Slow light with flat or offset band edges in multi-mode fiber with two gratings

We consider mode coupling in multimode optical fibers using either two Bragg gratings or a Bragg grating and a long-period grating. We show that the magnitude of the band edge curvature can be controlled leading to a flat, quartic band-edge or to two band edges at distinct, nonequivalent $k$-values, allowing precise control of slow light propagation.Comment: 6 pages, 3 figure

How much do disasters cost? A comparison of disaster cost estimates in Australia

Extreme weather events in Australia are common and a large proportion of the population are exposed to such events. Therefore, there is great interest as to how these events impact Australia's society and economy, which requires understanding the current and historical impact of disasters. Despite global efforts to record and cost disaster impacts, no standardised method of collecting and recording data retrospectively yet exists. The lack of standardisation in turn results in a range of different estimates of economic impacts. This paper examines five examples of aggregate disaster loss and impacts of natural disasters in Australia, and comparisons between them reveal significant data shortcomings. The reliability of data sources, and the methodology employed to analyse them can have significant impacts on conclusions regarding the overall cost of disasters, the relative costs of different hazards (disaster types), and the distribution of losses across Australian states. We highlight difficulties with time series comparisons, further complicated by the interdependencies of the databases. We reiterate the need for consistent and comparable data collection and analysis, to respond to the increasing frequency and severity of disasters in Australia

Flood Proofing Low-Income Houses in India: an Application of Climate-Sensitive Probabilistic Benefit-Cost Analysis

Poor communities in high risk areas are disproportionately affected by disasters compared to their wealthy counterparts; yet, there are few analyses to guide public decisions on pro-poor investments in disaster risk reduction. This paper illustrates an application of benefit-cost analysis (BCA) for assessing investments in structural flood proofing of low-income, high-risk houses. The analysis takes account of climate change, which is increasingly viewed as an important consideration for assessing long-term investments. Specifically, the study focuses on the Rohini river basin of India and evaluates options for constructing non-permanent and permanent residential structures on a raised plinth to protect them against flooding. The estimates show a positive benefit-cost ratio for building new houses on a raised plinth, while the ratio is less than one for demolishing existing houses to rebuild on a raised plinth. Climate change is found to significantly affect the BCA results. From a policy perspective, the analysis demonstrates the potential economic returns of raised plinths for ‘building back better’ after disasters, or as a part of good housing design practice

Civil society mobilisation after Cyclone Tracy, Darwin 1974

Major disasters challenge or exceed the capacity of the official emergency management sector to provide needed rescue services, support and relief. Emergency services in most jurisdictions do not have the surge capacity for unusual or extreme events without drawing on other jurisdictions or local people from outside the formal emergency management organisations. In such circumstances, those in the affected area need to organise themselves and make maximum use of local resources to cope with the immediate aftermath of impact. To find the required surge capacity, this suggests a whole of society response with the official system working with the capacities of people, commerce and organisations outside the emergency sector. An example is provided by the destruction of the northern Australian capital city of Darwin by Cyclone Tracy in December 1974. Informal volunteering and emergent leadership in Darwin and across Australia were critical to the immediate response and relief. Volunteering was widespread and worked well alongside official emergency management. With today’s information and communication technologies and a strong national resilience narrative, we would expect to do at least as well. However, governments now exercise much more control over civil society. We examine the implications for surge capacity and adaptability

Science for loss and damage. Findings and propositions

The debate on “Loss and Damage” (L&D) has gained traction over the last few years. Supported by growing scientific evidence of anthropogenic climate change amplifying frequency, intensity and duration of climate-related hazards as well as observed increases in climate-related impacts and risks in many regions, the “Warsaw International Mechanism for Loss and Damage” was established in 2013 and further supported through the Paris Agreement in 2015. Despite advances, the debate currently is broad, diffuse and somewhat confusing, while concepts, methods and tools, as well as directions for policy remain vague and often contested. This book, a joint effort of the Loss and Damage Network—a partnership effort by scientists and practitioners from around the globe—provides evidence-based insight into the L&D discourse by highlighting state-of-the-art research conducted across multiple disciplines, by showcasing applications in practice and by providing insight into policy contexts and salient policy options. This introductory chapter summarises key findings of the twenty-two book chapters in terms of five propositions. These propositions, each building on relevant findings linked to forward-looking suggestions for research, policy and practice, reflect the architecture of the book, whose sections proceed from setting the stage to critical issues, followed by a section on methods and tools, to chapters that provide geographic perspectives, and finally to a section that identifies potential policy options. The propositions comprise (1) Risk management can be an effective entry point for aligning perspectives and debates, if framed comprehensively, coupled with climate justice considerations and linked to established risk management and adaptation practice; (2) Attribution science is advancing rapidly and fundamental to informing actions to minimise, avert, and address losses and damages; (3) Climate change research, in addition to identifying physical/hard limits to adaptation, needs to more systematically examine soft limits to adaptation, for which we find some evidence across several geographies globally; (4) Climate risk insurance mechanisms can serve the prevention and cure aspects emphasised in the L&D debate but solidarity and accountability aspects need further attention, for which we find tentative indication in applications around the world; (5) Policy deliberations may need to overcome the perception that L&D constitutes a win-lose negotiation “game” by developing a more inclusive narrative that highlights collective ambition for tackling risks, mutual benefits and the role of transformation

Risk justice: Boosting the contribution of risk management to sustainable development

Comprehensively addressing different aspects of justice is essential to enable risk management to contribute to sustainable development. This article offers a new conceptual framework called risk justice that comprises procedural, distributive, and corrective justice in four dimensions related to sustainable development: social, ecological, spatial, and temporal issues. Risk justice is defined as the quality of being fair and reasonable while governing and managing a possible negative event. After explaining the conceptual framework, a detailed content analysis of two international guidelines for disaster risk management (the Sendai Framework for Disaster Risk Reduction 2015–2030 and the European Floods Directive) illustrates the analytical potential of the risk justice framework. Findings show strong emphasis on social and spatial aspects of distributive and procedural justice in the two documents, whereas considerations of corrective justice and temporal and ecological issues are scarce or indirect. This may result in conflicting impacts of disaster risk management on sustainable development. Therefore, discussing risk management with a risk justice viewpoint while elaborating guidelines or choosing risk management strategies provides new avenues for sustainable development and facilitates transparent trade-offs. Our risk justice framework enables risk practitioners and researchers to reflect systemically about justice in risk management in different risk contexts and can be used both as a proactive and as a retrospective tool

Understanding multiple resilience dividends and system boundaries in disaster- and climate-risk management: a systems approach for enhanced decision-making

Challenges in managing multi-hazards and multi-risks within complex risk landscapes—where numerous stakeholders with different priority needs and risk perceptions interact—remain unresolved. Here we suggest ways to tackle these pressing challenges in an integrated and comprehensive manner by applying key concepts from systemic risk research to triple- and multiple-dividend approaches. The central idea is that additional dividends (i.e., economic, social, and environmental co-benefits of disaster-risk reduction that go beyond loss-reduction benefits) can be related to different system boundaries (e.g., individual systems and system of systems) through their interdependencies. This approach allows for an integrated evaluation of interventions that may be more beneficial across various scales and for corresponding threats, thus increasing synergies (or co-benefits) and decreasing asynergies (or trade-offs) of disaster-risk reduction in a systemic way. Importantly, triple and multiple dividends, along with their related tools and approaches, can be seen as part of a ‘dividend continuum’, reflecting the varying levels of interdependencies across spatial and temporal scales within complex risk landscapes. As a consequence, dividends within and across systems can be managed simultaneously, based on determining priority needs, risk perceptions, and trade-offs involved in building resilience against current and future risks

Indirect Regulation of Environmental Hazards Through the Provision of Information to The Public: The Case of SARA, Title III

Title III of the Superfund Amendments and Reauthorization Act of 1986 seeks to reduce the risks of chemical accidents through a strategy of indirect regulation that relies on providing the public with information about chemical hazards. For this strategy to be effective, citizens must aggressively utilize the information provided to monitor industrial practices and press for risk reduction. Since prior research suggests it is very difficult to evoke the degree of citizen action that would be required to make a strategy of indirect regulation successful, and since the federal legislation provided no funds for implementation, there is a question o/whether the structures set up by Title III are sufficient to achieve its objectives. This article reports the results of a national study that examined selected aspects of the implementation of Title III in an effort to assess the likely outcome of its attempt at indirect regulation. Our focus is on the degree to which the Title Ill-mandated Local Emergency Planning Committees are pursuing policies that are likely to get the necessary information to citizens and foster community debate on hazardous materials issues

Business recovery from disasters: Lessons from natural hazards and the COVID-19 pandemic

This paper compares economic recovery in the COVID-19 pandemic with other types of disasters, at the scale of businesses. As countries around the world struggle to emerge from the pandemic, studies of business impact and recovery have proliferated; however, pandemic research is often undertaken without the benefit of insights from long-standing research on past large-scale disruptive events, such as floods, storms, and earthquakes. This paper builds synergies between established knowledge on business recovery in disasters and emerging insights from the COVID-19 pandemic. It first proposes a disaster event taxonomy that allows the pandemic to be compared with natural hazard events from the perspective of economic disruption. The paper then identifies five key lessons on business recovery from disasters and compares them to empirical findings from the COVID-19 pandemic. For synthesis, a conceptual framework on business recovery is developed to support policy-makers to anticipate business recovery needs in economically disruptive events, including disasters. Findings from the pandemic largely resonate with those from disasters. Recovery tends to be more difficult for small businesses, those vulnerable to supply chain problems, those facing disrupted markets, and locally-oriented businesses in heavily impacted neighborhoods. Disaster assistance that is fast and less restrictive provides more effective support for business recovery. Some differences emerge, however: substantial business disruption in the pandemic derived from changes in demand due to regulatory measures as well as consumer behaviour; businesses in high-income neighborhoods and central business districts were especially affected; and traditional forms of financial assistance may need to be reconsidered