Search Results (13)

Objective: To assess the educational impact of a worldwide webinar approach to myopia progression management in children <8 years and 8–12 years old. Design: Cross-sectional study. Methods: A self-administered survey was conducted for attendees of a 3 h worldwide webinar held in two parts on consecutive days on the management of myopia progression in children. The survey was administered before, immediately after completion of the webinar, and 8 weeks later; responses were recorded on a Likert scale. Questions were posed to assess (a) the confidence of attendees in managing myopia in children <12 years old, (b) attendees’ understanding of latest treatment options, (c) any improvement in attendees’ knowledge after the webinar, and (d) any changes made to practice 8 weeks after the webinar. Pre- and post-responses were analyzed using an unpaired two-tailed t-test. Results: The webinar had 701 and 606 global attendees on the first and second days, respectively. Based on a comparison of contact information, 372 attendees participated on days 1 and 2, meaning 288 and 233 participants attended only day 1 and day 2, respectively. There was a significant increase in the percentage of attendees who were “very confident” in managing myopia after the webinar (p < 0.05). Ninety-nine attendees completed the survey at 8 weeks. Of these, 76% believed that the webinar had “very significantly” or “significantly” improved their ability to manage pediatric myopia and 91% had implemented or intended to implement a change in their practice. The respondents who did not implement a change identified cost and patient compliance as the common barriers. Conclusion: There is a tsunami of research and management options in the field of myopia management at present. We demonstrate that an effective way of disseminating information and education about myopia management is a pre-designed comprehensive webinar held over two consecutive days. There is evidence that such a webinar may also influence a change in clinical practice. Full article

Following an earthquake, abnormal travel demand causes traffic congestion and poses significant problems for relief efforts. Research on post-earthquake travel demand is essential for disaster management. An effective disaster management strategy ensures achieving sustainable development goals. This study focused on this critical period and analyzed post-earthquake trip decisions. The city of Elazığ, a region not at risk of tsunami, was used as a case study. A 6.8 magnitude earthquake hit Elazığ in January 2020. After the earthquake, data from 2739 individuals were collected by a household survey conducted face-to-face. The data were segregated into two categories, depending on the earthquake’s intensity. The study used a binary logit model to examine the potential factors of trip decisions after an earthquake. The results showed that 75% of participants made at least one trip within 24 h after the earthquake. It was observed that household, building-and disaster-related attributes influence earthquake survivors’ trip decisions. The initial location at the time of the earthquake was the most significant factor affecting trip decisions. It was also found that individuals who experienced the earthquake outside their homes in both datasets were more likely to make a trip. Additionally, the dataset with higher earthquake intensity had more significant variables affecting the trip decision. Full article

Tsunami monitoring and early warning systems are mainly established to deal with seismogenic tsunamis generated by sudden seafloor fault displacement. However, a global tsunami triggered by the 2022 Tonga volcanic eruption promoted the need for tsunami early warning and hazard mitigation of non-seismogenic tsunamis in coastal countries. This paper studied the spatiotemporal distribution characteristics of historical volcanic tsunamis and summarized high-risk areas of volcanic tsunamis. The circum southwestern Pacific volcanic zone, including the Sunda volcanic belt and the Indo-Australian plate, is a concentrated area of active volcanoes and major volcanic tsunamis. In addition, the challenges associated with adapting seismogenic tsunami techniques for use in the context of volcanic tsunamis were elucidated. At the same time, based on historical records and post-disaster surveys, typical historical volcanic tsunami events and involved mechanisms were summarized. The results show that a majority of volcanic tsunamis may involve multiple generation mechanisms, and some mechanisms show geographical distribution characteristics. The complexity of volcanic tsunami mechanisms poses challenges to tsunami early warning by measuring tsunami sources to evaluate the possible extent of impact, or using numerical modeling to simulate the process of a tsunami. Therefore, a concise overview of the lessons learned and the current status of early warning systems for volcanic tsunamis was provided. Finally, a conceptual scheme of monitoring systems for volcanic tsunamis based on historical volcanoes, real-time volcanic eruption information and sea level data, as well as remote sensing images, was presented. Full article

Despite the potentially catastrophic nature of disasters, survivors can be highly resilient. Resilience, the capacity to successfully adapt to adversity, is both individual and collective. Policymakers and academics have recently emphasised the importance of community resilience, but with little consideration of local survivors’ perspectives, particularly young survivors within low- and middle-income countries. Therefore, this exploratory study aims to give voice to disaster-affected caregivers, teachers and female adolescent students by examining their conceptualisations of community coping and priorities for resilient recovery following the 2018 Central Sulawesi earthquake and tsunami. A total of 127 survivors of the devastating disaster, including 47 adolescents, answered open-ended survey questions related to post-disaster resilience. A content analysis identified key constituents of community resilience. The results indicate that survivors highly value community cohesion and participation, drawing on the community’s intra-personal strengths to overcome post-disaster stressors. Student conceptualisations of and recommendations for a resilient recovery often differ from the views of important adults in their lives, for example, regarding the role played by the built environment, “trauma healing” and religiosity in the recovery process. These findings have implications for the design of disaster resilience interventions. Full article

This study aimed to clarify how local agriculture and social capital in disaster-affected areas were transformed by the Great East Japan Earthquake and tsunami in March 2011 and to identify the factors that influenced the transformation of social capital—especially trust—after the disaster. A questionnaire survey was conducted in the Miyagi prefecture’s disaster-affected areas. Survey responses were analyzed using descriptive statistics and linear regression analysis with ordinary least squares; the trust index was used for explained variables and personal-attribute disaster-related variables as explanatory variables. The results indicate that regional agriculture was integrated into agricultural corporations or communal management as individual farmers were unable to recover their disaster-related losses. After the disaster, participation in collaborative efforts to manage community resources decreased, while participation in community activities, such as volunteering, increased. Respondents lost trust in the people around them owing to relocation after the disaster and exposure to crime. Steps necessary to maintain or improve social capital in disaster areas include maintaining public safety in the disaster area, securing sources of income, and providing people with interaction opportunities, such as hobby groups. The findings offer practical applications for post-disaster agricultural resource management in developed countries. Full article

In this paper, we explored the local tsunami hazards induced by an active local seismic Quanzhou fault, along the coastlines of the City of Putian, Fujian Province, in the southeast of China. The simulation results indicated that the tsunami wave will hit the nearest coast of Putian 0.5 h after the earthquake occurs. The most serious tsunami inundation depth in Putian was less than 3.0 m. This study also conducted a sensitivity test of the tsunami amplitude and inundation in response to different seismic source parameters, particularly the rake and strike angles of the Quanzhou fault. Based on the post-earthquake survey and the most updated geophysical data, the uniform dislocation distribution is applied in the range of scientific geometrical characteristic parameters for numerical modeling. A 20° change in the rake angle increases the inundation area from 50.0 km² to more than 100.0 km², and increases the tsunami amplitude from 0.2 m to 1.0 m. In this study, the tsunami hazard of Putian is more sensitive to the rake than to the strike angle for a local fault. Tsunamis generated by seismic fault could also result in serious coastal flooding along the coastlines locally, and the time for emergency response is limited. The research results could provide technical support for refining local tsunami hazard assessment and contingency plans, to save decision-making time and avoid waste of social resources. Full article

Even now, ten years after the Great East Japan Earthquake (GEJE), thousands of residents of Fukushima Prefecture are still living as evacuees. To understand the mental health states and needs for psychological care of the survivors, we conducted a questionnaire survey of survivors who were evacuated from Fukushima to Ibaraki due to the nuclear power plant accident and of the residents of two areas in Ibaraki where damage was particularly severe due to the tsunami or liquefaction. Our results show that stress related to participants’ hometowns and to the disaster was a risk factor for depression and post-traumatic stress among the survivors in the medium to long term in all regions examined. Other risk factors for post-traumatic stress differed by region. This study shows that in a complex disaster such as the GEJE, where damage is widespread, the causes of damage and the experiences of disaster survivors differ greatly from region to region and that risk factors for depression and post-traumatic stress among disaster survivors over the medium to long term may also differ. To provide appropriate care to disaster survivors, it is necessary to determine what is causing the risk of depression and post-traumatic stress at any given time and in specific regions. Full article

The long-term mortality risk of natural disasters is a key threat to disaster resilience improvement, yet an authoritative certification and a reliable surveillance system are, unfortunately, yet to be established in many countries. This study aimed to clarify the mechanism of post-disaster indirect deaths in Japan, to improve the existing disaster recovery evaluation system and support decision making in public policy. This study first investigated the definition of indirect deaths via a literature review before examining the observed number of indirect deaths via case study, census data from the Population Demographic and Household Surveys, other social surveys, and reports in the case of the Great East Japan Earthquake and Tsunami, which severely damaged northeastern Japan, especially the three prefectures, which are the target areas in this context (i.e., Fukushima, Iwate, and Miyagi). It was found that the reported number of indirect deaths was significantly underestimated. In total, 4657 indirect deaths were estimated to have occurred in the target prefectures. This was higher than the reported number, which was 3784. The overall statistics established via collaboration between local administrations and governments can be improved to provide better reference for researchers and policymakers to investigate the long-term effects of natural disaster. Full article

Little is known about whether the provision of aid in the aftermath of a large-scale natural disaster affects psychological well-being. We investigate the effects of housing assistance, a key element of the reconstruction program implemented after the 2004 Indian Ocean tsunami. Population-representative individual-level longitudinal data collected in Aceh, Indonesia, during the decade after the tsunami as part of the Study of the Tsunami Aftermath and Recovery (STAR) are used. Housing aid was targeted to people whose homes were destroyed and, to a lesser extent, damaged by the tsunami and to those who lived, at the time of the tsunami, in communities that sustained the greatest damage. The effects of receipt of aid on post-traumatic stress reactivity (PTSR) are examined using panel data models that take into account observed and unobserved individual-specific fixed characteristics that affect both PTSR and aid receipt, drawing comparisons in each survey wave between individuals who had been living in the same kecamatan when the tsunami hit. Those who received aid have better psychological health; the effects increase with time since aid receipt and are the greatest at two years or longer after the receipt. The effects are concentrated among those whose homes were destroyed in the tsunami. Full article

The tsunami generated by the offshore Samos Island earthquake (M_w = 7.0, 30 October 2020) is the largest in the Aegean Sea since 1956 CE. Our study was based on field surveys, video records, eyewitness accounts and far-field mareograms. Sea recession was the leading motion in most sites implying wave generation from seismic dislocation. At an epicentral distance of ~12 km (site K4, north Samos), sea recession, followed by extreme wave height (h~3.35 m), occurred 2′ and 4′ after the earthquake, respectively. In K4, the main wave moved obliquely to the coast. These features may reflect coupling of the broadside tsunami with landslide generated tsunami at offshore K4. The generation of an on-shelf edge-wave might be an alternative. A few kilometers from K4, a wave height of ~1 m was measured in several sites, except Vathy bay (east, h = 2 m) and Karlovasi port (west, h = 1.80 m) where the wave amplified. In Vathy bay, two inundations arrived with a time difference of ~19′, the second being the strongest. In Karlovasi, one inundation occurred. In both towns and in western Turkey, material damage was caused in sites with h > 1 m. In other islands, h ≤ 1 m was reported. The h > 0.5 m values follow power-law decay away from the source. We calculated a tsunami magnitude of M_t~7.0, a tsunami source area of 1960 km² and a displacement amplitude of ~1 m in the tsunami source. A co-seismic 15–25 cm coastal uplift of Samos decreased the tsunami run-up. The early warning message perhaps contributed to decrease the tsunami impact. Full article

Objective: As most studies relating to mental health and disasters have employed cross-sectional or follow-up assessments about psychological health with post-disaster information, the association between changes in social ties and mental health remains unclear. We examined the relationship between the changes in survivor neighborhood ties and depressive symptoms before and after a natural disaster. Methods: Participants were 3567 individuals aged ≥65 years living in Iwanuma city who had responded to questionnaires by the Japan Gerontological Evaluation Study both predating the 2011 Great East Japan Earthquake and Tsunami, and 2.5 years afterward. Changes in the depressive symptoms were assessed using the geriatric depression scale (GDS) at the baseline and follow-up survey. Changes in the neighborhood ties were assessed by asking the participants about their interactions with people in their neighborhood. Possible confounders were adjusted in a linear regression model. Results: Among the 3111 participants in this analysis, 1073 (34.5%) had increased GDS score after the disaster. There were 336 (10.8%) individuals who had neighborhood ties before the disaster, but had no ties afterward; their mean GDS score increased from 2.93 points in 2010 to 3.19 points in 2013. Among those who had not had ties before and after the disaster the mean GDS score remained almost stable, from 2.19 points in 2010 to 2.12 points in 2013. The participants with post-disaster ties were significantly less likely to have an increased GDS score compared with those who had not had ties before and after the disaster (β = −0.39; 95% confidence interval: −0.72, −0.06). Conclusions: Increased neighborhood ties after the disaster reduced the risk of depressive symptoms even when survivors suffered disaster damages. The study reinforces the importance of social capital in disaster recovery and suggests to local governments and local communities that fostering horizontal, neighborhood ties may improve disaster preparedness and mental health resilience. Full article

Satellite-based Emergency Mapping (SEM) mechanisms provide information for emergency response in relation to different types of disasters, including tsunamis, based on the analysis of satellite imagery acquired in the aftermath of an event. One of the main critical aspects of a SEM service is the timeliness in providing relevant information in the hours following the event. The availability of a relevant post-event image is crucial; therefore, satellite sensors need to be programmed as soon as possible. The integration of a tsunami alerting system, like the one offered by the Global Disaster Alert and Coordination System (GDACS), can be highly beneficial in a SEM mechanism for streamlining and accelerating the satellite programming task and for generating first damage estimates. The GDACS tsunami model is validated using tidal gauge data and a post-event field survey. Tsunami model outputs are then exploited to automatically identify areas of interest to be used for immediate satellite acquisition triggering. Three alternative operational integration approaches are proposed, described and discussed, taking as use case the tsunami that struck the central Chilean coast after the 8.3 magnitude earthquake on 16 September 2015. Full article

Accurate and high resolution bathymetric data is a necessity for a wide range of coastal oceanographic research topics. Active sensing methods, such as ship-based soundings and Light Detection and Ranging (LiDAR), are expensive and time consuming solutions. Therefore, the significance of Satellite-Derived Bathymetry (SDB) has increased in the last ten years due to the availability of multi-constellation, multi-temporal, and multi-resolution remote sensing data as Open Data. Effective SDB algorithms have been proposed by many authors, but there is no ready-to-use software module available in the Geographical Information System (GIS) environment as yet. Hence, this study implements a Geographically Weighted Regression (GWR) based SDB workflow as a Geographic Resources Analysis Support System (GRASS) GIS module (i.image.bathymetry). Several case studies were carried out to examine the performance of the module in multi-constellation and multi-resolution satellite imageries for different study areas. The results indicate a strong correlation between SDB and reference depth. For instance, case study 1 (Puerto Rico, Northeastern Caribbean Sea) has shown an coefficient of determination (R²⁾ of 0.98 and an Root Mean Square Error (RMSE) of 0.61 m, case study 2 (Iwate, Japan) has shown an R² of 0.94 and an RMSE of 1.50 m, and case study 3 (Miyagi, Japan) has shown an R² of 0.93 and an RMSE of 1.65 m. The reference depths were acquired by using LiDAR for case study 1 and an echo-sounder for case studies 2 and 3. Further, the estimated SDB has been used as one of the inputs for the Australian National University and Geoscience Australia (ANUGA) tsunami simulation model. The tsunami simulation results also show close agreement with post-tsunami survey data. The i.mage.bathymetry module developed as a part of this study is made available as an extension for the Open Source GRASS GIS to facilitate wide use and future improvements. Full article