Diurnal Cycle of Land–Sea Breeze and Coastal Abrasion in Bengkulu Region

Abstract

This study examines the diurnal cycle of land–sea breeze and its association with micro-scale coastal abrasion along the Bengkulu coast from 2020 to 2025. Hourly wind data were analyzed to characterize the zonal and meridional components, as well as divergence patterns, revealing persistent diurnal wind reversals and spatially coherent circulation features. Concurrently, shoreline change was quantified across 163 transects using the Linear Regression Rate (LRR), End Point Rate (EPR), Net Shoreline Movement (NSM), and Weighted Shoreline Evolution (WSE) metrics, identifying locations prone to abrasion and accretion. The results show shoreline change analysis in the Digital Shoreline Analysis System (DSAS) identifies localized segments (transects 41–44) with significant negative rates, indicating persistent abrasion. Atmospheric analysis reveals a robust diurnal cycle, with nighttime land-breeze divergence over coastal land and convergence offshore, reversed during the daytime by sea-breeze convergence over land and offshore divergence. This cycle persists year-round, while seasonal monsoon winds modulate zonal and meridional components. The spatial correspondence between high abrasion zones and strong diurnal wind convergence suggests a potential physical linkage whereby repeated atmospheric forcing may influence nearshore wave energy and sediment transport. Integrating DSAS-derived shoreline trends with diurnal circulation analysis provides a physically grounded framework for assessing coastal vulnerability and informing management strategies in tropical coastal environments.