Study the effect of natural factors on the spatial distribution of ancient centers using GIS in West Azerbaijan

Archeology as a scientific system for processing of models and making rational analogy and rebuilding natural environment، is indebted to geography، and is inseparably relevant to landscape and environment in rebuilding past natural environments of human settlings. Although particular patterns of life is formed on Earth by the result of interaction between humans and the environment there. Changes in the natural environment have provided spatial differentiation in terms of Population and housing density and the cause of formation have been patterns of living in different historical periods. Hence، the present study intends to study the manner of special distribution of ancient centers in regard to natural variables including elevation، slope، aspect، landforms، distance from rivers، land uses، climate parameters such as rainfall، temperature and evaporation using GIS and ''Moran'' model. The descriptive-analytical research method was used in this study. For this purpose، 1408 ancient centers of different eras (prehistoric، beginning of history، historical and Islamic) were recognized، and spatial geo database of them was created، and then the pattern of spatial distribution of them in regards to natural factors was investigated. The result of this study indicates that accessibility to water resources، rainfall، weather، land uses، and landforms have had the most effect on distribution of ancient centers، as a results of ''Moran'' model application indicate that the change in spatial distribution of ancient centers from random model in prehistoric era (Z score of 0. 4) to somewhat strong cluster model in Islamic era (Z score of 2. 04) with average spatial distribution. The natural field of ancient centers in historical eras in the era''s of Iron age is mostly distributed on mountainous areas of south and south eastern of the province with humid and very humid climate. This situation according to the accessibility to rangelands provides a suitable environment for animal husbandry. However، the clusters of Islamic and Historic eras are mostly distributed on the catchments of rivers and foothills in relation to agricultural or mixture of rangeland and dry farming lands.