Numerical and Spatial Assessment of Coastal Vegetation and Topographic Elevation for Tsunami Mitigation in Southern Java

This study presents a numerical and spatial assessment of tsunami mitigation strategies using CADMAS-SURF 2D and ArcGIS. Two scenarios are evaluated: coastal vegetation belts and topographic elevation management. Simulation results show that vegetation buffers reduce wave velocity and run-up through frictional resistance, while elevated landforms act as physical barriers to wave propagation. Spatial analysis identifies high-risk zones and supports evacuation planning. The findings highlight the potential of hybrid mitigation strategies combining nature-based and structural approaches to enhance coastal resilience in tsunami-prone regions. Numerical simulation with vegetation belts in scenario #1 was able to reduce waves from 6 meters to 2 m, while with ditch formation in scenario #2 it was able to reduce waves to only about 0.5 meters at measurement point X3 (600 m). The results of GIS analysis of the coastal areas of Banyuwangi city that are vulnerable to tsunami impacts based on numerical simulations are 4.68 km2 (22.50%) in the red zone and 9.02 km2 (43.35%) in the yellow zone or at moderate risk. • Coastal vegetation buffers reduce tsunami wave velocity and run-up through frictional resistance. • Elevated landforms act as physical barriers, dissipating tsunami energy effectively. • CADMAS-SURF 2D simulations confirm the hybrid mitigation potential of vegetation and elevation. • ArcGIS-based spatial analysis identifies high-risk zones and supports evacuation planning. • The study offers a replicable model for nature-based and structural tsunami mitigation in subduction-prone regions.