Coastal vulnerability and protection strategy gaps in indonesia: a systematic literature review

Abstract

Indonesia's extensive coastline, vital to its economy and population, faces escalating threats from climate change and intense human activity. This systematic literature review synthesizes evidence from 20 empirical studies (2015-2025) to evaluate coastal vulnerability drivers, protection strategy efficacy, and implementation barriers across Indonesia's diverse geographies. Explicitly following PRISMA guidelines, this study aims to: (1) map regional vulnerability patterns, (2) compare the contextual performance of hard, soft, and hybrid protection strategies, and (3) identify critical systemic gaps in policy and data. Our findings reveal that Java faces synergistic erosion and subsidence crises, Sumatra is dominated by high-energy waves, and small islands confront existential sea-level rise. Analysis demonstrates that hard structures offer immediate mitigation but carry high costs, soft solutions enable natural recovery but lack durability, and hybrid systems balance benefits but face scalability constraints. The novel contribution of this review is the identification of pervasive, cross cutting barriers, including fragmented governance, a lack of standardized design guidelines, and insufficient monitoring, that hinder effective implementation. We conclude that optimizing resilience requires regionally tailored strategies, and we provide actionable recommendations for integrated governance, thereby offering a critical evidence base for enhancing sustainable coastal development and climate adaptation in Indonesia..