SECTION III Meteorological, climatological and biological risk

Transcription

1 Chapter 3 Understanding disaster risk: hazard related risk issues SECTION III Meteorological, climatological and biological risk Virginia Murray Coordinating lead author Thomas Frame Lead author 3.7 Giles Harrison Tim Hewson Nigel Roberts Glenn McGregor Lead author 3.8 Angie Bone Florian Pappenberger Henny A. J. van Lanen Jürgen V. Vogt Lead authors 3.9 Joaquin Andreu Hugo Carrão Lucia de Stefano Emanuel Dutra Luc Feyen Giovanni Forzieri Michael Hayes Ana Iglesias Christophe Lavaysse Gustavo Naumann Roger Pulwarty Jonathan Spinoni Kerstin Stahl Robert Stefanski Nikolaos Stilianakis Mark Svoboda Lena M. Tallaksen Jesus San Miguel Lead author 3.10 Emilio Chuvieco John Handmer Andy Moffat Cristina Montiel-Molina Leif Sandahl Domingos Viegas Rishma Maini Virginia Murray Cathy Roth Lead author 3.11 Mike Catchpole Kristie Ebi Michael Hagenlocher Camila M. Montesinos Guevara Chloe Sellwood Tiffany Yeung 241

2 CONTENTS 3 Understanding disaster risk: hazard related risk issues Section III. Meteorological, climatological and biological risk Introduction Meteorological risk: extra-tropical cyclones, tropical cyclones and convective storms Storm types and associated hazardous phenomena Storms Extra-tropical cyclones Tropical cyclones Convective systems Frequency and geographical distribution of severe storm related hazards High winds associated with extra-tropical cyclones High winds associated with tropical cyclones High winds associated with convective systems Precipitation: rain, snow and hail Lightning Estimating potential for future severe storm related events Forecasting and monitoring Current predictive capabilities and future developments Use of observational updates/nowcasting Severe weather warnings Impacts Human impact Infrastructure and environment Conclusions and key messages Meteorological risk: extreme temperatures Temperature extremes in a disaster risk management context What are temperature extremes? Climatic variability and change and temperature extremes Health impacts of temperature extremes Health impacts Determinants of vulnerability Other impacts of temperature extremes Managing temperature extremes Forecasting

3 Early warning systems Urban design and planning Conclusions and key messages Climatological risk: droughts Introduction Drought definition and characteristics Past trends and future projections Drought impact Drought impacts on society and environment Health impacts Analysing drought risk Analysing hazard, exposure and vulnerability Estimating drought risk Managing drought risk Drought monitoring Drought forecasting Drought management Conclusions and key messages Climatological risk: wildfires Introduction wildfires in the context of natural and man-made hazards Wildfires definitions Wildfire risk Definition Components Existing knowledge and the issue of scale in fire risk assessment Wildfire information systems: regional, national, global Wildfire management: prevention, preparedness, impact assessment, restoration Other hazards such as windstorms and pests and their relationship to wildfire risk Harmful effects of wildfires on human population and health Contextual factors affecting wildfire risk Climate change Socio-spatial factors of wildfires: population, land cover and land use change, and landscape dynamics Innovation for better understanding and wildfire management Research gap Partnerships and networks, international collaboration in wildfire management Conclusions and key messages Biological risk: epidemics Introduction Diseases of contention Severe acute respiratory syndrome (SARS) Ebola Zika Human immunodeficiency virus (HIV) The International Health Regulations and pandemic preparedness Innovative approaches for early warning and surveillance Conclusions and key messages Recommendations References

4 Introduction The following subchapters cover meteorological, climatological and biological risks. In terms of meteorological risks, hazards from different types of storm systems as well as extremes of temperature are covered. Climatological risks include droughts and wildfires, and the biological risks posed by epidemics and pandemics are also examined. Each of these hazards is described in turn: There are two types of storm in meteorology: (1) the hazardous weather phenomena themselves (e.g. windstorms, rainstorms, snowstorms, thunderstorms and ice storms) and (2) the meteorological features in the atmosphere or storm systems that are responsible for the adverse weather. The latter includes tropical cyclones, extra-tropical cyclones and convective systems. Temperature extremes are rare high- or low-temperature events that may occur over a range of time and geographical scales. They usually occur because of a change in the weather pattern over a few days or several weeks. In terms of climatological risks, droughts result either from a shortfall in precipitation over an extended period of time, from its inadequate timing in relation to the needs of the vegetation cover, or from a negative water balance due to increased potential evapotranspiration caused by high temperatures. Wildfires refer to fires affecting grasslands, shrublands and other non-forest land covers. Although they are mainly initiated by human actions, their intensity and the effects they cause are mainly driven by fuel condition and availability, vegetation structure and prevalent meteorological and topographic conditions, and thus they are termed a natural hazard. An epidemic is the widespread, and often rapidly extending, occurrence of an infectious disease in a community or population at a particular time. A pandemic is the extension of an epidemic to many populations worldwide or over a very wide area, crossing many international boundaries and affecting a large number of people. All of these hazards can lead to a range of substantive direct and indirect impacts on human activity and infrastructure. Compared with other meteorological disasters, extreme temperatures (particularly high rather than low temperatures) can cause the most severe consequences in terms of human lives lost. Droughts can affect extended areas and large populations, putting socioeconomic systems and the environment at risk. Wildfires emit large volumes of smoke and gases that can aggravate respiratory problems, resulting in the 244

5 deaths of susceptible individuals. Demographic, physical, socioeconomic, behavioural and institutional factors may moderate a population s vulnerability to most hazards, particularly temperature extremes and epidemics. Thunderstorm asthma is a term used to describe an observed increase in acute bronchospasm cases following severe thunderstorms, which can have significant impacts on individuals health and on health services. Of particular concern is the evidence that human-related climate change is increasing the frequency of these hazards. The accelerated growth in global mean temperature since 1975 and the projected increase over the next several decades have implications for the occurrence of temperature extremes. A number of researchers have also highlighted the potential changes in fire climate regimes in different parts of the world, which may result in increased fire risk and an exacerbation of the effects of wildfires. However, these hazards do not always occur in isolation and can often interact with or influence one another. This is explained in chapter 2.5 where evolution of risk can be even so complicated that one hazard changes the vulnerability conditions for the next. For example, epidemics of Rift Valley fever often commence when a period of drought is followed by flooding or intense rainfall, so climate perturbations may herald an increased risk of outbreaks in at-risk regions. Similarly, prolonged droughts and heat waves dry out fuels, creating conditions which can exacerbate uncontrollable wildfires. The following subchapters describe the current knowledge regarding the risk assessment and management of each hazard in detail, identifying a set of recommendations for key stakeholders to reduce and manage their risks. 245