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Natural hazards 6-2013
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Natural hazards 6-2013


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  • 1. Natural Hazards 6„Nature to be commanded, must be obeyed“ (Francis Bacon, 1561-1626) W. Eberhard Falck 1
  • 2. Exogenic Hazards continued 2
  • 3. Extraterrestrial Hazards • Magnetic storms • Meteoroids 3
  • 4. Coronal Mass Ejection•  CME is an ejection of material from the solar corona and may occur together with solar flares•  The ejected material is a plasma consisting primarily of electrons, protons (plus small quantities of heavier elements, e.g. He, O, and Fe), plus the entraining coronal magnetic field•  CMEs may disrupt the Earths magnetosphere, compressing it on the day side and extending the night-side tail•  When the magnetosphere reconnects on the nightside, it creates trillions of watts of power that is directed back toward the Earths upper atmosphere 4
  • 5. Impacts of CME•  CMEs can cause particularly strong aurorae borealis•  changes in the Earth‘s magnetic field induce electric currents in power- and communication lines that may destroy equipment and cause power outages•  CMEs may interfere (differential electric charges, damage to ICs) with communication and navigation equipment, e.g. satellites, causing failure or disturbance•  a slight heating of the Earth‘s atmosphere causes its expansion and thus increased drag on low-flying satellites that throws them out of orbit•  the possible biological effects of changes in the magnetic field are not well understood yet•  magnetic storms may disorient pigeons, whales and dolphins 5
  • 6. Mitigating the impacts•  current methods of prediction are still problematic•  the ‘space weather’, namely the magnetic fluxes and solar activities are being constantly monitored•  solar activity induced magnetic storms typically reach the Earth after several hours, but travelling times can be as short as 15 mins.•  warning on increased solar (flare) activity can give time to react•  electricity companies can temporarily disconnect grids to avoid damage to the transformers•  navigation equipment can be disconnected to avoid false signals that could lead to accidents•  underground power-/communication lines and optical fibres are less prone to disturbances 6
  • 7. Meteors•  7
  • 8. Meteoroids•  „a solid object moving in interplanetary space, of a size considerably smaller than an asteroid and considerably larger than an atom“ (IAU)•  the visible path of a meteoroid that enters Earths atmosphere is called a meteor•  if a meteor reaches the ground and survives impact, then it is called a meteorite•  a Near-Earth Object (NEO) is a Solar System object whose orbit brings it into close proximity with the Earth 8
  • 9. Near-Earth Objects•  some NEO orbits intersect that of Earths so they pose a collision danger•  objects with diameters of 5-10 m impact the Earths atmosphere about once per year; they ordinarily explode in the upper atmosphere, and most or all of the solids are vaporized•  objects of diameters of the order of 50 meters strike the Earth approximately once every thousand years•  objects with a diameter of one kilometer hit the Earth an average of twice every million year interval•  large collisions with five kilometer objects happen approximately once every ten million years 9
  • 10. Historic events•  various features on the Earth‘s surface, such as the Nördlinger Ries (Germany) are thought to originate from impacts•  the Cretaceous/Tertiary extinction event that lead to the demise of dinosaurs is thought to have been caused by an impact•  the Tunguska event in 1908 over Siberia was caused by an object of about 50 m diam.•  the Eastern Mediterranean event in 2002 was caused by an object of about 10 m diam. 10
  • 11. Recent event•  On 15 February 2013, a small asteroid entered Earths atmosphere over Russia at about 09:20 YEKT (03:20 UTC) with an estimated speed of 18 km/s.•  It became a brilliant meteor over the southern Ural region•  It exploded over Chelyabinsk Oblast at a height of about 23 km, generating small fragmentary meteorites and a powerful shock wave.•  About 1,500 people were injured, 2 seriously, mainly by flying debris caused by the shockwave 11
  • 12. Impacts and their mitigation•  the USA, European Union and other nations are currently scanning for NEOs in an effort called Spaceguard•  while the events are rather infrequent, their potential impact can be dramatic•  devastation in the zone around the impact point•  global cooling due to ash etc. being injected into the atmosphere•  devastation of agricultural land by ash covering•  to date no realistic countermeasures are available 12
  • 13. After the event ... 13
  • 14. Emergency Management•  Emergency = active hazard•  Risk management intends to break the loop or reduce the need for response•  Preparedness is a good strategy to reduce the impact of events•  Emergency management must include long-term work on infrastructure, public awareness, and human justice issues 14
  • 15. Disaster risk reduction frameworks•  to minimize vulnerabilities and disaster risks throughout a society•  to avoid (prevention)•  to limit (mitigation and preparedness) the adverse impacts of hazards within the broad context of sustainable development.•  A disaster risk reduction framework is composed of the following fields of action: –  Risk awareness and assessment including hazard analysis and vulnerability/ capacity analysis; –  Knowledge development including education, training, research and information; –  Public commitment and institutional frameworks, including organisational, policy, legislation and community action; –  Application of measures including environmental management, land-use and urban planning, protection of critical facilities, application of science and technology, partnership and networking, and financial instruments; –  Early warning systems including forecasting, dissemination of warnings, preparedness measures and reaction capacities. 15
  • 16. Risk GovernanceHow to deal with risk in a societal context 16
  • 17. What is Governance ?•  The exercise of political authority and the use of institutional resources to manage societys problems and affairs. (World Bank)•  The traditions and institutions by which authority in a country is exercised. This considers the process by which governments are selected, monitored and replaced; the capacity of the government to effectively formulate and implement sound policies and the respect of citizens and the state of the institutions that govern economic and social interactions among them. (World Bank)•  Governance has been defined as the rules of the political system to solve conflicts between actors and adopt decision (legality). It has also been used to describe the "proper functioning of institutions and their acceptance by the public" (legitimacy). And it has been used to invoke the efficacy of government and the achievement of consensus by democratic means, i.e. participation. (UNDP) 17
  • 18. Scope of good governance•  Considers the social, institutional, legal and economic context of risk management•  Looks at the complex web of actors, rules, conventions, processes and mechanisms•  Employs a holistic approach as opposed to a reductionist approach 18
  • 19. Governance Models•  Technocratic•  Decision-oriented•  Deliberative 19
  • 20. Technocratic governance model•  ‚Decide-announce-defend‘-model based on: – Rational and scientific approach – classification of wide societal issues according to narrow categories = powerful reduction method – judgemental aspects of the decisions are hidden•  This method fails, when confronted with – irreducible factors of complexity – unfamiliarity with the subject on the side of stakeholders – lack of common vocabulary and value system 20
  • 21. Decision-oriented model•  Largely a ‚technocratic‘ model, but considers the socio-econonmic context of risk assessment and management•  However, the underlying risk management policy is largely formulated on a scientific-technological basis alone 21
  • 22. Deliberative / inclusive GovernanceInvolves all stakeholders by Arnstein‘s ladder•  including the physical and the social dimension of an issue•  transparent decision framing•  mediation between the scientific and the wider societal aspects of the problem•  clearly defining the roles and responsibility of all stakeholders•  allowing for human errors•  creating trust by openess and transparency 22
  • 23. Conflicts in (natural) risk perception•  Whether perceptions have a direct correspondence with the physical world is irrelevant as long as people feel that these perceptions matter to them•  Such concerns are legitimate in their own right and valid for the respective decision making arena•  Specific perceptions may be clearly in violation of the best scientific knowledge about the likely effects of events, technologies or human actions•  It is the task of risk managers to provide evidence-based information that help people to understand the causal relationships that they may have misjudged 23
  • 24. Mediating between normative systems•  Studies on risk perception and concerns tends to show that most of the worries are not related to blatant errors or poor judgement, but to•  divergent views about the tolerability of remaining uncertainty•  short-term vs. long-term impacts,•  trustworthiness of risk-regulating or risk-managing agencies•  experience of inequity or injustice with regard to the distribution of benefits and risks 24
  • 25. What is relevant ?•  Managing natural risks will inevitably be directed by•  relevance claims, i.e. what matters to society and what are important phenomena that should receive attention ?•  evidence claims, i.e. what are the causes and what are the effects?•  normative claims, i.e. what is good, acceptable and tolerable ?•  It is often enlightening to review what is not investigated and why•  The scope of risk assessments and selection of evidence typically reflect value and normative positions 25
  • 26. Risk management conflicts•  Modernist (natural) science cannot alone resolve conflicts that arise out of differences in values and expectations re. risk management•  Reflexion raises the awareness of possible dead-locks in policy making resulting from diverging value systems•  New approaches recognises the fact that ‚risk knowledge‘ is/ may be conditional - depending on many societal and cultural factors local implemtability polycy scientific making evidence 26
  • 27. The socio-ecological system•  Different stakeholders will relate to risks in different ways•  Different stakeholders will provide different angles of view and value natural risks and vulnerabilities differently•  Some stakeholders will hold views and believes that are not necessarily compatible with a ‚reductionist‘ view of the risk•  Stakeholders will ask questions such as –  how will it influence me ? –  what will be the impact on my environment ? –  what will be the future state ? –  how sure are you about the risk assessment ?•  It results in complex decision making procedures on complex systems 27
  • 28. Summary• Hazards and risk are defined by what humans would like to see protected• Thus natural hazards are a societal problem• Most natural processes cannot be stopped or even diverted• Risk management has to balance cost and benefits• „Nature to be commanded, must be obeyed“ 28
  • 29. FIN - END - ... 29