The use of “space syntax” for the study of city planning and household from geophysical maps: the case of Dura-Europos (Syria)

International audienceThe site of Dura-Europos is located on the right bank of the river Euphrates at 30 km from the Iraqi border. This city is certainly one of the most well documented site concerning the classical urbanism in the Near East. The site of Dura-Europos was discovered at the beginning of the 20th century and has been excavated successively by F. Cumont (1922-23), a French and American mission directed by M. Rostovtzeff (Yale University), and since 1986 by the French and Syrian mission directed by P. Leriche (CNRS). A geophysical survey has been carried out between 2001 and 2003 in the southern part of the site with a caesium gradiometer (G-858, Geometrics). The magnetic image shows therefore the result of more than 4 centuries of urban living. Founded at the end of the IVth century B.C. by the Macedonians, Dura-Europos was originally a military fort. The concept of the city planning (and therefore the extension into the actual shape, about 60 ha, delimited by the circuit wall of fortifications), started in the middle of the 2nd century B. C. About 133 B. C., the city fell under Parthian domination; by this date, only the sector of the agora and also some administrative and religious buildings had been constructed. The new Parthian authorities continued the urban program respecting the Hippodamian plan that had been established by the Macedonians. In 165 A.D., the city was taken over by the Romans, and the city planning was subsequently deeply modified, mainly due to the installation of a military camp in the northern part of the city. The Romans constructed many buildings in this sector without taking the pre-existing Hippodamian plan into account. Finally, in 256 A. D., Dura-Europos was pillaged by the Sassanids and practically abandoned. The interpretation of the geophysical image is based on the study of space following the “space syntax” developments. Such an approach allows a more accurate use of the geophysical data and a new and original vision of the city planning. Trough this study, it is possible to approach the evolution of the original theoretical concept of the hippodamian plan. Even if the main characteristics of the hellenistic city planning of Dura-Europos have been maintained, we can observe a hierarchical organization of the streets network and a categorization of the blocks (two types of original division, 6 or 8 units, more or less conserved). We will present also an approach of the spatial organization of the domestic dwellings in two steps : . Spatial analysis of the excavated blocks and characterization of the main elements of the domestic unit (entrance, courtyard, reception room). . Spatial analysis of the geophysical image and identification of the previous elements This study offers a very detailed and homogeneous vision of the southern quarter of Dura-Europos, where the Hellenistic urban model has been the most well preserved during the Roman period