Assam Floods: How Climate Change, River Erosion and Human Activity Fuel the Crisis

Staff Reporter

GUWAHATI: Assam's flood crisis is becoming increasingly complex, driven by the amount of rainfall, a combination of more intense rainfall, Himalayan warming, changing river dynamics, accelerated erosion, and expanding human settlements in flood-prone areas. Together, these interacting factors are making floods more frequent, harder to predict and increasingly destructive, said climatologists.

Mahesh Palawat, vice president of Meteorology and Climate Change, Skymet Weather, said, "There is no denying the fact that the increasing rainfall variability and shifting monsoon behaviour continue to amplify floods' unpredictability. Despite the decline in the mean rainfall, the rise in temperature over the surface and ocean on account of climate change has altered the weather pattern over Assam. This not only includes high-intensity rainfall but also glacial and snowmelt, deforestation triggering landslides and mudslides, and urbanisation."

A study on floods in Assam said, "Despite technological progress in flood forecasting and early warning systems, their effectiveness remains constrained by sparse observations, inadequate data sharing, and limited transboundary coordination."

The Assam State Action Plan on Climate Change (2021-2030) has projected a 5-38 per cent increase in extreme rainfall events and more than a 25 per cent rise in flood events under future climate scenarios. In addition, climate models project that increasing precipitation and temperature could lead to a 13 per cent increase in the Brahmaputra's annual stream flow, while sediment loads may rise by nearly 40 per cent by the end of the century, intensifying riverbank erosion and flood hazards across the state. Besides this, human interventions such as deforestation, urbanisation and unplanned land use changes further exacerbate flood vulnerability by increasing runoff and reducing natural water retention.

Dr Akshay Deoras, a research scientist at the Natural Centre for Atmospheric Science, UK, said, "We have been witnessing sharp intra-seasonal variations in the rainfall patterns: either the rainfall is very intense, or break monsoon periods are quite long, triggering extreme weather events. This is a direct impact of global warming. Most parts of East and Northeast India, including Assam, have been rainfall deficient so far in the monsoon. However, Assam is battling the worst flooding in the decade. It's high time we prepared for the monsoon, keeping in mind these changes in the rainfall pattern and not just the amount of rainfall. "                          

The Assam government considers floods an economic crisis and not a seasonal disaster. A report of the state government said, "On average, floods inundate 9.31 hectares of land every year, damaging crops, roads, bridges, schools, health facilities and public infrastructures. The economic survey of Assam for 2025-26 estimates average annual flood losses of around Rs 200 crore. Beyond direct damage, recurrent flooding disrupts agriculture, tea plantations, fisheries, transport and livelihood, while riverbank erosion permanently removes productive lands from cultivation."

Experts emphasise that understanding the Brahmaputra is essential to grasp Assam's flood narrative. This transboundary river system flows through China, Bhutan, India and Bangladesh, affecting millions of people annually due to recurrent and severe flooding. The World Bank has identified the Brahmaputra basin as one of the river basins with the highest projected increases in extreme flooding, noting that 36 per cent of the basin's drainage area in India lies within Assam.

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