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Pressure and Release (PAR) Model

Watch the video where Ron Mountain discusses the Pressure and Release (PAR) Model for studying emergencies and disasters.
Climate change has contributed to Bangladesh becoming one of the most vulnerable countries in the world. Between 1980 and 2008 the country experienced 219 natural disasters, causing more than 16 billion dollars in damage. And then there’s the loss of human life and damage to property experienced, plus the long lasting effects on its society, ecosystems, and economy. So the use of a conceptual framework or model can help us to understand why disasters in places such as Bangladesh occur. Let’s take a look at the Pressure and Release model, or PAR for short. We have hazards, but when we consider these hazards in the context of vulnerability, we can better understand risk as the basis for disaster.
In the PAR model there are three stages of vulnerability.
These are: root causes, dynamic pressures, and unsafe conditions. Collectively they are called the progression of vulnerability. Let’s first consider root causes. This relates to the basic social, economic, and political factors that can give rise to vulnerability to hazards, leading to emergencies or disasters. As a developing nation, the population of Bangladesh has limited access to resources. There may also be limited access to political power, which may work against sections of the population earning a livelihood. And in Bangladesh nearly 40% of the country’s population live in poverty. Now let’s consider the dynamic pressures affecting that society. For a country such as Bangladesh, these include macro forces such as population growth, rapid urbanisation, deforestation, and soil erosion. There are many more.
Beyond this we also have deficiencies such as a lack of institutions providing services such as health and education. Other deficiencies in Bangladesh range from the insufficient regulation of river systems to inadequate early warning system education. Then there are the negative effects of debt repayments on the ability of countries such as Bangladesh to develop. And Bangladesh is one of the most densely populated countries in the world. These dynamic pressures exacerbate and focus the underlying root causes, which are then manifested by more specific unsafe conditions. These unsafe conditions include a fragile physical environment, dangerous locations, and exposed buildings. We can also include fragile local economies and vulnerable groups here, too.
And a lack of public actions and disaster preparedness - plus, there is the presence of endemic diseases to consider. These unsafe conditions leave a society vulnerable to various hazards. Bangladesh experiences cyclones and storm surges, floods, earthquakes, droughts, arsenic contamination of groundwater, tornadoes, and landslides. They have all caused significant problems. Bangladesh has experienced many disasters. These include several catastrophic tropical cyclones in the last ten years. Much of the country is low-lying, exposing it to regular flooding, and its rural communities are ill-equipped to deal with disaster. Rising water levels and more intense and frequent storms force many families to abandon their homes and livestock. Crops are regularly devastated, and livelihoods wrecked.
Some residents mistrust the reliability of warning messages, particularly in coastal areas - this deters early evacuation. Numbers of shelters and poor transportation discourages late evacuation. All of this combined worsens the effects of a disaster. So let’s return to our simple equation as one way of understanding the causes and contributors to disaster. Risk equals hazards combined with vulnerability. UN scientists predict that by 2050, rising sea levels will flood nearly a fifth of Bangladesh, making nearly 30 million people homeless. With the combined impact of hazard and vulnerability, all too often in countries such as Bangladesh, the only response to an emergency or disaster can be to pick up the pieces afterwards.
You have now explored some of the individual concepts and explored different approaches to their study.
We have also considered two different approaches to studying emergencies and disasters, the natural environment approach and the political/economic/social approach. Watch the video in which Ron examines a model that proposes possible relationships amongst some of these concepts.
The Pressure and Release Model sets out a series of steps that come together to produce what is described as the progression of vulnerability.
The progression of vulnerability begins with a variety of what are termed root causes. Progressing from these, the model sets out a range of more specific dynamic pressures in the society of a country. Finally, the progression leads to what are termed unsafe conditions.
A disaster occurs as a result of not only the potential hazards, but with them acting in combination with these vulnerabilities.

Your task

The ‘formula’ for the relationship between risk, vulnerability and hazard has been defined in alternative manners by academics. For example, later editions of the text referenced above differ from those printed previously.
The two possible relationships that are seen are:
Risk = Hazard x Vulnerability
Risk = Hazard + Vulnerability
Which more accurately portrays how hazard and vulnerability come together to produce risk?
What makes you think this relationship is more accurate?
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Emergencies and Disasters: Trends and Issues

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