Drone-Based Coastal Monitoring Under Harsh Monsoon Conditions: A Case Study of E-Fence at Pantai Batu Rakit

Abstract

Coastal monitoring is essential for understanding beach morphology changes, particularly in regions prone to seasonal storms. Monsoonal storms erode sandy beaches worldwide including Malaysia coast. This study evaluates the feasibility of using unmanned aerial vehicles (UAVs) for coastal monitoring under harsh monsoon conditions at Pantai Batu Rakit, Terengganu. UAV-derived beach profiles were validated against high-precision RTK-GPS measurements using root mean square error (RMSE) and the coefficient of determination (R²). Results demonstrated a strong correlation between UAV and RTK-GPS data, with RMSE values ranging from 0.093 to 0.103, confirming the accuracy of drone-based topographic surveys. The study also examined the role of sand-trapping E-Fences in mitigating coastal erosion through sediment accumulation and shoreline stabilization. Despite photogrammetric limitations near the waterline, UAV surveys proved to be a reliable, cost-effective, and efficient method for coastal assessment, even during extreme weather conditions. The ability to rapidly collect high-resolution data enhances long-term coastal management. Future research should explore integrating LiDAR-equipped UAVs and hybrid survey methods to improve data accuracy and nearshore terrain analysis.