BharatNotes What is Drought Types and Declaration?
Drought is a creeping disaster marked by a prolonged shortfall of water relative to normal availability, arising from deficient rainfall and the consequent depletion of soil moisture, surface water and groundwater. In India it is studied as a four-fold classification, and its official declaration follows a defined scientific and administrative procedure prescribed by the Manual for Drought Management, 2016, issued by the Ministry of Agriculture and Farmers Welfare.
Types of Drought
| Type | Meaning | Lead monitoring agency |
|---|---|---|
| Meteorological | Rainfall deficiency of 25% or more below the long-period average ("moderate" 26–50%, "severe" above 50%) | India Meteorological Department (IMD) |
| Agricultural (soil-moisture) | Insufficient soil moisture to sustain crops, causing crop stress/failure | Mahalanobis National Crop Forecast Centre (MNCFC) and state agriculture departments |
| Hydrological | Depletion of surface and sub-surface water — rivers, reservoirs, aquifers | Central Water Commission (CWC); Central Ground Water Authority (CGWA) for aquifers |
| Socio-economic | Demand for water/food outstripping supply, with economic and welfare impacts | Cross-sectoral assessment |
A fifth, emerging category — flash drought — describes a rapid onset of drought conditions over weeks rather than months, driven by heatwaves and high evapotranspiration.
How Drought Is Declared (Manual, 2016)
The 2016 Manual replaced a patchy older system with a two-step, evidence-based method:
- Trigger 1 — mandatory indicators: rainfall deviation and related indices (such as dry-spell and Standardized Precipitation Index) are checked first. If the rainfall trigger is set off, the assessment proceeds.
- Trigger 2 — impact indicators: four categories are then examined — (1) crop-situation indices, (2) remote-sensing vegetation indices (e.g., NDVI/VCI), (3) soil-moisture indices, and (4) hydrological indices (reservoir/streamflow/groundwater).
- Ground-truthing: district and state officials carry out a field sample survey to confirm conditions on parameters like crop sown area, crop condition, soil moisture and storage levels.
- Categorisation: the severity is graded as "moderate" or "severe" depending on how many impact-indicator categories breach thresholds (severity rests on at least two of the four categories).
Each state must run a Drought Monitoring Cell that apprises the State Executive Committee, and the State Government formally declares the drought.
Significance and Current Status
Drought is eligible for relief under the SDRF; the Centre supplements a state through the National Disaster Response Fund (NDRF) only when the calamity is of "severe" nature and SDRF funds are inadequate (NDRF is constituted under Section 46 of the Disaster Management Act, 2005). The 15th Finance Commission allocated a total SDRF corpus of about Rs 1,28,122 crore to all states for 2021-22 to 2025-26, with an NDRF corpus of about Rs 54,770 crore (15th Finance Commission award period). Critics argue the 2016 Manual's stringent matrix has made "severe" declarations harder, delaying central assistance in genuinely distressed regions — a live federal and agrarian-distress debate.
