Risk assessment of future beach erosion along the eastern coast of the Korean peninsula

다국어 초록 (Multilingual Abstract)

This study develops an integrated coastal risk assessment framework to quantify future shoreline vulnerability along the eastern coast of the Korean Peninsula by combining long term sea level rise (SLR) driven retreat, wave climate induced deformation, and short term storm erosion. Future wave climate projections (2075–2099) indicate systematic intensification of mean and extreme significant wave heights, accompanied by directional concentration of energetic waves. These wave height changes increase offshore wave energy flux and amplify event scale erosion, leading to greater short term retreat (DSLP) and substantial shifts in the deformation based CHA and Damage Curves. In contrast, SLR under SSP2-4.5 and SSP5-8.5 produces a persistent long term landward translation of the shoreline, elevating baseline erosion exposure through profile adjustment processes. The distinction between these two drivers demonstrates that wave height intensification primarily governs high frequency hazard escalation, whereas SLR dictates the cumulative background retreat that elevates all risk categories simultaneously. The CHA Curve and Damage Risk Curve reveal strong spatial contrasts across the ten study beaches. The largest projected increases are observed at Chilpo (CHA: 29.6 to 47.4 m; Risk: 12.4 to 27.1 m²), Jeongja (24.4 to 48 m; 6.6 to 21.9 m²), and Wonpyeong (31.6 to 44 m; 10.3 to 28 m²), where combined SLR driven retreat and wave height intensification produce pronounced nonlinear amplification of exposure. Sites such as Hujeong and Deungmyeong also exhibit substantial growth in CHA under SSP5-8.5, reflecting high sensitivity to future storm events. Under the high emission scenario, nearly all beaches transition into higher risk classes, indicating the critical dependence of late century hazards on wave climate intensification and accelerated SLR. Coastline positions extracted using CoastSAT allowed quantitative validation of short term erosion estimates derived from the Duration Limited Shoreline Position (DSLP) model. Error statistics show strong agreement between satellite derived shoreline variability and modeled erosion at most study sites (±2–3 m), confirming the physical consistency of DSLP for reflective microtidal environments such as the eastern Korean coast. This framework provides a transferable methodology for climate informed shoreline management and supports targeted adaptation in highly vulnerable sections of the Korean coastline.

다국어 초록 (Multilingual Abstract)

This study develops an integrated coastal risk assessment framework to quantify future shoreline vulnerability along the eastern coast of the Korean Peninsula by combining long term sea level rise (SLR) driven retreat, wave climate induced deformation, and short term storm erosion. Future wave climate projections (2075–2099) indicate systematic intensification of mean and extreme significant wave heights, accompanied by directional concentration of energetic waves. These wave height changes increase offshore wave energy flux and amplify event scale erosion, leading to greater short term retreat (DSLP) and substantial shifts in the deformation based CHA and Damage Curves. In contrast, SLR under SSP2-4.5 and SSP5-8.5 produces a persistent long term landward translation of the shoreline, elevating baseline erosion exposure through profile adjustment processes. The distinction between these two drivers demonstrates that wave height intensification primarily governs high frequency hazard escalation, whereas SLR dictates the cumulative background retreat that elevates all risk categories simultaneously. The CHA Curve and Damage Risk Curve reveal strong spatial contrasts across the ten study beaches. The largest projected increases are observed at Chilpo (CHA: 29.6 to 47.4 m; Risk: 12.4 to 27.1 m²), Jeongja (24.4 to 48 m; 6.6 to 21.9 m²), and Wonpyeong (31.6 to 44 m; 10.3 to 28 m²), where combined SLR driven retreat and wave height intensification produce pronounced nonlinear amplification of exposure. Sites such as Hujeong and Deungmyeong also exhibit substantial growth in CHA under SSP5-8.5, reflecting high sensitivity to future storm events. Under the high emission scenario, nearly all beaches transition into higher risk classes, indicating the critical dependence of late century hazards on wave climate intensification and accelerated SLR. Coastline positions extracted using CoastSAT allowed quantitative validation of short term erosion estimates derived from the Duration Limited Shoreline Position (DSLP) model. Error statistics show strong agreement between satellite derived shoreline variability and modeled erosion at most study sites (±2–3 m), confirming the physical consistency of DSLP for reflective microtidal environments such as the eastern Korean coast. This framework provides a transferable methodology for climate informed shoreline management and supports targeted adaptation in highly vulnerable sections of the Korean coastline.

목차 (Table of Contents)

• Chapter 1. INTRODUCTION １
• 1.1 Research Motivation １
• 1.2 Objectives ５
• Chapter 2. TYPES OF COASTAL EROSION ６
• 2.1 Analysis of Sediment Budget and Sea Level Rise Impact ７
• 2.2 Erosion Due to Shoreline Redistribution １６
• 2.3 Short-Term Erosion (Storm-Driven) ２０
• Chapter 3. WAVE CLIMATE CHANGE AT STUDY SITES ２３
• 3.1 Wave Climate Change ２９
• 3.1.1 Wave Height and Period ３０
• 3.1.2 Wave Direction ３３
• 3.1.3 Extreme Value – Gumbel Method ３５
• 3.2 Future Sea Level Rise ３７
• Chapter 4. RISK ASSESSMENT OF BEACH EROSION ３９
• 4.1 Introduction to CHA Curve ３９
• 4.2 Target Shoreline of Beach Management ４５
• 4.3 Construction of the CHA Curve ４９
• 4.4 GUI Integration: Beach Hardness Assessment Tools ５１
• 4.5 Case Study: Application in Korean Coastal Sites ５４
• Chapter 5. DISCUSSION ７３
• Chapter 6. CONCLUSIONS ７７
• Reference ８１
• Reference non paper ８５
• 논문요약 ８６