ROOPAK GOSWAMI
Shillong, Sept 20: Meghalaya’s reputation as one of the world’s wettest regions may not shield it from a growing drought risk.
A new study has found that changing rainfall patterns, fewer rainy days and rising temperatures could increase the state’s vulnerability to drought—even as parts of Meghalaya continue to receive some of the heaviest rainfall in the world.
The study, “When more rain means more drought: hydroclimatic drivers of increasing drought risk in the world’s wettest region,” by Ashesh Rudra Paul of IIT Kharagpur and Pankaj Kumar Roy of Jadavpur University, examines historical climate data and future climate projections for Meghalaya and adjoining areas of Bangladesh. It was published online in April 2026 in Theoretical and Applied Climatology.
The researchers point to a rainfall-drought paradox: more rain does not necessarily mean more water remains available for use.
Heavier rain, fewer rainy days
The study found a significant increase in rainfall intensity, with the locally observed maximum trend in the Simple Daily Intensity Index reaching 0.08 mm per day per year.
At the same time, light rainfall events—defined in the study as rainfall below 10 mm a day—are projected to decline. The number of rainy days is also projected to fall, with an average decline of 0.40 days a year.
In other words, rainfall is increasingly being concentrated into fewer, heavier events.
That matters in Meghalaya, where steep slopes can send intense rainfall rapidly downhill. Large volumes of water can run off before they have time to infiltrate the soil and contribute to groundwater recharge.
The paradox is not simply about heavier rain. The researchers point to fewer rainy days, declining light rainfall, longer dry intervals and rising temperature-driven evaporative demand as factors that could leave less water available between rainfall events.
The result could be too much water during intense downpours, followed by reduced availability during dry periods.
Warming adds to the pressure
The researchers also found rising trends in both maximum and minimum temperatures, with minimum temperatures increasing by as much as 0.08°C per year.
Higher temperatures increase atmospheric evaporative demand, resulting in greater water loss from soil and vegetation through evapotranspiration. This can speed up the depletion of soil moisture when rainfall is absent.
To assess the combined effect of rainfall and temperature on moisture conditions, the researchers used the Standardised Precipitation Evapotranspiration Index (SPEI) over three months.
The study projects more frequent and intense drought events, particularly under the high-emissions SSP585 scenario.
Extreme drought events are also projected to become more common. Their baseline annual occurrence was estimated at 0.282, rising to as high as 0.61 in the far-future period under SSP585.
River flows may also decline
The researchers also examined what these climate changes could mean for river flows.
Using the HEC-HMS hydrological model, they simulated future streamflow in the Sari-Gowain and Surma-Meghna river basins, which are connected to Meghalaya’s hill catchments.
The modelling points to declining mean annual streamflow in both basins, particularly towards the end of the century under SSP585.
For the Sari-Gowain catchment, the projected maximum decline is 9.8% in the far future under SSP585. For the Surma-Meghna basin, the decline reaches 11.6%.
The two analyses address different parts of the water cycle. SPEI-3 measures seasonal climatic moisture deficits, while the HEC-HMS modelling looks at how changing climate conditions could affect river discharge.
The river systems are strongly seasonal, with streamflow peaking around June-July before falling through the post-monsoon and dry-season months. The researchers say this could increase the potential for hydrological drought later in the year.
Why Meghalaya is vulnerable
Meghalaya’s terrain is an important part of the picture.
Steep slopes encourage rapid runoff during intense rainfall. Instead of gradually entering the soil and contributing to groundwater recharge and base flow, a larger share of the water can leave the landscape quickly.
This could mean more flash flooding during intense rainfall while leaving less water available during subsequent dry spells.
The researchers caution that their modelling does not explicitly account for several human factors, including land-use change, deforestation, urban expansion and groundwater extraction. These could also affect future water availability.
Rethinking what a “wet” Meghalaya means
The findings challenge the assumption that high annual rainfall automatically protects a region from drought.
The study does not suggest that Meghalaya is becoming a dry region. Instead, it points to a change in the way rainfall is distributed—and the implications this could have for soil moisture, groundwater, ecosystems and rivers.
For a state whose water cycle is heavily dependent on the monsoon, the changing relationship between rainfall, temperature, runoff and groundwater recharge could become an important consideration for water-resource planning.
The question for Meghalaya may therefore be not just how much rain falls, but how much of that water stays in the landscape long enough to be useful.
