Potential seismic risk assessment of urban cities based on macro-zonation concept

This paper describes a potential seismic risk of a city or a group of cities based on the "macro-zonation concept" in which regional macro information such as topography, number of active faults and historical earthquakes, population, accessibility from neighboring cities etc. is considered. In this study, typical cities in Japan are selected and their potential seismic risk is estimated based on statistical data related to macro information. Also the relationship between the estimated potential seismic risk and damage observed in Kobe districts damaged by 1995 Hyogoken-nambu earthquake are investigated. (AU)

Gender differences in risk and communication behabior : Responses in the New Madrid earthquake prediction

This study examines gender differences in communication behavior, risk perception, and preparedness in response to the highly publicized New Madrid earthquake prediction for a 6.5-7.5 Richter magnitude earthquake on December 2-3, 1990. A survey of 629 respondents in November and a follow-up survey of 496 respondents in February 1991 in the Cape Girardeau, Missouri, community provided the opportunity to assess public response to the false alarm. The analysis includes a panel survey of 290 respondents who agreed in November to a second interview. When compared with men, women were associated with higher levels of interpersonal discussion about the prediction and perceived higher levels of news and media influence on their perceptions of the importance of the earthquake prediction. Contrary to previous studies reporting higher levels of news media use for men, no gender differences in news media use were found. A majority of studies of risk perception suggest higher levels of perceived risk for women than men. In this study, men were associated with higher levels of risk and lower levels of preparedness (AU)

Estudio prospectivo : Los futuros desastres en México

Trabajo que trata sobre los futuros desastres en México; el trabajo se compone de tres partes, a saber: 1.Breve exposición de las bases teóricas y metodológicas para la construcción de la prospectiva, 2.Visualización de los desastres para el próximo siglo, 3.Diseño de los posibles escenarios de la Protección Civil y su construcción futura. La primera parte esta basada en los planteamientos formulados por el Dr. Tomas Milkos, para desarrollar una prospectiva sobre los desastres y la Protección Civil en México, conforme las siguiente premisas: 1era.Descripción de los futuros, 2da.Visualización del futuro, 3era.diseño del futuro, y 4ta.Construcción del futuro. En donde dichas premisas corresponderán al desarrollo de la segunda y tercera parte de este trabajo, que consiste en visualizar los desastres para diseñar escenarios y obtener algunas líneas o estrategias a adoptar para la construcción de la Protección Civil

Use of ANN for seismic risk assessment

Implementation and efficiency of artificial neural network (ANN) for earthquake predictions related to probabilistic risk analysis of structures are investigated. Feedforward-back propagation neural networks are trained to predict: (1) peak ground acceleration (PGA), given the earthquake magnitude and epicentral distance; and (2) the probability of exceedence of earthquake of certain magnitude, given the magnitude of the earthquake. Also, the same type of ANN is trained to map the relationship between the response spectrum of earthquake and its power spectral density function (PSDF). The latter is used for random vibration analysis of structures for risk consistent response spectrum of earthquake. The neural net uses sigmoid function as the activation function at the nodes and has fully connected feedforward net architecture. A feedback propagation with momentum algorithm is used to train the neural nets. The results of the study show a great promise for the use of ANN for seismic disaster risk management and indicate the need for dedicated ANN tools to be included in the earthquake data base programs

Preparation of spatial data sets for physically based hydrological models

Hydrological modeling is essential for impact assessment and forecasting of both droughts and floods, which are two of the most frequent natural disasters. Physically based hydrologic models simulate the hydrologic processes based on the governing equations, which depend on the physical characteristics of the catchment. This approach is useful in assessing human impacts as well as changes to catchment characteristics on the hydrological cycle. Physically based hydrologic models are especially useful in simulating regional hydrology where catchment heterogeneity is important and observations available for calibration are sparse. To use such models, spatial distribution of physical characteristics of the catchment such as elevation, land cover, soil properties, etc., should be prepared and registered to a common coordinate system. This paper describes data preparation methodology, improvements, sensitivity and estimation of hydrologic parameters for such modeling

GIS for efficient natural disaster preparedness and mitigation in Sri Lanka

Use of geographical information system (GIS) for efficient planning and implementation of the natural disaster risk reduction in Sri Lanka is illustrated. GIS facilitates the researchers, authorities and relief organizations to efficiently plan, implement and monitor the natural disaster preparedness and mitigation activities such as predictions, preventive actions, relief operations, rehabilitation, reconstruction, awareness creation and public education. Flow chart of operations are proposed to objectively analyze the data in different layers coupled with the specialized software programs to spatially model the risk of different types of natural disasters and to minimize the damage

Monitoring network for earthquake risk management

Natural disaster monitoring has advanced much with the emergence of new technologies. Weather satellite and Doppler radar have revolutionized the way severe storms are forecasted and prepared against. At the same time, close communication between weather services, emergency management agencies, the media and the public has made the advance warning effective in reducing loss of lives. While early warning of other devastating disasters has not been as well established as severe weather, their near-term advances are certain. In anticipation of scientific advancement, the issue of data sharing and information dissemination deserves more and more attention. This paper considers aspects of a disaster monitoring network based on a "culture of networking and sharing". Network-based earthquake monitoring using different techniques including geomagnetic measurement, will be considered for appropriate data validation, processing, and dissemination. The goal is to validate the potential of using the network for timely data sharing and integration with public administration in earthquake risk management

Database centered simulation using WWW

A model for WWW based simulation environment is presented. The simulation environment is coordinated through a RDBMS that contain both spatial and time series data for use with forecast and simulation programs. Any client WWW browser can communicate with the Database either through the Web Server or directly through Java applets. The data preparation and execution as well as storage of the output in the database is automated through database scripts that are stored within the database. Communication with operating system resident simulation programs is carried out through server side Java programs initialized by the database trigger scripts. This approach provides a generic mechanism for integrating spatial and time series data with simulation programs to carry out scenario modeling and impact assessment studies. The methodology is scalable and can evolve into a decision support system incorporating database and simulation functionality

Severe local storms

Severe weather associated with thunderstorms (tornadoes, hail, high winds, and flash floods) is reviewed with emphasis on the processes that are responsible. The basis for forecasting severe thunderstorms in reviewed. The parts of the world that are most vulnerable to various kinds of severe weather and the nature of the threats are described. The current state of the climatology of severe thunderstorms and problems and importance of improving climatological information are described. The lack of high-quality climatological information makes it very difficult to determine differences in event occurrence during different periods of the El Niño-Southern Oscillation (ENSO) in most of the world and almost impossible to detect changes associated with global climate change. It is argued, however, that the threats from severe thunderstorms are generally underestimated in many parts of the world. In genera, the effects of severe local storms are concentrated in a small number of events. Death tolls and damage in "average "years are typically smaller than the totals from individual events in other years. As a result, maintaining public awareness and preparedness activities is difficult since the threat of rare, extremely damaging events, is small at any individual location and time. (AU)

Drought monitoring and prediction for disaster preparedness

The overall theme of the forum is to address the roles of science and technology in natural disaster reduction. This review will be devoted to drought early warning and preparedness. The review will highlight, among others, what we must know in order to reduce the impacts of droughts; the current state, achievements and limitations of science and technology; and a way forward into the next century. The first part addresses the various definitions that have been used for the term drought. The devastating socio-economic impacts of droughts are highlighted in the second section, with special reference to Africa where drought has been associated with many socio-economic miseries. Section 2 also highlights the potential use of drought monitoring and prediction products in early warning and reduction of the negative drought impacts. Recent drought monitoring and prediction efforts are addresses in section three, with special reference to the use of El Niño and the Southern Oscillation (ENSO). Section 3 further highlights the need to take full advantage of any existing information regarding the climatology of past droughts. This requires policies that will ensure optimum utilization of any positive water stress including the availability of adequate water resources during the normal and wet rainfall years in planning for the drought years. Specific success stories regarding the use of ENSO indicators in drought monitoring and prediction over some parts of the tropics are also presented in section 3, with special reference to the recent worldwide regional climate outlook fora. The last part of this review is, however, devoted to the limitations of current drought monitoring and prediction science and technology. Enhanced sectoral demands and challenges of drought monitoring / prediction science and technology in drought early warning and disaster preparedness during the next century are also addressed in the last part of the review. (AU)

Mitigating the effects of earthquakes : Problems, progress and future trends

Over the past few decades, seismologist have made enormous progress is understanding the physical processes that govern the occurrence of earthquakes. For example, we now know that most earth tremors are generated by stresses that accumulate along the boundaries between the giant tectonic plates that constitute the Earth's outermost rigid layer. Seismologists have estimated the sense of ground displacement to be expected in many seismically active regions, and experience has shown that damage caused by direct shaking of the ground can be augmented markedly by such secondary effects as fires, landslides and tsunamis. Moreover, the number of fatalities and level of damage created by an earthquake are not only dependent on the size and location of the event, but they are also affected significantly by the quality of the buildings and the local ground conditions. Nevertheless, on of the major goals of seismology, that of short - term (days to weeks) earthquake prediction, remains as elusive as ever. Although some seismologists claim that earthquake may be predicable in the not - too - distance future, others suggest that their occurrence is essentially random and that research into earthquake prediction may be futile. By comparison, trustworthy earthquake hazard and risk assessment based on time scales of tens to hundreds of years are realizable. In many regions, these assessments are benefiting from the results of global projects aimed at. (i) compiling dependable earthquake statistics, (ii) ascertaining the present state of stress and strain rate, (iii) mapping the distribution of active faults, (iv) determining the rate of seismicity in the distant past, and (v) estimating the expected level of ground - shaking by means of computer modelling. Furthermore, fast inexpensive computer technologies are allowing early warning and early - damage assessment strategies to be developed, such that disaster response personnel can be either forewarned of damaging waves approaching of informed where the most intense ground - shaking has occurred. As the International Decade of Natural Disaster Reduction (IDNDR) comes to an end, it is appropriate to consider how mitigation and preparedness measures for the natural disaster that will inevitably affect our planet may be better promoted and implemented. One approach is to concentrate our efforts on the large urban centres of the developing world, where the effects of natural disasters can be devastating to the people, their economy, their culture, and their environment. Several programs aimed at improving capacities for natural disaster mitigation and preparedness in the megacities of the developing world are currently underway. (AU)

Successes and failures in fighting landslides : Some experiences from Italy and elsewhere

When is an action taken to cope with a hazardous mass movement considered a success? When is it necessary to admit failure? This paper attempts to give an answer to these questions by examining the three main aspects of a landslide risk management programme: prediction, prevention (or mitigation) and emergency planning. Examples of successes and failures are given with reference to some of the best known case histories that have occurred, more or less recently, in Italy and elsewhere in the world. The recent developments of scientific research regarding the different aspects of landslide risk management are briefly outlined. As far as the prediction phase is concerned, the state - of - the - art on landslide risk assessment and the basic differences between spatial and temporal prediction are briefly summarized and discussed. The GIS database of the Emilia - Romagna region, containing over 30000 individual landslide, is presented as a successful example of a spatial prediction containing elements for temporal forecasting. The exceptional 1996 Versilia rainstorm that triggered more than 1450 debris flows, causing 13 casualties, is described as a representative case of an unpredictable event. A general framework for the main strategies and techniques employed for landslide risk prevention is proposed. A successful case history, the urban transformation accomplished in the second half on the 19th century on the San Miniato hill of Florence is presented: the architectonic transformation, of high artistic and landscape value, was combined with an effective stabilization of the hill, the instability of which was documented in a number of historic documents starting form the 11th century. The 1998 Sarno disaster is illustrated as an example of prevention failure: a series of debris flows caused 161 casualties in the suburbs of Sarno and Quindici, where uncontrolled urban development took place on areas historically exposed to high hazard. The basic requirements of a successful emergency plan are therefore discussed, such as monitoring and warning system and simulation techniques for risk scenario analyses. The emergency plan devised and implemented after the occurrence of the 1993 La Josefina landslide in Ecuador is presented as a success: the landslide produced a dam on the Rio Paute and the successive emergency measures managed to reduce the losses caused by the dam breaching and overtopping to a minimum. Finally, the well - known 1963 Vaiont disaster is proposed as a representative example of unsuccessful emergency planning: more than 1700 casualties were caused by the catastrophic flood wave generated by the sudden failure of a huge mass of rock into a reservoir. (AU)