New study paints worrying climate picture of Maharashtra; rising temperatures can now trigger and amplify droughts even during the monsoon
A climatology study published in the International Journal of Climatology analysed Compound Drought and Heatwave (CDHW) events across Maharashtra's districts from 1960 to 2025
The study, involving researchers from MANIT Bhopal's Hydro-climatology Lab, found 1990 as a turning point after which the frequency and severity of compound drought-heatwave events intensified sharply
Post-1990, eastern districts such as Gondia and Yavatmal recorded over 25 such events, compared to fewer than 15 in western/coastal districts (Thane, Nashik, Raigad) in the pre-1990 period
The most significant finding is that rising temperatures alone can now trigger and amplify droughts during the monsoon season, not only during traditional pre-monsoon summer months — monsoon-season events now exceed 25-35 occurrences in most districts, with Raigad and Thane crossing 35
Nashik, Yavatmal, Amravati and Jalgaon were identified as recurrent hotspots, with compound events recurring at intervals of under 8 months in some cases
Compound Drought and Heatwave (CDHW) Events
A compound event, as defined in IPCC AR6 (Working Group I, Chapter 11), occurs when multiple climate drivers or hazards combine to produce impacts more severe than either hazard would cause in isolation. A compound drought-heatwave event is the simultaneous or closely sequential occurrence of below-normal soil moisture/rainfall and above-normal temperature, which reinforce each other through a land-atmosphere feedback loop: dry soil reduces evaporative cooling, which raises surface temperature, which further dries the soil.
Key Details
- IPCC AR6 (2021) formally recognised compound extremes as a distinct category of climate risk requiring dedicated assessment, separate from single-hazard events
- Compound heat-drought events are associated with disproportionately higher agricultural yield losses, water stress and wildfire risk than either hazard alone
- Anthropogenic climate change has been linked in recent research to a doubling of compound drought-heatwave frequency in low- and middle-income regions
- Distinguished from meteorological drought (rainfall deficit), hydrological drought (reduced streamflow/groundwater) and agricultural drought (soil moisture deficit affecting crops) — a CDHW event can now emerge even without a meteorological drought, driven purely by heat
The Maharashtra study's core finding — that rising temperature alone can trigger monsoon-season drought stress even when rainfall is not deficient — is a direct real-world manifestation of the CDHW mechanism the IPCC has flagged as an emerging global risk.
Rain Shadow Effect and Maharashtra's Drought Geography
The Western Ghats (Sahyadri range) intercept moisture-laden monsoon winds from the Arabian Sea, causing heavy rainfall on the windward (western) side and creating a rain shadow of low rainfall on the leeward (eastern) side — the Marathwada and parts of Vidarbha regions of Maharashtra.
Key Details
- Marathwada receives only about 600-800 mm of annual rainfall against the state's coastal Konkan belt, which receives over 2,500-3,000 mm
- The rain shadow effect is a physical geography concept: as air rises over the windward slope it cools and precipitates; on descending the leeward slope it warms and dries, suppressing rainfall
- Marathwada has historically been classified among India's most drought-prone regions, with recurring water scarcity, groundwater depletion and agrarian distress
- The study's finding of a post-1990 eastward shift in high-frequency CDHW events (Gondia, Yavatmal) reflects the pre-existing structural rainfall deficit of Maharashtra's eastern and interior districts, now compounded by rising temperatures
The districts flagged as new CDHW hotspots (Nashik, Yavatmal, Amravati, Jalgaon) lie substantially within or adjacent to Maharashtra's traditional rain-shadow and drought-prone belt, indicating that climate warming is intensifying an existing structural vulnerability rather than creating an entirely new one.
India's Drought and Heatwave Management Framework
Drought management in India falls under the National Disaster Management Authority (NDMA) framework, with the India Meteorological Department (IMD) responsible for heatwave declaration and monsoon monitoring, and state governments implementing Heat Action Plans.
Key Details
- NDMA's Drought Management Manual classifies drought severity using indicators such as rainfall deviation, soil moisture, and vegetation indices (NDVI)
- IMD declares a heatwave when maximum temperature departs from normal by 4.5-6.4°C (for plains, threshold ≥40°C) or when actual temperature crosses 45°C; a "severe heatwave" applies stricter departure/threshold criteria
- Ahmedabad's Heat Action Plan (2013) was India's first city-level heat action plan and is now a template replicated by other states, including parts of Maharashtra
- India's Third National Communication and updated NDC under the UNFCCC recognise increasing compound climate extremes as a national adaptation priority
Findings like this Maharashtra study feed directly into IMD/NDMA risk assessments and state-level Heat Action Plan revisions, since compound monsoon-season heat-drought stress falls outside the assumptions of older drought-management frameworks built around pre-monsoon heatwaves and post-monsoon rainfall deficits.
- Study period analysed: 1960-2025 (65 years), published in the International Journal of Climatology
- Turning point identified: 1990, after which CDHW frequency and severity rose sharply
- Post-1990 eastern district events: Gondia and Yavatmal exceeded 25 CDHW events
- Pre-1990 western/coastal district events: Thane, Nashik, Raigad recorded fewer than 15 events
- Monsoon-season CDHW frequency (post-1990): 25-35+ events in most districts; Raigad and Thane exceeded 35
- Hotspot districts with recurrence under 8 months: Nashik, Yavatmal, Amravati, Jalgaon
- Marathwada annual rainfall: approximately 600-800 mm, against Konkan's 2,500-3,000+ mm