Morphological Transformation of a Saharan Ksar: A Diachronic and Relational Reading of Spatial Structure in Béchar, Algeria

Saharan ksour are undergoing a profound transformation as urbanization spreads, building practices change, and old functions give way to new ones. Their architecture and building materials have been studied extensively. What has not been documented is how these pressures reshape the spatial relations that bind a historic core’s parts together. This matters because it is morphological continuity, not architectural fabric alone, that keeps a historic settlement legible once it is absorbed into a modern city. This study addresses that gap through a diachronic morphological reading of the Ksar of Béchar, in southwestern Algeria. It traces seven structuring components, the perimeter wall (Essour), defensive towers (Bordjs), gates (Bâb), the alley network (droub), collective open spaces (Rahbas/Nouader), the El Masdjid El Atik mosque, and the housing stock, across more than a century of change. The analysis draws on a triangulated corpus of historical archives, redrawn historic plans, archival photographs, 1952 and 1962 aerial imagery, recent satellite imagery, field observations, and testimonies from long-standing residents. Rather than comparing historical and current states at the level of individual components alone, the relational reading combines two analytical levels: it traces the differentiated trajectories of the seven components while simultaneously examining the persistence, transformation, and recomposition of the spatial relations between them across documented temporal states. This relational analysis reveals two differentiated morphological trajectories and one cross-cutting process. The defensive envelope (Essour, Bordjs, Bâb) has fragmented and largely disappeared. The internal structures (droub, Nouader, the mosque, housing) show strong spatial permanence beneath their architectural and functional change. And across all seven components, spatial relations have been recomposed as a system, progressively opening the once-enclosed core to the surrounding city. The Ksar of Béchar’s evolution is therefore neither integral conservation nor outright erasure. It is a relational recomposition in which peripheral, boundary-defining elements erode while internal structuring relations persist. Beyond this case, the study offers a transferable, source-triangulated analytical framework for reading morphological recomposition in Saharan and other vernacular historic settlements, one directly usable in heritage conservation and historic urban landscape management strategies.