Maharashtra’s semi-arid districts face highest risk from rapidly intensifying flash droughts, study says
A 44-year study (1981-2024) published in the journal Physics and Chemistry of the Earth analysed drought patterns across Maharashtra's districts
The study found that five semi-arid interior districts — Ahilyanagar, Beed, Dharashiv, Sangli, and Solapur — face the highest risk of rapidly intensifying "flash droughts," with intensification rates exceeding 9% per eight-day period in these hotspots
Eastern districts (Bhandara, Gadchiroli, Gondia, Wardha) and coastal areas showed comparatively lower flash-drought severity, attributed to better rainfall distribution and higher humidity
Flash droughts were found to be rare during the monsoon season (fewer than two events across 44 years in most areas) but far more frequent and prolonged (15-25+ events, lasting 20-25 days) in the non-monsoon season
Researchers recommended dedicated flash-drought monitoring and early-warning systems, noting that existing drought-response frameworks are designed for slower-onset, conventional droughts
Flash Drought — A Distinct Category from Conventional Drought
A flash drought is the rapid onset or intensification of drought conditions, developing within days to a few weeks rather than the months typical of conventional (meteorological/agricultural) drought. It is driven not primarily by rainfall deficiency alone but by a combination of low precipitation with abnormally high temperatures, wind, and radiation that sharply raise evapotranspiration and deplete soil moisture.
Key Details
- Distinguishing mechanism: rapid soil-moisture depletion driven by elevated evapotranspiration demand, rather than slow-building precipitation deficit
- Global flash-drought assessment methods use indices such as the Soil Moisture Volatility Index (SMVI) and Evaporative Demand Drought Index (EDDI)
- Because onset is fast, flash droughts leave little lead time for standard drought-relief mechanisms designed around seasonal rainfall monitoring
- Distinct from meteorological, agricultural, hydrological, and socio-economic drought — the four classical drought categories used in India's drought classification framework
The Maharashtra study applies this newer flash-drought lens (intensification rate per short time window) rather than the conventional seasonal-deficit lens, identifying risk that standard drought indicators may under-capture.
India's Drought Classification Framework (Manual for Drought Management)
The Manual for Drought Management, issued by India's Ministry of Agriculture and Farmers Welfare, is the operative framework for declaring and classifying drought, using rainfall, vegetation indices, soil moisture, and reservoir storage as parameters.
Key Details
- Meteorological drought is declared when seasonal rainfall deficiency exceeds a threshold relative to the long-period average (LPA); it is classified moderate at 26-50% deficiency and severe above 50%
- Agricultural drought follows from inadequate soil moisture and rainfall during the crop-growing season, causing crop stress
- Hydrological drought reflects below-normal levels in rivers, reservoirs, and groundwater following sustained precipitation shortfall
- The Manual does not yet have a dedicated operational category or index for flash droughts, which the Maharashtra study's authors flag as a monitoring gap
The researchers' call for dedicated flash-drought monitoring is effectively a call to update or supplement the existing Drought Manual framework, since rapid-onset events can occur even when seasonal rainfall totals appear adequate.
Marathwada and the Rain-Shadow Geography of Semi-Arid Maharashtra
Several of the flagged high-risk districts (Beed, Dharashiv, and parts of Ahilyanagar and Solapur) lie in or near the Marathwada region, which sits in the rain-shadow zone east of the Sahyadri (Western Ghats) range.
Key Details
- The Sahyadri range intercepts the southwest monsoon on its windward (western/coastal) side, leaving the leeward Deccan Plateau interior, including Marathwada, comparatively rainfall-deficient
- Marathwada receives roughly 600-800 mm of annual rainfall against the semi-arid classification, and is historically drought-prone (recurring drought roughly every 6-10 years)
- Marathwada comprises eight districts (Chhatrapati Sambhajinagar/Aurangabad, Jalna, Parbhani, Hingoli, Nanded, Latur, Dharashiv/Osmanabad, Beed), several of which overlap with the study's high-risk list
- Sangli and Solapur, though technically in the Western Maharashtra/Desh region rather than Marathwada proper, share the same rain-shadow semi-arid character
The geographic clustering of flash-drought risk in these interior semi-arid districts is consistent with their structural rainfall deficit from the Sahyadri rain-shadow effect, which leaves less buffer moisture when a rapid dry spell hits.
- Study period: 44 years (1981-2024)
- High-risk districts identified: Ahilyanagar, Beed, Dharashiv, Sangli, Solapur
- Flash-drought intensification rate in hotspots: greater than 9% per eight-day period
- Non-monsoon flash-drought event duration in many districts: 20-25 days
- Non-monsoon flash-drought frequency in high-risk areas: 15-25+ events over the study period
- Monsoon-season flash-drought occurrence: fewer than two events across 44 years in most districts
- Marathwada's average annual rainfall: approximately 600-800 mm
- India's meteorological drought thresholds: moderate at 26-50% rainfall deficiency, severe above 50% (per the Manual for Drought Management)