A new study has found that the Ganges-Brahmaputra, Brahmani and Mahanadi deltas are sinking faster than the regional sea level is rising, with Calcutta experiencing land subsidence at rates equal to or exceeding the regional average. Scientists say their analysis suggests that the land subsidence dominates even when compared to future worst-case scenarios of sea level rise, implying that for millions of coastal city residents, the immediate threat is not just sea level rise but their sinking ground. “But we also noticed some encouraging signals — aggressive and large-scale recharge of groundwater can help slow down the land subsidence,” Chaudhary, who was not associated with the global deltas study, told The Telegraph. Between 2017 and 2021, the Indian study found that subsidence rates decreased by 2mm to 3mm specifically in areas with large-scale groundwater recharge measures. Besides flooding, Chaudhary said, long-term high subsidence rates could also put structures such as buildings and other infrastructure at an enhanced risk of damage.

Source: The Telegraph January 15, 2026 01:39 UTC