Researchers from multiple disciplines have proposed classification systems for waterfront transformations: generational (according to the date of their construction) and functional (based on the function assigned to the land post-harbor use). However, an analysis based on the spatial features of the former port areas and their meaning for the waterfront transformation has been missing. This contribution is an attempt to fill this gap by proposing a classification based on morphological approach. It uses selected case studies based on cluster sampling method, following a fractal reading approach of the waterfronts, to capture a representative sample and to generalize the study following a deductive logic. Using satellite images and maps, this article first identifies the areas where the waterfront was revitalized and then it analyzes the type and function of these spaces according to the classical classifications existing in the literature on the subject. A morphological approach used as methodology framework was based on the analysis of satellite images and the cartography of the waterfront areas with simplification algorithm on ArcGIS. The resulting morphological classification of waterfront transformations reveals the relationship between the built form of the former port areas, classified here as convex, concave, or linear spaces, and the kind of revitalization type respectively classified as ribbon-shaped, convergence, or dilatation. The conclusions about the relationships between the built form available for waterfront transformations and the most appropriate type of revitalization can provide concrete indications for a sustainable future transformation of port cities, especially cities whose reconversion is lagging behind.

Sustainable development projects require careful balancing of economic interests and ecological needs. The case of Skikda, a city in northeast Algeria, located on the Mediterranean coast, illustrates the challenges connected with such a development. The ancient city coexists with a young hydrocarbon port and industrial pole that serves as a transfer hub in the flow of petroleum between hinterland and sea. The installation of the port and petrochemical refining plants on the banks of the estuary of the Safsaf River presents many challenges to local citizens and the ecosystem, including pollution of the water system, groundwater, and river water, and damage to the area’s ancient heritage. This study argues that we need new and less polluting forms of intermodality between hinterland and seaport to make urban mobility more sustainable. It asks whether and how the existing rivers and wadis (river channels that are dry except during rainy periods) can be transformed into artificial canals for river navigation to improve the transport fluidity and sustainability of Skikda. To answer this question, the study adopts a prospective approach using the MICMAC scenario method. This approach entails, first, presenting and evaluating the potentialities of the existing rivers of Skikda using QGIS, and second, discussing and proposing scenarios for transforming these rivers into urban waterways, that is, artificial canals for inland navigation. The prospect of inland waterway transport in Skikda may be a radical scenario, yet, despite its hydraulic capacity and advantages, this system is not receiving attention in Algeria. We suggest that water transport can breathe sustainable blue life into a vulnerable industrial port city, transforming its challenges into opportunities.

This research aims to evaluate the sustainability of urban strategies in Skikda, a prehistoric, ancient, and Mediterranean port city of northeastern Algeria, known as by the Punic name Russicade. The port city of Skikda shows a diverse landscape of heritage sites and the industrial reality of a city, rich by its under-exploited cultural and tourist capacities. Nevertheless, the industrial port activities of the petrochemical refinery impose a state of urban vulnerability for the inhabitants and built, landscape, and natural heritage. The use of the open software Boussole21 of the "Smart" trend as a qualitative method allows assessment of decisions by the actors. The sustainability assessment (findings) shows that smart thinking contributes to the development of port performance and competitiveness in the international context.

This article traces the centuries-long morphological development of Algiers’ port-city interface across four historically relevant time periods that together span from the dawn of the 16th century up until today. Through a diachronic and geo-historical approach, we identify and analyse the origins of Algiers’ persistent port-city divide. In doing so, the notion of the interface is interpreted as a spatial threshold between city and port, which nevertheless supports the material flows of both entities. As a multi-purpose area, the interface holds the potential to weave the disparate entities of a port city back together. To further complement this conceptual angle, we provide investigations of porosity that determine the differing degrees of connectivity between the city and port of Algiers. This is combined with a spatial-functional analysis of Algiers’ current port-city interface, which is ultimately characterised as a non-homogeneous entity composed of four distinct sequences. These results contribute to a better orientation of imminent plans for waterfront revitalisations in Algiers. Whereas the interface was long considered as some kind of no man’s land in the past, port and municipal authorities nowadays aim to turn the interface into a tool of reconciliation, and can do so by acting upon its potential porosity. Finally, this article’s critical examination of the previously neglected case of Algiers can and should also be considered as an applicable model for the continuing study of southern Mediterranean and African port metropolises in general, which share a particular evolution in the relations between city and port.