Revealing Coastal Dynamics off Visakhapatnam, coastal Andhra Pradesh, India
Bheemunipatnam is a coastal town located in the Indian state of Andhra Pradesh, popularly known as Bheemili. It is situated near Visakhapatnam, which is around 46 km away and is known for its picturesque beaches, historical significance and cultural heritage. The Gosthani River, originates in the Ananthagiri Hills of the Eastern Ghats and flows eastward, eventually drains into the Bay of Bengal near Bheemili coast. The Gosthani River and its associated watershed contribute to the freshwater supply, support agriculture and influences the local ecosystem. The river’s flow and sediment transport can have implications for coastal processes, including sediment deposition and erosion along the Bheemili coast. The Visakhapatnam field site was selected just south of Divis Bridge (marine outfall), in a region where no fishing activity occurs due to the release of pollutants in the water.
Prior to the Visakhapatnam SWOT Cal/Val campaign, the understanding of coastal dynamics was fragmented, with limited data and anecdotal observations. While surface currents and some information existed, a comprehensive understanding of the water level and subsurface conditions remained elusive. Some studies in this region have revealed the presence of Internal waves.
A significant knowledge gap existed in the understanding of water level variations and subsurface dynamics in the coastal waters. The interaction between local oceanographic features and the broader coastal environment in this region was insufficiently characterized. There were no periodic measurements or permanent gauges available at the site to monitor water level changes.
The broader goal of the Visakhapatnam campaign is to understand how the coastal processes are being controlled and contribute to hydrodynamics of the coastal ocean.
A campaign was carried out for 15 days by deploying Directional Wave and Tide Recorder (DWTR) at around 30 m depth. This instrument can measure various parameters like water level, waves, turbidity, salinity, temperature of the water etc. The data can be utilized to model the coastal processes and to understand how the processes are related to each other. The data sampling was set to 10-min interval (high frequency) ensuring the comprehensive coverage of diurnal and tidal variations synchronous to the SWOT measurements.
The research conducted during the Visakhapatnam SWOT Cal/Val expedition holds global significance by enhancing our comprehension of coastal dynamics. The data collected reveal intricate water level variations and their interplay with broader oceanographic processes. This knowledge is essential for informed coastal management, resource sustainability, and the protection of coastal ecosystems worldwide.
Principal Investigators: Praveen K Gupta (pkgupta@sac.isro.gov.in), Neeraj Agrawal (neeraj@sac.isro.gov.in), Surisetty V V Arun Kumar (arunkumar@sac.isro.gov.in).
Institutes involved in the campaigns: Space Applications Centre (SAC-ISRO, Ahmedabad), Department of Meteorology and Oceanography (Andhra University, Visakhapatnam).
Contact point for the study site: Praveen K Gupta (pkgupta@sac.isro.gov.in).