VISAKHAPATNAM: Visakhapatnam is projected to see a clear rise in sea levels by the end of the century, with a new scientific study estimating an increase of 41 cm under a low-emissions scenario (SSP1-2.6), 70 cm under a middle-emissions (SSP2-4.5), and up to 98 cm under a high-emissions (SSP5-8.5) for the period 2091-2100.
These findings come from a recently published study titled “Recent Past and Future Projection of Sea Level: A Case Study of Puri, Chennai, and Visakhapatnam,” authored by researchers Vijay K Kannaujiya, Abhishek K Rai and Sukanta Malakar. The study uses satellite altimetry, tide-gauge records, and climate model projections under CMIP6 to examine both past sea-level trends, and future scenarios.
The study warns that the city’s vulnerability is also likely to increase, driven by its expanding urban footprint, port-related infrastructure, and the exposure of low-lying coastal zones that are already sensitive to flooding and erosion.
The assessment also reports projections for two other Bay of Bengal cities. By 2091-2100, sea levels in Puri could rise by 40 cm under a low-emissions pathway, 67 cm under a middle-emissions, and up to 95 cm under a high-emissions, while Chennai may record an increase between 42 cm, 72 cm and 100 cm.
For Visakhapatnam, the researchers report a historical rise of about 4.96 mm per year between 1995 and 2020. This places Visakhapatnam between Chennai and Puri in the rate of increase, with Chennai showing the highest trend at around 5.2 mm per year, followed by Visakhapatnam, and Puri at about 4.6 mm per year.
The rise became more noticeable after 2010, with several peaks close to 0.1 metres.
While tide-gauge data recorded at fixed points show slightly lower values, satellite observations covering a larger coastal area point to a steady upward trend. The study also finds mostly positive sea-level trends along the Visakhapatnam coast, especially in central and southern stretches, though a small negative pocket appears in the far north.
The authors link the rising sea levels to both global and regional factors. These include ocean warming, which causes water to expand, melting glaciers and ice sheets, changes in Bay of Bengal currents, and shifts in salinity.
Local influences, such as land subsidence linked to groundwater extraction, and port-related development, may also contribute to relative sea-level change in some parts of the city.
Looking ahead, the study’s Dynamic Vulnerability Index suggests that Visakhapatnam’s vulnerability will continue to rise across all emissions scenarios from 2021-2030 through 2091-2100. Although Chennai shows the sharpest increase overall, Visakhapatnam’s projected rise remains important because of its dense coastal settlements, concentration of industries and the strategic role of its port.
The authors note that higher late-century sea levels could lead to more frequent flooding, shoreline erosion, and stress on port and industrial facilities. They recommend strengthening early-warning systems, improving drainage, guiding new development away from exposed areas, and investing in long-term coastal planning.