IIT-Kanpur, Namami Gange tap 5 decades of satellite data to map Ganga’s transformation

The Corona images capture the Ganga in an almost untouched form, while the 2019 images reveal the changing reality — where barrages, embankments, and urban sprawl have restricted the river’s meandering pace. Scientists now have concrete maps that indicate areas where restoration could help the Ganga regain its old rhythm and where improved land use could enhance its health.

This NMCG project is not only creating a scientific record of changes in the river’s geomorphology but is also highlighting, through a comparative study of Land Use and Land Cover (LULC), how encroachment, rapid urban expansion, and agricultural growth are impacting the river’s natural balance. Based on these findings, an advanced Web-GIS library is being developed, which will be directly used in future policies, river management strategies and restoration plans.

As a step forward, NMCG would be hosting the Corona and LULC data on an interactive user interface and the Google Earth Engine application, allowing both analysis and planning to be done on the same platform. The project will also prepare special digital displays for nine major windows — Haridwar, Bijnor, Narora, Kanpur, Allahabad, Varanasi, Patna, Bhagalpur, and Farakka — which will play a vital role in decision-making from local to national levels.

To create a scientific health map of the Ganga, several decisive steps are being undertaken in the new project. First, the entire Ganga basin’s boundaries will be delineated and accurately mapped using the Corona imagery. Comparing images from 1965-75 with the present-day landscape will provide a clear visualization of land use and geomorphic changes. All data will be organised into a Web-GIS module with an advanced query system, enabling researchers and planners to instantly access the specific data they need. A system for public dissemination of data would facilitate its use in future research on Ganga across the diverse stakeholders.

According to IIT Kanpur scientists, this development marks the beginning of a new era of “data-driven” planning in Ganga conservation. Technical challenges remain, but the research team is continually refining its methodology — with each step toward greater accuracy and faster processing bringing the picture of the Ganga’s future into sharper focus.