides, and a large chemical explosion. The Pacific coast is at greatest risk from tsunamis because of the high incidence of earthquakes and landslides in that region. The most destructive historical tsunamis, however, have been in Atlantic Canada – one in 1917 in Halifax Harbour, which was triggered by a catastrophic explosion on a munitions ship, and another in 1929 in Newfoundland, caused by an earthquake-triggered landslide at the edge of the Grand Banks. The tsunami risk along Canada's Arctic coast and along the shores of the Great Lakes is low in comparison to that of the Pacific and Atlantic coasts. Public awareness of tsunami hazard and risk in Canada is low because destructive tsunamis are rare events.  相似文献   

9.
  相似文献   

10.
Estimating tsunami potential is anessential part of mitigating tsunami disasters. Weproposed a new method to estimate the far-fieldtsunami potential by assuming faultmodels on the Pacific Rim. We find thata tsunami that generates in the areas wherethere is no tsunami in the history can damagethe Japanese coast. This shows that it isimportant to estimate tsunami potential byassuming fault models other than the pastearthquake data.Another important activity to mitigate tsunamidisasters is to provide appropriatewarnings to coastal communities when dangerfrom a tsunami is imminent. We applied anew inversion method using wavelet transformto a part of the real-time tsunami forecastsystem for the Pacific. Because this inversionmethod does not require fault location, it ispossible to analyze a tsunami in real timewithout all seismic information. In order tocheck the usability of the system, anumerical simulation was executed assuming anearthquake at sea off Taiwan. The correlationcoefficient for the estimated initialwaveform to the assumed one was calculatedto be 0.78. It takes 90 min to capturetime-series waveform data from tsunamigauges and 5 sec to estimate the 2-D initialwaveform using the inversion method. After that,it takes 2 minutes to forecast thetsunami heights at the Japanese coast. Since thesum of these times is less than the 105minutes transit time of the tsunami fromTaiwan to Japan, it is possible to give a warningto the residents before the tsunami attacksthe Japanese coast. Comparing the tsunamiheights forecasted by this system with thosecalculated by the fault model, the averageerror was 0.39 m. The average error ofthe arrival time was 0.007 min.  相似文献   

11.
Since 2003, a series of over eighty sensors has been installed at Turtle Mountain, site of the 1903 Frank Slide. The purpose of these instruments is to both characterize and provide warning for a second large rock avalanche from the eastern face of the mountain, where various unstable masses have been identified. Although studies continue on the mountain to better understand the deformation patterns and interpretations of the slope kinematics, significant effort has been expended to develop a structure for the warning and emergency response that clearly outlines not only responsibilities and communications protocols during an emergency, but also day-to-day operational responses and procedures to ensure that the system remains operational. From a day-to-day operational perspective, a systematic and repeatable set of procedures is required in order to ensure that not only are data trends reviewed and reported on, but scheduled checks of system functionality are undertaken. An internal Roles and Responsibilities Manual has been developed to clearly outline responsibilities for geoengineering, information technology (IT), and management staff to ensure that system checks are completed and that support is in place on a 24/7 basis should components of the system cease to operate properly or should unacceptable deformations require review. In addition to that, a clear and concise troubleshooting manual has been developed. This document provides simple diagnoses of problems within the system and a clear roadmap of how to fix each component. From a warning and emergency response perspective, a series of color-coded alert conditions has been developed should unacceptable deformations be observed. At each alert level, clear responsibilities for actions and communications have been identified for geoengineering staff, provincial emergency management authorities, municipal officials, and first responders. This has been documented in the emergency response protocol. All documents described here are “living” documents that are updated on a regular basis as changes to the system are made. An annual mock warning exercise has been developed and run in order to test responses to a hypothetical emergency and generate updates to the system documentation.  相似文献   

12.
In the aftermath of a hurricane, local emergency managers need to communicate reentry plans to households that might be scattered over multiple counties or states. To better understand evacuees’ households’ reliance on different information sources at the time they decided to return home, this study collected data on reentry after Hurricane Ike. The results from a survey of 340 evacuating households indicated that there was low compliance with official reentry plans and that none of the information sources produced greater compliance with official reentry plans. Nonetheless, there were significant changes in the utilization of different sources of emergency information over the course of an evacuation but local news media remained the most common sources throughout the event. There also were significant differences in the relative importance of different sources of reentry information, with people relying most on information from peers. In summary, local authorities need to identify more effective ways to communicate with evacuees that have relocated to distant communities and to motivate them to comply with official reentry plans.  相似文献   

13.
Awareness about the threats posed by different types of coastal disasters has increased throughout the world, as people are exposed to the nature of these hazards through media reports on events in distant countries. This has resulted in coastal residents being aware about the destructive power of tsunamis, despite no such events having taken place in their country in recent times. Regardless of this increased awareness, it has been hypothesized that there is still need for local governments to enact adequate policies to raise the awareness of local residents, for example, by holding regular evacuation drills. The present research presents a comparative assessment of tsunami awareness in two tourist destinations in Japan and the USA, which was derived through structured questionnaire surveys of beach users in the city of Kamakura and various coastal cities in Florida. The results show how despite relatively high level of awareness tsunamis still pose a considerable risk to each of the communities, for example, due to shortcoming in evacuation knowledge and infrastructure.  相似文献   

14.
Earthquakes and tsunamis along Morocco’s coasts have been reported since historical times. The threat posed by tsunamis must be included in coastal risk studies. This study focuses on the tsunami impact and vulnerability assessment of the Casablanca harbour and surrounding area using a combination of tsunami inundation numerical modelling, field survey data and geographic information system. The tsunami scenario used here is compatible with the 1755 Lisbon event that we considered to be the worst case tsunami scenario. Hydrodynamic modelling was performed with an adapted version of the Cornell Multigrid Coupled Tsunami Model from Cornell University. The simulation covers the eastern domain of the Azores-Gibraltar fracture zone corresponding to the largest tsunamigenic area in the North Atlantic. The proposed vulnerability model attempts to provide an insight into the tsunami vulnerability of building stock. Results in the form of a vulnerability map will be useful for decision makers and local authorities in preventing the community resiliency for tsunami hazards.  相似文献   

15.
Smith  Grant  Juria  Nover 《Natural Hazards》2019,99(1):189-216

Inhabitants of low-lying coral atolls benefit from disaster risk reduction decision makers receiving early warnings of coastal inundation leading to heightened levels of alert and preparedness. Majuro, the capital of the Marshall Islands, is a coral atoll that experiences coastal inundation events on a near annual frequency and is likely to be exacerbated by sea-level rise, increasing the importance of early warning systems. However, current early warnings are not always provided for every inundation event. Inundation is driven by a combination of various oceanographic processes that contribute to sea level at the coastline, with the primary driver dependent on how extreme a particular process may be at the time. Incoming swell from distant storms and cyclones can trigger an inundation event, especially when coinciding with high spring tides and/or sea-level anomalies. Historical data from three directional scenarios were analysed to determine the critical values for offshore wave height, peak period, directional range, and sea level that had led to inundation in the past. Bulk wave statistics and static sea level were found to be sufficient information to identify the occurrence of an inundation event. These inundation thresholds serve as a reference to be used in conjunction with forecast models as an analogue for future events informing both the likelihood and impact. The analysis showed that inundation with a significant contributing swell factor propagates via three main routes, with approximately 50% occurring from the north-east. The two highest sea-level measurements on record both occurred during La Niña events, with both leading to inundation, suggesting that spring tides during La Niña events should exhibit a heightened level of alert for inundation at Majuro regardless of swell contribution.

  相似文献   

16.
Since the impoundment of the Three Gorges Reservoir in June 2003, a number of new landslides have occurred and existing landslides have been made worse. The 1,260 × 104 m3 Baishuihe landslide, located at 56 km west of the Three Gorges Dam, began to deform more noticeably after the first impoundment in early July 2003. The sliding of the two blocks comprising the landslide, one an active block and the other a relatively stable block, became apparent after approximately 5 years of monitoring. Field recordings show that the landslide displacement is affected by the combined effects of the rainfall and water level in the reservoir. These effects have been investigated in the present paper, including the deformation characteristics (movement pattern, direction, displacement and velocity) earmarking the temporal evolution of the active block. Based on a practical creep model of a large rock slide, alert velocity thresholds for pre-alert, alert and emergency phases have been computed corresponding to the imminence of failure. The alert velocity thresholds are being proposed to be included as a part of an early-warning system of an emergency plan drawn up to minimize the adverse impact in the event of landslide failure. The emergency plan is intended to be implemented as a risk management tool by the relevant authorities of the Three Gorges Reservoir in the near future.  相似文献   

17.
Luino  F.  Belloni  A.  Turconi  L.  Faccini  F.  Mantovani  A.  Fassi  P.  Marincioni  F.  Caldiroli  G. 《Natural Hazards》2018,94(1):471-488

A project to develop a flood hazard management plan along the east shore of Lago Maggiore was carried out. Several municipal territories along a coastal stretch have been analysed, identifying the rate of water rise and the limits of the submerged areas. This study discusses the overall methodological approach and presents the results for Porto Valtravaglia, as a significant case study. The first step was a detailed analysis of historical events to locate the most frequently damaged sites. Thousands of historical documents on past floods were collected, selected and validated, to map the most vulnerable sites. The second step was a morphological analysis of the studied coastal stretch. Multi-temporal aerial snap-shots were used and field surveys were conducted to verify the reliability of the historical data and to identify the critical hydraulic conditions along the shore. The third step was a review of the general urban development plans of the 17 studied municipalities. Aerophotogrammetric and cadastral maps were used to evidence and define the eight classes of land use destinations. In addition, the floodable areas were divided into three vulnerability and exposure categories considering different peculiarities of social and working life. Finally, using GIS spatial analysis tools, these data were compiled into risk maps and wielded as the municipal emergency plans’ baseline scenarios. For each studied municipality was hypothesised the alarm thresholds upon which were activated the flood emergency procedures.

  相似文献   

18.
  相似文献   

19.
Tsunami databases are not dissimilar from a wide variety of other data sources used by researchers, and yet users rarely, if ever, use them appropriately. They contain summary information of individual tsunamis, but they will always be incomplete because of the fragmentary data related to numerous past events and the difficulty of updating event information for those already included. Examples from AD1917 and AD1892 throw some light on this dilemma and show that not only is the uncritical use of such databases inappropriate, but that the data they contain may not be fit for the research questions being asked. This is unfortunate because it has probably led to at least one significant misconception developing within the tsunami community - that earthquakes are by far the most significant tsunami-genic source. When used appropriately though, tsunami database have the potential to inform and empower coastal communities.  相似文献   

20.
根据《国务院关于加强地质灾害防治工作的决定》,围绕调查评价体系、监测预警体系、防治体系和应急体系的建设工作编制铜川市地质灾害防治规划。旨在为铜川市政府指导地质灾害防治工作提供决策依据,也为铜川境内各区县编制地质灾害防治规划提供指导。我国目前尚无地质灾害防治规划技术要求,该文章为我省乃至全国市级地质灾害防治规划的编制提供示范。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号