Abstract

Coastal adaptation planning often focuses on keeping growth out of flood-prone areas, but in some coastal cities, business as usual growth may already avoid the most exposed locations while remaining concentrated near the shoreline. This problem is examined in Dalian, China, using the Land Use Evolution and Impact Assessment Model combined with connected bathtub flood exposure mapping at 30 m resolution. Existing model outputs are translated into planning support layers covering flood exposure, a coastal planning belt, and a proof-of-concept port-accessibility proxy, then used to classify growth constraint conflicts, define adaptation zones, and compare three scenarios under fixed demand inputs, spatial metrics, and sensitivity analysis across 75 parameter combinations. BAU growth concentrates within 5 km of the shoreline in high-suitability cells, indicating that coastal concentration rather than direct hazard exposure defines the main planning problem. Strong conservation, used here as a reused broad-constraint reference scenario rather than a newly designed coastal-adaptation scenario, compresses residential allocation closer to the shore, with a mean distance of 1.5 km compared with 3.1 km under BAU. Only selective adaptation redirects residential growth inland, increasing mean distance to 11.5 km and reducing residential allocation within the belt to 0%, while retaining more commercial allocation than strong conservation. Because the inundation input is based on a static connected-bathtub approximation rather than a validated hydrodynamic model, the flood-exposure component is interpreted as an exploratory screening layer rather than a flood prediction. Differentiated zoning offers a targeted pathway for reducing coastal residential exposure while recognizing commercial functions that may depend on port access.

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