Examining Coastal Alterations in the Godavari Delta Region using DSAS, Remote Sensing and GIS Techniques

Abstract

Abstract This research focuses on the Godavari delta coastline, extending from Upputeru Creek to Uppada Village in Andhra Pradesh, India. Spanning from 1977 to 2023, the study meticulously examines multi-temporal remote sensing datasets from 1977, 1988, 1992, 2001, 2016, and 2023. To establish an accurate shoreline configuration, this study employs image processing techniques leveraging algorithms such as the Land Surface Water Index (LSWI) and the Normalized Difference Vegetation Index (NDVI). For computing erosion and accretion rates within the GIS environment, the Digital Shoreline Analysis System (DSAS) is utilized, employing 100-meter transect intervals and techniques including Linear Regression Rate (LRR), Endpoint Rate (EPR), and Weighted Linear Regression (WLR). The analysis delineates distinct zones in the Godavari delta coastal region, classifying them into areas of high erosion, low erosion, stable coastlines, and varying degrees of accretion. Significant erosion is identified in regions from the left bank of Vashista to Parupalem Beach and between the Vainateya River Mouth and Gowthami River Mouth. Meanwhile, areas of low erosion extend from the right bank of Vashista River Mouth to Anthervedi Beach, with stable coastlines identified from Kakinada to Uppada Beach and Upputeru Creek to Perrupalem Beach. Additionally, the study pinpoints high accretion along Kakinada Spit and relatively lower accretion along other shoreline segments. This comprehensive assessment yields critical insights into erosion and accretion dynamics, laying a foundation for informed coastal management strategies in the Godavari delta region.