Drought is characterised by a temporary decline in the availability of water or moisture that is significantly below the average or expected level for a certain period of time.
According to the High-Powered Committee on Disaster Management Report, drought is defined as “any shortage of water to satisfy the usual needs of agriculture, livestock, industry, or a human population,”.
Types of Droughts
Various phenomena can be the reason for drought, following main types of droughts are mentioned below.
It defines a condition where the amount of rainfall falls below a certain level for a given time period (days, months, seasons, or years).
According to the India Meteorological Department (IMD), drought is a condition that occurs in any area when the mean annual rainfall is less than 25% of the average rainfall.
IMD has further divided droughts into two major categories:
Moderate drought, which occurs when rainfall varies between 25 and 50% below average level, and
Severe drought, which occurs when rainfall drops more than 50% below average.
It is important to note that, in terms of meteorological drought, the effectiveness of rainfall is significantly more crucial than the amount of rainfall. On average India receives 118 cm of annual rainfall which is considered to be the highest anywhere in the world for a country of comparable size.
However, the southwest monsoons’ unpredictable, unreliable, and variable rainfall causes drought conditions in many parts of the country. The major causes of meteorological drought are:
- Due to the lack of depressions over India, there have been weak monsoons and below-average rainfall.
- Early monsoon withdrawal or late monsoon onset
- prolonged breaks in monsoon.
- Re-establishment of the southern branch of the jet stream.
Hydrological drought is associated with a reduction in water. A meteorological drought often leads to a hydrological drought. In most cases, it takes two consecutive meteorological droughts before a hydrological drought manifests itself. There are two types of hydrological droughts viz.,
- Surface water drought
- Groundwater drought.
It is concerned with the drying up of surface water resources such as rivers, streams, lakes, ponds, tanks, reservoirs, etc.
There are many processes, besides meteorological drought, which lead to surface water drought. Surface water drought is primarily caused by extensive deforestation. Other undesirable human activities that enhance the drought condition are the expansion of non-terraced agriculture, environmentally hazardous mining, and indiscriminate road construction.
Groundwater drought is associated with a reduction in the groundwater level. This phenomenon happens due to excessive groundwater pumping without compensatory replenishment and creating more or less irreversible groundwater drought even during normal rainfall conditions.
There are soft, permeable alluvial soils in India’s northern plain. These soils allow water to penetrate and aid in replenishing groundwater. The peninsular plateau, in contrast, contains hard, impervious rocks that obstruct the replenishment of groundwater. Still, a situation of reduction in groundwater level pertains to Northern Indian Plain too.
Agricultural drought is concerned with the impact of meteorological/hydrological drought on crop yields. Agricultural drought results when soil moisture and rainfall levels are insufficient to support a healthy crop’s growth to maturity, leading to high moisture stress and the withering of important crop areas.
High Yielding Varieties (HYV) of seeds have taken the place of conventional drought-resistant seeds since the beginning of the green revolution in India in the 1960s. The water needs of various crops have increased as a result of the use of fertilisers.
The Green Revolution-based agriculture is incredibly reliant on irrigation, and any delay in the water supply will result in severe agricultural drought.
Moreover, the green revolution brought changes in cropping patterns.
For example, rice cultivation was practically unknown in Punjab, Haryana and Western Uttar Pradesh before Green Revolution and this region is not suitable for rice cultivation considering the amount of rainfall received by this region.
Due to the changing cropping patterns, limited water supplies are under severe stress, which occasionally results in severe droughts.
Soil Moisture Drought
This is a concern with insufficient soil moisture, especially in locations that receive rain, which may not sustain agricultural growth. This occurs during a meteorological drought when there is less water available to the soil and more water is lost through evaporation.
It reflects the reduction of availability of food and loss of income because of crop failures that endanger the food and social security of individuals in the affected areas.
A famine happens when access to food is reduced significantly, which could result in widespread starvation if assistance is not provided.
Ecological drought occurs when environmental harm caused by distress causes a natural eco-productivity system to decrease significantly.
Causes of Drought
- India experiences droughts when the southwest monsoon is weak. Droughts occur as a result of a weak monsoon’s inadequate rainfall.
- Droughts can also be brought on by the monsoons’ late arrival or early departure.
- Droughts are another consequence of prolonged monsoon breaks during the rainy season.
Although a drought may occur at any time and in any part of the country, most of the drought-prone areas are those having marginal rainfall and high variability of rainfall.
Effects of Drought
Droughts have a wide range of effects on the masses, especially in developing countries like India. The following categories best describe the impact of droughts in India:
- Physical Impact: adverse effect of drought on the recharge of soil moisture, surface runoff and groundwater table.
- Impact on Agriculture: Indian agriculture is largely dependent on monsoon rainfall. Approx two-thirds of the arable land is rainfed and lacks irrigation facilities. The effect results in the shortfalls of agricultural production in drought years.
- Social and Economic Impact: A drought can have more severe social and economic effects than it does physically or agriculturally. Drought is associated with famine which has its own social and economic consequences.
The effects of drought appear can cause severe damage, a few important them are mentioned below:
- Results in decline in cultivated area and fall in agricultural production.
- Fall in purchasing power.
- Fall in employment in the agricultural sector.
- Can create a scarcity of drinking water, fodder, and food.
- Causes Inflation
- Livestock deaths and distressed sales of cattle.
- Widespread malnutrition.
- Spread of diseases like diarrhoea, cholera and ophthalmia caused by malnutrition, hunger and starvation.
- Sale and mortgage of property, jewellery, etc. in distress.
- Migration of people from drought-hit areas to other areas for livelihood.
- Death due to malnutrition/starvation/diseases.
- Harsh impact on secondary and tertiary activities due to falling of primary production.
- Social stress and tension, disruption of social institutions and an increase in social crime.
The weaker segments of society are most affected by a drought. These people include migrant workers, small-scale and marginal farmers, and artists like weavers.
Drought Prone Areas
A drought-prone area is defined as one in which the probability of a drought year is greater than 20%.
A chronic drought-prone area is one in which the probability of a drought year is greater than 40%.
A drought year occurs when less than 75% of the normal rainfall is received.
In India, 16 per cent of the total area and 12 per cent of the population is drought affected, although the total average drought-prone area may be as much as 10 lakh sq km or about one-third of the total land area of the country.
Frequency of Drought
The number of times a drought occurs over a specific period of time is referred to as its frequency. Depending on the amount, fluctuation, and need for water, different regions of the country experience different frequencies of droughts.
The first systematic attempt at famine relief measures could be traced to the Great Famine or the Orissa Famine of 1866. Under Sir George Campbell’s chairmanship, the then government formed the first Famine Commission.
The formation of a Famine Commission in 1880 in the wake of the famines of 1873 and 1876–1878 was the second step. As a result of the Famine Commission’s suggestions, the government chose to introduce the Famine Codes started in 1883, bringing in the modern approach to relief administration.
Moving from Drought Relief to Drought Management
After Independence, India experienced major droughts in the years 1965-67, 1972-73, 1979 80 and 1985-88.
The High-Powered Committee on Disaster Management’s report 2002 states that “drought management is often done by focusing on water conservation and supply, standing crop saving, and public distribution supplies of essential commodities.”
Drought Prone Area Programmes (DPAP)
This programme was initiated in 1974. The intention was to change DPAP from a relief and employment-oriented programme into one aimed at ‘drought proofing’ through the adoption of an integrated area development approach which sought to mitigate the impact of future droughts by stabilizing both production and employment.
The objectives of the programme are:
- To minimise the adverse effects of drought on the production of crops and livestock and productivity of land, water and human resources through integrated development of the natural resource base of the area and adoption of appropriate technologies.
- to long-term preservation, development, and utilisation of land, water, and other natural resources, especially rainfall.
Integrated Watershed Management
The prevention of drought conditions is greatly aided by integrated watershed management.
This strategy guarantees coordinated planning, combined use of surface and groundwater, prioritisation of rational water use, and planning based on the entire amount of available water resources.
Various watersheds have been constructed throughout the country’s different rainfed regions as part of the National Watershed Programme for Rainfed Areas.
Article Written By: Priti Raj