Sea-land interdependence and delimitation of port hinterland-foreland structures in the international transportation system

Acknowledging that sea-land intermodal integration and transshipment are core transformations of the contemporary international logistic system, we study the spatial and functional structure of a port system across land and sea in this context. Previous port-driven regional development models have focused only on landside port-hinterland spatial structures in the local vicinity of ports, not seaside inter-port connections together. By revisiting the concepts of port triptych and hinterland-foreland continuum, we argue that the spatial structure of a port system should consider both flows to and from ports together when tracing spatial structures of hinterlands and forelands. Incorporating the network-based analytical model of the nonparametric weighted stochastic blockmodel, we study the global-scale structures of hinterlands and forelands under integrated landside-seaside freight flow dynamics. We investigate the network block structures of cargo shipping routes between Europe and the United States based on micro-level shipping flow data. We find a rich and meaningful collection of different network blocks of hinterlands, feeder and hub ports, and forelands that mirror the functional division of logistic processes across space, the interdependent relationships between hinterlands and forelands along a logistical continuum.