Evaluation of the role of environmental factors in the formation of Parthian settlements in Khosf County, South Khorasan province, East of Iran

Human activity are always carried out in the context of the geographical environment. On the one hand, the geographical context causes changes in human culture and action, and on the other hand, human beings make changes in the natural environment with their culture and technology in order to adapt and overcome environmental constraints. In fact, over time, human beings, by increasing their knowledge of the environment, try to establish their settlements in the places that environmental conditions are suitable and increase the productivity of its landscape. The study of the location of ancient settlements in the natural landscape leads to the discovery of environmental potentials and the way of life systems of their inhabitants. Due to the limitations and potentials of the region's ecology, we will see different spatial types of sites in the landscape. The main question of the research is about the relationship and role of environmental factors in the location of settlements pattern of Parthian sites in Khousf County in the eastern margin of Lut desert. This research have been done by descriptiveanalytical method and for data analysis and distribution pattern, GIS and SPSS software have been used with correlation and cluster analysis methods. The results show that due to the lack of permanent water resources in the region, access to sustainable water resources (Qanat) has been the most important factor in the formation of settlements in this period. After water sources, slope and soil type are other important factors in the formation of Parthian sites. Therefore, cluster analysis showed that two patterns, including a relatively large local center and a number of small villages around it, can be identified.