A Spatiotemporal Multi-Hazard Framework for Strategic Arctic Route-Feasibility Screening Using Grid-Based Environmental Modelling

Strategic Arctic route-feasibility screening requires environmental constraints, missing data, and route exposure to be distinguished rather than treated as a single availability condition. This study develops a grid-based multi-hazard framework that separates geographic feasibility, environmental data validity, hard feasibility thresholds, exposure-weighted routing, and constraint attribution. Natural Earth land polygons, the General Bathymetric Chart of the Oceans (GEBCO) 2024 sub-ice topography grid, Copernicus Marine Environment Monitoring Service (CMEMS) sea-ice concentration, and European Centre for Medium-Range Weather Forecasts Reanalysis v5 (ERA5) wind and wave fields are evaluated over an offshore Arctic gateway corridor using the July, September, and October fields from 2020 to 2024 under conservative, moderate, and permissive scenarios. No July case produces a connected route. September availability is 40%, 40%, and 100%, respectively, while October availability is 0%, 20%, and 20%. Bathymetry and sea-ice concentration both shape the feasible domain: stricter depth requirements disconnect the fixed gateway pair, while the sea-ice constraint substantially shifts the September 2023 route relative to depth-only routing. A controlled 0.5° resolution test preserves connectivity and the broad corridor while changing route distance by approximately 3% relative to the 1° baseline. The framework therefore separates route existence, environmental exposure, and node-level constraint attribution within a reproducible workflow for seasonal Arctic corridor screening and comparative multi-hazard assessment.