Volumetric consequences of particle loss by grading entropy.

Chemical and biological processes, such as dissolution in gypsiferous sands and biodegradation in waste refuse, result in mass or particle loss, which in turn lead to changes in solid and void phase volumes and grading. Data on phase volume and grading changes have been obtained from oedometric dissolution tests on sand–salt mixtures. Phase volume changes are defined by a (dissolution-induced) void volume change parameter (Λ). Grading changes are interpreted using grading entropy coordinates, which allow a grading curve to be depicted as a single data point and changes in grading as a vector quantity rather than a family of distribution curves. By combining Λ contours with pre- to post-dissolution grading entropy coordinate paths, an innovative interpretation of the volumetric consequences of particle loss is obtained. Paths associated with small soluble particles, the loss of which triggers relatively little settlement but large increase in void ratio, track parallel to the Λ contours. Paths associated with the loss of larger particles, which can destabilise the sand skeleton, tend to track across the Λ contours.

Competition and complementarity between seaports and hinterlands for locating distribution activities.

A locational duality in port-related distribution activities is emerging. In some regions, distribution activities have moved from ports to inland locations, driven in part by ‘push factors’ such as port congestion and scarcity of land for container handling activities, or by ‘pull factors’ such as the growth of intermodal corridors, the influence of inland terminals and the changing economic geography in the hinterland. In other regions, ports retain their traditional role as centres of distribution and warehousing activity. More recently, the focus on ‘port-centric logistics’ is indicative that some regions are refocusing on ports as potential locations for large distribution centres. The result has been a growing competition, but also complementarity, between ports and inland locations concerning the location of distribution activities, driven not only by market forces but also by institutional settings and the governance relations between the actors involved. This report provides an overview of regional differences across the world in order to develop a framework identifying for which type of distribution activities ports are suitable locations and which activities are best suited to the hinterland, taking into account geographical, economic and logistics settings. Empirical evidence is derived from a variety of regions in Europe, North America, South America, Southern Africa and Asia.