Key Points

A natural hazard is an element in the natural environment with the potential to cause harm. It becomes a disaster when it strikes, causing widespread disruption, death, and damage that exceeds the coping capacity of the affected community.

Natural disasters are broadly classified into four categories: Atmospheric (cyclones, droughts), Terrestrial (earthquakes, landslides), Aquatic (floods, tsunamis), and Biological (epidemics, pest attacks).

Disasters are not only caused by natural forces. Human activities can directly cause them, like the Bhopal Gas tragedy, or indirectly intensify them, such as deforestation leading to more severe floods and landslides.

Earthquakes in the Himalayas and northeastern India are primarily caused by tectonic activity. The Indian plate's continuous movement towards the north and its collision with the Eurasian plate builds up stress, which is released as earthquakes.

India is divided into five earthquake zones. The 'Very High Damage Risk Zone' includes the northeastern states, parts of Bihar and Uttarakhand, the Kashmir Valley, and the Kuchchh region of Gujarat.

Tsunamis are high vertical ocean waves caused by the sudden displacement of water, typically from an underwater earthquake or volcanic eruption. In shallow coastal waters, their wave height increases dramatically, causing massive destruction.

Tropical cyclones are intense low-pressure systems that form over warm ocean waters. Their formation requires a continuous supply of warm moist air and a strong Coriolis force, which is why they do not form near the equator.

India's coastal areas are vulnerable to cyclones from the Bay of Bengal and Arabian Sea. A major consequence is the storm surge, an abnormal rise in sea level that inundates low-lying coastal areas.

Floods are a recurrent problem in India, with Assam, West Bengal, and Bihar being among the most flood-prone states. States in northern India like Punjab and Uttar Pradesh are also vulnerable to occasional floods.

Drought is classified into four types: Meteorological (prolonged inadequate rainfall), Agricultural (low soil moisture affecting crops), Hydrological (low water levels in reservoirs and aquifers), and Ecological (ecosystem damage due to water shortage).

The most extreme drought-affected areas in India are in western Rajasthan (Marusthali) and the Kachchh region of Gujarat. Large parts of peninsular India, including Maharashtra and Karnataka, are also severely drought-prone.

The 'Very High Vulnerability Zone' for landslides includes the highly unstable Himalayan mountain areas, the Western Ghats, and the northeastern regions. Steep slopes, heavy rainfall, and human activities like road construction are major contributing factors.

The World Conference on Natural Disaster Reduction in Yokohama, Japan, in 1994 adopted a strategy for a safer world. It also declared the decade 1990-2000 as the International Decade for Natural Disaster Reduction (IDNDR).

Disaster management involves three key stages. These are pre-disaster (preparedness and mitigation), during disaster (rescue and relief operations), and post-disaster (rehabilitation, recovery, and future capacity building).

The Government of India passed the Disaster Management Bill in 2005. This act provides for a systematic and comprehensive approach to disaster management at national, state, and district levels.