Quantitative assessment of present and the future potential threat of coastal erosion along the Odisha coast using geospatial tools and statistical techniques

The eastern coast of India is one of the regions where most of the population resides in urban areas in the low-elevation coastal zone, making it vulnerable to frequent extreme weather events. The objectives of this study are to assess the short-to long-term shoreline changes of the Odisha coast, to understand how anthropogenic influences, and particu-larly extreme natural events, affect these changes, and to predict shoreline changes for 2050. This study utilized multi-temporal/spectral/spatial resolution satellite images and a digital shoreline analysis (DSAS) tool to appraise the short-(at five/six-year intervals) and long-term (1990-2019) shoreline dynamics along the coastal part of Odisha over the past three decades (1990-2019). The long-term shoreline analysis shows that the mean shoreline change is about 0.67 m/year and highlights that 52.47 %(227.4 km), 34.70 %(150.4 km), and 12.83 %(55.6 km) of the total Odisha coastline exhibit erosion, accretion, and stability, respectively. During the short-term analysis, the 2000-2005 period had the highest percentage of erosion (64.27 %), followed by the 2005-2010 period with an ero-sional trend of 59.06 %. The 1995-2000 period showed an accretion trend, whereas, during the last period, i.e., 2015-2019, the percentage of transects depicting erosion and accretion was almost similar. In 2050, 55.85 % of the transects are expected to show accretion, while 44.15 % would show erosion or a constant trend. The study iden-tified the hotspots of coastal erosion along delineated study zones by synthesizing data from previous studies as well.

Automated summary

This study aimed to assess the short-to long-term shoreline changes of the Odisha coast and predict shoreline changes for 2050. It utilized satellite images and a digital shoreline analysis tool to evaluate the shoreline dynamics over the past three decades. The analysis showed that the coastline experienced erosion, accretion, and stability, with a predicted increase in accretion by 2050.