GUWAHATI Human factors, and not necessarily climate change, worsened the floods in a part of eastern Assam that killed at least 103 people , a global collaborative study has said.
“Although limited datasets for the region mean there is some uncertainty, the analysis showed no clear evidence that climate change was altering the trend in the intensity or likelihood of the rainfall. The study found that unplanned urbanisation, rapid deforestation, wetland destruction, and riverbank erosion degraded Assam’s natural drainage capacity, increasing flood height and downstream impacts. The study also flagged historical vulnerability. “Historical land reallocation contributed to some indigenous communities living on marginal, flood-prone riverbanks, and sandbars (chars).
Instead, they found that the scale of the disaster stems largely from other human factors including colonial-era land regulations, displacement, land degradation, and a lack of sufficient flood mitigation,” the WWA study said on Friday (August 14, 2026).
The scientists said reliance on concrete engineering and hard embankments trapped silt, artificially raising riverbeds and blocking natural runoff. “Embankments frequently exacerbate flooding and increase the risk of catastrophic breaches,” they noted, observing that combining infrastructure with social and nature-based approaches could be more effective in mitigating floods. These historical patterns continue to trap low-income agricultural populations in cycles of repeated displacement,” it said. “Adaptation efforts must broaden to include floodplain restoration, wetland conservation, and expanded anticipatory disaster risk management using localised early warnings,” the study suggested. “To understand whether climate change played a role in the rainfall in the Upper (eastern) Assam region and the surrounding hill catchments that led to the landslides and flooding, we analysed short, high-intensity downpours, and longer rainfall accumulations,” Mariam Zachariah, a research associate in extreme weather and climate change at the Centre for Environmental Policy, Imperial College London, said.
Scientists from India, Sweden, the Netherlands, the United Kingdom, and the United States analysed historical weather records and climate models, finding that the rainfall totals were not exceptional and are expected at least every two years.
