Photogrammetry-derived metric documentation and proportional analysis of the Gazouli Zaouia lineage mausoleums in Sidi Ouriache, Algeria

Abstract Algerian zawiyas constitute a significant yet still under-documented component of the Maghrebi funerary landscape. Within these religious complexes, funerary architecture preserves spatial configurations transmitted across generations, yet their architectural documentation remains limited in comparison with their anthropological and religious study. In the Algerian context, however, scholarship on saintly mausoleums has remained predominantly anthropological, historical, and religious, whereas metrically controlled architectural comparison and heritage-oriented documentation remain extremely limited, and, to our knowledge, no metrically controlled comparative architectural corpus has yet been established for the Gazouli mausoleums themselves. Using terrestrial photogrammetry, three-dimensional reconstruction, metrically controlled orthographic extraction, and ratio-based comparison, the research generates photogrammetry-derived metric documentation models of three successive mausoleums and analyses their planimetric and volumetric relationships through geometric compatibility and proportional indicators. The results reveal high geometric compatibility and recurring proportional correspondences consistent with a shared funerary grammar transmitted within a genealogically coherent ritual and commemorative setting. Culturally, the three mausoleums are not treated as isolated architectural objects, but as material supports of lineage memory, saintly commemoration, visitation, and local recognition within the Gazouliya zawiya. More precisely, the study shows that the strongest continuity concerns the funerary core, whereas the principal variations affect the architectural envelope through controlled transformations across the lineage. These differences are therefore interpreted not as typological rupture, but as controlled transformations compatible with commemorative emphasis, differential formal investment, ritual use, and later histories of repair or regularisation. Methodologically, the study shows that photogrammetry-derived metric documentation models are useful not only for documentation, but also for reading how architectural continuity, commemorative hierarchy, and local funerary memory are materialised across the three mausoleums. The article therefore proposes a reproducible metric documentation workflow, oriented toward Digital Twin reuse but limited to static photogrammetric records, that links photogrammetric acquisition, metric model generation, orthographic extraction, and proportional comparison in order to support conservation baselines, risk-aware documentation, educational interpretation, and culturally grounded valorisation of under-documented vernacular funerary heritage.