Coastal ecosystems such as tidal flats, salt marshes, and seagrass meadows are referred to as “Blue Carbon” ecosystems. Although they occupy smaller areas than terrestrial forests, they can absorb and store carbon up to 50 times faster. Recognizing this value, this study established a Blue Carbon database and developed a GIS-based digital information map system for the Korean coast. The system serves as a GIS-based decision-support platform for the effective management of marine carbon sinks and for supporting international certification.

Blue Carbon ecosystems such as salt marshes, seagrasses, tidal flats, and sediments have attracted global attention for their remarkable ability to absorb and store carbon at much faster rates than terrestrial forests, yet examples of their integration into systematic management frameworks have been limited. To address this, between 2022 and 2024, data from 289 survey points along the Korean coastline were collected and integrated. The collected data included carbon cycling processes in salt marshes, biomass distribution of seagrasses and seaweeds, organic carbon content of intertidal and sublittoral sediments, and carbon storage in shellfish habitats. These diverse datasets were unified into a Blue Carbon database, enabling reliable estimation of carbon storage, time-series monitoring, and GIS-based visualization.

A distinctive methodological feature of this study was the combination of remote sensing and ground verification to enhance data reliability. For example, salt marsh habitats were initially detected through aerial RGB imagery, divided into 5 km grids, and the top 20% of grids with the largest habitat areas were selected for detailed field surveys. This approach reinforced remotely sensed results with species-level ground truthing, providing a robust data foundation applicable to both research and policy. Based on this dataset, the GIS-based digital information map provides decision-support functions beyond simple visualization. Users can query layers related to vegetation, sediments, and new carbon sinks, analyze data by administrative units or standardized grids, and perform spatial analyses within user-defined areas. In addition, a Site Suitability Index (SSI) was designed to evaluate optimal sites for establishing carbon-absorbing coasts in Korea by weighting environmental variables such as wave energy, slope, depth, and tidal range. Through these functions, policymakers, researchers, and stakeholders can effectively identify priority areas for conservation, restoration, and sustainable coastal development.

The platform also expands accessibility and international cooperation through multilingual support in Korean and English, and ensures transparency by including reliability metadata that indicates whether each dataset was derived from remote sensing or validated through field surveys. This improves scientific credibility and supports the future international certification of tidal flat Blue Carbon under IPCC frameworks. Ultimately, the Blue Carbon Digital Information Map provides an integrated and user-friendly environment that connects ecological science with geospatial technology. It contributes to achieving Korea’s 2050 carbon-negative strategy, conserving coastal ecosystems, and demonstrating the potential of open-source GIS as a global climate solution. By combining innovation, transparency, and accessibility, this study serves not only as a practical management tool but also as an international cooperation model for the sustainable use of Blue Carbon resources.