Framework for evaluating the maintenance of a Tsunami Early Warning System (TEWS) – A pilot case study in Patong, Thailand, of social and technical quality indicators

: Due to a tsunami being a rapid event (minutes or hours), it is necessary to have disaster risk reduction measures in place well in advance. TEWS is a warning system for reducing the consequences of a tsunami. A successful TEWS requires that i) people are aware of the risk, ii) people are prepared to evacuate and iii) the TEWS is working properly. This study aims to develop a framework with key quality indicators for technical, social, and governance maintenance of a TEWS, emphasizing the chain of activities from tsunami detection to evacuation. The framework is extended to novel indicators involving memory keeping and evacuation signage. The TEWS etsablished in Patong, following the Indian Ocean tsunami disaster 2004, is used as a pilot case study to test the framework related to technical and social maintenance by conducting a retrospective long-term analysis years 2005–2022. Data is collected from research and news articles 2005–2022, as well as field observations of Patong in 2022. The result shows that during these years there have been several events and actions that highlight both problems and positive developments related to technical and social maintenance of the TEWS. Because tsunamis are fast occurrences, dependable TEWS are vital.


Introduction-"first mile" Tsunami Early Warning System
Tsunamis are unavoidable complex hazards with low probability and high risk of severe consequences that are problematic to prepare for (Rafliana et al., 2022).Not only are tsunamis rare events but risk awareness is also limited, particularly in places where a major catastrophic event has not occurred over a significant period of time or coastal development and tourism have increased the exposure of assets and people.However, if warning systems and awareness activities are in place, and maintained, before a hazard occurs, it is possible to reduce the consequences (Rafliana et al., 2022).
Tsunami Early Warning Systems (TEWS) involve a chain of activities for reducing the consequences of a tsunami (Pal et al., 2022).It begins with the system technically detecting an indication of a tsunami built up offshore.A warning is disseminated through several channels.The warning is communicated to the people at risk who are then supposed to take correct procedures of evacuating (Pal et al., 2022;Twigg, 2004;UNEP, 2012).The chain of activities for TEWS is all-important to reduce the negative outcome of a tsunami.For instance, warnings alone are not enough to avoid a disaster, so it is essential to also provide evacuation plans and education (Rossetto et al., 2005).The preparations include identifying evacuation routes-both main and alternative, creating safe areas for evacuation, and organizing signage and maps of the routes possible for evacuees to follow (Beresford & Pettit, 2009).Therefore, much has to be done in terms of capacity building at the community level (Triandis & H.C, 2001).This got political support in January 2005 when the international community at the World Conference on Disaster Reduction (in Kobe) agreed about the essential need to establish TEWS to protect coastal communities (Birkmann et al., 2010).
Early warning systems can be designed with a people-centred approach, also called "first mile".This approach makes people at risk a primary focus throughout the chain of activities, which makes the system more socially robust (Villagrán de Leon, 2012).People at risk should then be involved in the process of implementing the warning system to reduce the gap between locals and authority/experts/military.However, in practice, the role of "expert" is often not given up and people are therefore excluded from the process.The exclusion may cause people not to trust the government or the official warnings (Thomalla & Larsen, 2010).
Priority number four of the 2015 Sendai Framework for Disaster Risk Reduction emphasizes the importance of strengthening disaster preparedness for response and taking action before hazards occur.One way to achieve this at local and national level is to maintain and strengthen peoplecentred early warning systems (Nations, 2015).According to the Sendai Framework, it is necessary to understand the local characteristics of disaster risks.To inform people at risk about disaster risk factors is also less resource demanding compared to post-disaster response and recovery.Moreover, number four of the Sendai Framework priorities mentions the importance of strengthening the capacity of local authorities to evacuate people at risk in a hazard area (Nations, 2015), which is central in a people-centered TEWS (Nations, 2015).
People-centred TEWS shall be considered as permanently active and therefore proactive instead of reactive, i.e. there does not have to be a hazard before the system is activated, compared to systems that are inactive until a hazard occurs (Villagrán de Leon, 2012).To prevent future tsunami disasters, there is a need for several measures combining detection, warning, response, and refuge.The key objective is to save lives, which will principally be achieved by evacuation to tsunami-safe areas before a tsunami landfall (Bell et al., 2005), i.e. the first mile approach highlights the need to ensure that i) people at risk are aware of the risk, ii) people are prepared to evacuate and iii) the TEWS is working properly.Since TEWS is a chain of activities, it depends on people being familiar with tsunami risk, the warning system, and how to respond to the disseminated warning to avoid the tsunami hazard area and reduce fatalities.This requires preparedness before hazards occur.At the same time, people are dependent on an effective TEWS to disseminate warnings, inform about where to evacuate, and explain how to reach zones outside of the tsunami hazard area.The warning system has to be maintained for people to be able to rely on it.The definition of maintenance in this context is that the links in the system must be possible to maintain over time to guarantee its reliability.This requires, for instance, local education and awareness as well as prepared evacuation routes-in line with the demands of the first mile principles.This study will target the maintenance of a TEWS, with focus on the first-mile perspective.

Previously identified maintenance issues of TEWS
After a disaster, measures can be enabled to reduce the probability of similar future consequences.The political will to implement measures during the emergency relief phase is often briefly present, since it is more prone to attention from media and the outside world compared to long-term recovery which is often given less media attention (Oloruntoba et al., 2018).It has been shown that long-term recovery to reduce disaster risk is difficult to maintain over a longer time perspective (Koswara et al., 2021;Syamsidik et al., 2021;Thomalla et al., 2009).There is also a difference in whether changes are made and how they are maintained as years pass by.This is a central consideration, since there can be decades before a catastrophic tsunami occurs again.For example in Aceh, Indonesia, which suffered extensive losses from the 2004 tsunami disaster, long-term activities to reduce the consequences of a future tsunami hazard have been implemented.The frequency of these activities did, however, decrease after 2012, and today improvements need to be made.The decrease in activities can be explained by less public attention to long-term recovery processes compared to the emergency phase, decreasing resources, and fewer involved actors (Syamsidik et al., 2021).
Parts of the TEWS, like evacuation signage, can last for a substantial period of time but have to be maintained over time for function, purpose, and updated information following community development.Neglect of maintenance needs was found in 2020-2021 in Pangaran Beach (Koswara et al., 2021), a tourism area in Indonesia prone to tsunamis.There are planned evacuation routes in the area, but signs marking the routes are not well maintained.Several are lost, covered, or faded from the sun, restricting public information on how to evacuate (Koswara et al., 2021).Also in Krabi Province of Thailand, the signage system implemented after the 2004 tsunami disaster was reported as inadequate in 2008.The signs are reported to be misleading, blocked, or barely visible.The information about evacuation distances is also unclear.One explanation for the neglected care of evacuation routes and signage systems is a lack of funding (Thomalla et al., 2009).
Tourist-dense coastal areas have special challenges in terms of communication and guidance linked to the large crowds of temporary visitors.Empirical research among Thais and tourists/ foreigners in Patong, Thailand, indicates that evacuation routes and signage system need to be maintained with correct information.When deciding where to evacuate during a tsunami alert, 23% of the Thais and 30% of foreigners would follow the evacuation route signs.Almost 70% of the local Thai residents would choose their own evacuation route, which makes it important to provide education about where to evacuate.The information can be implemented through activities such as evacuation drills and evacuation route maps.This would also help 38% of foreigners and 6.5% of local residents who tend to follow the crowd (Chalat et al., 2011).
The aim with this study is to contribute to the maintenance of TEWS.This is done by developing a framework with key quality indicators for the evaluation of technical, social, and governance maintenance of TEWS.Following the Indian Ocean tsunami disaster 2004, Patong in Thailand is used as a case study to test the framework related to technical and social maintenance, by conducting a retrospective long-term analysis of the period 2005-2022.

Patong as a case study to test the developed framework
Patong (Figure 1), Thailand, is used as a case in the present study.It is interesting as a case study due to the large number of tourists visiting the area each year, complicating the challenge of evacuation.In 2019, 9.89 million international tourists visited Phuket Island (Mastercard, 2019), and Patong is the most popular tourist destination on the island (Calgaro et al., 2009).Coastal locations relying on tourism can vary in population amount over a season or different times of the day.Moreover, visitors may be unfamiliar with both local risks and local evacuation routes (Rafliana et al., 2022).People within the vulnerable area during a tsunami include tourists, fishermen, employees, and residents, who need to know how to react during a tsunami warning and how to evacuate (UNDRR and UNESCO-IOC, 2019).
The Indian Ocean tsunami disaster of 26 December 2004, struck 14 unaware countries (Pomonis & Rossetto, 2005).Phuket province in Thailand was one of the six provinces along the western Andaman Coast to be hit by the tsunami (Poompoe, 2016).Phuket suffered 279 fatalities.Most of them occurred in Patong (Rossetto et al., 2005) 1 when the peak tsunami run-up height of 5-5.5 meters 2 struck the area (Bell et al., 2005).
The Government of Thailand took immediate action to establish a National Disaster Early Warning System.In 2005, the first two warning towers in Thailand were built in Patong as part of a comprehensive TEWS (Reliefweb, 2005).In 2008, Patong municipality developed a disaster preparedness plan with a focus on tsunamis (but also landslides and fire).One of the overall objectives was to evacuate to safe areas without confusion and panic (Patong Municipality, 2008).In Patong, the warning system may provide 20 minutes for evacuating (Leelawat et al., 2021), which requires a rapid decision to evacuate.To reduce the risk of a future tsunami disaster in Patong, a process designed by the United Nations Environment Programme (UNEP) was applied and coordinated by UNEP in cooperation with staff from the Swedish Rescue Services Agency (Räddningsverket) (UNEP, 2007).The process included local agencies such as the police and fire department, representatives from the community, and actors from the tourism sector such as travel agencies and hotel managers, to include specific tourism destination challenges (UNEP, 2008).The process is called Awareness and Preparedness for Emergencies at the Local Level (APELL).Its aim is to create public awareness of hazards and to ensure that the response of emergency services and communities is based on them and being trained and prepared.The process was adapted to tourism-specific needs with the project "Disaster Reduction through Awareness, Preparedness and Prevention Mechanisms in Coastal Settlements in Asia-Demonstration in Tourism Destinations" (UNEP, 2007).Vulnerability mapping identified areas at risk for disastrous events (UNEP, 2008).In Patong, the 2004 tsunami inundation area is considered the hazard zone.Elevated areas beyond this line are allocated as evacuation areas and buildings as evacuation shelters (Fakhruddin, 2015).
Since the 2004 Indian Ocean tsunami disaster, 19 years have passed.There has not been a new tsunami in Patong since 2004, although trembles from earthquakes in Sumatra outside of Indonesia are sometimes felt in Phuket Island, without causing a tsunami in Phuket, for instance on 7 December 2016 (Legacy Phuket Gazette, 2016) and 27 April 2007 (Legacy Phuket Gazette, 2007b).The TEWS has thus not been subjected to a real test so far.

Method
This is a pilot study for developing a framework for maintenance of TEWS.The methodology for the framework is presented in section 2.1.The methodology to test the framework with help of a case study is presented in section 2.2.

Framework for "first mile" key quality indicators of TEWS
To help explore the maintenance of a TEWS, a framework is compiled as a synthesis from Twigg (Twigg, 2004), UNEP (UNEP, 2012), Villagrán de Leon (Villagrán de Leon, 2012), Buckle (Buckle, 2012), Golnaraghi (Golnaraghi, 2012), UNESCO (UNESCO, 2017).Out of the literature included in the study, it is only UNESCO (UNESCO, 2017) that specifically focuses on early warning systems for tsunamis.The rest of the literature is focused on multi-hazard EWS (Golnaraghi, 2012), basic information about EWS (Early Warning System) (UNEP, 2012; Villagrán de Leon, 2012), and hazard preparedness and planning (Buckle, 2012;Twigg, 2004).The literature was found by conducting searches with a combination of the key words: "first mile", framework, and tsunami.The literature used consists of compilations of previous research and recommendations relevant to the field of which they represent.
The framework includes the chain of activities from hazard detection and warning to evacuation from a first mile perspective in the context of a tsunami hazard.The framework consists of key quality indicators for technical, social, and governance maintenance, identified by Villagrán de Leon (Villagrán de Leon, 2012) as crucial.Each key quality indicator has subcriteria indicators.The key quality indicators and subcriteria indicators are developed from the rest of the literature.Indicators that relate to each other are grouped into key quality indicators and specified with subcriteria indicators.The subcriteria indicators are used to specify the different components of each key quality indicator.When using the framework to analyse maintenance, both in long-term retrospective and in present perspectives, the subcriteria indicators are used to assess if the key quality indicator is maintained or not.
The framework does not include planning to ensure long-term evacuation.Included are people at risk who choose to evacuate in an acute situation by following the evacuation routes and signage system.Evacuation can be a response to the disseminated warning of a TEWS.Evacuation can also have other reasons such as a felt earthquake or recognition of natural signs of an oncoming tsunami.

Case study of Patong
The framework is tested by conducting a case study.There is a lack of long-term retrospective analyses of post-disaster measures and their causes and effects (cf (Hill & Gaillard, 2013)), including the establishment of early warning systems, the reason often being that greater attention is paid to short-term needs in the disaster aftermath.Since reconstruction after disaster is a process extending over years or decades, a long-term perspective can contribute with useful insights not found in a shorttime perspective.An example of a valuable insight is the necessary balance between post-disaster reconstruction, integration of Disaster Risk Reduction (DRR), and people's everyday life.Another example is the value of local knowledge to be used in the rebuilding process.Locals can bring other, more creative solutions not found by national or international actors (Hill & Gaillard, 2013).
The framework is applied in a retrospective long-term analysis to assess the TEWS in Patong, Thailand, from its establishment in 2005 after the 2004 Indian Ocean Tsunami until 2022.When designing and implementing the warning system, technical, social, and governance maintenance needs to be taken into consideration (Villagrán de Leon, 2012), with recurrent evaluations over the years as a quality control.The framework contains several indicators for technical, social, and governance maintenance and to describe them qualitatively or quantitatively requires different approaches and methodologies.An evaluation that covers all indicators demands, amongst others, the involvement of responsible organizations, especially with regard to governance maintenance assessments.In this pilot study, the approach is to carry out an evaluation from an outside perspective, without the involvement of responsible authorities and organizations.For that reason, only two aspects of the framework are tested-technical and social maintenance.
The chosen maintenance indicators (technical and social) and approach required collection of data in three ways-published empirical research, "grey" literature consisting of news articles and web pages, and field observation in Patong.Empirical research and grey literature provide the historical aspect while the field observation adds present-day data.The empirical research and grey literature provide data on all of the indicators, while the fieldwork focuses on evacuation routes and signage system.
Data from identified research, grey literature, and field observation were categorized and analysed in the framework according to the different key quality indicators and subcriteria indicators.The assessment makes it possible to explore the technical and social maintenance of a TEWS at local level.

Search strategy for empirical research articles
Empirical research is based on experiences and examples from reality (Bryman & Nilsson, 2018).Searches for empirical research were performed using the databases Scopus and Web of Science.Included years were 2005-2022.The following key words were used both individually and combined: tsunami, Thailand, Phuket, Patong, evacuation, "early warning", drill, memorial, anniversar*.
The initial screening of empirical research articles resulted in 224 495 articles for Scopus and 799 241 for Web of Science.With keyword combinations, 220 hits were left for Scopus and 396 for Web of Science.The inclusion criteria were English language, Patong, and topics related to the created framework.After reading titles and abstracts, the first selection resulted in eight articles for Scopus and two for Web of Science.The final selection was made by reading the articles in full, leaving six articles as relevant according to the inclusion criteria.

Search strategy for grey literature
Grey literature consisting of news articles and web pages was also included.Searches were conducted at ReliefWeb (Reliefweb) and news web pages of The Phuket News (The Phuket News) and The Thaiger (The Thaiger).The news web pages were found by using the database LibraryPressDisplay and a list of newspapers by country (Wikipedia, n.d.).The following key words were used: drill, warning, sign, memorial, and anniversary.All key words were combined with the key word "tsunami".Included years were 2005-2022 except for The Phuket News which was created in 2011 and therefore only contains articles from 2011.The inclusion criteria were English language, Patong, and topics related to the created framework.In total, 61 different publications and news articles were found and included.

Field observation
To determine the current state of the tsunami evacuation routes and signage system, a site visit to Patong was conducted between 30 December 2021 and 26 January 2022.According to Patong's disaster management plan, there are 11 evacuation routes, starting from the four-kilometer beach, going in a west-east direction towards high ground (Patong Municipality, 2008).
The 11 evacuation routes were followed by foot and driven with a motorbike, one at a time.The starting point was the beach area.The routes were then followed by using the existing signage system.The purpose of the field inspection was to explore both the evacuation routes and the evacuation signage system, using the framework's evacuation key quality indicators.
Information was collected with the help of field notes, recorded immediately or shortly afterwards to ensure the details.Pictures were taken of the signs informing about anything related to tsunami evacuation, and the evacuation routes were filmed.
Performing an observation study makes it possible to get information about the influence of the physical environment.It also makes it possible to enter the field with an initial idea of what to observe and if necessary change the focus due to findings which increase the experience (Mulhall, 2003).The study is conducted from an outside perspective where the researcher enters the studied area to conduct field observations.The data collection then becomes a subjective estimation based on the conducting researcher, which is always an issue considering qualitative research.To reduce bias, the created framework was used to establish basic principles of what to include during field observation.A strength of this methodology is that the observation study made it possible to develop insights about the local context.Another strength is the possibility to understand how measures taken to ease evacuation are maintained today.

Result
The result of the developed framework is presented in section 3.1.The result from testing the framework by conducting a case study is presented in section 3.2.

Result-framework for "first mile" key quality indicators of TEWS
The framework consists of first mile key quality indicators for technical, social, and governance maintenance at local level (Figure 2).Some indicators have overlapping relationships across these three spheres.The indicators can be regarded as links in a chain that need to be held together for the system to function as intended.Technical maintenance is related to physical technical issues of detecting tsunamis and disseminating warnings.Technical maintenance also includes communication with the public.This is not a solely technical function, since it has to be adapted to the public for them to perceive it as intentional.The three key quality indicators for technical maintenance are detect, disseminate, and communicate.Each key quality indicator has subcriteria indicators.For detect these are i) basic functions.For disseminate the subcriteria indicators are i) warning issuance and ii) warning transmission.For communicate the subcriteria indicators are i) reach the public, ii) achieve public understanding, and iii) involve the public.Social maintenance includes "softer" parts of the warning system to make people aware of how to behave when they receive the disseminated warning.The primary goal of social maintenance is to increase the likelihood of people at risk to evacuate by both preparing them and providing evacuation routes before a tsunami.The two key quality indicators for social maintenance are preparedness and evacuation.Each key quality indicator has subcriteria indicators.For preparedness, these are i) awareness and education, ii) memory keeping, and iii) evacuation drills.For evacuation, the subcriteria indicators are i) general factors, ii) evacuation routes, and iii) signage systems.
Governance maintenance includes governance and institutional structures for operating the TEWS, relevant for all parts of the system-from detection to evacuation.Technical and social maintenance of a TEWS depends on the organisations behind the TEWS for it to be reliable and fulfill its purpose.The five key qualities for governance maintenance are proactive governance, detect governance, disseminate and communicate governance, preparedness governance, and evacuation governance.Each key quality indicator has subcriteria indicators.For proactive governance, these are i) governance model, ii) management plans and budgeting processes, and iii) risk assessment.For detect governance the subcriteria indicators are i) detection and ii) experienced staff and analysis tools.For disseminate and communicate governance, the subcriteria indicators are i) effective internal communication and ii) guidelines.For preparedness governance, the subcriteria indicator is i) authorities and civil protection agencies.For evacuation governance, the subcriteria indicators are i) plans, ii) evacuation procedures, and iii) adequate funding.

Technical maintenance
A TEWS depends on technical functions, both initially and over time.This means that implemented technical solutions for detection and warning should be possible to use, maintain, upgrade, and permanently sustain.For this to work properly, technical maintenance includes human, technical, and financial resources (Golnaraghi, 2012;Twigg, 2004;Villagrán de Leon, 2012).There should be people with competence to use the TEWS, technical functions should be maintained and updated, and financial resources must be in place to ensure operation.Without these resources, the TEWS function to detect hazards and disseminate and communicate warnings will not prevail over time (Golnaraghi, 2012;Villagrán de Leon, 2012).
Detect key quality indicator: • Basic functions of technical solutions for detecting a hazard (Twigg, 2004;UNEP, 2012), for instance, a buoy system monitoring sea-surface variations and wave heights.
Disseminate key quality indicators: • Warning issuance.If a detected hazard constitutes a call for a community at risk to mobilize, it is important that the warning is issued by a single authority.This helps avoid confusion and different warnings from different sources.The authority should be responsible for issuing the external warning and assure people about the accuracy of taking action (Golnaraghi, 2012;Twigg, 2004;Villagrán de Leon, 2012).
• Warning transmission should be sent through as many channels as possible.The warning message should, however, be the same in all channels and include information about the hazard, location of impact, time of impact, and instructions for those at risk (Golnaraghi, 2012;Villagrán de Leon, 2012).
Communicate key quality indicators: • Reach public.The external communication system for warning transmission should be robust and effectively reach people at risk in a timely manner (Golnaraghi, 2012;Twigg, 2004).Media forwarding the warning message issued by the responsible authority helps spread the warning and increase the probability of reaching more people (UNESCO, 2017; Villagrán de Leon, 2012).
• Public understanding.There are differences in how people at risk receive and perceive a warning (Buckle, 2012;Twigg, 2004).The probability of warning instructions being followed can be increased if the warning message is: ○ In languages represented in the community (Villagrán de Leon, 2012).
○ Adapted to the receiver.For instance, there can be separate warnings to schools and radio stations with instructions and responsibilities clearly formulated (Golnaraghi, 2012;Villagrán de Leon, 2012).
○ In layman's terms without scientific terminology.Otherwise, there is risk of a communication gap between those working with the TEWS in question and the receiver of the warning (Golnaraghi, 2012;Twigg, 2004;UNEP, 2012;UNESCO, 2017).
• Involved public.The probability of warning instructions being followed can increase if the warning is adapted to the community at risk.Community members should be involved in: ○ Identifying optimal communication mechanisms and strategies (Twigg, 2004;Villagrán de Leon, 2012), for instance, which radio station will be most effective in reaching people (Villagrán de Leon, 2012).
○ Designing warning messages to make sure that they are correctly understood by the receiver (Twigg, 2004;Villagrán de Leon, 2012).
○ Defining different levels of warnings (if used), for instance, levels that indicate time for hazard, since there can be local context to consider such as the meaning of colors (Villagrán de Leon, 2012).

Social maintenance
People need to be aware of how to react when a warning reaches them.People at risk should know how to minimize losses and possess knowledge and resources to move themselves and their key assets to safety.Therefore, people at risk need to implement measures to minimize losses before the hazard manifests (Villagrán de Leon, 2012).There is a direct link between TEWS, preparedness, and evacuation.Preparedness makes people aware of how to follow warning instructions and move away from the hazard (Buckle, 2012;Twigg, 2004) by evacuating temporarily (hours, days) before returning home (Buckle, 2012).
If no one evacuates successfully, the purpose of the TEWS has failed (De Marchi, 2007).Rapidonset hazards require functioning TEWS and people being prepared to follow evacuation directions.Preparedness and evacuation are social processes existing within the society exposed to hazard (Buckle, 2012).It is crucial to continue raising public awareness to establish a fully operational TEWS (Pal et al., 2022).Knowledge needs to be initiated as well as sustained over time.This requires efforts in the form of education and awareness activities (Villagrán de Leon, 2012).
Preparedness key quality indicators: • Awareness and education; Awareness campaigns (Buckle, 2012;Villagrán de Leon, 2012) and education activities (De Marchi, 2007) are useful for: ○ Increasing preparedness by generating knowledge of the risk and how to appropriately respond to it (Golnaraghi, 2012;Twigg, 2004;UNESCO, 2017).
○ Reducing mistrust against the TEWS in case of false alarm.False alarms can occur, but by handling them in a way that shows that there are lessons learned and improvements made, for example more effective forecasting, authorities can avoid mistrust and doubt in the system (UNESCO, 2017; Villagrán de Leon, 2012).
• Memory keeping of historic disaster.Maintained memory of historic disaster(s) can increase preparedness for future hazards.The memory of a disaster does not have to be self-experienced; it can be told and still be effective for preparedness (Haque et al., 2022).Not only is the memory of the disaster helpful but memory-keeping activities can also help maintain the knowledge of implemented measures after the historic disaster which can ease the outcome of a future event (Xu, 2017).The long-time memory of historic disaster can be kept with memorial sites, anniversary commemorations (Pal et al., 2022;Xu, 2017), museums (Pal et al., 2022), and evacuation drills (Villagrán de Leon, 2012).
• Evacuation drills should be undertaken regularly.To maintain awareness of tsunami risk and how to evacuate, it is crucial with tsunami evacuation exercises since evacuation planning needs to be rehearsed (Golnaraghi, 2012;Rafliana et al., 2022).Moreover, drills are useful for: ○ Testing the TEWS and detecting maintenance and update needs (Twigg, 2004;Villagrán de Leon, 2012).
○ Making those involved in different phases of the TEWS aware of the functionality of the system and maintaining required skills and knowledge (Golnaraghi, 2012;Twigg, 2004;Villagrán de Leon, 2012).
Evacuation key quality indicators: • General factors.Factors that cannot be affected but can influence the evacuation response should be taken into consideration.These factors can include, for instance, different times of day, holidays, and the weather (Buckle, 2012;UNESCO, 2017).For instance, is there a difference during the day when permanent residents and temporary visitors spend most time in the beach area?Permanent residents in e.g.Patong, Thailand, spend most time at the beach between 3 and 6 pm, while the most popular time for visitors is between 3 and 9 pm (Charnkol & Hanaoka, 2011).
• Evacuation routes for escaping the hazard should be well known to people at risk (Buckle, 2012;Twigg, 2004;UNESCO, 2017).The routes should not be blocked by people evacuating or cut off by the hazard itself (Buckle, 2012;Twigg, 2004).If the routes are not passable, there should be alternative routes and people should be aware of them (Twigg, 2004).
• Signage systems help guide evacuees to evacuation routes during a hazard (Rafliana et al., 2022).Evacuation route signs also raise community awareness of the correct evacuation route and make people more prepared and educated on how to behave during a tsunami (Dengler, 2005).Both individual and community education and awareness of evacuation routes are equally important and a relatively cheap investment (Imamura et al., 2019;Suppasri et al., 2013).To improve the probability of the signage system being identified and followed during an evacuation, it is important to consider the following: ○ Evacuation route signs should be clearly seen and not blocked from view (Thomalla et al., 2009).
○ The signage system should be more extensive near the beach front since people in this area need to evacuate abruptly (Chalat et al., 2011).
○ A higher signage cover area would better guide pedestrians due to the angle of located signs and the distance between the pedestrian and the sign, since longer viewing distances hinder the interaction between the pedestrian and the sign (Nassar, 2011; W. L. Wang et al., 2014).
○ To minimize causalities and optimize evacuation speed due to limited time, pedestrians should have well-placed evacuation signs to follow (Lonergan et al., 2012;Nguyen et al., 0000), since the guidance efficiency is largely dependent on the signage location (Zhang et al., 2017).
○ Plans and maps for evacuation should clearly inform residents and visitors how to reach safety during a hazard (Rafliana et al., 2022).The direction of evacuation signs should be correct for following the evacuation route (Thomalla et al., 2009).
The framework is extended with more subcriteria indicators related to social maintenance than found in the used literature on EWS (specifically; Memory keeping of historic disaster and Signage system of the evacuation routes) due to reasons as follows.
Of the research used for creating the framework, none mentioned the importance of memory keeping of historic disaster (Buckle, 2012;Golnaraghi, 2012;Twigg, 2004;UNEP, 2012), except Villagrán de Leon (Villagrán de Leon, 2012) who briefly mentions the importance of evacuation drills as a way to keep long-time memory of a historic disaster.Since memorial places and the spreading of people's experiences do contribute to the 2015 Sendai Framework for DRR (Imamura et al., 2019), memory keeping of historic disaster is here included in the framework.The research included for creating the framework does mention the importance of evacuation routes (Buckle, 2012;Golnaraghi, 2012;Twigg, 2004;UNEP, 2012;Villagrán de Leon, 2012;Wong, 2012).However, the importance of the signage system for guiding evacuees to the nearest evacuation route or direction of the route to reach safety zones outside of the tsunami hazard area was not mentioned at all in (Buckle, 2012;Golnaraghi, 2012;Twigg, 2004;UNEP, 2012;Villagrán de Leon, 2012) or just briefly in (UNESCO, 2017).Since both local residents and tourists are helped by the signage system during a tsunami evacuation (Chalat et al., 2011), this is an important aspect of the TEWS to be included.

Governance maintenance
A well-functioning TEWS requires proactive governance recognizing the value of conducting activities related to early warning systems and DRR, as opposed to a reactive governance that responds after a disaster has occurred (Villagrán de Leon, 2012).Reliable, effective governance and organized involved parts are necessary for operating all of the components of a TEWS, both separately and together as a system (Golnaraghi, 2012;Twigg, 2004;UNESCO, 2017;Villagrán de Leon, 2012).To do so, there should be an understanding of the need to involve a variety of individuals and institutions (Buckle, 2012;Golnaraghi, 2012;Villagrán de Leon, 2012).There should also be acceptance that the TEWS is being designed to empower communities at risk, which in turn requires an understanding that the responsibility for the operation of the system belongs to everyone involved and not just government agencies (Golnaraghi, 2012;Legacy Phuket Gazette, 2010a;Villagrán de Leon, 2012).
○ Due to numerous actors involved, responsibilities and decision-making frameworks should be decided before a hazard occurs (UNEP, 2012).
○ Identification of vulnerable groups, level of exposure, geographical location, strategies for warning communication and evacuation procedure (Golnaraghi, 2012;Twigg, 2004;UNESCO, 2017;Villagrán de Leon, 2012).Vulnerability patterns at local level need to be monitored continuously to identify changes, such as rapid urbanization or nearby civil conflict, that affect the economic, social, or environmental conditions of an area (Twigg, 2004).
○ Scientifically validating indigenous knowledge that can be used to forecast hazards and including this in the warning system could increase community response to disseminated warnings and reduce the risk of people ignoring warnings due to their own risk assessment (Twigg, 2004).
Preparedness governance key quality indicators: • Authorities and civil protection agencies should possess knowledge and resources to respond to the warning (Twigg, 2004;UNEP, 2012).To ease this task there can be: ○ Response plans or standard operating procedures (SOP) for coordinating organizations (Twigg, 2004;UNEP, 2012).
○ Dialogue and constant review, which should be seen as an opportunity to improve and make action efficient, instead of seeing preparedness plans as the end result (Twigg, 2004).
Evacuation governance key quality indicators: • Plans for public awareness of evacuation arrangements, such as identifying safe areas (UNESCO, 2017).
○ Mobilization of strategic resources to direct traffic and facilitate evacuation of vulnerable groups to safe areas (UNESCO, 2017; Villagrán de Leon, 2012).
• Adequate funding.Before hazards occur, there should be a system in place for funding and management of emergency response operations, for example shelter and search and rescue (Twigg, 2004).

Case study of technical maintenance key quality indicators
Two key quality indicators of the framework, technical and social, are tested (Figure 3).
The collected data from empirical research, grey literature, and field observation of the TEWS in Patong are categorised according to the key quality indicators for technical maintenance to establish if they are fulfilled or if there are issues.

Summary technical maintenance in Patong
The result shows that there are or have been issues with all of the subcriteria indicators since the TEWS was implemented (except the subcriteria indicator involved public, where no information was found).For instance, there have been several issues with the buoy system for detecting tsunami waves.Tsunami waves can still be detected through the system, however, since Patong authorities are cooperating with other countries.Contributing to the system being unmaintained is that the following steps of the TEWS chain also have issues.The next step, dissemination of the warning, has had problems with the warning not being issued by a single authority which can cause confusion.Moreover, there are several examples of issues with the warning towers malfunctioning or tests not being heard.To communicate the warning, the media is supposed to help authorities reach the public.However, there are trust issues between the media and NDWC (National Disaster Warning Centre) as well as an example of the media not informing the public correctly.There is also the language barrier, for instance, in relation to the Burmese language, spoken by many locals, which is not included in the warning messages, or in relation to the limited languages available in the mobile application for receiving tsunami warnings.
Between 2005 and 2022, the technical aspect of the TEWS in Patong has experienced issues with the entire chain of activities from detection to communicating warnings to people at risk.It can therefore not be considered as maintained over time.The key quality indicators and subcriteria indicators are presented separately below and with an overview in Table 1.

Basic functions
To help detect tsunami waves, there are buoys located in the Indian Ocean outside of Phuket Island.The result has here identified 10 different events of the buoy(s) malfunctioning or drifting.Already when the first buoy was deployed in December 2006, the location of it was poorly chosen and it would give little or no warning to Phuket before a tsunami wave reaches land (Legacy Phuket Gazette, 2007e), and, in June 2009, the same buoy stopped transmitting data when the battery ran out (Terdkiatkhachorn & Fein, 2009).In 2010, the buoy was reported to be drifting, probably because of a ship colliding with it, and out of order for 6 months (Choksakulpan & Fein, 2010).Later in 2010, the damaged buoy was repaired and a second buoy added (Upatising, 2010).In July 2016, it was reported that one of the buoys had not been working for the past 4 months (Sirirat, 2016;Summast, 2016).A third buoy was added at the end of 2016 (Summast, 2016).In August 2017 (Musika, 2017), again one of the buoys was malfunctioning and, 2 months later, in October, it was reported that the buoy was going to be repaired (Thongtub, 2017b).In 2019, it was reported that the buoy that was supposed to be repaired in 2017 had not been working and was instead replaced with a new one (Sakoot, 2019).
Again in 2018 one of the warning buoys outside of Phuket Island had not been functioning for the past 6 months and was going to be replaced the following month (Sakoot, 2018).In September 2020, two of the three buoys were inspected due to malfunctions.One was detected to have been scavenged for parts.The other one was both damaged and had been drifting from its location, probably caused by a passing ship colliding with it.Two months later, in November, the two buoys were reinstalled and repaired (The Phuket News, 2020b; Sakoot, 2020).

Warning issuance
The subcriteria indicator for warning issuance is that warnings should be issued by a single authority to make sure that the warning message is the same.Two examples have here been found when this has not been fulfilled.The first example is that there is information available for fishermen about tsunami forecast information, but the forecasts do not correspond when issued by different sources making people at risk uncertain about what information to rely on (Fakhruddin, 2015).The second example is from 11 April 2012.There was a false tsunami alarm which resulted in evacuation of Patong.However, there was confusion when officials of the authorities of Phuket and Patong police announced different advice to the public on whether or not to evacuate (Sakoot, 2012a).

Warning transmission
The subcriteria indicator for warning transmission is that the warning message should be sent in as many channels as possible.One way to transmit the warning is with the use of warning towers.There have been six events found of malfunctions during year 2005 (Legacy Phuket Gazette, 2005g), 2009 (Calgaro & Cochrane, 2009), 2012 (Wong, 2012), 2015 (Fakhruddin, 2015), 2017 (Musika, 2017) and 2018(The Phuket News, 2018b, 2018c;Sakoot, 2018), which is problematic in terms of transmitting the warning and therefore categorized here as the subcriteria indicator not being fulfilled.
The warning towers were first implemented in 2005.During the same year, the first warning test was conducted, revealing that two of the seven warning towers were not working properly.Also the warning message announced was not clear enough for the warning to be heard (Legacy Phuket Gazette, 2005g).Reports from 2009 (Calgaro & Cochrane, 2009) and 2015 (Fakhruddin, 2015) also said that the sound from the tsunami warning towers could not be heard in all of the areas.In 2017, it was reported that 11 of the 19 warning towers were out of order (Musika, 2017).In 2018, there were reports of minor problems with all 19 warning towers in Phuket (The Phuket News, 2018b, 2018c;Sakoot, 2018).The different reasons mentioned for the warning towers to malfunction were in 2009 stolen parts from the towers (Calgaro & Cochrane, 2009), in 2012 rapid corrosion (Wong, 2012), and in 2018 a limited budget for maintenance (The Phuket News, 2018c).

Reach public
Reaching the public with the warning transmission should be a robust function and effectively focus on people at risk.Media can help spread the warning when forwarding it from the authority.Three examples have been identified when this subcriteria indicator has not been fulfilled.The first example is that there are constraints when communicating warning messages.For instance, there are barriers in reaching the fishing community with information through radio, and the information is not adapted to the receiver (Fakhruddin, 2015).The second case is from 2010 when a warning was forwarded incorrectly by the media.There was no warning to evacuate transmitted to Patong, but instead a notice to be prepared in case of a tsunami warning.Some of the media channels misreported this as a warning to evacuate immediately, causing people to evacuate.No warning towers sounded and SMS messages were only sent to governors (Fein & Choksakulpan, 2010).The third and last example is from 2014 and concerns the relationship between NDWC and the media.NDWC in Thailand was created in 2005 immediately after the 2004 tsunami disaster.Its purpose was to assist DDPM (Department of Disaster Prevention and Mitigation, the main official organization of disaster management-related issues) and increase the ability to respond to disaster.The mandate of NDWC is related to warning and dissemination, while other aspects are handled by DDPM.In case of a detected tsunami, a warning is sent to the media who then inform the public.However, the relationship between the media and NDWC is not optimal.NDWC is sceptical about the ability of the media to assist and the media tends to mistrust the warnings provided (Fakhruddin & Chivakidakarn, 2014).
Since the media is an important part of the TEWS, it is not satisfying that there is mistrust between the media and NDWC as well as incorrect warnings forwarded by the media.

Public understanding
To improve the probability of people at risk understanding and following the warning message, it should be adapted to the receiver and presented in layman's term.Two languages are not represented in the warnings, but represent a significant part of the community-Russian and Burmese.The warning message sounding from the warning towers (after the siren) is in five languages: Thai, English, German, Chinese, and Japanese.The languages have been used since 2005 and represent the most common nationalities living in and visiting Phuket.There was a request in 2012 to add Russian language, since Russians are the second largest nationality visiting Phuket, but the NDWC did not want to add another language since the message would then be too long to transmit (Narabal, 2012).In Phuket Province there is also a Burmese population, but the Burmese language is not represented in either the tsunami warning alert or reading material and educational information on disaster preparedness.One explanation is that the Burmese workers are to a larger extent in the country illegally, and another explanation is that

Unmaintained Year Reference
Mistrust between media and NDWC.

Field work
Involved public the employer of the Burmese people is responsible for providing information in their language (Fakhruddin, 2015).
Another aspect of languages not being represented in the TEWS is found in an application for Apple and Android launched in 2012.The application is useful for receiving instant tsunami notifications.The application was only available in Thai, but there were plans to make it available in English, however still in 2014 no other languages were available.The reason was that the budget for tsunami preparedness had been used for maintenance needs (Prasertphol, 2014).No information has been found about the languages available today.The evacuation signage system which indicates the evacuation route direction was earlier (at least until 2015) in Thai and English (Fakhruddin, 2015).The fieldwork in Patong conducted for this paper shows that the tsunami evacuation signage system is now in three languages-Thai, English, and Chinese.

Involved public
No information has been found about involving the public to improve the communication.

Case study of social maintenance key quality indicators
Found data from empirical research, grey literature, and field observation of the TEWS in Patong are categorized according to the key quality indicators for social maintenance to establish if they are fulfilled or if there are issues.

Summary social maintenance in Patong
The result shows that there are or have been issues with all of the subcriteria indicators since the TEWS was implemented (except the subcriteria indicator general factors where no information was found).There have been several false alarms since the implementation of the system, causing people to evacuate even if there were no tsunami.During 2005, there were three false alarms, the first one only 4 months after the tsunami disaster.
There have been issues about the evacuation routes and the signage system for guidance of the routes, but the field observation in 2022 shows that maintenance needs are met and improvements made.One improvement is that the routes are now possible to follow in different directions in case of obstacles.To increase preparedness, there have most years been events such as memory-keeping activities and evacuation drills.The social aspect of the TEWS chain in Patong can therefore be seen as partly maintained, despite various issues over time.However, other aspects such as excluding the Burmese population are not socially sustainable.The key quality indicators and subcriteria indicators are presented separately below and with an overview in Table 2.

Awareness and education
Awareness and education as a subcriteria indicator are important to increase preparedness and reduce mistrust in the TEWS in case of a false alarm.Found here are six separate events that can be categorized as false alarms in Patong.The reason for these false alarms is remote earthquakes that occur without causing a tsunami.In 2005, there were two false alarms at night-time caused by earthquakes, March 29 and July 25, issued through the newly installed TEWS.The warning towers sounded and TV broadcasted warnings causing people in Patong to evacuate to high ground.In both cases, the warning was cancelled a few hours later (2005f; Legacy Phuket Gazette, 2005c).On December 14, also in 2005, there was another false alarm caused by a mistake made by the NDWC.The alarm was supposed to be tested but accidentally activated the sirens on the warning towers.The towers sounded in all six provinces in Thailand affected by the 2004 tsunami disaster (Legacy Phuket Gazette, 2005h).
False alarms in Patong caused by earthquakes are also reported in 2007 (Legacy Phuket Gazette, 2007c), 2009(Legacy Phuket Gazette, 2009), and twice in 2010 (Fein & Choksakulpan, 2010;Legacy Phuket Gazette, 2010a).For the reported false alarms, no information is found on how or if the false alarms were handled afterwards.The only information found is from a false alarm in 2005, which is described as a success since the TEWS was working and people were evacuating (Legacy Phuket Gazette, 2005f).The subcriteria indicator awareness and education highlights that false alarms can cause mistrust in the TEWS and therefore should be managed in appropriate ways.No such information about false alarm management has been found, however, and the subcriteria indicator is therefore assessed as unmaintained.
The information found about awareness campaigns or educational activities is related to memory keeping (ii) and evacuation drills (iii) presented in the two following sections.

Memory keeping
Memory keeping of historic disasters can increase preparedness for future hazards, both for people who experienced the original disaster and for those who did not.In 2005, the Cabinet declared December 26 as National Disaster Prevention Day (The Phuket News, 2015).Every year since 2005, except 2020 due to COVID-19 restrictions, there is a tsunami memorial day at Loma Park located in Patong Beach on December 26 to remember the 2004 tsunami disaster (2006, 2011, 2015, 2016, 2018a, 2019a, 2019b, 2020a;Khamlo, 2009;Legacy Phuket Gazette, 2005a, 2007d, 2008a, 2010b;The Phuket News, 2004, 2014;Sakoot, 2012b;Temram, 2011;Thongtub, 2017aThongtub, , 2021;;Wicheetthagoon, 2013).The memorial day is not only to honor the victims but also to increase preparedness among people in case of a future tsunami (2011, 2015, 2016, 2018a, 2019a, 2019b;Legacy Phuket Gazette, 2010b;The Phuket News, 2004;Temram, 2011;Thongtub, 2017a), for instance, by providing educational information and exhibitions about tsunamis that can help people learn how to respond to a tsunami hazard (The Phuket News, 2015).There have also been public discussions involving the Thai Meteorological Department and representatives from Rangsit University to provide education to people and children in Patong (2011;The Phuket News, 2004;Temram, 2011).The tsunami memorial day is also an opportunity to think about the future and improvements to be made, to make sure that lessons learning from the 2004 disaster were not all in vain (The Phuket News, 2014).
The memorial day was called "Light up Phuket" between 2007 and 2017 and contained a candle light ceremony at the beach to honor the victims (2011, 2015, 2016, 2018a, 2019a, 2019b, 2020a;Khamlo, 2009;Legacy Phuket Gazette, 2007d, 2008a, 2010b;The Phuket News, 2004;Sakoot, 2012b;Temram, 2011;Thongtub, 2017a;Wicheetthagoon, 2013).In 2018, the ceremony was no longer called "Light up Phuket" and the ceremony was removed from the formal schedule.The reason was to reduce the emotional impact on those still suffering and instead increase focus on raising awareness with the help of a tsunami-education exhibition (Legacy Phuket Gazette, 2006).In 2019, on the 15 th anniversary of the disaster, the "Light Phuket up" ceremony returned.There were also a seminar and exhibition to educate people about tsunamis (2019b; The Phuket News, 2019a).In 2021, the name of the memorial day had been changed to "Soul of the Sea" (Sakoot, 2012b).
In 2021, there was an exhibition in Loma Park between December 1 and December 31.The exhibition contained educational information such as the reason behind a tsunami and global historic tsunami events.There were also art and light installations and different activities during December such as street music, skateboarding, aerobics, and a religious ceremony, and on December 26 candles were lit in remembrance of the tsunami victims (Figure 4).
The subcriteria indicator memory keeping is well fulfilled in Patong with yearly anniversaries on the day of the disaster.The disaster memory is turned into an opportunity here to provide education and create awareness in case of a future hazard, both for those who experienced the disaster and those who did not.However, at the exhibition in 2021 no information was found about the TEWS or how people at risk should be prepared or behave during a tsunami alarm.2005 (reported three times), 2006, 2007, 2009, and 2010 (reported twice).(Legacy Phuket Gazette, 2005f;Fein & Choksakulpan, 2010;Legacy Phuket Gazette, 2005c, 2005g, 2005h;2007c, 2009;Legacy Phuket Gazette, 2010a) Volunteers are trained on how to handle emergencies and how to assist tourists in the area.

Table 2. Overview of social maintenance of the TEWS in
2006 (Reliefweb, 2006) The importance of people at risk participating in training to be prepared to evacuate was highlighted by authority representative.

2012
(The Phuket News, 2012) Lack of evacuation information from hotels to tourists.Hotels do not provide information about evacuation routes or preparedness which makes tourists oblivious about how to behave in case of a tsunami hazard.

Evacuation drills
Tsunami evacuation drill.

2008
(Legacy Phuket Gazette, 2008b) Lack of evacuation drills, evacuation drills that do take place are not very well publicized and do not include the Burmese population.

2019
(The Phuket News, 2019) In March 2019 an evacuation drill was called off in order not to cause panic among tourists.(2015b;Calgaro & Cochrane, 2009;Leelawat et al., 2021;Phuket Gazette, 2015a;Wong, 2012) The evacuation routes are planned for following in a north-south direction instead of "just" west-east (Figure 5).No signs are covered with for instance shops and stalls.Signs inform when you are within the tsunami hazard zone.Signs inform people to seek high ground in case of earthquake Sign/s at the beach front indicating the entrance of the evacuation route.
Signs indicating the direction of the evacuation route when not entering from the beach front.
Street markings indicating the distance left until the safety zone is reached.
The frequency of signs is higher at the beach front and within the tsunami hazard area. 2022

Field work 2022
Unclear information during tsunami false alarm on 11 April 2012.
2012 (Sakoot, 2012a) Correct information (for instance direction) on the signage system of the nine found tsunami evacuation routes.

Evacuation drills
Evacuation drills have several benefits.They can create awareness and increase the probability of people at risk evacuating during a warning and are important to raise awareness among tourists.The mayor of Patong said in an interview in 2017 that since 2004, there are annual evacuation drills (Thongtub, 2017a).However, only 10 drill activities were identified in the literature searches 2005-2022.They were conducted twice a year in 2005 (2005d; Legacy Phuket Gazette, 2005b) and 2010 (Choksakulpan, 2010;Khamlo, 2010) and once a year in 2007 (Legacy Phuket Gazette, 2007a), 2008(Legacy Phuket Gazette, 2008b), 2009(Terdkiatkhachorn, 2009), 2014 (Mitrarat, 2014), 2015(Thepbamrung, 2015) and 2016 (Tanthavanich, 2016).Empirical research indicates that there is a lack of drills that evacuation drills that do take place are not well publicized and that not all people, for instance the Burmese population, are included (Fakhruddin, 2015).
The first evacuation drill in Patong was held on 29 April 2005, as a pilot project for the newly established NDWC.The TEWS had then been implemented with warning towers, satellites, tsunami warnings through radio and TV, and warning signs indicating evacuation routes (Legacy Phuket Gazette, 2005b).Later in 2005, in December, there was a second drill (Legacy Phuket Gazette, 2005d).The drills have had different approaches.Most common are local drills taking place by evacuating the beach through Bangla Road to reach a safe area (Choksakulpan, 2010;Legacy Phuket Gazette, 2007a;Terdkiatkhachorn, 2009;Thepbamrung, 2015).One drill in 2010 was conducted among school students (The Phuket News, 2016).There is an example from 2016 when drills were being held all over Phuket Island simultaneously (Tanthavanich, 2016) and in 2019 the drill was held in every province along the Andaman Coast under the banner of Integrated Disaster Management Exercise (The Phuket News, 2019).In 2018, there was a global tsunami exercise including 40 countries organized by UNESCO's Intergovernmental Oceanographic Commission.The exercises consist of several scenarios during September to November and is named PacWave.It is not an annual event but has been conducted eight times between 2006 and 2018 (Reliefweb, 2018).
It is important for tsunami evacuation drills to be conducted regularly to maintain awareness.In Patong drills have been held most years since 2005.The years that no information was found about drills in Patong are 2006Patong are , 2011Patong are , 2012Patong are , 2013Patong are , and 2020.Since 2014 there have been drills held both locally and regionally which can be considered as regularly.
Evacuation drills are said to be in favor of both tourists and locals (Legacy Phuket Gazette, 2008b;Mitrarat, 2014), but, in 2019, a second planned drill was cancelled in order not to cause panic among tourists (Prompinpiras, 2019).Another example is from the drill in 2008 when only some tourists had been informed by their hotel about the drill and knew about the warning towers being used.Other tourists had not been informed and were therefore unaware of the drill.Despite not being aware of the drill, they still chose not to evacuate when the warning towers sounded (Legacy Phuket Gazette, 2008b).
The importance of drills as a subcriteria indicator is also seen in the section about warning transmission (3.2.3),where drills have revealed technical malfunctions in the warning towers.

General factors
No information has been found about the subcriteria indicator general factors.

Evacuation routes
For evacuation routes to be seen as a fulfilled subcriteria indicator, they should be well known and passable and there should be alternate routes in case of obstruction.The evacuation routes in Patong were implemented in 2008.They start from the four-kilometer beach and stretch east through the city to high ground.To reach the safety zones from the risk areas, there are 11 evacuation routes with a distance of 300-800 meters.Pictorial signs and warning signs inform and guide both tourists and locals on how to evacuate (Municipality, 2008).Field visits in Patong in 2019 raised concerns about the evacuation routes (Leelawat et al., 2021).It has been reported that some evacuation routes are blocked by trees and development (Calgaro & Cochrane, 2009).The length of the evacuation routes is questioned as an issue (Wong, 2012).Concerned citizens have asked about Sansabai road as an evacuation route during night-time since it is often blocked by motorbikes.This was, however, not considered as a problem by DDPM who says that the road should be possible to evacuate from (Phuket Gazette, 2015a).Another concern from a citizen perspective is about Bangla road and where its evacuation points are located.Here, the answer from DDPM is to follow the crowd in case of evacuation and DDPM also mentions three evacuation points on the road (Phuket Gazette, 2015b).
The field inspection conducted in 2022 shows that the 11 evacuation routes still start at the same location as the previous, the beach front, and follow the same streets.But the routes are longer and are also planned for going in a north-south direction instead of "just" west-east (Figure 5).This is important improvements since there should be alternate routes in case of obstructions.
Two evacuation routes from the beach front of Patong could not be found.No signs were found indicating the direction of these two routes.The consequence is that on the beach front there is now a distance of 730 meters without a marked evacuation route to follow (Figure 5).As a subcriteria indicator, this raises some concerns since there is a fairly long distance before reaching an evacuation route.
The field inspection in 2022 also shows that for the (nine) found evacuation routes in Patong, they all are passable without permanent observed obstacles such as trees or buildings.The routes are possible to follow by foot or vehicle (might though be difficult during traffic jam) and all of the routes do have streetlights.The subcriteria indicator evacuation routes can therefore be considered as being fulfilled currently in 2022.The only concern is the two evacuation routes that are not possible to find.There are evacuation routes both north and south of the two missing routes, but the distance may be an issue.

Signage systems
For the signage systems to be seen as a fulfilled subcriteria indicator, the signage system should be clearly seen, have a high signage cover area, and be more extensive close to the beach front.Different issues have been raised about the signage system since 2009 when it was said to be "irregular" (Calgaro & Cochrane, 2009).The first report about maintenance needs related to the signage system is from 2012 (Wong, 2012) and again in 2015 (Suppasri et al., 2015).In 2015, there was also a request for an additional budget to purchase new tsunami evacuation route signs since the old ones were described as not possible to read (Sirirat, 2015).Still in 2018, there are issues with the evacuation signs.A full review was made for the signage system of the tsunami evacuation routes within Patong and other popular beach areas (The Phuket News, 2018b).It was said that all of the 110 tsunami evacuation signs had been checked and that all of them needed replacement or relocation.The reason for the initiated review was the tsunami that struck Sulawesi in Indonesia with thousands of dead, missing, and homeless that same year (The Phuket News, 2018b).
On 11 April 2012, there was a false tsunami alarm resulting in evacuation of Patong.Unclear information about how and where to evacuate caused traffic jams and the traffic stood still when people tried to reach Patong Hill (Sakoot, 2012a).Field visits conducted in 2019 also revealed that the visibility of evacuation signs could be improved to assist people looking for the evacuation direction.There was no information about any updates of the signage system since its original establishment (Leelawat et al., 2021).
The field inspection conducted in Patong in January 2022 showed that the evacuation signage system has now been updated and maintenance needs fulfilled.Today the signage system in Patong consists of signs indicating the direction of the evacuation route as well as painted street markings.The street markings count down the distance left until the safety area is reached and can be found along the evacuation route inside the hazard area.
The result from the field inspection confirms the following about the signage system of all the tsunami evacuation routes.When leaving the tsunami hazard area, there are still evacuation routes to follow for reaching shelters and evacuation sites, but the signage system on these routes outside of the tsunami hazard zone is more scattered.The signs are still possible to follow for finding the evacuation route but may also cause hesitation whether or not you have taken a wrong turn since the number of signs is decreasing rapidly.The marked area in Figure 5 has only one sign indicating the direction.However, this is outside the hazard area where rapid evacuation is required.
An example of the signage system is presented in Figure 5. Bangla Road is one of the most popular tourist streets.It is 350 meters long and crowded with stores, bars, and restaurants.On Bangla Road there are several signs indicating the evacuation route, distance to safe area and that you are within a tsunami hazard area.This is true for all of the followed evacuation routes within the tsunami hazard area.
The signage system for tsunami evacuation routes has been in need of maintenance since 2012 (Table 2).However, the field inspection in January 2022 contradicts the previous results since the signage system has recently been updated and maintained.There are now signs along the beachfront informing people to seek high ground in case of an earthquake.The nine found evacuation routes were followed with help from the signage system, and all of them provided correct information on the direction to evacuate.The subcriteria indicator for signage system is in this respect currently fulfilled, but there have been issues historically which may not be considered as maintained.

Discussion
This pilot study has presented a framework with indicators to assess the technical, social, and governance maintenance of a TEWS, in a "first mile" perspective.The framework was then partially tested in a retrospective long-term analysis of technical and social maintenance by conducting a case study of the TEWS in Patong, Thailand, for the years 2005-2022.

Framework and its application
The 2015 Sendai Framework for DRR aims at substantially reducing disaster risk and fatalities, for instance, through preventing disaster risk and increasing preparedness for response.One of the seven global targets to support this aim is to "increase the availability of and access to multihazard early warning systems" by 2030 (Nations, 2015).However, it is not enough to implement early warning systems, they must also be maintained.Early warning systems require maintenance, technical, social, and governance, over time to be reliable and fulfill their purpose.
Essential building blocks of a successful early warning system consist of the ability to detect hazards, emergency planning, warning dissemination, and community preparedness.Shortages in any of these four building blocks can undercut the integrity of the TEWS as a whole.Lack of detection makes it impossible to issue a timely warning and deficiencies in the communication system can result in people at risk not receiving a warning (Golnaraghi, 2012).The main contribution of this study is the presentation of a framework that focuses on TEWS's components and its maintenance.Only one existing framework, proposed by UNESCO (UNESCO, 2017), has been found focusing on TEWS.Combining their framework with the previous research, literature, and frameworks related to TEWS in general (Buckle, 2012;Golnaraghi, 2012;Twigg, 2004;UNEP, 2012;UNESCO, 2017;Villagrán de Leon, 2012), led to a developed framework including several important indicators not found in UNESCO (UNESCO, 2017).For instance, key quality indicators for warning issuance, warning transmission, involved public, and signage systems.This combination made it possible to create a framework to determine the maintenance of technical, social, and governance maintenance of a TEWS.
By adding the two subcriteria indicators (Signage systems and Memory keeping of historic disaster), the intention was to increase understanding of different possibilities for tsunami preparedness and evacuation.The intention was also to act as an inspiration to include more key quality indicators and subcriteria indicators for early warning systems developed for other types of hazards.
The framework developed here can contribute as a tool in long-term evaluations to highlight necessary system maintenance and reduce the consequences of a future tsunami hazard.The intention is that the created framework will contribute with key quality indicators that can be useful recurrently to assess the maintenance status of TEWS and through corrective actions reduce the negative outcome of future tsunami hazards.The framework can also be useful during implementation of a new TEWS in hazard prone areas to improve the outcome of the technical, social, and governance functions.
The test of the framework was conducted by a long-term retrospective analysis (which there is a need to perform more of (Hill & Gaillard, 2013)) as well as present-day analysis, of a TEWS in Phuket, which was proven useful to identify maintenance needs.Post-disaster recovery actions are difficult to maintain over a longer time perspective (Koswara et al., 2021;Syamsidik et al., 2021;Thomalla et al., 2009).One reason to why that is is offered by Blackman, Nakanishi, and Benson (Blackman et al., 2017) who say that there is a gap between the purpose of long-term disaster recovery and implementation.The transformation between different disaster recovery cycles is assumed to be linear and smooth.However, the changes in the recovery process over time are not linear but instead complex.The problem is transformed from being urgent and predictable in the short-time response phase, to being a complex systems problem in the long-term recovery phase.The reason for the complexity is that during the different recovery phases there are different forms of social capital, different actors and stakeholders, and tension between actors due to top-down leadership where local community members risk to be put aside (Blackman et al., 2017).
The evaluation of the TEWS maintenance in Patong contradicts the results of Thomalla and Larsen (Thomalla & Larsen, 2010) that the implementation of TEWS in the Indian Ocean Region after the Indian Ocean tsunami in 2004 has been more focused on the technological aspect of forecasting and warning dissemination compared to the human aspect of risk perception and decision-making, which has reduced its effectiveness (Thomalla & Larsen, 2010).The results show that since the TEWS was implemented in Patong, issues related to key quality indicators for technical maintenance have been dominating.Activities for memory keeping, evacuation drills, and improvements in the evacuation routes and signage system indicated a more robust social maintenance.
The framework and first mile approach have highlighted the importance of people at risk throughout the chain of early warning activities.In Patong, there have been issues with both technical and social maintenance.If the TEWS is not technically and socially maintained, people at risk may not be safer with an evacuation system than without.As seen in Mentawai Island in 2010 (Satake et al., 2013), the official tsunami warning did not reach coastal communities due to lack of communication infrastructure.And, in Palu 2018 (UNDRR and UNESCO-IOC, 2019), there was a disconnection in the warning chain which caused the warning system to not be able to provide enough time to evacuate before tsunami landfall.These examples of failed first mile and the 2004 tsunami disaster in the Indian Ocean make clear that it is unrealistic to expect people who are not prepared to react properly to a disseminated warning or natural signs of tsunami.It also shows how important the chain of a TEWS is.When a part is missing, the purpose of the TEWS will fail.
The importance of functioning and reliable tsunami warning system, as well as working together with the society, goes in line with Dhellemmes, Leonard, Johnston, Vinnell, Becker, Fraser, and Paton (Dhellemmes et al., 2021).As seen in New Zealand, experience of tsunami disasters in 2004 and 2011 have increased awareness of what causes a tsunami, time until tsunami landfall and awareness of living within a tsunami hazard zone, but it is still no guarantee for increased preparedness.People can be aware of the procedure to evacuate after feeling an earthquake but still choose not to.The reason is that people are waiting for a public warning to confirm that there should be an evacuation (Dhellemmes et al., 2021).Hence, it is crucial to monitor the warning system recurrently over time to ensure its functions and be transparent about the results.

Framework
The framework has the potential of both capturing the development of a TEWS over time, as well as present-day status.The framework can be used to explore issues with the warning system and which aspect of the system that needs improvements related to technical, social, or governance key quality indicator.It can also identify aspects of the chain that are maintained and therefore do not need immediate attention.
Identified from the case study were issues over the past 19 years related to the technical and social maintenance of the TEWS in Patong.The technical and social maintenance aspects depend on functioning governance and organization that provide guidance for operating and maintaining the TEWS.The fact that the key quality indicators for technical and social maintenance identify issues with the TEWS in Patong indicates that there are also issues with the governance.It is not possible within the scope of this study to answer if this is true and, if so, what specific issues are related to governance.Governance maintenance is an important next step to study or for the authorities in Patong and Thailand to acknowledge and manage to ensure a functioning and reliable TEWS.
Governance related to TEWS is surrounded by complex relationships between institutions, officers, and governance (Sakalasuriya et al., 2020).To study governance may require other data approaches than the ones used in this study.Self-evaluations conducted by the authorities and people involved in operating the TEWS could be important sources of information.For an external researcher, interviews with relevant representatives could provide insight into the authorities and governance systems.However, the data should capture both historical and present-day aspects for conducting a long-term retrospective analysis of the governance.Depending on the chosen methodology for studying the governance aspect, the framework could be modified to include other key quality indicators.This study does not include interviews or surveys representing the perspective of people living in or visiting Patong and how they perceive the information about awareness and preparedness.Since this pilot study is a first step towards a framework focusing on TEWS, it has carried out an evaluation from the outside with help from research, grey literature, and observations.However, the people perspective is an important aspect of the first mile and should be subjects of future research by conducting interviews, focus groups, or surveys.
There is potential for further development of the created framework by incorporating additional aspects of technical, social, and governance maintenance.For example, adding indicators for economic funding and inundation area.
In terms of technical maintenance and the key quality indicator detect, it would be beneficial to address different types of forecasts for tsunamis (see, for example, Y. Wang et al. (2021)).It would also be beneficial to include indicators regarding location, working principles, and sampling rates about the buoy system.Additionally, international collaboration for tsunami forecasting can be enhanced by utilizing the Deep-ocean Assessment and Reporting of Tsunamis (DART) system (Pal et al., 2022).
Regarding social maintenance and the subcriteria indicator evacuation routes, it would be beneficial to add indicators about the suitability of evacuation routes for vulnerable populations such as the elderly, disabled individuals, and children.Moreover, regarding the subcriteria indicator memory keeping, it would be useful to explore how various activities can enhance memory preservation and contribute to behavior that promotes better tsunami preparedness.Additionally, memory keeping is linked to false alarms, which, as seen in the Patong case study, cannot be avoided.However, addressing false alarms and reducing mistrust in the TEWS are crucial.Developing indicators to mitigate mistrust caused by false alarms would be a valuable addition to the memory preservation indicator.It is important to note that memories of false alarms can increase mistrust, while memories of tsunami hazards can enhance preparedness.Furthermore, the framework was specifically tested on tsunamis generated by seismic activities.However, there are other sources that can trigger tsunamis, such as landslides and atmospheric pressure, which may require different indicators within the framework.Tsunamis can originate from both near and far distances from land.Depending on the location of the tsunami, detection methods may rely on international collaboration and information sharing with local agencies.If a tsunami occurs nearby, local detection measures might be sufficient.However, nearby tsunamis offer very limited time, tenths of minutes or less, to evacuate, which requires a reliable and effective chain of activities for the early warning system to provide warning to people at risk (Papadopoulos et al., 2020).Exploring these aspects would also be worthwhile for further development of the framework.
In this pilot, the framework has been used to determine the technical and social maintenance of a TEWS at the local level.Future research can also include regional, national, and international level to determine the framework's possibilities and how to develop it with regard to other levels.

Case study
The data collection to test the framework has been carried out in three ways: published empirical research, grey literature, and field observation in Patong.The two search methodologies combined with field inspection complement each other, making it possible to explore both long-term retrospective analysis of maintenance as well as the condition signage system and evacuation routes in Patong.
The lack of empirical research papers from Patong (six articles) highlighted a need to use grey literature and field inspection to explore the maintenance of the TEWS.The search results for both empirical research and grey literature are dependent on the chosen key words, and other words might have given a different result.There is a possibility that data have been missed due to the language barrier.The review of grey literature could have been improved further by including more languages than English.However, the two newspapers included (The Phuket News and The Thaiger) are located in Thailand and are reporting about, amongst other places, Patong.Grey literature may over-represent negative events related to the TEWS due to increased media interest, making it difficult to identify maintained examples.On the other hand, examples of lack of maintenance in relation to the TEWS should be acknowledged and managed.There can be maintained examples, but they are not acknowledged in the media.To reduce this bias, the conducted field observation adds another perspective on the current state.To reduce possible bias from the researcher during fieldwork, the data collection has had a foundation in the created framework.The fieldwork shows that there have recently been significant improvements in the evacuation signage system, which the grey literature and empirical research do not show.Hence, the long-term retrospective analysis through the created framework should also consider the present status of the TEWS and not only what is found historically.
The field inspection was conducted during the Corona pandemic with high restrictions for tourists to enter Thailand.The number of tourists during data collection was significantly reduced compared to prepandemic times, with fewer shops and other possible blocking activities as a consequence.There were almost no street carts or temporary shops on the streets during the time of data collection.This may have contributed to the signs not being blocked.

Conclusion
This study has presented a framework with indicators to assess the technical, social, and governance maintenance of a TEWS.This has been a pilot study and a first step to present a peoplecentred framework for evaluation of early warning systems with a focus on tsunami.Two aspects of the framework, technical and social maintenance, were tested by conducting a case study of the TEWS in Patong.
It has been 19 years since the 2004 Indian Ocean tsunami.During these years, there have been several issues related to both technical and social maintenance of the TEWS in Patong.Issues related to key quality indicators for technical maintenance have been dominating.There are issues with the key quality indicators for social maintenance but also indicators well achieved.The framework for first mile key quality indicators helps to clarify the importance of the TEWS chain of activities, which is only as strong as its weakest link.Both present and historical data have shown to be important when using the framework to explore the maintenance (needs) of a TEWS at local level.The test of the tsunami framework has indicated its usefulness.

Figure 1 .
Figure 1.Map of the location of Patong, Phuket Island, Thailand and the Andaman Sea.

Figure
Figure 2. Framework for first mile key quality indicators to determine the technical, social, and governance maintenance of a TEWS at local level.There are three key quality indicators for technical maintenance, two key quality indicators for social maintenance, and five key quality indicators for governance maintenance.Each key quality indicator has subcriteria indicators.

Figure
Figure 3. Framework for first mile key quality indicators to determine the technical and social maintenance of a TEWS over time at local level.There are three key quality indicators for technical maintenance and two key quality indicators for social maintenance.Each key quality indicator has subcriteria indicators.
Patong with the key quality indicators preparedness and evacuation and their subcriteria indicators.Included is the result from empirical research, grey literature,

Figure 4 .
Figure 4. Exhibition in Loma Park in Patong Beach.Pictures taken on December 31, 2021.

Figure
Figure 5. Illustration of the nine found evacuation routes in Patong.The map show the tsunami hazard area which is the 2004 tsunami inundation area.Two evacuation routes from the beach front are not possible to find, and these routes are marked with "?".The distance between the existing evacuation routes is 730 meters.One of the evacuation routes to use instead of the ones not found is Bangla Road.An illustration of the signage system on Bangla Road is in the red box.There are signs indicating the direction (number 1, 3-5) of the evacuation route, street markings counting down to safety zone (number 6) and signs indicating when you are within the tsunami hazard area (number 2).The frequency of signs on Bangla Road is higher compared to outside of the hazard area, illustrated by the orange box.The map is originally from https://commons.wikimedia.org/wiki/user:Gezginrocker and has been modified to contain evacuation routes, markings for evacuation routes not possible to find, hazard area, color boxes for example inside and outside of hazard area, compass and information box.Pictures of evacuation signage was taken in January, 2022.