What is the threshold for natural hazards to become natural disasters? Extreme weather conditions such as rain, wind, hail and snow pose weather risks. Climate change has exacerbated weather hazards. Hazard profiles help to understand the various impacts of hazards, vulnerabilities and resilience and serve as a mitigation plan. It is completed for each type of natural hazard and takes into account physical processes, including size, speed of occurrence and spatial extent, duration, frequency and spatial predictability. Hazard profiles allow you to assess and identify the different hazards you should focus on and invest in to reduce the potential impact. Natural hazards can also cause secondary natural hazard events that create additional hazards. For example, volcanic activity can cause other hazards, such as the spread of ash and lava. The national risk index only considers the most important natural events and not their outcomes or consequences. Natural hazards are physical phenomena caused by atmospheric, aquatic or tectonic processes that threaten people, property or the environment. A natural hazard is considered a natural disaster if it has exceeded a certain threshold, i.e. if it has caused significant damage to society or a community and the community can no longer cope with its resources. Vulnerability is the characteristic of society or community that affects its vulnerability to danger.

Flight – The most obvious reaction to a natural hazard is to fly or flee! It can be an organized event if there is enough notice, or it can be chaotic and random – «every man for himself» California Natural Hazard Profile, cahazardprofilemitigationplan.com The three main categories of natural hazards are: Each of the types of natural hazards described above has very different characteristics in terms of spatial and temporal scales that influence them, frequency and period of recurrence of risks, and measures of intensity and effects. This complexity means that «individual hazard» assessments are common, when the hazard potential of a particular type of hazard is limited. In these examples, hazards are often treated in isolation or independently. An alternative is a «multi-risk» approach, which attempts to identify all possible natural hazards and their interactions or relationships. [5] [6] Climate change can increase or decrease weather hazards and directly threaten property through sea-level rise and biological organisms through habitat destruction. Effective risk analysis in a given area (e.g. for disaster risk reduction) should ideally include an examination of all relevant hazards and their interactions. In order to be most beneficial for risk reduction, the hazard analysis should be extended to a risk assessment that takes into account the vulnerability of the built environment to each hazard.

This step is well developed for seismic risk, which assesses the potential impact of future earthquakes on structures and infrastructure, as well as the risk of extreme wind and, to a lesser extent, the risk of flooding. For other types of natural hazards, risk calculation is more difficult, mainly due to the lack of functions that link the intensity of a hazard and the probability of different levels of damage (fragility curves). [9] ThinkHazard! is an online tool that provides an overview of the hazards of eight natural hazards (river floods, earthquakes, water scarcity, cyclones, coastal floods, tsunamis, volcanoes and landslides) developed by the Global Facility for Disaster Reduction and Recovery in collaboration with other agencies. [10] [11] The National Risk Index presents natural hazards as an expected annual loss that includes exposure data, annualized frequency and historical loss ratio. Hydrological hazards arise from heavy rainfall, melting ice and snow, and storm surges. Deforestation and the breaking of dams and banks with steep banks exacerbate these dangers. A hazard profile includes data in three categories: Biological hazards are hazards caused by biological processes. These include various types of diseases, including infectious diseases, that spread from person to person and threaten to infect a large portion of the human population. Many discussions on natural hazards exclude biological hazards and instead place them in the field of medicine and public health. When biological hazards are counted, they include the deadliest disasters in world history, including the bubonic plague epidemic by the Black Death in the 1300s, which killed 75 to 100 million people, and the «Spanish» flu pandemic of 1918, a global affair (the name «Spanish» is due to a historic accident) that killed 50 to 100 million people.

A more recent example is the COVID-19 pandemic. Understanding geographic concepts has been a key part of answering questions such as where the virus is more common, where it is more deadly, how fast it moves, and how we can prevent it from spreading. It also helps us realize that natural disasters are not always purely natural. Human action was important for both the spread and containment of the virus. While biological hazards are undoubtedly important, they are not covered in detail in this module. For better or worse, natural disasters occur frequently and cause great damage, increasing the need for dedicated natural hazard professionals. Risk management professionals work in governmental, private, for-profit and not-for-profit organizations, as well as universities and research institutes. People work to characterize hazards, prepare communities for hazards, provide emergency services after disasters, help communities rebuild, document disasters, and raise public awareness. People work as project managers, database analysts, operations analysts, environmental experts and mental health consultants. The U.S.

government`s largest employer for disaster management is the Federal Emergency Management Agency (FEMA). The main international organizations dealing with natural hazards are the United Nations World Food Programme and the United Nations Educational, Scientific and Cultural Organization (UNESCO). The main non-governmental and non-profit organizations are the Red Cross Red Crescent, Catholic Relief Service, Oxfam and Mercy Corps. Many people within these and other organizations focus exclusively on projects related to natural hazards. Others combine work on natural hazards with work on other issues, which is appropriate given the close link between natural hazards and so many other issues. Natural hazards can be divided into several broad categories: geological hazards, hydrological hazards, meteorological hazards, and biological hazards. Prediction – This is essentially the mechanism we use to predict when and where a hazard will occur. There is now a wide range of forecasting methods for a variety of hazards, think avalanche risk charts you may have seen while skiing. We can use satellites, flow meters, sulfur dioxide meters, inclinometers, etc. to predict various hazards.

We are better at predicting some hazards, such as floods, than others, such as earthquakes, because some of the warning signs are clearer and because the response time to each hazard is so great. Hazards can have social, economic and environmental impacts on the affected country or community. The possible consequences are loss of life, injury, damage to infrastructure, businesses and ecosystems. Natural hazards can also cause secondary hazards. Floods, for example, can trigger landslides, which can then cause further damage. Hydrological hazards arise from heavy rainfall, melting ice and snow, and storm surges. Some limitations exist because of the difficulty of comparing different types of hazards. The challenge of comparing hazards in different countries, for example, lies in different socio-economic situations. The overall economic loss in developed countries may be much higher than in developing countries, but the ratio to GDP is lower.