Dynamic Coastlines and Maritime Baseline Stability: A Review of Legal and Geospatial Perspectives

Abstract

Coastlines are continuously shaped by natural processes and human activities, creating an important challenge for maritime law because many maritime zones are measured from coastal reference features. This article reviews the relationship between coastline change, maritime baseline stability, and geospatial evidence from legal and spatial perspectives. A structured literature review was conducted using peer-reviewed studies, international legal materials, and technical literature concerning shoreline change, sea-level rise, maritime baselines, remote sensing, geographic information systems, and the law of the sea. The review shows that satellite remote sensing has significantly improved the ability to monitor erosion, accretion, and long-term coastline movement, while geospatial analysis provides detailed information on the spatial consequences of these changes. However, physical movement of the coastline does not necessarily result in an equivalent change in legally recognized maritime baselines or established maritime boundaries. Recent developments in international legal discussion increasingly emphasize stability and legal certainty, particularly in response to climate-related sea-level rise. The review also finds that differences between an observed shoreline, a legally relevant low-water line, and an officially recognized baseline must be clearly distinguished when geospatial data are used in maritime governance. This article concludes that remote sensing and geospatial technologies are most useful when they support legal interpretation rather than determine legal outcomes independently. Greater integration between maritime law and geospatial science is needed to manage dynamic coastlines while maintaining both spatial accuracy and legal certainty.