Evaluation and Forecasting of Periodic Shoreline Changes Using Geoinformatics Application in the Severe Storm Surge Region of India

Abstract

The coastline is constantly prone to change as a consequence of natural processes and actions carried out by humans along coastal zones. These natural and human disturbances contribute to the erosion and accretion processes within the coastal environment and are responsible for shifting shorelines. To effectively manage coastal areas, it is necessary to determine how extensive the erosion is and identify the most vulnerable areas. This investigation uses ArcGIS's built-in DSAS toolbar to assess the shifting of the coastline along one of India's severe storm surge regions, i.e., the Krishna coastal tract in Andhra Pradesh State. The spatiotemporal shoreline dynamics on the Krishna coast were examined for the years 1990, 2000, 2010, and 2020. The research also intends to highlight the extent of coastline changes by predicting erosion and accretion in the study region for 2030 and 2040. The geoinformatics tools of the linear regression rate (LRR), net shoreline movement (NSM), and end point rate (EPR) were used in this study as statistical techniques. Based on EPR, the highest erosion was identified to be -26.5m/yr in Nagayalanka Mandal, while the highest accretion was calculated to be 18.75m/yr at Machilipatnam Mandal. Similarly, based on LRR, the maximum erosion rate was observed to be -28.1m/yr at Nagayalanka Mandal, while the highest accretion rate was estimated to be 18.71m/yr at Machilipatnam Mandal. According to NSM, between 1990 and 2020, the shoreline retreated by as much as -498.8 meters at Nagayalanka and advanced by 500.2 meters at Machillipatnam. In 2030, accretion will be greatest in Machillipatnam, at about 229 meters, while erosion will be greatest in Nagayalanka, at around 284 meters. Similarly, by 2040, erosion might cause Nagayalanka's shoreline to recede as much as 375 meters, with the greatest accretion again occurring at Machillipatnam, at around 318 meters. This study identified that the coastline of the Krishna district is extremely vulnerable to erosion and accretion. The results of this research will be extensively relied on by scientists, engineers, and administrators working in coastal regions to guide their plans for adopting sustainable coastal management.

Keywords: Shoreline change, Erosion and Accretion, Krishna Coast, DSAS, Statistical Analysis