Hazards of Floods and Droughts in India

Abstract

India is a land of monsoons of which the South-West Monsoon is a wet monsoon while the North-East Monsoon is a dry one. Yet the rainfall produced by them is not uniformly distributed either in space or in time which therefore leads to the occurrence of floods and droughts in different parts of the country from time to time. While floods are confined to restricted areas based on the distribution of the major river systems, droughts are only on account of rainfall failures following late onset or early withdrawal or both of the monsoons. The paper describes the main features of the annual and seasonal rainfall distribution over India and discusses their implications in the occurrence of floods and droughts. References are made to storm surges in coastal areas as well as flash floods due to dam failures.

Droughts unlike floods are slow-acting but a sure distress sapping the lives, property and economy of the population. Though floods and droughts are both triggered by natural meteorological causes, their impact is determined to a large extent by human factors — unpreparedness, ignorance and neglect, apart from improper design and poor execution of the hydrological projects. Examples are cited to illustrate the above points and measures proposed for the mitigation of these natural hazards are indicated in specific instances.

’Floods and Droughts are the two faces of the same coin — the Spell of Weather’, said Ivan Ray Tannehill as early as 1947. They have been the scourge of mankind since times immemorial; while droughts hit food production mainly through water scarcity, floods disrupt national economy through water surplus causing wide-spread inundation, destruction of crops, dislocation of communications besides loss of human lives and live-stock.