Analyzing shoreline dynamicity and the associated socioecological risk along the Southern Odisha Coast of India using remote sensing-based and statistical approaches

The coastal zone is an extremely volatile environment and is constantly changing. We assessed short- and long-term shoreline changes in the Ganjam district of Odisha on the eastern coast of India from 1990 to 2019 using Landsat satellite imagery and the Digital Shoreline Analysis System (DSAS) tool in a geographic information system. In addition, we have also projected the likely future coastline position for the 2030-2040 period and the possible impact on the socioecology of the shoreline. In this study, we used the endpoint rate (EPR) analysis, weighted linear regression (WLR) analysis, and trigonometric functions to analyze the shoreline from 1990 to 2019 and also forecasted for year 2030 and 2040. The shoreline of the Ganjam coastal zone is one of the most biologically productive ecosystems in the world, and it is well-known due to the breeding and mass nesting grounds of olive ridley turtles and the economically connected ports, famous beaches, and cyclone-prone areas. During the study period (1990-2019), the average erosion and accretion rates in the Ganjam shoreline were -2.58 m/year and 11.63 m/year, respectively. The rate of shoreline erosion increased during years of cyclone landfall, which was revealed during the short-term shoreline analysis of the periods from 1995 to 2000 (1999 super cyclone) and 2015 to 2019 (2019 category - IV cyclone Fani). The short- to long-term analyses of the shoreline assisted in identifying erosion (Ramyapatna, Podampetta) and accretion (southern part of Gopalpur port, spits along the Bahuda and Rushikulya Rivers) hotspots within the Ganjam coastal zone. The identified erosion hotspots could submerge a significant number of coastal villages that serve as breeding and mass nesting grounds for olive ridley turtles. The dominant erosion along the Ganjam coastline are likely to enhance socioecological risk and further threaten coastal communities in the future. The output of the undertaken research will benefit coastal planners, policymakers, and conservationists by helping them to formulate the most suitable action plan for coastal zone management with consideration of all stakeholders.

Automated summary

The study assessed short- and long-term shoreline changes in Ganjam district of Odisha on the eastern coast of India from 1990 to 2019 using Landsat satellite imagery and DSAS tool. Future coastline positions for 2030-2040 were also projected, with a focus on potential impacts on socioecology. Analysis revealed increasing erosion rates during cyclone landfall years, with identified erosion and accretion hotspots indicating potential threats to coastal communities and biodiversity.