41-60 of 147 Results

Article

Tropical cyclones, also known as hurricanes or typhoons, are one of the most violent weather phenomena on the planet, posing significant threats to those living near or along coastlines where tropical cyclone–related impacts are most pronounced. About 80 tropical cyclones form annually, a rate that has been remarkably steady over the period of reliable historical record. Roughly two thirds of these storms form in the Northern Hemisphere from about June to November, while the remaining third form in the Southern Hemisphere typically during the months of November to May. Our understanding of the global and regional spatial patterns, the year-to-year variability, and temporal trends of these storms has improved considerably since the advent of meteorological satellites in the 1960s because of advances in both remote-sensing technology and operational analysis procedures. The well-recognized spatial patterns of tropical cyclone formation and tracks were laid out in a series of seminal papers in the late 1960s and 1970s and remain an accurate sketch even to this day. Concerning the year-to-year variability of tropical cyclone frequency, the El Niño Southern Oscillation (ENSO) has by far the most dominant influence across multiple ocean basins, so much so that it is typically used as the main predictor for statistical forecasts of seasonal tropical cyclone activity. ENSO has a modulating influence on atmospheric circulation patterns, even in regions remote to the tropical Pacific, which, in turn, can act to enhance or inhibit tropical cyclone formation. While the meteorological and climate community has come a long way in our understanding of the global and regional climatological features of tropical cyclones, as well as some aspects of the broader relationship between tropical cyclones and climate, we are still hindered by temporal inconsistencies within the historical record of storm data, particularly pertaining to tropical cyclone intensity. Despite recent efforts to homogenize the historical record using satellite-derived intensity data back to the early 1980s, the relatively short period makes it difficult to discern secular trends due to anthropogenic climate change from natural trends occurring on decadal to multidecadal time scales.

Article

Non-governmental organizations (NGOs) play important roles in that they: strengthen natural hazard governance through service delivery and humanitarian response; mobilize local actors and work for advocacy, knowledge access, and integration; promote disaster risk reduction (DRR), development, and climate change adaptation (CCA) perspectives; and facilitate calls for transformative approaches. Some roles are best undertaken by large international and national NGOs (INGOs and NNGOs) and some are the province of smaller local NGOs (LNGOs). The sector as a whole plays a vital role by both challenging actors and bridge-building among them, as well as by modeling innovative practice, highlighting changing risk drivers, and engaging in policy advocacy. However, the growth of the sector has brought about challenges. The potential of NGOs is reduced by the constraints attached to much institutional funding, pressure for upward rather than downward accountability, and limited engagement by large INGOs and NNGOs with LNGOs and local people. Initiatives such as the Grand Bargain, emerging from the World Humanitarian Summit, seek to refashion and rebalance the sector. If NGOs, particularly the larger and more established organizations, prove able to address such challenges then the ability of the whole sector to support transformative change will be strengthened.

Article

Earthquakes involve sudden shear sliding motion between large rock masses across internal contact surfaces called faults. The slip on the fault releases strain energy previously stored in the surrounding rock that accumulated due to frictional resistance to sliding. Most earthquakes are directly caused by plate tectonics, and locate in the cool, brittle rock near Earth’s surface. Events with seismic magnitude measured 8.0 or greater are called great earthquakes and involve slip of from several to tens of meters across faults with lengths from 100 to more than 1,000 kilometers. These huge ruptures tend to occur on or near plate boundaries; the largest are on shallow-dipping plate boundary faults (megathrusts) found in compressional regions called subduction zones, where one tectonic plate is thrusting under another. Some great earthquakes occur within bending or detaching plates as they deform seaward of or below a subduction zone. Yet others occur on plate boundary strike-slip faults where two plates are shearing horizontally past one another, or within deforming plate interiors. Elastic wave energy released during the fault sliding is recorded and studied by seismologists to determine the fault location, orientation and sense of sliding motion, amount of radiated elastic wave energy, and distribution of slip on the fault during the event (co-seismic slip). Geodetic methods measure elastic strain accumulation prior to an earthquake, co-seismic slip, and afterslip on the fault that occurs without earthquakes, along with viscous deformation of the mantle as it responds to the fault offset. Great earthquakes commonly locate under the ocean, and the sudden motion of the seafloor generates tsunami—gravitational water waves that can be recorded with ocean floor pressure sensors (these waves are also used to determine co-seismic slip). As seismic, geodetic. and tsunami modeling methods have progressed over the past 50 years, our understanding of great earthquake rupture processes and earthquake interactions has advanced steadily in the context of plate tectonics and improved understanding of rock friction. All faults have heterogeneous frictional properties inferred from non-uniform sliding during each event, with areas of large slip instabilities called asperities having slip-velocity weakening friction and other areas having slip-velocity strengthening friction that results in stable sliding. The seismic wave shaking and tsunami waves can cause great devastation for humanity, so efforts are made to anticipate future earthquake hazards. As plate tectonics steadily move Earth’s plates, elastic strain around plate boundary faults accumulates and releases in a repeated stick-slip sliding process that causes a limited degree of regularity of faulting. Given the history of prior earthquakes on a given fault, we can identify seismic gaps where future slip events are likely to occur. With geodesy we can also now measure locations of accumulating slip deficit relative to plate motions, as well as variation in seismic coupling, which characterizes the fraction of plate motion accounted for by earthquake failure.

Article

Jan Reinhardt, Binhua Fu, and Joseph Balikuddembe

A public health disaster occurs when the adverse health effects of an event such as a natural hazard or threat exceed the coping capacity of the affected human population. The coping capacity of the affected population is hereby dependent on available resources including financial and human resources, health infrastructure, as well as knowledge, planning and organizational capabilities, and social capital. Disasters therefore disproportionally affect lesser resourced regions and countries of the world and pose specific challenges to their health systems as well as to the international humanitarian community in terms of dealing with mortality and injuries, communicable and noncommunicable disease, mental health effects, and long-term disability. Challenges for healthcare delivery in disaster situations in lesser resourced settings include deficiencies in the construction of resilient healthcare facilities, the lack of disaster response plans, shortage of specialized medical personnel, shortcomings regarding training in disaster response, and scarcity of resources such as medicines and portable medical devices and supplies. Other challenges include the absence of appropriate algorithms for the distribution of scarce resources; lack of coordination of medical teams and other volunteers; limited awareness of particular health issues such as mental health problems or disability and rehabilitation; and lack of plans for evacuation, sheltering, and continuation of treatment of those with pre-existing health conditions. Many challenges lesser resourced settings face with regard to healthcare delivery after disasters such as the organization of mortality management, triage and treatment of the injured, or the delivery of rehabilitative and mental health care cannot be reduced to the lack of baseline resources in terms of health infrastructure, technology, and personnel but are related to the absence of proper planning for future disaster scenarios including implementation strategies and simulation exercises. This not only encompasses the formal drafting of disaster preparedness and response plans, contingency planning of hospitals, and the provision of disaster-related training to health personnel but in particular the identification and involvement of the potentially and traditionally affected communities and especially vulnerable groups in all the process of disaster risk reduction.

Article

Russ S. Schumacher

Heavy precipitation, which in many contexts is welcomed because it provides the water necessary for agriculture and human use, in other situations is responsible for deadly and destructive flash flooding. Over the 30-year period from 1986 to 2015, floods were responsible for more fatalities in the United States than any other convective weather hazard (www.nws.noaa.gov/om/hazstats.shtml), and similar findings are true in other regions of the world. Although scientific understanding of the processes responsible for heavy rainfall continues to advance, there are still many challenges associated with predicting where, when, and how much precipitation will occur. Common ingredients are required for heavy rainfall to occur, but there are vastly different ways in which the atmosphere brings the ingredients together in different parts of the world. Heavy precipitation often occurs on very small spatial scales in association with deep convection (thunderstorms), factors that limit the ability of numerical models to represent or predict the location and intensity of rainfall. Furthermore, because flash floods are dependent not only on precipitation but also on the characteristics of the underlying land surface, there are fundamental difficulties in accurately representing these coupled processes. Areas of active current research on heavy rainfall and flash flooding include investigating the storm-scale atmospheric processes that promote extreme precipitation, analyzing the reasons that some rainfall predictions are very accurate while others fail, improving the understanding and prediction of the flooding response to heavy precipitation, and determining how heavy rainfall and floods have changed and may continue to change in a changing climate.

Article

A range of environmental and social dimensions of disasters occur in or are affected by the mountain cryosphere (MC). Core areas have glaciers and permafrost, intensive freeze-thaw, and seasonally abundant melt waters. A variety of cryospheric hazards is involved, their dangers magnified by steep, high, and rugged terrain. Some unique threats are snow or ice avalanches and glacial lake outburst floods. These highlight the classic alpine zones, but cryospheric hazards occur in more extensive parts of mountain ecosystems, affecting greater populations and more varied settings. Recently, habitat threats have become identified with global climate warming: receding glaciers, declining snowfall, and degrading permafrost. Particularly dangerous prospects arise with changing hazards in the populous mid-latitude and tropical high mountains. Six modern calamities briefly introduce the kinds of dangers and human contexts engaged. Disaster style and scope differs between events confined to the MC, others in which it is only a part or is a source of dangerous processes that descend into surrounding lowlands. The MC is also affected by non-cryospheric hazards, notably earthquake and volcanism. In human terms, the MC shares many disaster risk issues with other regions. Economy and land use, poverty or gender, for instance, are critical aspects of exposure and protections, or lack of them. This situates disaster risk within human ecological and adaptive relations to the predicaments of cold and steepland terrain. A great diversity of habitats and cultures is recognized. “Verticality” offers a unifying theme; characterizing the MC through ways in which life forms, ecosystems, and human settlement adjust to altitudinal zones, to upslope transitions, and the downslope cascades of moisture and geomorphic processes. These also give special importance to multi-hazard chains and long-runout processes including floods. Traditional mountain cultures exploit proximity and seasonality of different resources in the vertical, and avoidance of steepland dangers. This underscores sustainability and changing risk for the many surviving agro-pastoral and village economies and the special predicaments of indigenous cultures. Certain common stereotypes, such as remoteness or fragility of mountain habitats, require caution. They tend to overemphasize environmental determinism and underestimate social factors. Nor should they lead to neglect of wealthier, modernized areas, which also benefit most from geophysical research, dedicated agencies, and expert systems. However, modern developments now affect nearly all MC regions, bringing expanding dangers as well as benefits. Threats related to road networks are discussed, from mining and other large-scale resource extraction. Disaster losses and responses are also being rapidly transformed by urbanization. More broadly, highland–lowland relations can uniquely affect disaster risk, as do transboundary issues and initiatives in the mountains stemming from metropolitan centers. Anthropogenic climate warming generates dangers for mountain peoples but originates mainly from lowland activities. The extent of armed conflict affecting the MC is exceptional. Conflicts affect all aspects of human security. In the mountains as most other places, disaster risk reduction (DRR) policies have tended to favor emergency response. A human ecological approach emphasizes the need to pursue avoidance strategies, precautionary and capacity-building measures. Fundamental humanitarian concerns are essential in such an approach, and point to the importance of good governance and ethics.

Article

Like any other species, Homo sapiens can potentially go extinct. This risk is an existential risk: a threat to the entire future of the species (and possible descendants). While anthropogenic risks may contribute the most to total extinction risk natural hazard events can plausibly cause extinction. Historically, end-of-the-world scenarios have been popular topics in most cultures. In the early modern period scientific discoveries of changes in the sky, meteors, past catastrophes, evolution and thermodynamics led to the understanding that Homo sapiens was a species among others and vulnerable to extinction. In the 20th century, anthropogenic risks from nuclear war and environmental degradation made extinction risks more salient and an issue of possible policy. Near the end of the century an interdisciplinary field of existential risk studies emerged. Human extinction requires a global hazard that either destroys the ecological niche of the species or harms enough individuals to reduce the population below a minimum viable size. Long-run fertility trends are highly uncertain and could potentially lead to overpopulation or demographic collapse, both contributors to extinction risk. Astronomical extinction risks include damage to the biosphere due to radiation from supernovas or gamma ray bursts, major asteroid or comet impacts, or hypothesized physical phenomena such as stable strange matter or vacuum decay. The most likely extinction pathway would be a disturbance reducing agricultural productivity due to ozone loss, low temperatures, or lack of sunlight over a long period. The return time of extinction-level impacts is reasonably well characterized and on the order of millions of years. Geophysical risks include supervolcanism and climate change that affects global food security. Multiyear periods of low or high temperature can impair agriculture enough to stress or threaten the species. Sufficiently radical environmental changes that lead to direct extinction are unlikely. Pandemics can cause species extinction, although historical human pandemics have merely killed a fraction of the species. Extinction risks are amplified by systemic effects, where multiple risk factors and events conspire to increase vulnerability and eventual damage. Human activity plays an important role in aggravating and mitigating these effects. Estimates from natural extinction rates in other species suggest an overall risk to the species from natural events smaller than 0.15% per century, likely orders of magnitude smaller. However, due to the current situation with an unusually numerous and widely dispersed population the actual probability is hard to estimate. The natural extinction risk is also likely dwarfed by the extinction risk from human activities. Many extinction hazards are at present impossible to prevent or even predict, requiring resilience strategies. Many risks have common pathways that are promising targets for mitigation. Endurance mechanisms against extinction may require creating refuges that can survive the disaster and rebuild. Because of the global public goods and transgenerational nature of extinction risks plus cognitive biases there is a large undersupply of mitigation effort despite strong arguments that it is morally imperative.

Article

Communities facing urban flood risk have access to powerful flood simulation software for use in disaster-risk-reduction (DRR) initiatives. However, recent research has shown that flood risk continues to escalate globally, despite an increase in the primary outcome of flood simulation: increased knowledge. Thus, a key issue with the utilization of urban flood models is not necessarily development of new knowledge about flooding, but rather the achievement of more socially robust and context-sensitive knowledge production capable of converting knowledge into action. There are early indications that this can be accomplished when an urban flood model is used as a tool to bring together local lay and scientific expertise around local priorities and perceptions, and to advance improved, target-oriented methods of flood risk communication. The success of urban flood models as a facilitating agent for knowledge coproduction will depend on whether they are trusted by both the scientific and local expert, and to this end, whether the model constitutes an accurate approximation of flood dynamics is a key issue. This is not a sufficient condition for knowledge coproduction, but it is a necessary one. For example, trust can easily be eroded at the local level by disagreements among scientists about what constitutes an accurate approximation. Motivated by the need for confidence in urban flood models, and the wide variety of models available to users, this article reviews progress in urban flood model development over three eras: (1) the era of theory, when the foundation of urban flood models was established using fluid mechanics principles and considerable attention focused on development of computational methods for solving the one- and two-dimensional equations governing flood flows; (2) the era of data, which took form in the 2000s, and has motivated a reexamination of urban flood model design in response to the transformation from a data-poor to a data-rich modeling environment; and (3) the era of disaster risk reduction, whereby modeling tools are put in the hands of communities facing flood risk and are used to codevelop flood risk knowledge and transform knowledge to action. The article aims to inform decision makers and policy makers regarding the match between model selection and decision points, to orient the engineering community to the varied decision-making and policy needs that arise in the context of DRR activities, to highlight the opportunities and pitfalls associated with alternative urban flood modeling techniques, and to frame areas for future research.

Article

Atta-ur Rahman, Shakeel Mahmood, Mohammad Dawood, Ghani Rahman, and Fang Chen

This chapter analyzes the impacts of climate change on flood factors and extent of associated damages in the Hindu Kush (HK) region. HK mountains system is located in the west of the Himalayas and Karakorum. It is the greatest watershed of the River Kabul, River Chitral, River Panjkora, and River Swat in the eastern Hindu Kush and River Amu in western Hindu Kush. The Hindu Kush system hosts numerous glaciers, snow-clad mountains, and fertile river valleys; it also supports large populations and provides year-round water to recharge streams and rivers. The study region is vulnerable to a wide range of hazards including floods, earthquakes, landslides, desertification, and drought. Flash floods and riverine floods are the deadliest extreme hydro-meteorological events. The upper reaches experience characteristics of flash flooding, whereas the lower reach is where river floods occur. Flash floods are more destructive and sudden. Almost every year in summer, monsoonal rainfall and high temperature join hands with heavy melting of glaciers and snow accelerating discharge in the river system. In the face of climate change, a significant correlation between rainfall patterns, trends in temperature, and resultant peaks in river discharge have been recorded. A rising trend was found in temperature, which leads to early and rapid melting of glaciers and snow in the headwater region. The analysis reveals that during the past three decades, radical changes in the behavior of numerous valley glaciers have been noted. In addition, the spatial and temporal scales of violent weather events have been growing, since the 1980s. Such changes in water regimes including the frequent but substantial increase in heavy precipitation events and rapid melting of snow in the headwater region, siltation in active channels, excessive deforestation, and human encroachments onto the active flood channel have further escalated the flooding events. The HK region is beyond the reach of existing weather RADAR network, and hence forecasting and early warning is ineffective. Here, almost every year, the floods cause damages to infrastructure, scarce farmland, and sources of livelihood.

Article

Populations that are rendered socially invisible by their relegation to realms that are excluded—either physically or experientially—from the rest of society tend to similarly be left out of community disaster planning, often with dire consequences. Older adults, persons with disabilities, linguistic minorities, and other socially marginalized groups face amplified risks that translate into disproportionately negative outcomes when disasters strike. Moreover, these disparities are often reproduced in the aftermath of disasters, further reinforcing preexisting inequities. Even well-intentioned approaches to disaster service delivery have historically homogenized and segregated distinct populations under the generic moniker of “special needs,” thereby undermining their own effectiveness at serving those in need. The access and functional needs perspective has been promoted within the emergency management field as a practical and inclusive means of accommodating a range of functional capacities in disaster planning. This framework calls for operationalizing needs into specific mechanisms of functional support that can be applied at each stage of the disaster lifecycle. Additionally, experts have emphasized the need to engage advocacy groups, organizations that routinely serve socially marginalized populations, and persons with activity limitations themselves to identify support needs. Incorporating these diverse entities into the planning process can help to build stronger, more resilient communities.

Article

Nibedita Ray-Bennett, Daniel Mendez, Edris Alam, and Christian Morgner

Although the concept of natural hazard management as the central institutional mode of governance for coping with disasters appeared in the 1970s, inter-agency collaboration in natural hazard management came to the fore with the declaration of the United Nations (UN) Yokohama Strategy in 1994. The Yokohama Strategy focused on collaboration amongst international and regional organizations, donors, early-warning systems, the scientific community and national emergency agencies, among others. The successors of the strategy, the Hyogo Framework for Action launched in 2005, and the Sendai Framework for Disaster Risk Reduction in 2015, continue to emphasize the same. Inter-agency collaboration in governing hazard management is a collective effort, and these efforts have been promoted through cooperation, communication, and effective decision making between actors and organizations, enabled by enhanced technology. The content of the UN’s Yokohama Strategy, Hyogo Framework, Sendai Framework, and the cluster system bear this out. However, more research is required to understand the extent to which national governments have translated the UN’s frameworks into action. Studying how governments and responders coordinate and cooperate and what they coordinate, cooperate on, and communicate will clarify the realized processes that underpin hazard management.

Article

Vincenzo Bollettino, Tilly Alcayna, Philip Dy, and Patrick Vinck

In recent years, the notion of resilience has grown into an important concept for both scholars and practitioners working on disasters. This evolution reflects a growing interest from diverse disciplines in a holistic understanding of complex systems, including how societies interact with their environment. This new lens offers an opportunity to focus on communities’ ability to prepare for and adapt to the challenges posed by natural hazards, and the mechanism they have developed to cope and adapt to threats. This is important because repeated stresses and shocks still cause serious damages to communities across the world, despite efforts to better prepare for disasters. Scholars from a variety of disciplines have developed resilience frameworks both to guide macro-level policy decisions about where to invest in preparedness and to measure which systems perform best in limiting losses from disasters and ensuring rapid recovery. Yet there are competing conceptions of what resilience encompasses and how best to measure it. While there is a significant amount of scholarship produced on resilience, the lack of a shared understanding of its conceptual boundaries and means of measurement make it difficult to demonstrate the results or impact of resilience programs. If resilience is to emerge as a concept capable of aiding decision-makers in identifying socio-geographical areas of vulnerability and improving preparedness, then scholars and practitioners need to adopt a common lexicon on the different elements of the concept and harmonize understandings of the relationships amongst them and means of measuring them. This article reviews the origins and evolution of resilience as an interdisciplinary, conceptual umbrella term for efforts by different disciplines to tackle complex problems arising from more frequent natural disasters. It concludes that resilience is a useful concept for bridging different academic disciplines focused on this complex problem set, while acknowledging that specific measures of resilience will differ as different units and levels of analysis are employed to measure disparate research questions.

Article

Natural hazard governance in countries in the Global South is shifting from a state-centered approach, which has predominantly focused on disaster risk management, with limited involvement of citizens, and a disaster response to a hazard event, to an approach which is more participatory, inclusive and proactive. This emerging approach aims to be transformative, as it draws on the knowledge and skills of multiple actors, including community members; focuses on risk reduction and adaptation; and builds new models of participatory risk governance at the local and city scale. Progressive legislation has played a major role in supporting this evolution toward a more transformative approach to natural hazard governance, which recognizes the political economy and political ecology of risk. This includes acknowledging the vulnerability of communities in particular contexts, and the need to address development deficits to build resilience in the face of natural hazards. However, a significant gap exists between progressive legislation and policy, and implementation. Informal settlements experience some of the worst impacts of natural hazards due to their exposure, vulnerability, and social and political marginalization. However, they are also resilient and adaptive, developing innovative approaches in partnership with the state and other actors, to plan for and respond to natural hazards. Empirical research on particular case studies where these shifts in governance are evident, is necessary to explore the opportunities for and barriers to transformative, participatory natural hazard governance in cities in the South.

Article

In the context of this article, risk governance addresses the ways and means—or institutional framework—to lead and manage the issue of risk related to natural phenomena, events, or hazards, also referred to popularly, although incorrectly, as “natural disasters.” At the present time, risk related to natural phenomena includes a major focus on the issue of climate change with which it is intimately connected, climate change being a major source of risk. To lead involves mainly defining policies and proposing legislation, hence proposing goals, conducting, promoting, orienting, providing a vision—namely, reducing the loss of lives and livelihoods as part of sustainable development—also, raising awareness and educating on the topic and addressing the ethical perspective that motivates and facilitates engagement by citizens. To manage involves, among other things, proposing organizational and technical arrangements, as well as regulations allowing the implementation of policies and legislation. Also, it involves monitoring and supervising such implementation to draw further lessons to periodically enhance the policies, legislation, regulations, and organizational and technical arrangements. UNISDR was established in 2000 to promote and facilitate risk reduction, becoming in a few years one of the main promoters of risk governance in the world and the main global advocate from within the United Nations system. It was an honor to serve as the first director of the UNISDR (2001–2011). A first lesson to be drawn from this experience was the need to identify, understand, and address the obstacles not allowing the implementation of what seems to be obvious to the scientific community but of difficult implementation by governments, private sector, and civil society; and alternatively, the reasons for shortcomings and weaknesses in risk governance. A second lesson identified was that risk related to natural phenomena also provides lessons for governance related to other types of risk in society—environmental, financial, health, security, etc., each a separate and specialized topic, sharing, however, common risk governance approaches. A third lesson was the relevance of understanding leadership and management as essential components in governance. Drawing lessons on one’s own experience is always risky as it involves some subjectivity in the analysis. In the article, the aim has, nonetheless, been at the utmost objectivity on the essential learnings in having conducted the United Nations International Strategy for Disaster Reduction—UNISDR—from 2001 to around 2009 when leading and managing was shared with another manager, as I prepared for retirement in 2011. Additional lessons are identified, including those related to risk governance as it is academically conceived, hence, what risk governance includes and how it has been implemented by different international, regional, national, and local authorities. Secondly, I identify those lessons related to the experience of leading and managing an organization focused on disaster risk at the international level and in the context of the United Nations system.

Article

Jörn Birkmann and Joanna M. McMillan

The concepts of vulnerability, disaster risk reduction and climate change adaptation are interlinked. Risk reduction requires a focus not just on the hazards themselves or on the people and structures exposed to hazards but on the vulnerability of those exposed. Vulnerability helps with the identification of root causes that make people or structures susceptible to being affected by natural and climate-related hazards. It is therefore an essential component of reducing risk of disasters and of adapting to climate change. The need to better assess and acknowledge vulnerability has been recognized by several communities of thought and practice, including the Disaster Risk Reduction (DRR) and Climate Change Adaptation (CCA) communities. The concept of vulnerability was introduced during the 1980s as a way to better understand the differential consequences of similar hazard events and differential impacts of climate change on different societies or social groups and physical structures. Since then, the concept gradually became an integral part of discourses around disaster risk reduction and climate change adaptation. Although the history of the emergence of vulnerability concepts and the different perspectives of these communities mean the way they frame vulnerability differs, the academic discourse has reached wide agreement that risk—and actual harm and losses—are not just caused by physical events apparently out of human control but primarily by what is exposed and vulnerable to those events. In the international policy arena, vulnerability, risk, and adaptation concepts are now integrated into the global agenda on sustainable development, disaster risk reduction, and climate change. In the context of international development projects and financial aid, the terms and concepts are increasingly used and applied. However, there is still too little focus on addressing underlying vulnerabilities.

Article

Risk reduction is a policy priority in governments at all levels. Building community resilience is one of the keys to reducing disaster risks. Resilience-focused risk reduction considers the wider social, political, and cultural environments of a community and emphasizes the importance of working with community members. This is in stark contrast to the previous vulnerability-focused risk management that treats disasters as unavoidable natural events and recognizes people as passive or helpless under the unavoidable disasters. Community resilience is a critical concept in identifying visions and directions for risk reduction strategies. Community resilience has two major qualities: inherent community conditions (inherent resilience) and the community’s adaptive capacity (adaptive resilience). There are at least four components that should be included in risk reduction strategies to enhance both inherent and adaptive community resilience: risk governance, community-based risk reduction policies, non-governmental disaster entrepreneurs, and people-centered risk reduction measures. Risk governance is required to bridge the gap between national policies and local practices, scientific knowledge of natural hazards and locally accumulated knowledge, and national assistance and local actions. Community-based risk reduction policies should complement national disaster policies to reflect locally specific patterns of hazard, exposure, and resilience that are otherwise ignored in policy design process at the international and national levels. Risk reduction strategies should also encourage emergence of non-governmental entrepreneurs who can contribute to the speed and success of community relief and recovery following a disaster by resolving the immediate needs of the affected communities and transitioning people toward autonomy and self-reliance. Finally, risk reduction strategies should include people-centered policy measures that are designed to change the awareness, attitudes, and behaviors of people so that they are more prepared when facing a disaster.

Article

Parvin Sultana and Paul Thompson

Floodplains are ecologically diverse and important sources of livelihood for rural people. Bangladesh is one of the most floodplain-dominated countries and supports the highest density of rural population in the world. The experience of Bangladesh in floodplain management efforts provides evidence, lessons, and insights on a range of debates and advances in the management of floodplain natural resources, the challenges of climate change, and the role of local communities in sustaining these resources and thereby their livelihoods. Although floodplain areas are primarily used for agriculture, the significance and value of wild common natural resources—mainly fish and aquatic plants—as sources of income and nutrition for floodplain inhabitants has been underrecognized in the past, particularly with respect to poorer households. For example, capture fisheries—a common resource—have been adversely impacted by the building of embankments and sluice gates and by the conversion of floodplains into aquaculture farms, which also exclude poor subsistence users from wetland resources. More generally, an overreliance on engineering “solutions” to flooding that focused on enabling more secure rice cultivation was criticized, particularly in the early 1990s during the Flood Action Plan, for being top down and for ignoring some of the most vulnerable people who live on islands in the braided main rivers. Coastal embankments have also been found to have longer term environmental impacts that undermine their performance because they constrain rivers, which silt up outside these polders, contributing, along with land shrinkage, to drainage congestion. Locals responded in an innovative way by breaking embankments to allow flood water and silt deposition in to regain relative land levels. Since the early 1990s Bangladesh has adopted a more participatory approach to floodplain management, piloting and then expanding new approaches; these have provided lessons that can be more general applied within Asia and beyond. Participatory planning for water and natural resource management has also been adopted at the local level. Good practices have been developed to ensure that disadvantaged, poor stakeholders can articulate their views and find consensus with other local stakeholders. The management of smaller water-control projects (up to 1,000 ha) has been taken on by community organizations, and in larger water-control projects, there is collaborative management (also called “co-management”) among a hierarchy of groups and associations and the appropriate government agency. In fishery and wetland management, many areas have been managed by community organizations to sustainably restore common resources, although their rights to do this were lost in some cases. Associated with community management are successful experiments in adopting a more system-based approach, called “integrated floodplain management,” which balances the needs of agriculture and common natural resources, for example, by adopting crops with lower water demands that are resilient to less predictable rainfall and drier winters, and enable communities to preserve surface water for wild aquatic resources. Bangladesh also has had success in demonstrating the benefits of systematic learning among networks of community organizations, which enhances innovation and adaptation to the ever-changing environmental challenges in floodplains.

Article

Christina Hanna, Iain White, and Bruce Glavovic

Managed retreat is a deliberate strategy to remedy unsustainable land use patterns that expose people, ecosystems, and assets to significant natural (and socio-natural) hazard and climate induced risks. The term is all-encompassing, broadly capturing planned relocation in the fields of disaster risk reduction and climate change adaptation, as well as managed retreat or realignment in coastal management and environmental planning practice. Managed retreat helps to ensure that people and the resources they value are no longer exposed to extreme events and to the adverse impacts of slow-onset environmental change. Distinct from migration and displacement, managed retreat is the strategically planned withdrawal from development in risky spaces. It can be applied at a range of spatial scales, in an anticipatory, staged, or reactive manner. Unlike traditional risk management alternatives, managed retreat affords space to natural processes and minimizes long-term maintenance and emergency management costs. While it has great promise as a sustainable disaster risk reduction and climate change adaptation strategy, there are a number of socio-political-cultural, environmental, economic, and institutional barriers affecting its implementation, particularly in contexts with extensive existing development. There may also be significant challenges in integrating relocated and receiving communities. In practice, people are deeply connected to, and reliant upon, the security, networks and cultural values of their lands, homes, communities, and livelihoods. To realize the long-term benefits, managed retreat needs to be considered as an integrated approach that uses information, regulation, and various financial levers in a strategic manner, and recognizes the need to work alongside communities in a fair, transparent, and inclusive way.

Article

Communication underpins all phases of disaster risk reduction: it is at the heart of risk mitigation, by increasing resilience and preparedness, and by interacting with affected communities in the response phase and throughout the reconstruction and recovery after a disaster. Communication does not alter the scope or severity of a disaster triggered by natural hazards, but the extent to which risk reduction strategies impact on affected regions depends greatly on existing differences inherent in the society of these regions. Ethnic minorities and multilingual language groups―which are not always one and the same―may become vulnerable groups when there has been little or no planning or no awareness of the impact of limited access to trustworthy information when the disaster strikes. Furthermore, large-scale disasters are likely to involve personnel from the humanitarian sector from both local and international offices. Communication in most large-scale events has progressively become multilingual; from the late 20th and early 21st centuries, it is expected that large disasters see collaboration between intergovernmental, governmental, local, national, and international entities that operate in different ways in rescue and relief operations. Regardless of linguistic contexts, communication of reliable information in a trustworthy manner is complex to achieve in the aftermath of a disaster, which may instantaneously affect telecommunication infrastructures (overloading VOIP and GPS systems). From coordination to information, clear communication plays a role in any activity intending to reduce risks, damages, morbidity, and mortality. Achieving clear communication in crisis management is a feat in a monolingual context: people from different organizations and with different capacities in multi-agency operations have at least a common language, nonetheless, terminology varies from one organization to another, thus hampering successful communication. Achieving effective and clear communication with multilingual communities, while using one language (or lingua franca), such as English, Arabic, Spanish, or Hindi, depending on the region, is impossible without due consideration to language translation.

Article

Marian Muste and Ton Hoitink

With a continuous global increase in flood frequency and intensity, there is an immediate need for new science-based solutions for flood mitigation, resilience, and adaptation that can be quickly deployed in any flood-prone area. An integral part of these solutions is the availability of river discharge measurements delivered in real time with high spatiotemporal density and over large-scale areas. Stream stages and the associated discharges are the most perceivable variables of the water cycle and the ones that eventually determine the levels of hazard during floods. Consequently, the availability of discharge records (a.k.a. streamflows) is paramount for flood-risk management because they provide actionable information for organizing the activities before, during, and after floods, and they supply the data for planning and designing floodplain infrastructure. Moreover, the discharge records represent the ground-truth data for developing and continuously improving the accuracy of the hydrologic models used for forecasting streamflows. Acquiring discharge data for streams is critically important not only for flood forecasting and monitoring but also for many other practical uses, such as monitoring water abstractions for supporting decisions in various socioeconomic activities (from agriculture to industry, transportation, and recreation) and for ensuring healthy ecological flows. All these activities require knowledge of past, current, and future flows in rivers and streams. Given its importance, an ability to measure the flow in channels has preoccupied water users for millennia. Starting with the simplest volumetric methods to estimate flows, the measurement of discharge has evolved through continued innovation to sophisticated methods so that today we can continuously acquire and communicate the data in real time. There is no essential difference between the instruments and methods used to acquire streamflow data during normal conditions versus during floods. The measurements during floods are, however, complex, hazardous, and of limited accuracy compared with those acquired during normal flows. The essential differences in the configuration and operation of the instruments and methods for discharge estimation stem from the type of measurements they acquire—that is, discrete and autonomous measurements (i.e., measurements that can be taken any time any place) and those acquired continuously (i.e., estimates based on indirect methods developed for fixed locations). Regardless of the measurement situation and approach, the main concern of the data providers for flooding (as well as for other areas of water resource management) is the timely delivery of accurate discharge data at flood-prone locations across river basins.