Stying the Sassanid Settlement Pattern of Farsan in Termontane Plain Chahar Mahal and Bakhtiyari Province

Of the important purposes of Archaeology, is studying the interaction of communities with each other and the environment; the cultural processes of highlands with more than 2000 m. elevation above sea level is a considerable subject in the Iranian archaeology has not been followed yet. In the present research with environmental approach and using GIS software, on the basis of examining the geographical factors respect to the settlement pattern of Sassanid era, we came to study that why and how Sassanid settlements in the Farsan county, as a region with such intermountain valleys and plain, formed and goes on, and determined which all the geographical factors didn’t possess an equal importance as the most important factors in this process were water and adequate pasture accessibility. That’s it, locating in the close area with enough pasture for pastoral nomad communities, settling in the area with irrigation agriculture potential for the sedentary people, and communicating roads availability for both groups has a considerable role in the formation of settlement pattern of Sassanid Farsan.Compare to the Parthian, Sassanid settlement pattern of the region didn’t show a significant change, except the larger size of Sassanid sites. Respecting this, we have to note that more than half - 51.74 % - of the Sassanid sites of the region formed on Partian settlements; 31 % newly assessed and 17.24 % of them including sites which were occupied once over the prehistoric times.In the continuation process which have been started by the Elymais period, settlement pattern of the region in the Sassanid period; here, on the influence of the developed socio-political system control and probably shaped under Sassanid centralized power investment. Regard to the connection between settlement pattern and the roads, the sites are not necessarily next to the riverbeds. In the Sassanid Period as precedent eras, habitation in mountain slopes and on the hills beside the plain have continued; we apparently saw that the settlements concentration have moved to the center of the plains. In this Period, the size of the sites are greater than before, which is a sign of population growth by the Sassanid period. It seems that the population growth in this period is the consequence of vast exploitation of resources with habitation on the center of the plains and more resources accessibility, using strategic situation of Farsan region and communication roads, which long before identified by nomads. The interaction between this region and other cultural zones, i.e. Khuzestan and Fars in the Sassanid period reflected by the archaeological data, e.g. pottery form and decoration; this similarity is matched with migration roads of the Bakhtiyari tribes.To sum up, there is an important difference between Sassanid settlement pattern and modern patterns of population distribution and cities of Farsan County are consequence of different socio-economic and technologic situation. This case indicates that beside geographical variety, factors like socio-economic interactions and statistic characteristics plays an important role in the site distribution and settlement patterns.