Mangrove ecosystems as tsunami reducers on small islands in Bunaken National Park, North Sulawesi Province, Indonesia

Dewi Handayani; Joshian N.W. Schaduw; Lefrand Manoppo; Ping A. Angmalisang; Wilmy E. Pelle; Deiske A. Sumilat

doi:10.35800/jasm.v13i1.59467

Authors

Dewi Handayani Universitas Sam Ratulangi https://orcid.org/0000-0001-5523-067X
Joshian N.W. Schaduw https://orcid.org/0000-0003-2513-3179
Lefrand Manoppo https://orcid.org/0000-0002-9154-4470
Ping A. Angmalisang https://orcid.org/0009-0003-8878-1162
Wilmy E. Pelle
Deiske A. Sumilat https://orcid.org/0000-0001-9942-7001

DOI:

https://doi.org/10.35800/jasm.v13i1.59467

Keywords:

mangrove, tsunami, Bunaken National Park, disaster mitigation

Abstract

This research aims to analyse the role of mangrove ecosystems in reducing tsunami wave impacts on the small islands of Bunaken National Park. Numerical modelling was conducted to simulate tsunami wave propagation under different scenarios, including with and without mangroves, using data on tree density, mangrove width, and coastal bathymetry. Spearman correlation analysis was applied to evaluate the relationship between mangrove density and width with the percentage of tsunami height reduction. Results revealed there was a strong positive correlation between mangrove density (r = 0.79, P = 0.00036) and mangrove width (r = 0.87, P = 0.00045) with tsunami height reduction, indicating that denser and wider mangroves result in greater wave attenuation. The modelling also highlighted the influence of coastal bathymetry and land topography on mangrove effectiveness, where steeper coasts produced lower tsunami heights compared to flatter areas. In conclusion, mangrove ecosystems play a critical role in mitigating tsunami impacts and should be prioritised in coastal conservation strategies to enhance disaster resilience and protect vulnerable coastal communities.

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