Authors : Pubudu Karunarathna

Volume/Issue : Volume 11 - 2026, Issue 4 - April

Google Scholar : https://tinyurl.com/4tjhj6nh

Scribd : https://tinyurl.com/muxn4dn8

DOI : https://doi.org/10.38124/ijisrt/26apr128

Note : A published paper may take 4-5 working days from the publication date to appear in PlumX Metrics, Semantic Scholar, and ResearchGate.

Abstract : Sandy beaches face a significant threat due to coastal erosion worldwide. Artificial beach nourishment has become an emerging approach to overcoming this threat. However, empirical assessments of nourishment effectiveness, particularly in data scarce regions, are essential for evidence based coastal management. This study assesses the impact of the artificial beach nourishment conducted in 2017 to 2020 in the Calido Beach area of Kalutara, Sri Lanka, in mitigating shoreline erosion. A multi decadal shoreline change analysis was conducted using Landsat 5, 7, and 8 imagery (1992 - 2017) and Sentinel 2 imagery (2021 -2024). The Modified Normalized Difference Water Index (MNDWI) was used for shoreline extraction and shoreline change rates were calculated using the Digital Shoreline Analysis System (DSAS). Results indicate a marked transformation in shoreline behavior following nourishment. Pre nourishment, 36.65% of transects exhibited erosion with an average End Point Rate (EPR) of -1.18 m/yr, while 63.35% showed accretion averaging 2.21 m/yr. Post nourishment, erosional transects declined to just 9.77% (average -0.89 m/yr), while accretional transects increased to 90.23% (average 6.74 m/yr). The overall average EPR increased from 0.96 ± 0.07 m/yr to 6.00 ± 2.83 m/yr, and the Shoreline Change Envelope (SCE) decreased from 60.10 m to 20.87 m, indicating enhanced shoreline stability. The findings demonstrate that the artificial beach nourishment at Calido Beach has been highly effective in reversing historical erosion trends and promoting sustained accretion. This study provides critical empirical evidence for coastal managers in Sri Lanka and the broader South Asian region, highlighting the utility of remote sensing and DSAS based monitoring for evaluating coastal interventions. Long term monitoring is recommended to assess nourishment longevity and inform adaptive management strategies.

Keywords : Artificial Beach Nourishment, Shoreline Change, DSAS, MNDWI, Coastal Erosion

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