The conceptual connotation and key issues of the key zone of land-sea integration: Based on the perspective of coastal human settlement environment system research

Land-sea integration is the core value orientation for the synergistic utilization of terrestrial and marine space and resources in China. To construct a coastal human settlement environment system featuring human-land (sea) interaction under the multidimensional goals of land-sea integration, this paper proposes the concept of the "Key Zone of Land-Sea Integration" and its spatial structure of "supporting zone-core zone-associated zone-hinterland zone". The Key Zone of Land-Sea Integration implements the research perspective of the coastal human settlement environment system in terms of scope definition, hierarchical structure, research priorities, and development dimensions. It follows the research approach of "spatial structure-geomorphic pattern-ecological network-human settlement order", couples the multidimensional values of "ecology-economy-space-culture-society", and puts forward key research issues. Specifically, in scope definition, it clarifies the spatial scope integrating land and sea, covering both coastal areas and their adjacent terrestrial and marine extensions. In hierarchical structure, it establishes a multi-level system to adapt to analyses and management at different scales. In research priorities, it focuses on the dynamic interactions between human activities and the natural environment within the zone. In development dimensions, it emphasizes the balance among economic growth, social progress, and ecological protection. Focusing on the integration of human-land (sea) interaction and the integration of land-sea multidimensional values at the urban scale from the perspective of the coastal human settlement system environment, the Key Zone of Land-Sea Coordination proposes clear spatial objects and carriers. It will further promote the integration of land-sea coordinated territorial spatial planning and governance, break down traditional barriers between land and sea management, and facilitate high-quality development of coastal human settlement by guiding rational spatial layout, efficient resource utilization, and harmonious coexistence between human and nature. Thus, it provides theoretical support and practical guidance for advancing systematic management of coastal areas and optimizing the sustainable development pattern of coastal human settlement.