Coastal environments face growing pressure from climate change, accelerated sea-level rise, and intense human activity. Managing these sensitive dynamic zones requires a robust multiscale geomatic framework that integrates satellite observations, in situ measurements, and advanced spatial modeling across temporal and spatial dimensions.

Coastal morphodynamics operate on distinct scales, ranging from acute storm-driven erosion occurring over days, to seasonal wave fluctuations, inter-annual teleconnections like El Niño, and multi-decadal coastline evolution. To track these shifts, high-resolution satellite imagery enables continuous shoreline monitoring. Standard satellite pixel resolutions often obscure fine-scale coastline changes, making sub-pixel shoreline extraction essential. Using isoradiometric approaches and index-based methods—such as the Normalized Difference Water Index (NDWI) combined with algorithms like Marching Squares—scientists map the exact water-sand interface. Incorporating real-time tidal data and wave-induced water levels through local tide gauges and GNSS-RTK reduces positioning errors from approximately four pixels down to a single pixel.

Beyond physical tracking, assessing compound hazard risks is crucial for protecting vulnerable coastal infrastructure and cultural heritage sites. Risk is defined as the product of Hazard, Vulnerability, and Exposure ($R=H\times V\times E$). Hazards encompass physical processes such as seismic activity, flooding, and coastal erosion, while vulnerability reflects intrinsic factors like slope, elevation, and distance to the shore. Exposure accounts for socio-economic assets, visitor density, and ecosystem services. Multi-hazard modeling also addresses dynamic and cascading risks, where initial damage—such as seismic structural weakening—heightens future vulnerability to subsequent events like storm surges or heavy rainfall.

Ultimately, these geomatic applications support sustainable coastal governance and nature-based solutions. Mapping coastal habitats and seagrass meadows enables accurate estimation of Blue Carbon storage, while targeted vulnerability indices guide dune restoration, managed retreat, and adaptive management in protected networks.