Natural Hazards and DisastersClass 11 India Physical Environment Notes

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Natural Hazards and Disasters

Change is a fundamental law of nature, happening all around us continuously. Some changes are slow and gradual, like the formation of mountains, while others are sudden and swift, like earthquakes or volcanic eruptions.

From nature's point of view, these changes are neutral—neither good nor bad. However, from a human perspective, we assign values to them. We see the changing of seasons or the ripening of fruit as good, but we consider events like earthquakes, floods, and wars to be bad and undesirable because they cause harm and suffering. This chapter focuses on these "bad" changes, which we often call disasters.

What is a Disaster?

A disaster is a sudden, undesirable event, often caused by forces beyond human control, that strikes with little warning. It causes serious disruption to life and property, including death and injury to many people. The scale of a disaster is so large that it requires a response beyond what normal emergency services can provide.

For a long time, people viewed disasters as purely natural events, with humans as helpless victims. However, we now understand that human activities can also cause or worsen disasters.

  • Direct Human-Caused Disasters: These are events directly caused by human actions. Examples include the Bhopal Gas tragedy, the Chernobyl nuclear disaster, wars, and environmental pollution.
  • Indirect Human Impact: Sometimes, human actions don't directly cause a disaster but make a natural event much worse. For instance, deforestation can lead to more severe landslides and floods. Unscientific construction in fragile areas also increases the risk.
Example
Think about building a new neighborhood on a floodplain next to a river. The river naturally floods sometimes (a hazard), but by building homes there, we've made the community vulnerable to a devastating flood (a disaster).

While it's possible to prevent some human-made disasters, preventing natural disasters is very difficult. Therefore, the focus has shifted to natural disaster mitigation and management—finding ways to reduce their impact and prepare for them.

Natural Hazards vs. Natural Disasters

People often use the terms "natural hazard" and "natural disaster" interchangeably, but they have distinct meanings.

  • Natural Hazards are elements or circumstances in the natural environment that have the potential to cause harm to people or property. A steep, unstable slope in the Himalayas is a hazard; the potential for a landslide is always there.
  • Natural Disasters are the actual events that cause large-scale, widespread death, loss of property, and social disruption. A hazard becomes a disaster when the event happens and its impact is severe.
Note
A simple way to remember the difference: A hazard is the threat, while a disaster is the event that causes widespread damage. An active volcano is a hazard; its eruption that destroys a town is a disaster.

Over time, the damage caused by natural disasters has increased. This is partly because technology has allowed humans to move into and develop disaster-prone areas, like building cities on coastlines vulnerable to tsunamis and cyclones. This increases our vulnerability, or our exposure to risk.

Recognizing that disasters are a global problem, the United Nations took action, leading to the World Conference on Disaster Management in May 1994 at Yokohama, Japan. This meeting produced the Yokohama Strategy, a global plan to make the world safer from disasters.

Classification of Natural Disasters

To deal with disasters effectively, it's helpful to classify them. Natural disasters can be broadly grouped into four categories:

  • Atmospheric: Blizzards, thunderstorms, cyclones, drought, hailstorms, heat waves.
  • Terrestrial: Earthquakes, volcanic eruptions, landslides, avalanches, soil erosion.
  • Aquatic: Floods, tidal waves, storm surge, tsunami.
  • Biological: Pests (like locusts), insect infestations, and diseases like bird flu or dengue.

India's vast size and diverse environment make it vulnerable to most of these disasters, which cause significant loss of life and property every year.

Yokohama Strategy and International Decade for Natural Disaster Reduction (IDNDR)

The World Conference on Natural Disaster Reduction in Yokohama, Japan (May 23rd-27th, 1994) acknowledged that the impact of natural disasters had grown, especially affecting poor and disadvantaged groups in developing countries. The conference adopted the Yokohama Strategy and Plan of Action for a Safer World to guide disaster mitigation efforts.

Key principles of the resolution include:

  • Each country is responsible for protecting its own citizens.
  • Priority attention should be given to developing countries.
  • Countries should strengthen their own capabilities for disaster prevention and mitigation, involving non-governmental organizations and local communities.
  • International cooperation should be promoted, focusing on capacity-building, technology sharing, and mobilizing resources.

The conference also declared the decade 1990-2000 as the International Decade for Natural Disaster Reduction (IDNDR).