Ecological and Cultural Adaptation of Ancient Communities in Dynamic Riverine Environments: Insights from the Óc Eo Civilization in the Mekong Delta

Background and objective: The Mekong Delta in southern Vietnam is a dynamic fluvial environment influenced by seasonal flooding, sediment deposition and saline intrusion. In this context the Óc Eo civilisation (1st–7th centuries CE (Common Era) established a water management system that combined technical innovation with cultural adaptation. Far beyond a simple hydraulic installation, the network contributed to a deliberate landscape design that supported urban habitation and ecological interaction. The study is intended to examine the hydraulic and spatial configuration of the Óc Eo–Ba Thê complex in order to evaluate how ancient societies shaped their settlement patterns in response to environmental constraints and sustained long term occupation.Methods: This study employed an interdisciplinary approach to examine ecological and cultural adaptation in the lower Mekong Delta. Archaeological data, remote sensing imagery, historical maps, and sediment analysis were used to reconstruct past environmental conditions and canal systems. GIS-based spatial analysis clarified the relationships between hydraulic infrastructure, settlement patterns, and geomorphology.Results: Settlements of the Óc Eo culture emerged in flood-prone lowlands influenced by sea level shifts and monsoonal climate. Urban structure centered on a canal network used for transport, drainage, agriculture, and ritual practices.Canal Number 16 served as the principal axis connecting habitation zones and sacred areas. Over 700 kilometers of canals reflect intentional planning for environmental adaptation. Archaeological and spatial data reveal a complex and resilient water-based urban system.Conclusion: The spatial and hydraulic systems of Óc Eo present a coherent model of ecological adaptation that operated in harmony with cultural continuity. These historical insights offer valuable perspectives for current water governance and landscape planning in the climate sensitive Mekong Delta, where flood risk, land subsidence, and rising sea levels continue to challenge sustainable development.