This contribution proposes to analyze a single archaeological object crossed by different conservation processes, to isolate and understand the role of geomorphological parameters in the formation and the conservation of anthropogenic geomorphic features. For these purposes, this study characterizes the remnant morphologies of the WW1 railroad in the Montagne de Reims on the western front (France, Rheims sector) through LiDAR-derived digital terrain models combined with archival documents (maps and historical photographs), spatial analysis and field surveys. This study shows that the Heavy Railway Artillery (Artillerie Lourde sur Voie Ferrée - ALVF) is a significant morphogenic feature, preserved at more than 70%. However, this morphology is subject to a strong variability. Ruggedness analysis shows a much more pronounced morphology on the slopes than on the plateaus, demonstrating a difference in formation and preservation processes. For formation processes, the study's findings reveal that geotechnical constraints related to lithology and geomorphology can be overridden for military purposes. For conservation processes, they are largely dependent on land use practices. This research demonstrates that (i) the role of landscape and topographical parameters in the interpretability of features is predominant; (ii) military engineering has been able to adapt to a much diversified topography.

The World War I strongly marked the landscapes, especially on the western front, from Flanders to Alsace. The mine craters, shell craters, dugouts, trenches and communication trenches give off war landscapes characteristic of the front area. Theses geomorphic impacts subsist under forest cover, highlighted using the airborne LiDAR, while they are completely leveled in cultivated areas. In Champagne area, the archaeological survey linked to the urban extension of Rheims allows a better understanding of the spatial organization and the nature of the filling of these forms, by an archaeometric approach (dynamic penetrometry, mechanical oriented cross-sections, and UAV photography). Analysis conducted on an experimental area of 2 ha, in the first line of defense, makes it possible to characterize archaeological structures from the WW1 in a context of rendosols, developed on a stretched cryoclastic polygonal network, typical of the Champagne chalk surface. The results show that the forms of the WW1 are levelled by a multiphase fill with fine sedimentation synchronous with the conflict, followed by a poorly consolidated heterometric backfill. The latter coming from dismantled parados and parapet geomaterials, is rich in metallic fragments of accessory defense networks, and surmounted by an addition of topsoil. The bombturbation also determines a metallic contamination by << nugget effect >> circumscribed in the shell crater, filled with earth fillings. These anthropogenic pedoturbations determine large spatial disparities in soil water reserves (crop marks) and are associated with geotechnical and pyrotechnic risks.

The toponymy of battlefield and more particularly the trench names of the Great War remains little known without spatial analysis or statistics. The study of trench maps reveals the western front is made of a dense and complex defense network structured according to the geomorphological conditions. To improve the operational aspect of trench maps, the soldiers increased the names, designations and numbers associated with nameboards. The typological study of the 2,500 trench names of Champagne, on 13,000 km of linear for 115 km of front, and their spatial organization from a database under GIS, allows us to better understand the naming logic of these places. Their astonishing diversity and their conventional random designation actually hide a spatial organization into groups of fire trench segments and communication trench or "quarters", of regimental and non-divisional origin. This organisation around cultural themes guarantees the movement of troops and liaison officers in the defense network. The toponyms and trench names constitute a socio-cultural representation of the front area and are today part of the memorial and collective heritage of societies. Trench names raise a lot of scientific questions (authorship, origin of designations, scalar and temporal permanence) and deserve a spatial analysis of the entire western front area.

Les fortifications du système Séré de Rivières du second rideau défensif autour de Reims sont, à la veille la Grande Guerre, désarmées et abandonnées. L'exemple du fort de Brimont, situé sur une butte-témoin de la cuesta d'Ile de France, montre que ces ouvrages servant de point d'appui sont englobés dans les réseaux de tranchées et de boyaux. Cet ensemble de polémoformes est d'abord étudié à partir d'une analyse spatiale des plans directeurs des Groupes de Canevas de Tirs des Armées (GCTA). Le flanc de la butte présente de bonnes potentialités de crêtes militaires et de sites d'observation en lisière de forêt alors que le sommet, coiffé du fort, à découvert donc trop exposé à l'ennemi, est peu fortifié en surface. Mal orienté par rapport à la ligne de front, il fait l'objet de réhabilitations (boyaux d'accès creusé dans le front de tête, souterrains), abrite de nombreux postes d'observationsselon une organisation cellulaire, dont les morphologies révélées en image Lidar et repérées sur le terrain, restent bien conservées sous forêt. De nombreux impacts d'artillerie sont visibles, notamment sur les ouvrages de gorge (entrée, casernement), sur les caponnières et les traverses-abris.