Droughts

A drought is a prolonged period of abnormally low rainfall, leading to a severe hydrological imbalance. Unlike sudden disasters like flash floods, a drought is a “creeping phenomenon” that develops over time, with impacts that ripple across ecological, agricultural, and socio-economic systems. The India Meteorological Department (IMD) defines meteorological drought based on the percentage of rainfall deficiency compared to the Long Period Average (LPA).

• Normal Rainfall: Rainfall within ±10% of the LPA.
• Moderate Drought: A region experiences a rainfall deficiency of 26% to 50% compared to the LPA.
• Severe Drought: A region experiences a rainfall deficiency exceeding 50% of the LPA.

Types of Droughts recognized in India

Meteorological Drought

This type is defined purely by a deficit in precipitation over an extended period. The IMD monitors meteorological drought at the district and sub-divisional levels across the country on a weekly basis during the monsoon season.

Hydrological Drought

This occurs when a meteorological drought is prolonged, causing a marked depletion of surface water resources like rivers, lakes, and reservoirs, as well as a drop in groundwater tables. It directly impacts hydropower generation, municipal water supplies, and industrial operations.

Agricultural Drought

This type happens when soil moisture and rainfall are inadequate during the crop growing season, leading to extreme soil moisture stress, wilting of crops, and drastic reductions in agricultural yield. It is closely monitored using satellite-derived vegetation indices.

Socio-Economic Drought

This manifests when the physical water shortage begins to affect the health, well-being, and quality of life of human populations. It restricts the availability of food, fodder, and employment, triggering large-scale distress migration from rural to urban centers.

Ecological Drought

This occurs when natural ecosystems suffer structural damage due to a lack of water. It results in a decline in primary ecological productivity, drying up of forest canopies, increased frequency of forest fires, and the degradation of native wildlife habitats.

Core Causal Factors of Droughts in India

Meteorological Failures and Climate Modes

• Monsoon Variability: Over 75% of India’s annual rainfall is concentrated during the Southwest Monsoon (June to September). A delayed onset, prolonged breaks in the monsoon, or its early withdrawal can trigger immediate drought conditions.
• The El Niño Phenomenon: The warming of the central and eastern Pacific Ocean alters global atmospheric circulation patterns (the Walker Circulation), often weakening the Indian monsoon and historically coinciding with major Indian droughts.
• The Indian Ocean Dipole (IOD): A negative phase of the IOD—characterized by cooler sea surface temperatures in the western Indian Ocean relative to the eastern part—impedes the flow of moisture toward the subcontinent, compounding monsoon deficits.

Hydrological and Anthropogenic Drivers

• Over-Exploitation of Groundwater: Indiscriminate pumping of groundwater for water-intensive cash crops in low-rainfall zones has led to a critical drop in water tables, transforming seasonal water scarcity into structural hydrological droughts.
• Deforestation and Land Use Changes: The clearing of forests and native vegetation reduces the moisture-retention capacity of the soil and limits regional evapotranspiration, disrupting localized, moisture-driven precipitation cycles.
• Inadequate Water Harvesting Infrastructure: The degradation of traditional water harvesting systems (such as Baolis, Johads, and Tankaas) eliminates natural community-level safety buffers during periods of low rainfall.

Geo-Spatial Distribution and Chronically Vulnerable Regions

The Central Water Commission (CWC) and the National Disaster Management Authority (NDMA) classify approximately 68% of India’s cultivable area as vulnerable to various degrees of drought.

Chronology of Major Historical Droughts in India

Monitoring Framework, Early Warning, and Technology Stack

India utilizes a tiered institutional mechanism incorporating satellite remote sensing and ground-based meteorological indices to declare and manage droughts.

National Agricultural Drought Assessment and Monitoring System (NADAMS)

Managed by the Mahalanobis National Crop Forecast Centre (MNCFC), NADAMS provides real-time, remote-sensing-based regular updates on agricultural drought conditions at the district and sub-district levels across multiple states.

Key Scientific Monitoring Indices

• Standardized Precipitation Index (SPI): A meteorological index based on the probability of precipitation over any specified time scale, mapping long-term moisture surpluses or deficits.
• Normalized Difference Vegetation Index (NDVI): A satellite-derived index that measures the health and density of green vegetation canopies based on the absorption and reflection of near-infrared light.
• Crop Moisture Index (CMI): An agricultural index that monitors short-term, week-to-week changes in soil moisture and crop water demands across agricultural zones.

The New Manual for Drought Management (2016)

Issued by the Ministry of Agriculture and Farmers Welfare, this manual establishes a standardized, mandatory two-step process for the formal declaration of a drought by state governments.

• Step 1 (Mandatory Trigger 1): Assessment of meteorological parameters, specifically looking at a rainfall deficiency or a high Standardized Precipitation Index value.
• Step 2 (Impact Indicators): Evaluation of at least four impact categories: vegetation health (NDVI), soil moisture status, hydrological storage levels, and socio-economic ground factors like fodder availability.

Institutional Framework, Policy, and Mitigation Strategies

Drought Prone Areas Programme (DPAP)

Launched in 1973–74, DPAP is one of the oldest area-development initiatives designed to minimize the adverse impacts of drought on crop production, livestock, and land productivity through integrated watershed management.

Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA)

MGNREGA serves as a key economic cushion during droughts. The act permits state governments to extend the guaranteed employment period from 100 to 150 days in officially notified drought-affected districts, focusing rural labor on building water conservation assets like farm ponds and check dams.

Structural Mitigation Measures

• Integrated Watershed Management: Constructing rainwater harvesting structures, check dams, gully plugs, and contour trenches across vulnerable river basins to intercept surface runoff and maximize local groundwater recharge.
• Micro-Irrigation Infrastructures: Promoting the adoption of drip and sprinkler irrigation systems under the Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) to reduce agricultural water consumption.
• Inter-Basin Water Transfer: Planning and executing river-linking projects to transfer surplus water from perennial rivers to water-scarce, drought-prone basins (e.g., the Ken-Betwa River Link Project).

Non-Structural Mitigation Measures

• Crop Diversification Strategies: Encouraging farmers in rain-shadow areas to shift from water-intensive crops (like sugarcane and paddy) to drought-resilient crops, millets (Shree Anna), pulses, and oilseeds.
• Weather-Based Crop Insurance: Utilizing the Pradhan Mantri Fasal Bima Yojana (PMFBY) to provide financial compensation to farmers for crop losses caused by severe monsoon deficits or localized seasonal droughts.
• Groundwater Governance Regulations: Enforcing state-level groundwater management bills to restrict commercial drilling and regularize extracting operations within critical aquifers.

High-Yield Trivia for Civil Services Strategy

The Concept of “Deficit Sowing”

Deficit sowing refers to an agricultural situation where farmers, anticipating a normal monsoon, complete crop planting, but a subsequent prolonged monsoon break causes the young crops to wilt. This creates a hidden agricultural drought that is not immediately apparent from cumulative seasonal rainfall metrics alone.

The Paradigm Shift in Famine Codes

Following the structural lessons of the 1966 Bihar drought, India transitioned its policy framework from administrative “famine management” (focused on reactive food relief distribution) to systemic “drought management” (focused on building local economic safety nets, managing water resources, and stabilizing long-term food security).

Composite Water Management Index (CWMI)

Published by NITI Aayog, this index evaluates and ranks Indian states on their water management efficiencies across key themes, including groundwater restoration, major irrigation management, watershed development, and rural drinking water supply policies.