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.
Children and youth are greatly affected by disasters, and as climate instability leads to more weather-related disasters, the risks to the youngest members of societies will continue to increase. Children are more likely to live in risky places, such as floodplains, coastal areas, and earthquake zones, and more likely to be poor than other groups of people. While children and youth in industrialized countries are experiencing increased risks, the children and youth in developing countries are the most at risk to disasters.
Children and youth are vulnerable before, during, and after a disaster. In a disaster, many children and youth experience simultaneous and ongoing disruptions in their families, schooling, housing, health and access to healthcare, friendships, and other key areas of their lives. Many are at risk to separation from guardians, long-term displacement, injury, illness, and even death. In disaster planning, there is often an assumption that parents will protect their children in a disaster event, and yet children are often separated from their parents when they are at school, childcare centers, home alone, with friends, and at work. Children do not have the resources or independence to prepare for disasters, so they are often reliant on adults to make evacuation decisions, secure shelter, and provide resources. Children also may hide or have trouble articulating their distress to adults after a disaster. In the disaster aftermath, it has been found that children and youth—no matter how personally resilient—cannot fully recover without the necessary resources and social support.
Social location—such as social class, race, gender, neighborhood, resources, and networks—prior to a disaster often determines, at least in part, many of the children’s post-disaster outcomes. In other words, age intersects with many other factors. Girls, for example, are at risk to sexual violence and exploitation in some disaster aftermath situations. In addition, a child’s experience in a disaster could also be affected by language, type of housing, immigration status, legal status, and disability issues. Those living in poverty have more difficulties preparing for disasters, do not have the resources to evacuate, and live in lower quality housing that is less able to withstand a disaster. Thus, it is crucial to consider the child’s environment before and after the disaster, to realize that some children experience cumulative vulnerability, or an accumulation of risk factors, and that disasters may occur on top of other crises, such as drought, epidemics, political instability, violence, or a family crisis such as divorce or death.
Even as children and youth are vulnerable, they also demonstrate important and often unnoticed capacities, skills, and strengths, as they assist themselves and others before and after disaster strikes. Frequently, children are portrayed as helpless, fragile, passive, and powerless. But children and youth are creative social beings and active agents, and they have played important roles in preparedness activities and recovery for their families and communities. Thus, both children’s vulnerabilities and capacities in disasters should be a research and policy priority.
Abdelghani Meslem and Dominik H. Lang
In the fields of earthquake engineering and seismic risk reduction the term “physical vulnerability” defines the component that translates the relationship between seismic shaking intensity, dynamic structural uake damage and loss assessment discipline in the early 1980s, which aimed at predicting the consequences of earthquake shaking for an individual building or a portfolio of buildings. In general, physical vulnerability has become one of the main key components used as model input data by agencies when developinresponse (physical damage), and cost of repair for a particular class of buildings or infrastructure facilities. The concept of physical vulnerability started with the development of the earthqg prevention and mitigation actions, code provisions, and guidelines. The same may apply to insurance and reinsurance industry in developing catastrophe models (also known as CAT models).
Since the late 1990s, a blossoming of methodologies and procedures can be observed, which range from empirical to basic and more advanced analytical, implemented for modelling and measuring physical vulnerability. These methods use approaches that differ in terms of level of complexity, calculation efforts (in evaluating the seismic demand-to-structural response and damage analysis) and modelling assumptions adopted in the development process. At this stage, one of the challenges that is often encountered is that some of these assumptions may highly affect the reliability and accuracy of the resulted physical vulnerability models in a negative way, hence introducing important uncertainties in estimating and predicting the inherent risk (i.e., estimated damage and losses).
Other challenges that are commonly encountered when developing physical vulnerability models are the paucity of exposure information and the lack of knowledge due to either technical or nontechnical problems, such as inventory data that would allow for accurate building stock modeling, or economic data that would allow for a better conversion from damage to monetary losses. Hence, these physical vulnerability models will carry different types of intrinsic uncertainties of both aleatory and epistemic character. To come up with appropriate predictions on expected damage and losses of an individual asset (e.g., a building) or a class of assets (e.g., a building typology class, a group of buildings), reliable physical vulnerability models have to be generated considering all these peculiarities and the associated intrinsic uncertainties at each stage of the development process.
Humankind has always lived with natural hazards and their consequences. While the frequency and intensity of geological processes may have remained relatively stable, population growth and infrastructure development in areas susceptible to experiencing natural hazards has increased societal risk and the losses experienced from hazard activity. Furthermore, increases in weather-related (e.g., hurricanes, wildfires) hazards emanating from climate change will increase risk in some countries and result in others having to deal with natural hazard risk for the first time.
Faced with growing and enduring risk, disaster risk reduction (DRR) strategies will play increasingly important roles in facilitating societal sustainability. This article discusses how readiness or preparedness makes an important contribution to comprehensive DRR. Readiness is defined here in terms of those factors that facilitate people’s individual and collective capability to anticipate, cope with, adapt to, and recover from hazard consequences. This article first discusses the need to conceptualize readiness as comprising several functional categories (structural, survival/direct action, psychological, community/capacity building, livelihood and community-agency readiness).
Next, the article discusses how the nature and extent of people’s readiness is a function of the interaction between the information available and the personal, family, community and societal factors used to interpret information and support readiness decision-making. The health belief model (HBM), protection motivation theory (PMT), person-relative-to-event (PrE) theory, theory of planned behavior (TPB), critical awareness (CA), protective action decision model (PADM), and community engagement theory (CET) are used to introduce variables that inform people’s readiness decision-making. A need to consider readiness as a developmental process is discussed and identifies how the variables introduced in the above theories play different roles at different stages in the development of comprehensive readiness.
Because many societies must learn to coexist with several sources of hazard, an “all-hazards” approach is required to facilitate the capacity of societies and their members to be resilient in the face of the various hazard consequences they may have to contend with. This article discusses research into readiness for the consequences that arise from earthquake, volcanic, flood, hurricane, and tornado hazards. Furthermore, because hazards transcend national and cultural divides, a comprehensive conceptualization of readiness must accommodate a cross-cultural perspective. Issues in the cross-cultural testing of theory is discussed, as is the need for further work into the relationship between readiness and culture-specific beliefs and processes.
Vulnerability is complex because it involves many characteristics of people and groups that expose them to harm and limit their ability to anticipate, cope with, and recover from harm. The subject is also complex because workers in many disciplines such as public health, psychology, geography, and development studies (among others) have different ways of defining, measuring, and assessing vulnerability. Some of these practitioners focus on the short-term identification of vulnerability, so that maps and lists of people living “at risk” can be generated and used by authorities. Others are more concerned with reasons why some people are more vulnerable when facing a hazard or threat than others. Professionals working at the scale of localities are interested in methods that bring out residents’ own knowledge of hazards and help them to cooperate with each other to find ways of reducing risk. There are some interpretations of vulnerability that seek its root cause in the creation of risk by political and economic systems that make investment and locational decisions for the benefit of small elites without regard for how these decisions affect the majority. Finally, whatever success there may be in treating vulnerability in any of the ways just mentioned, it will always be a part of the human condition, and this fact in itself is puzzling.
Janine M. H. Selendy
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Natural Hazard Science. Please check back later for the full article.
Increasingly frequent and intense extreme climatic events are wreaking havoc in regions all over the world, not only causing immediate death and destruction, but also destroying prospects for attaining the most basic of human needs—water, food, and secure shelter. What is more, the problems brought about by extreme events are often exacerbated by ecosystem destruction due to human activities. This is a universal, global problem. Children are the most vulnerable. Insufficient and polluted water afflicts a third or more of the people of the world causing over a billion illnesses, illnesses often related to 2.5 billion people lacking sanitation, and illnesses often combined with malnutrition. In 2013, 783 million people lacked clean water. Procurement and allocation of water are major problems in rural and urban areas. More than 70% of fresh water is used for irrigation of crops, much of it lost to evaporation, and much resulting in build up of salinization on bordering farmland. Cities, now home to 54% of the world’s population, often lack adequate infrastructure to provide clean drinking water. In the United States, cities are faced with contaminated water from their pipes, as in Flint Michigan and in New Jersey schools. Naturally occurring water pollutants that can harm ecosystems, aquatic organisms, and humans are becoming more prevalent due to physical developments and climate change. For example, toxic cyanobacteria, also known as blue-green algae, in coastal and inland waters are causing mortality and morbidity in humans, livestock, and wild animals. Over the last three decades, one of these bacteria, C. raciborskii has been increasingly recognized as a public health exigency for drinking water supplies across all inhabited continents.
While food today is more readily available worldwide than in the past, nearly a billion people go hungry. The roughly billion people who rely on fish from the oceans are faced with dwindling harvests due to overfishing, warming waters that harm coral reef breeding grounds, and the loss of mangrove spawning grounds. Crops and livestock are hurt by climate change. Productivity is diminished by reliance on monoculture, poor storage, and transportation problems. The situation is drastically worsened by unnecessary waste and spoilage. The world is producing more than enough food, according to the Food and Agriculture Organization of the United Nations, which says that “Recovering just half of what is lost or wasted” alone could feed the world. Regarding spoilage, aflatoxins—poisonous, cancer-causing chemicals produced by certain molds—are found in spoiled food, including staples such as corn, millet, peanuts, and wheat, affecting not only immediate consumers, but also those who buy processed food. Droughts causing dead livestock and wilted crops have driven millions from their homes and farmland, as happened in Syria. Subsequent conflict led millions of Syrians to become both political and climate refugees, living in refugee camps and traveling thousands of treacherous miles to resettle. Poverty, whether experienced in slums, refugee camps, or other rural and urban settings, causes lack of land and shortages of material for soundly built housing that can withstand weather changes, even screens to help reduce exposure to mosquitoes, flies, and other disease vectors. The nearly quarter of the world’s urban population who live in slums live mostly in overcrowded, unsafe shelters that lack structural security, water for drinking, cooking, and hygiene, and sanitation. They are exposed to communicable diseases and suffer mental stress. Community space, adequate education, and chances for employment or a way out of the slums are rare. In numerous coastal communities, houses are endangered by extreme weather conditions exasperated by climate change. The sea’s rise in India has caused river delta islands to vanish. In 2016, the first climate refugees in the United States, an entire community of Native American Indians, are being forced to move from their ancestral homes on Isle de Jean Charles, Louisiana. The present challenges are aggravated by climate change, population growth, and forced migration. It is critical to focus on these basic, inextricably interlocked needs for water, food, and secure shelter, with a view to preventive measures, and to do so with extreme sensitivity to cultures, communities, ecosystems, and ramifications to human health.