A disaster is a serious problem occurring over a short or long period of time that causes widespread human, material, and economic, or environmental loss that exceeds the ability of the affected community or society to cope using its own resources. A disaster is a sudden, calamitous event that seriously disrupts the functioning of a community or society and causes human, material, and economic or environmental losses that exceed the community’s or society’s ability to cope using its own resources.
Though often caused by nature, disasters can have human origins. Developing countries suffer the greatest costs when a disaster hits – more than 95% of all deaths caused by hazards occur in developing countries, and losses due to natural hazards are 20 times greater (as a percentage of GDP) in developing countries than in industrialized countries.
No matter what society disasters occur in, they tend to induce change in government and social life. They may even alter the course of history by broadly affecting entire populations and exposing mismanagement of Corruption regardless of how tightly information is controlled in society.
Disasters are classified per origin, into natural and man-made disasters. As per severity, disasters are classified as minor or major (in impact). However, such classifications are more academic than real as major disasters could simply be events that received relatively more media coverage (Parasuraman and Unnikrishnan, 2005.
Natural disasters in India
A) Floods: Seventy-five percent of rainfall is concentrated over four months of monsoon (June – September) as a result of which almost all the rivers carry heavy discharge during this period. The problems of sediment deposition, drainage congestion, and synchronization of river floods compound the flood hazard with sea tides in the coastal plains. The Brahmaputra and the Gangetic Basin are the most flood-prone areas.
The other flood-prone areas are the northwest region of the west-flowing rivers like Narmada and Tapti, Central India, and the Deccan region with major east-flowing rivers like Mahanadi, Krishna, and Cauvery. While the area liable to floods is 40 million hectares, the average area affected by floods annually is about 8 million hectares.
B) Droughts: India has a largely monsoon-dependent irrigation network. An erratic pattern, both low (less than 750 mm) and medium (750 – 125 mm) makes 68 percent of the total area vulnerable to periodic droughts. A 100-year analysis reveals that the frequency of occurrence of below normal rainfall in arid semi-arid, and sub-humid areas are 54-57 percent.
Severe and rare droughts occur in arid and semi-arid zones every 8-9 years. The semi-arid and arid climatic zones are subject to about 50 percent of severe droughts that cover generally 76 percent of the area. In this region, rare droughts of the most severe intensity occurred on an average once in 32 years and almost every third year was a drought year.
C) Cyclones: India has a long coastline. There are two distinct cyclone seasons: premonsoon (MayJune) and post-monsoon (October-November).
The impact of these cyclones is confined to the coastal districts, the maximum destruction being within 100 Km. from the center of the cyclones and on either side of the storm track. Most casualties are caused by coastal inundation by tidal waves, storm surges, and torrential rains.
D) Earthquakes: The Himalayan mountain ranges are considered to be the world’s youngest fold mountain ranges. The subterranean Himalayas are geologically very active.
In a span of 53 years, four earthquakes exceeding magnitude 8 on the Richter scale have occurred in this region. The peninsular part of India comprises a stable continental crust.
Although these regions were considered seismically least active, an earthquake that occurred in Latur in Maharashtra on September 30, 1993, of magnitude 6.4 on the Richter scale caused substantial loss of life and damage to infrastructure.
E) Landslides and Avalanches: The Himalayan, the northeast hill ranges, and the Western Ghats experience considerable landslide activity of varying intensities.
River erosions, seismic movements, and heavy rainfalls cause considerable activity. Heavy monsoon rainfall often in association with cyclonic disturbances results in considerable landslide activity on the slopes of the Western Ghats.