- Drought is a complex, slow-onset phenomenon of ecological challenge that affects people more than any other natural hazards by causing serious economic, social and environmental losses in both developing and developed countries.
- The period of unusual dryness (i.e. drought) is a normal feature of the climate and weather system in semi-arid and arid regions of the tropics, which covers more than one-third of the land surface and is vulnerable to drought and desertification.
- A drought is an extended period where water availability falls below the statistical requirements for a region.
- Drought is not a purely physical phenomenon, but instead is interplay between natural water availability and human demands for water supply.
- There is no universally accepted definition of drought. It is generally considered to be occurring when the principal monsoons, i.e. southwest monsoon and northeast monsoon, fail or are deficient or scanty.
- Monsoon failure causing crop failure, drying up ecosystems and shortage of drinking water results in undue hardship to the rural and urban communities.
- Although droughts are still largely unpredictable; they are a recurring feature of the climate. Drought varies with regard to the time of occurrence, duration, intensity and extent of the area affected from year to year.
- Land abuse during periods of good rains and its continuation during periods of deficient rainfall is the combination that contributes to desertification.
- Dry regions in India include about 94 mha and about 300 million people (one-third of India’s population) live in these areas; more than 50% of the region is affected by drought once every four years.
- Different countries and states have developed codes, manuals, procedures, processes and policies for monitoring and management of drought with varying understanding.
- Over the years, India has developed a fairly elaborate governance system of institutionalized drought monitoring, declaration and mitigation at different levels.
- India’s response to the need for enhanced drought management has contributed to overall development. For example, the drought of 1965–1967 encouraged the ‘green revolution’, after the 1972 drought employment generation programmes were developed for the rural poor; the 1987–1988 drought relief effort focused on preserving the quality of life.
Drought classification systems
Classification by British Rainfall Organization (BRO, 1936)
- Absolute drought -When there are at least 15 consecutive days with less than 0.01 inch of rainfall per day.
- Partial drought -When there are at least 29 days having mean rainfall of 0.01 inch or less.
- Dry spell -When 15 consecutive days receive less than 0.04 inch of rain per day.
Thornthwaite (1947) classification
- Permanent drought -Characteristics of the desert climate, possibility of vegetation and agriculture only by irrigation.
- Seasonal drought -Planting dates and crop duration should be synchronized with rainy season and residual moisture storage.
- Contingent drought -Irregular occurrence and there is no regular season of occurrence.
- Invisible drought -Occurs even when there is frequent rainfall and occurs in humid region.
Classification based on physical aspects
- Agricultural drought – When soil moisture is inadequate to support healthy growth of crops, resulting in very low yield.
- Hydrological drought – Associated with shortfalls in surface or subsurface water supply (stream flow, reservoir and lake levels, and groundwater) on a watershed or river basin-scale.
- Meteorological drought -Related to the deficiency of rainfall compared to the average mean annual rainfall of an area.
Indian National Commission on Agriculture (1978)
- Meteorological drought –Normal precipitation below 25%.
- Hydrological drought – Prolonged meteorological drought and drying of reservoirs, lakes, streams and rivers, cessation of spring flows and fall in groundwater levels.
- Agricultural drought -Depletion of soil moisture during the growing season. A dry situation with 20% probability and rainfall deficiency of more than 25% in drought-prone states of India
Occurrence and effects of droughts in India during 1900–2002
- July 2002 —–Uttar Pradesh, Madhya Pradesh, Rajasthan, Punjab, Haryana, Delhi, Karnataka, Kerala, Nagaland, Orissa, Chhattisgarh, Himachal Pradesh Gujarat, Maharashtra, Andhra Pradesh and Tamil Nadu —–300,000,000 affected; damage – US$ 910,721,000
- May 2001 —–New Delhi, Rajasthan, Gujarat, Orissa ——-20 deaths
- November 2000 —–Mahasamund, Raipur, Kawardha, Rajnandgaon and Durg districts in Chhattisgarh region
- April 2000 —–Gujarat, Rajasthan, Madhya Pradesh, Orissa, Andhra Pradesh and Maharashtra —–90,000,000 affected; damage – US$ 588,000,000
- March 1996 —–Rajasthan
- March 1993 —–Bihar, Orissa, Andhra Pradesh, Maharashtra, Gujarat, Madhya Pradesh, Uttar Pradesh and Karnataka —–1,175,000 affected
- July 1987 —–Orissa —–110 deaths
- 1987 —–Gujarat, Rajasthan, Orissa, Madhya Pradesh, Andhra Pradesh, Maharashtra and four Union Territories —–300 deaths, 300,000,000 affected
- 11 April 1983 —–Kerala, Tamil Nadu and Rajasthan —–100,000,000 affected
- 1972 —–Central India 100,000,000 affected; damage – US$ 50,000,000
- August 1964 —–Mysore —–166,000,000 affected
- 1964 —–Rajasthan, center —–500,000 affected
- 1942 —–Kolkatta, Bengal region —–1,500,000 deaths
- 1900 —–West Bengal —–1,250,000 deaths
Preventive measures and preparedness plan for drought mitigation
- Dams/reservoirs and wetlands to store water
- Improvement in agriculture through modifying cropping patterns and introducing drought-resistant varieties of crops
- Watershed management
- Water rationing
- Management of rangeland with improvement of grazing patterns, introduction of feed and protection of shrubs and trees
- Cattle management
- Proper selection of crop for drought-affected areas
- Development of water resource system with improved irrigation, development of improved storage facilities, protection of surface water from evaporation and introduction of drop irrigation system
- Levelling, soil-conservation techniques
- Reducing deforestation and fire-wood cutting in the affected areas
- Alternative land-use models for water sustainability
- Checking of migration and providing alternate employment
- Animal husbandry activities can help in mitigation with use of improved and scientific methods
- Education and training to the people
- Participatory community programmes
The basic objective of the Draught Prone Area Programme is to minimise the adverse effects of drought on production of crops and livestock and productivity of land, water and human resources ultimately leading to drought proofing of the affected areas. The programme also aims to promote overall economic development and improving the socio-economic conditions of the resource poor and disadvantaged sections inhabiting the programme areas.
- Minimize adverse effects of droughts on the productivity of land, water and human resources
- Promote overall economic development and improve the socio-economic condition of poor and disadvantaged sections inhabiting the programme areas Capacity building and empowerment of village community, ensuring participation of Panchayati Raj Institutions and NGOs in programme implementation at grassroots level and transfer of funds as well as decision-making power to the local people
- Since 1995-96, a watershed development based approach has been adopted
The common Guidelines for Watershed Development provide for a uniform strategy in the implementation of all area development programmes. The main features of this strategy are:
✷ Area development programmes to be implemented exclusively on watershed basis.
✷ Programme activities to be confined to the identified watershed of about 500 hectares and to be executed on a project basis spanning a period of four to five years.
✷ Watershed project to be, as far as possible, co-terminus with village boundary.
✷ Direct participation of the people in planning and development of watershed areas and maintenance of assets in the post project period.
✷ Panchayati Raj Institutions have the right to monitor and review the programme at district, block and village levels. They can also function as Project Implementation Agencies if they so desire.
✷ Voluntary agencies to be given effective role in the implementation of the programme particularly in motivating people, community organisation and training