Community-led Nature-based Coastal Protection for Disaster Risk Reduction and Climate Change Adaptation: A Comparative Socio-Ecological Perspective from the Yilan Coast, Taiwan

Coastal regions are increasingly confronted with compounded risks driven by sea-level rise, extreme wave conditions, and climate-induced hydrological change. Many conventional coastal protection strategies in East Asia have relied heavily on hard engineering structures; however, these approaches face growing challenges under non-stationary climate conditions, rising maintenance burdens, and the redistribution of risk across spatial and social boundaries. In recent years, Nature-based Solutions (NbS) and community-led adaptation approaches have been proposed as alternative pathways for Disaster Risk Reduction (DRR) and Climate Change Adaptation (CCA), yet empirical comparisons across different governance and protection logics remain limited.

This study examines the Yilan coast in northeastern Taiwan as an in-depth case study from a socio-ecological systems perspective. The Yilan coastal zone is exposed to interacting hazards, including typhoon-driven storm surges, extreme wave action, riverine flooding, and long-term sea-level rise. Unlike many intensively engineered coastlines in the region, Yilan retains wetlands, sandbars, river-mouth systems, and coastal agricultural settlements, allowing different coastal protection strategies to be examined within a shared environmental and institutional setting.

Based on long-term field observations, stakeholder interviews, and analysis of coastal planning and policy documents, this research compares three coastal protection logics: (1) engineering-dominated structural defenses, (2) hybrid approaches integrating selective engineering with natural buffering systems, and (3) community-led NbS embedded in local governance and land-use adaptation practices. The comparison focuses on adaptability under climate uncertainty, maintenance demands, social acceptance, and long-term risk reduction performance.

The results indicate that community-led NbS provide advantages over engineering-dominated and institution-led approaches by reducing exposure while sustaining ecological functions and enabling continuous adaptive learning. In Yilan, community participation strengthens stewardship of coastal landscapes, supports locally grounded monitoring practices, and allows incremental adjustment to evolving climate risks rather than reliance on static structural resistance.

By explicitly comparing coastal protection paradigms within a single socio-ecological system, this study contributes to the ITS4.11 and NH13.9 sessions by framing NbS as governance processes shaped by community agency rather than solely technical interventions. The findings offer transferable insights for coastal regions seeking resilient, community-led adaptation pathways under accelerating climate change.