A cascade effect is an inevitable and sometimes unforeseen chain of events due to an act affecting a system. [1] If there is a possibility that the cascade effect will have a negative impact on the system, it is possible to analyze the effects with a consequence / impact analysis. Cascade effects are commonly visualised in tree structures, also called event trees.
Cascade effects seen in the perspective of space travelling are theoretical possibilities that "space junk" or a satellite destroyed by a meteor will send debris throughout the orbits of most telecommunication satellites destroying them in the process and subsequently sending that debris into all possible orbits, destroying everything in orbit around the Earth, known as the Kessler syndrome. It is theorized that if this occurs, space flight beyond Earth will become very difficult if not impossible.
In biology, according to Mold and Stein, the term cascade refers to "a process that, once started, proceeds stepwise to its full, seemingly inevitable, conclusion". [2] The main cause of a cascade of injury in medicine is by misdiagnosis and medical error. These result in iatrogenic injury and from medical error flows a cascade of effects and results often including pain, disability, loss of job, poverty and homelessness which obviously cause mental health problems and may cause death. In medicine, a cascade effect may also refer to a chain of events initiated by an unnecessary test, an unexpected result, or patient or physician anxiety, which results in ill-advised tests or treatments that may cause harm to patients as the results are pursued. An example would be ordering a full body CT scan without a clear reason, finding an incidentaloma and undergoing a debilitating surgery to remove it, despite the fact that the condition was asymptomatic and possibly benign. [3] [4]
There is also an ecological definition of cascade effects, in which the death of one key species in an ecosystem triggers the extinction of other species.
Cascading effects are the dynamics present in disasters, in which the impact of a physical event or the development of an initial technological or human failure generates a sequence of events in human subsystems that result in physical, social or economic disruption. Thus, an initial impact can trigger other phenomena that lead to consequences with significant magnitudes. Cascading effects are complex and multi-dimensional and evolve constantly over time. They are associated more with the magnitude of vulnerability than with that of hazards. Low-level hazards can generate broad chain effects if vulnerabilities are widespread in the system or not addressed properly in sub-systems. For these reasons, it is possible to isolate the elements of the chain and see them as individual (subsystem) disasters in their own right. In particular, cascading effects can interact with the secondary or intangible effects of disasters.
— Pescaroli and Alexander 2015 [5]
In this definition, it is embraced the multidimensional and complex nature of cascades. The different possible failures that can generate chain effects are integrated, while progression and magnitude become important. As it provides a mechanism for spreading cascades in space and time, vulnerability is considered critical. This is related to the technique of isolating single effects and seeing them as possible autonomous cause-effect sequences, while in some events cascading effects coincide with secondary or intangible ones.
— Pescaroli and Alexander 2015 [5]
The figure above illustrates the differences between: (a) linear paths of chain -effects, and (b) complex paths of cascades. In "cascading disasters," secondary emergencies escalate and become the centre of a crisis, challenging the coordination of emergency relief and long-term recovery.
The different levels of cascading effects that are present in complex events suggest a differentiation between cascading effects and Cascading disasters have been defined as:
Cascading disasters are extreme events, in which cascading effects increase in progression over time and generate unexpected secondary events of strong impact. These tend to be at least as serious as the original event, and to contribute significantly to the overall duration of the disaster's effects. These subsequent and unanticipated crises can be exacerbated by the failure of physical structures, and the social functions that depend on them, including critical facilities, or by the inadequacy of disaster mitigation strategies, such as evacuation procedures, land use planning and emergency management strategies. Cascading disasters tend to highlight unresolved vulnerabilities in human society. In cascading disasters one or more secondary events can be identified and distinguished from the original source of disaster.
— Pescaroli and Alexander 2015 [5]
A disaster is a serious problem occurring over a period of time that causes widespread human, material, economic or environmental loss which exceeds the ability of the affected community or society to cope using its own resources. Disasters are routinely divided into either "natural disasters" caused by natural hazards or "human-instigated disasters" caused from anthropogenic hazards. However, in modern times, the divide between natural, human-made and human-accelerated disasters is difficult to draw.
Risk management is the identification, evaluation, and prioritization of risks followed by coordinated and economical application of resources to minimize, monitor, and control the probability or impact of unfortunate events or to maximize the realization of opportunities.
A natural disaster is the highly harmful impact on a society or community following a natural hazard event. Some examples of natural hazard events include: flooding, drought, earthquake, tropical cyclone, lightning, tsunami, volcanic activity, wildfire. A natural disaster can cause loss of life or damage property, and typically leaves economic damage in its wake. The severity of the damage depends on the affected population's resilience and on the infrastructure available. Scholars have been saying that the term natural disaster is unsuitable and should be abandoned. Instead, the simpler term disaster could be used, while also specifying the category of hazard. A disaster is a result of a natural or human-made hazard impacting a vulnerable community. It is the combination of the hazard along with exposure of a vulnerable society that results in a disaster.
Fault tree analysis (FTA) is a type of failure analysis in which an undesired state of a system is examined. This analysis method is mainly used in safety engineering and reliability engineering to understand how systems can fail, to identify the best ways to reduce risk and to determine event rates of a safety accident or a particular system level (functional) failure. FTA is used in the aerospace, nuclear power, chemical and process, pharmaceutical, petrochemical and other high-hazard industries; but is also used in fields as diverse as risk factor identification relating to social service system failure. FTA is also used in software engineering for debugging purposes and is closely related to cause-elimination technique used to detect bugs.
A cascading failure is a failure in a system of interconnected parts in which the failure of one or few parts leads to the failure of other parts, growing progressively as a result of positive feedback. This can occur when a single part fails, increasing the probability that other portions of the system fail. Such a failure may happen in many types of systems, including power transmission, computer networking, finance, transportation systems, organisms, the human body, and ecosystems.
The International Nuclear and Radiological Event Scale (INES) was introduced in 1990 by the International Atomic Energy Agency (IAEA) in order to enable prompt communication of safety significant information in case of nuclear accidents.
Failure mode and effects analysis is the process of reviewing as many components, assemblies, and subsystems as possible to identify potential failure modes in a system and their causes and effects. For each component, the failure modes and their resulting effects on the rest of the system are recorded in a specific FMEA worksheet. There are numerous variations of such worksheets. An FMEA can be a qualitative analysis, but may be put on a quantitative basis when mathematical failure rate models are combined with a statistical failure mode ratio database. It was one of the first highly structured, systematic techniques for failure analysis. It was developed by reliability engineers in the late 1950s to study problems that might arise from malfunctions of military systems. An FMEA is often the first step of a system reliability study.
Failure causes are defects in design, process, quality, or part application, which are the underlying cause of a failure or which initiate a process which leads to failure. Where failure depends on the user of the product or process, then human error must be considered.
Data loss is an error condition in information systems in which information is destroyed by failures or neglect in storage, transmission, or processing. Information systems implement backup and disaster recovery equipment and processes to prevent data loss or restore lost data. Data loss can also occur if the physical medium containing the data is lost or stolen.
Anthropogenic hazards are hazards caused by human action or inaction. They are contrasted with natural hazards. Anthropogenic hazards may adversely affect humans, other organisms, biomes, and ecosystems. They can even cause an omnicide. The frequency and severity of hazards are key elements in some risk analysis methodologies. Hazards may also be described in relation to the impact that they have. A hazard only exists if there is a pathway to exposure. As an example, the center of the earth consists of molten material at very high temperatures which would be a severe hazard if contact was made with the core. However, there is no feasible way of making contact with the core, therefore the center of the earth currently poses no hazard.
The design of spacecraft covers a broad area, including the design of both robotic spacecraft, and spacecraft for human spaceflight.
Emergency psychiatry is the clinical application of psychiatry in emergency settings. Conditions requiring psychiatric interventions may include attempted suicide, substance abuse, depression, psychosis, violence or other rapid changes in behavior. Psychiatric emergency services are rendered by professionals in the fields of medicine, nursing, psychology and social work. The demand for emergency psychiatric services has rapidly increased throughout the world since the 1960s, especially in urban areas. Care for patients in situations involving emergency psychiatry is complex.
The Kessler syndrome, proposed by NASA scientist Donald J. Kessler in 1978, is a scenario in which the density of objects in low Earth orbit (LEO) due to space pollution is high enough that collisions between objects could cause a cascade in which each collision generates space debris that increases the likelihood of further collisions. In 2009 Kessler wrote that modeling results had concluded that the debris environment was already unstable, "such that any attempt to achieve a growth-free small debris environment by eliminating sources of past debris will likely fail because fragments from future collisions will be generated faster than atmospheric drag will remove them". One implication is that the distribution of debris in orbit could render space activities and the use of satellites in specific orbital ranges difficult for many generations.
Mitigation is the reduction of something harmful or the reduction of its harmful effects. It may refer to measures taken to reduce the harmful effects of hazards that remain in potentia, or to manage harmful incidents that have already occurred. It is a stage or component of emergency management and of risk management. The theory of mitigation is a frequently used element in criminal law and is often used by a judge to try cases such as murder, where a perpetrator is subject to varying degrees of responsibility as a result of one's actions.
Ecological collapse refers to a situation where an ecosystem suffers a drastic, possibly permanent, reduction in carrying capacity for all organisms, often resulting in mass extinction. Usually, an ecological collapse is precipitated by a disastrous event occurring on a short time scale. Ecological collapse can be considered as a consequence of ecosystem collapse on the biotic elements that depended on the original ecosystem.
In its broadest sense, social vulnerability is one dimension of vulnerability to multiple stressors and shocks, including abuse, social exclusion and natural hazards. Social vulnerability refers to the inability of people, organizations, and societies to withstand adverse impacts from multiple stressors to which they are exposed. These impacts are due in part to characteristics inherent in social interactions, institutions, and systems of cultural values.
STARMAD deals with the latest trend in the space industry is towards space missions, spacecraft, systems and products, which require quick solutions for system design and software development.
A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would allow them, even just theoretically, to cause damage to health, life, property, or any other interest of value. The probability of that harm being realized in a specific incident, combined with the magnitude of potential harm, make up its risk, a term often used synonymously in colloquial speech.
A tsunami is a series of water waves caused by the displacement of a large volume within a body of water, often caused by earthquakes, or similar events. This may occur in lakes as well as oceans, presenting threats to both fishermen and shoreside inhabitants. Because they are generated by a near field source region, tsunamis generated in lakes and reservoirs result in a decreased amount of warning time.
Climate resilience is defined as the "capacity of social, economic and ecosystems to cope with a hazardous event or trend or disturbance". This is done by "responding or reorganising in ways that maintain their essential function, identity and structure while also maintaining the capacity for adaptation, learning and transformation". The key focus of increasing climate resilience is to reduce the climate vulnerability that communities, states, and countries currently have with regards to the many effects of climate change. Efforts to build climate resilience encompass social, economic, technological, and political strategies that are being implemented at all scales of society. From local community action to global treaties, addressing climate resilience is becoming a priority, although it could be argued that a significant amount of the theory has yet to be translated into practice.