ICT for Disaster Management/ICT for Disaster Prevention, Mitigation and Preparedness< ICT for Disaster Management
ICT for Disaster Prevention, Mitigation and PreparednessEdit
The first important steps towards reducing disaster impact are to correctly analyse the potential risk and identify measures that can prevent, mitigate or prepare for emergencies. ICT can play a significant role in highlighting risk areas, vulnerabilities and potentially affected populations by producing geographically referenced analysis through, for example, a geographic information system (GIS). The importance of timely disaster warning in mitigating negative impacts can never be underestimated. For example, although damage to property cannot be avoided, developed countries have been able to reduce loss of life due to disasters much more effectively than their counterparts in the developing world (see Table 1). A key reason for this is the implementation of effective disaster warning systems and evacuation procedures used by the developed countries, and the absence of such measures in the developing world.
A major landslip after the earthquake in Muzaffarabad, Pakistan
Table 1: Comparison of Damage Caused by Three Recent Disasters
All the figures reported in Table 1 are rough estimates as it is impossible to have exact figures in such situations. However, Table 1 clearly shows that in the case of Hurricane Katrina, although the economic loss and damage to property were much higher, the number of deaths was remarkably less than that resulting from the Indian Ocean tsunami in Sri Lanka and the Pakistan earthquake. This is largely because in Sri Lanka and Pakistan, the victims were mainly communities living below the poverty line – a factor that significantly contributed to their vulnerability – and because effective disaster warning systems were not in place. In New Orleans, official warnings were dispatched in advance and many in the affected areas were evacuated in time. In addition, the disaster management process was much better than what it had been in Sri Lanka and Pakistan, despite the heavy criticism it received.
A warning can be defined as the communication of information about a hazard or threat to a population at risk, in order for them to take appropriate actions to mitigate any potentially negative impacts on themselves, those in their care and their property (Samarajiva et al., 2005).
The occurrence of a hazard does not necessarily result in a disaster.While hazards cannot be avoided, their negative impacts can be mitigated. The goal of early public warning is to ensure to the greatest extent possible that the hazard does not become a disaster. Such warnings must be unambiguous, communicate the risks succinctly and provide necessary guidance.
The success of a warning can be measured by the actions that it causes people to take, such as evacuation or avoiding at-risk areas. In a disaster situation, there is no doubt that timely warnings allow people to take actions that save lives, reduce damage to property and minimize human suffering. To facilitate an effective warning system, there is a major need for better coordination among the early warning providers as well as those handling logistics and raising awareness about disaster preparedness and management.
While disaster warnings are meant to be a public good, they are often most effectively delivered through privately-owned communication networks and devices. There are many new communication technologies that allow warning providers not only to reach the people at risk but also to personalize their warning message to a particular situation. Opportunities are available right now to significantly reduce loss of life and potential economic hardship if disaster warning systems can be improved.
It is important to note that disaster warning is indeed a system, not a singular technology, constituting the identification, detection and risk assessment of the hazard, the accurate identification of the vulnerability of a population at risk, and finally, the communication of information about the threat to the vulnerable population in sufficient time and clarity so that they can take action to avert negative consequences. This final component underscores the importance of education and creating awareness in the population so that they may respond with the appropriate actions (Samarajiva et al., 2005).
Key Players in Disaster WarningEdit
The United Nations International Strategy for Disaster Reduction (UN/ISDR) identifies several key parties that play major roles in the disaster management process, especially in disaster warning (UN/ISDR, 2006).
Communities, particularly those most vulnerable, are vital to people-centred early warning systems. Their input into system design and their ability to respond ultimately determine the extent of risk associated with natural hazards. Communities should be aware of hazards and potential negative impacts to which they are exposed and be able to take specific actions to minimize the threat of loss or damage. As such, the geographic location of a community is an essential determinant in the selection of disasters on which the system should focus their community education.For example, coastal communities need to be educated and prepared for the possibility of a tsunami, while a mountain community can be educated to respond to an early warning system for landslides.
Local governments should have considerable knowledge of the hazards to which their communities are exposed. They must be actively involved in the design and maintenance of early warning systems, and understand information received to be able to advise, instruct or engage the local population in a manner that increases their safety and reduces the potential loss of resources on which the community depends.
National governments are responsible for policies and frameworks that facilitate early warning, in addition to the technical systems necessary for the preparation and issuance of timely and effective hazard warnings for their respective countries. They should ensure that warnings and related responses are directed towards the most vulnerable populations through the design of holistic disaster response and early warning frameworks that address the specific needs of the related micro- and macro-level actors. The provision of support to local communities and local governments to develop operational capabilities is an essential function to translate early warning knowledge into risk reduction practices.
Regional institutions and organizations should provide specialized knowledge and advice in support of national efforts to develop or sustain the operational capabilities of countries that share a common geographical environment. Regional organizations are crucial to linking international capabilities to the particular needs of individual countries and in facilitating effective early warning practices among adjacent countries.
International bodies should provide support for national early warning activities and foster the exchange of data and knowledge between individual countries. Support may include the provision of advisory information, technical assistance, and policy and organizational support necessary to ensure the development and operational capabilities of national authorities or agencies responsible for early warning practice.
Non-governmental organizations (NGOs) play a critical role in raising awareness among individuals and organizations involved in early warning and in the implementation of early warning systems, particularly at the community level. In addition, they play an important advocacy role to help ensure that early warning stays on the agenda of government policy makers.
The private sector has a diverse role to play in early warning, including developing early warning capabilities in their own organizations. The private sector is also essential as they are usually better equipped to implement ICT-based solutions. The private sector has a large untapped potential to help provide skilled services in the form of technical manpower, know-how, or donations of goods or services (in-kind and cash), especially for the communication, dissemination and response elements of early warning.
The media plays an important role in improving the disaster consciousness of the general population and in disseminating early warnings.The media can be the critical link between the agency providing the warning and the general public.
The scientific community has a critical role in providing specialized scientific and technical input to assist governments and communities in developing early warning systems. Their expertise is critical to analysing the risks communities face from natural hazards, supporting the design of scientific and systematic monitoring and warning services, fostering data exchange, translating scientific or technical information into comprehensible messages, and disseminating understandable warnings to those at risk.
Channels Used for Disaster WarningEdit
The following are some of the media – both traditional and new – that can be effectively used for disaster warning purposes. Some may be more effective than the rest, depending on the nature of the disaster, the regions affected, the socio-economic status of the affected communities and their political architecture. However, it is not a question of one medium against another. All are means to a common goal of passing along disaster warnings as quickly and as accurately as possible. Any one or combination of the following media can be used for that purpose.
Radio and TelevisionEdit
Considered the most traditional electronic media used for disaster warning, radio and television have a valid use. The effectiveness of these two media is high because even in developing countries and rural environments where the tele-density is relatively low, they can be used to spread a warning quickly to a broad population.The only possible drawback of these two media is that their effectiveness is significantly reduced at night, when they are normally switched off. A study on media, perception and disaster-related behaviour in Bangladesh revealed that early, easily understandable and language-appropriate warning dissemination through radio can reduce the potential death toll of catastrophic cyclone and tidal bore. The study, conducted by the Forum for Development, Journalism and Communication Studies, recommended that relevant authorities develop innovative warning signal systems and take necessary steps to disseminate the warning in easily understood language through radio at least two days before a cyclone hits, hence mitigating the loss of lives and property every year in Bangladesh. Mohammad Sahid Ullah, the Chittagong University professor who led the study, suggests that part of the process is increasing public confidence in broadcast media since self-evacuation and the poor quality of shelters are the major causes of death (Sahid Ullah, 2003). After the Indian Ocean tsunami of 2004,many radio manufacturers considered introducing new digital radio alert systems that react even if the set is switched off. In order to trigger this alarm, a special flag integrated into the received signal from a terrestrial transmitter or a satellite would be used and the set would automatically tune to the emergency broadcast channel. The only disadvantage of this system is that to introduce a new generation of receivers in analogue environment generally takes 5 to 10 years. With digital receivers, this would be somewhat easier (Dunnette, 2006).
Telephone (Fixed and Mobile)Edit
Telephones can play an important role in warning communities about the impending danger of a disaster.There were many examples of how simple phone warnings saved many lives in South Asian countries during the 2004 tsunami. Perhaps the most famous was an incident that occurred in one small coastal village of Nallavadu in Pondicherry, India. A timely telephone call – warning about the impending tsunami – was said to have saved the village’s entire population of 3,600 inhabitants, as well as those of three neighbouring villages. Villagers of Nallavadu were involved in the M.S. Swaminathan Research Foundation’s Information Village Research Project. Vijayakumar, a former project volunteer, was working in Singapore and heard a tsunami alert issued there. He immediately phoned the research centre in Nallavadu, which issued an alert. His quick thinking, followed by swift and coordinated action, led to the evacuation of the four villages before the tsunami hit the coast (Subramanian, 2005). In some countries, mechanisms called ‘telephone trees’ are used to warn communities of impending dangers. An individual represents a ‘node’ in a telephone tree.When that individual receives a warning message (either through phone or by other means), s/he is supposed to make a pre-determined number of phone calls (usually four or five) to others in a pre-prepared list. This arrangement not only ensures the timely delivery of the warning message, but also ensures the minimum duplication of efforts. However, there are two drawbacks to using telephones for disaster warning. Telephone penetration in many areas is still not satisfactory – particularly in rural and coastal areas most at risk. Even with the exponential increase in the number of phones that has occurred in recent years, there are still many regions in the Asia-Pacific region, where a telephone is considered a luxury. The other drawback is the congestion of phone lines that usually occurs immediately before and during a disaster, resulting in many phone calls in that vital period that cannot be completed.
Short Message ServiceEdit
Short message service (SMS) is a service available on most digital mobile phones that permits the sending of short messages (also known as ‘text messages’, ‘SMSes’, ‘texts’ or ‘txts’) between mobile phones, other handheld devices and even landline telephones. During the 2005 Hurricane Katrina disaster in the US, many residents of affected coastal areas were unable to make contact with relatives and friends using traditional landline phones. However, they could communicate with each other via SMS more easily when the network was functional. This is because SMS works on a different band and can be sent or received even when phone lines are congested. SMS also has another advantage over voice calls in that one message can be sent to a group simultaneously.
Most of today's wireless systems support a feature called cell broadcasting. A public warning message in text can be sent to the screens of all mobile devices with such capability in any group of cells of any size, ranging from one single cell (about 8 kilometres across) to the whole country if necessary. CDMA, D-AMPS, GSM and UMTS  phones have this capability. There are four important points to recall about the use of cell broadcasting for emergency purposes:
- There is no additional cost to implement cell broadcasting. It is already resident in most
network infrastructure and in the phones, so there is no need to build any towers, lay any cable, write any software or replace handsets.
- It is not affected by traffic load; therefore it will be of use during a disaster, when load spikes
tend to crash networks, as the London bombings in 2005 showed. Also, cell broadcasting does not cause any significant load of its own, so it would not add to congestion.
- Cell broadcasting is geo-scalable, so a message can reach hundreds of millions of people
across continents within a minute.
- It is geo-specific, so that government disaster managers can avoid panic and road jamming
by telling each neighbourhood specifically if they should evacuate or stay put.
The only possible disadvantage to cell broadcasting is that not every user may be able to read a text message when they receive it. In many Asia-Pacific countries, a sizeable population of the phone users cannot read and understand a message sent in English.Thus, it is essential to send warning messages in local languages. However, these messages would still be inaccessible to those who cannot read, even in their own language. The Dutch Government plans to start using cell broadcasting for emergency warnings. The infrastructure is already in operation with the operators KPN, Telfort and Vodafone. It is believed to be the first multi-operator warning system in the world, based on cell broadcasting with government use (Clothier, 2005).
A satellite radio or subscription radio is a digital radio that receives signals broadcast by communications satellite, which covers a much wider geographical range than terrestrial radio signals. Satellite radio functions anywhere there is line of sight between the antenna and the satellite, given there are no major obstructions such as tunnels or buildings.Satellite radio audiences can follow a single channel regardless of location within a given range. Satellite radio can play a key role during both disaster warning and disaster recovery phases. Its key advantage is the ability to work even outside of areas not covered by normal radio channels. Satellite radios can also be of help when the transmission towers of the normal radio station are damaged in a disaster.
Table 2: Radio Communication Media Used in Disaster Warning and Management
The International Telecommunication Union (ITU) has identified various radio communication media that can be used in disaster-related situations (see Table 2).
The role Internet, email and instant messages can play in disaster warning entirely depends on their penetration within a community and usage by professionals such as first responders, coordinating bodies, etc.While these media can play a prominent role in a developed country, where nearly half of all homes and almost all offices have Internet connections, this is not the case in the developing world. In many developing countries, less than 5 percent of the population uses the Internet and even those who are users do not use it on a regular basis. In such a situation, it is difficult to expect Internet and email to play any critical role. In spite of that drawback, many disaster-related activities are already underway within the Internet community. For example, a new proposal for using the Internet to quickly warn large numbers of people of impending emergencies is currently being drafted by the Internet Engineering Task Force.
At a 1997 international conference on ‘Harnessing the Internet for Disasters and Epidemics’, participants raised issues affecting their ability to use the Internet for improving crisis management. Concerns included the high cost of technology, a lack of content in local languages, and governmental controls on information exchange.“The most significant obstacle impeding widespread Internet usage was the widening gap between those with unlimited access and those, whose access to information and new technologies was restricted by economic, linguistic, cultural or administrative constraints”, highlights the Pan American Health Organization’s report on the conference. Without direct communication between decision-makers and without a free flow of reliable information among all involved, effective contingency planning and emergency response are at risk (Putnam, 2002).
Amateur and Community RadioEdit
For almost a century, amateur radio (also known as ‘ham radio’) operators have assisted their communities and countries during disasters by providing reliable communications to disaster relief organizations at a moment’s notice – especially when traditional communications infrastructure breaks down. In such a situation, amateur radio operators transmit emergency messages on voice mode about the well-being of survivors and information on casualties to friends and relatives. As was evident during the Indian Ocean tsunami that destroyed electricity and communications infrastructure in the Andaman and Nicobar Islands, amateur radio operators were the critical link between the islands and the Indian mainland and helped in the coordination of rescue and relief operations.
Besides disseminating voice-based messages, some amateur radio operators can also transmit in digital modes that include technologies such as radio teletype, tele-printing over radio, packet radio transmission and the recent Phase Shift Keying, 31 Baud – a type of modulation. Amateur radio broadcasters are authorized to communicate on high frequency (HF), very high frequency (VHF), ultra high frequency (UHF) or all three bands of the radio spectrum. They require a license from the licensing authority to ensure that only competent operators use their skills. However, depending on the country, obtaining a license can be a long process.
The most effective mode to exchange messages in an email-style is pactor using Airmail as email client and Winlink2000 as network on shortwave. A very valuable advantage is that the user can address any valid emailaddress worldwide through hf-radio and winlink. Destroyed internetinfrastructure can be bridged by this technology until a gateway (more than 150 worldwide RMS) with working internetaccess can be reached. More information about Winlink2000.
Messages can be disseminated using one or more of the available bands. HF waves travel long distances, while VHF and UHF waves travel very short distances as these are line-of-sight propagation. However, repeaters increase the communications range and temporary repeaters can be set up in an emergency so that messages can reach the nearest town or city (Acharya, 2005).
There are no well-known case studies where community radio has been successfully used for disaster warning purposes. The main reason can be because this is not a widespread media channel in many countries. Even where there are community radio systems, they operate within limited areas. Nevertheless, community radio is a medium that can be very effectively used for disaster warning purposes.The effectiveness of this medium is being tested through a disaster warning system implemented by Sarvodaya, the most widespread NGO in Sri Lanka (Daily News, 2006).
Though not necessarily an ICT-based solution, sirens can be used in tandem with other ICT media for final, localized delivery. The strengths of each medium and the challenges in using them are summarized in Table 3.
Table 3: Comparison of Different Communication Channels Used in Disaster Warning
GIS can be loosely defined as a system of hardware and software used for storage, retrieval, mapping and analysis of geographic data. Spatial features are stored in a coordinate system (latitude, longitude, state, plane, etc.) that references a particular place on the earth.Descriptive attributes in tabular form are associated with spatial features. Spatial data and associated attributes in the same coordinate system can then be layered together for mapping and analysis. GIS can be used for scientific investigations, resource management and development planning.
Remote sensing is the measurement or acquisition of information about an object or phenomenon by a recording device that is not in physical or intimate contact with the object. In practice, remote sensing is the remote utilization (as from aircraft, spacecraft, satellite or ship) of any device for gathering information about the environment. Thus, an aircraft taking photographs, earth observation and weather satellites, monitoring of a foetus in the womb via ultrasound, and space probes are all examples of remote sensing. In modern usage, the term generally refers to techniques involving the use of instruments aboard aircraft and spacecraft. As disaster management work usually involves a large number of different agencies working in different areas, the need for detailed geographical information in order to make critical decisions is high. By utilizing a GIS, agencies involved in the response can share information through databases on computer-generated maps in one location. Without this capability, disaster management workers have to access a number of department managers, their unique maps and their unique data. Most disasters do not allow time to gather these resources. GIS thus provides a mechanism to centralize and visually display critical information during an emergency. There is an obvious advantage to using a map with remote sensing or GIS inputs instead of a static geographical map. A static map is mostly analogous and is not interactive. On the other hand, a vulnerability map with GIS input provides dynamic information with cause and effect relationship. As shown in Figure 6, the visualization effect is much more effective in the latter case.
Figure 6: Difference Between an Ordinary (2D) Map and a Map with GIS Input
GIS-based space technology solutions have become an integral part of disaster management activities in many developed and some developing countries. The United Nations Office for Outer Space Affairs has been implementing a Space Technology and Disaster Management Programme to support developing countries in incorporating space-based solutions in disaster management activities. The use of GIS in different phases can be illustrated as follows:
Locating and identifying potential problems is a core requirement in disaster management. GIS can be used effectively to achieve this objective. Using a GIS, it is possible to pinpoint hazard trends and start to evaluate the consequences of potential emergencies or disasters. When hazards are viewed with other map data, such as buildings, residential areas, rivers and waterways, streets, pipelines, power lines, storage facilities, forests, etc., disaster management officials can formulate mitigation, preparedness, response and possible recovery needs. Information derived from remote sensing and satellite imagery plays an important role in disaster management and crisis prevention. Their effective application depends not solely on technical specifications, but is influenced by factors such as data collection, processing and distribution, capacity building, institutional development and information sharing. Earth observation satellites could be used to view the same area over long periods of time and, as a result, make it possible to monitor environmental change, human impact and natural processes. This would facilitate scientists and planners in creating models that would simulate trends observed in the past, present and also assist with projections for the future.
After potential emergency situations are identified, mitigation needs can be addressed. This process involves analysing the developments in the immediate aftermath of a disaster, evaluating the damage and determining what facilities are required to be reinforced for construction or relocation purposes.Mitigation may also include implementing legislation that prevents building structures in areas prone to earthquake, flood or tsunami. Other mitigation approaches may target fire-safe roofing materials in wildfire hazard areas. Utilizing existing databases linked to geographic features in GIS makes the task of monitoring these possible.
During the preparedness and response phases, GIS can accurately support better response planning in areas such as determining evacuation routes or locating vulnerable infrastructure and vital lifelines, etc. It also supports logistical planning to be able to provide relief supplies by displaying previously available information on roads, bridges, airports, railway and port conditions and limitations.Apart from this, activities such as evacuee camp planning can also be done using GIS.
GIS can also provide answers to some of the questions important to disaster management officers, such as the exact location of the fire stations if a five-minute response time is expected or the number and locations of paramedic units required in a specific emergency. Based on the information provided by GIS, it is also possible to estimate what quantity of food supplies, bed space, clothes and medicine will be required at each shelter based on the number of expected evacuees. In addition, GIS can display real-time monitoring for emergency early warning. Remote weather stations can provide current weather indexes based on location and surrounding areas.Wind direction, temperature and relative humidity can be displayed by the reporting weather station. Wind information is vital in predicting the movement of a chemical cloud release or anticipating the direction of wildfire spread upon early report. Earth movements (earthquake), reservoir level at dam sights, radiation monitors, etc. can all be monitored and displayed by location in GIS. If necessary, this type of information and geographic display can be delivered over the Internet to the public.
Case Study:The Tsunami Early Warning System (TEWS) for South-East AsiaEdit
The Indian Ocean tsunami of December 2004 took many Asian countries by surprise.There was virtually no warning until thousands of people suddenly found themselves in the middle of giant killer waves. In the aftermath of the tsunami, several international meetings have been held among countries in the Indian Ocean rim to concertedly address threats from similar disasters. It was agreed that arrangements for a Tsunami Early Warning System (TEWS) in the Indian Ocean and South-East Asia should build on existing institutions, strengthen national capacities, integrate early warning with preparedness, mitigation and response (end-to-end), and must furthermore be integrated into existing warning systems to promote a multi-hazard approach. The partner countries in this effort were Cambodia, China, Lao PDR, Myanmar, Philippines, Singapore,Thailand and Viet Nam. The Asian Disaster Preparedness Center (ADPC) is a non-profit organization supporting the advancement of safer communities and sustainable development through implementing programmes and projects that reduce the impact of disasters upon countries and communities in Asia and the Pacific, by:
- Developing and enhancing sustainable institutional disaster risk management capacities,
frameworks and mechanisms, and supporting the development and implementation of government policies;
- Facilitating the dissemination and exchange of disaster risk management expertise,
experience and information; and
- Raising awareness and enhancing disaster risk management knowledge and skills.
In March 2005, ADPC, in partnership with the Royal Thai Government and in collaboration with the United Nations Economic and Social Commission for Asia and the Pacific, organized a Regional Meeting of the above countries to assess the feasibility of implementing a Multi-Hazard Early Warning System in South-East Asia.
In April 2005, Bangladesh and Sri Lanka indicated interest in receiving similar support to enhance their national early warning capacity and capabilities. Consequently, ADPC has been working with these governments and in the Maldives to enhance emergency communication systems through an ITU-funded project. ADPC furthermore completed an assessment of Sri Lanka’s early warning systems through a separate UNDP-funded project.
The donor agencies for the implementation of TEWS are UNDP, The Danish National Development Agency and the United States Agency for International Development (USAID). This warning system is designed to be end-to-end, encompassing both technological components and the training of both affected and at-risk communities in preparedness and response measures. Each component is important and should be given equal development focus. The non-technical components of hazard mapping and risk assessment, risk reduction and preparedness activities, and efficient warning dissemination reaching vulnerable local coastal communities are the most challenging to develop in a comprehensive early warning system, as these involve societal dimensions.
Figure 7: Implementation Plan of the Tsunami Early Warning System
Some of the existing early warning systems in the region address recurrent hazards such as cyclones/typhoons, floods and drought. Investing in hazard monitoring and forecasting for a rare event such as a tsunami is costly in terms of capital and the required investment of human resources.
Hence, in the face of low tsunami frequency, but the prevalence of high-risk coastal zones (due to population growth and development), resources to undertake hazard monitoring and forecasting are pooled in a regional monitoring system and forecasting centre in order to provide an economically sustainable system. The technical components are comprised of a network of seismographic stations, sea-level gauges and deep-sea pressure sensors, a data-processing and tsunami forecasting centre, and communication links to regional tsunami warning centres. These are in turn linked to national disaster management and warning systems. The network will utilize relevant facilities already available in the countries (assessed by the Inter-Governmental Oceanographic Commission and in national workshops arranged by ADPC) and consider the establishment of new ones.
The network of accelerographs, to be located in islands close to the coastlines of Indonesia and the Nicobar and Andaman Islands, will provide rapid estimation of the tsunamagenic potential of an earthquake. Deep-ocean pressure sensors detect the early passage of a tsunami before it reaches shallow waters and the coast. Sea-level gauges, to be strategically located close to tsunami sources and in areas that would provide sufficient lead-time for response, are essential in determining the passage of a tsunami wave following an earthquake, to monitor its progress, estimate the severity of the hazard along the coast, and provide a basis for declaring the end of a hazard. The sea-level gauge stations are designed for long-term sea-level monitoring, but are capable of monitoring tsunami and storm surges. High-frequency sea-level data will be transmitted via the European Organisation for the Exploitation of Meteorological Satellites Meteosat-5 and the Japanese Meteorological Agency’s Geostationary Meteorological Satellites, and are connected to the Global Sea-Level Observation System Core Network.
Risk assessments and training will be conducted with the relevant national authority. Utilizing satellite imagery, GIS and further applicable technologies, ADPC will support bathymetric surveys and national training workshops on risk mapping, conduct a pilot risk-mapping survey (to be replicated in other vulnerable locations by the national authorities), and support regional workshops on numerical prediction models facilitated by the acquisition of the modelling tools. Community preparedness activities are the most critical component of this system. The technological capacity of a system is obsolete without a prepared or fully aware public. Despite the dissemination of a warning, communities that lack sufficient preparedness and training in effective responses to both the warning and the event remain acutely vulnerable.
Figure 8: AlertNet Website