Comparative landscape transformation in the Vietnamese Mekong Delta: towards regionally differentiated nature-based solutions

Developing deltas face interacting pressures from climate change, land-use transformation and engineered water management, yet adaptation planning often treats them as spatially uniform systems. This study examines how landscape transformation can inform regionally differentiated Nature-based Solutions (NbS) pathways across the upper alluvial, central and coastal regions of the Vietnamese Mekong Delta. Five case-study areas, Cao Lanh, Long Xuyen, Can Tho, Ben Tre and Soc Trang, were compared using contemporary landscape-pattern mapping, land-use and land-cover change from 2000 to 2022, contextual climate-risk and water-management mapping, documentary review and stakeholder consultations. The analysis reveals partly convergent land-use trajectories across regions that remain hydrologically and ecologically distinct. Cao Lanh shifted towards a more diversified mosaic of perennial crops, settlements and agricultural land, whereas Long Xuyen retained stronger rice intensification alongside diversification. Can Tho experienced the greatest built-up expansion, fragmenting relationships among the urban fabric, waterways and peri-urban productive land. Ben Tre increasingly developed an orchard–waterway mosaic, while Soc Trang retained a more engineered canal, rice and aquaculture landscape. These differences indicate that NbS should not be applied as a uniform delta-wide package. The findings indicate distinct regional adaptation priorities: freshwater retention and floodplain connectivity in upper-alluvial landscapes; integrated blue–green, drainage and cooling systems in the central urban region; and differentiated ecological buffering and productive adaptation across freshwater, brackish-water and saline coastal environments. The comparative approach provides an evidence-informed framework for identifying region-specific adaptation priorities in the Vietnamese Mekong Delta and other developing deltas.