survey of parthian sites in northern hillsides of alvand’s mountains (hamedan

during this survey 29 sites have been recognized totally. settlement patterns determined base of environmental characteristics such as altitude, ground slope, source of water, petrology and geology, vegetations, land use and specifications of sites including width, chronology, regional distribution and density and all of them have been divided by using geographic information systems (gis) and cluster analysis in five clusters including i, ii, iii, iv and v. on the basis of the collected data, effective reasons for development of permanent settlements in plain are: variant slope from higher part to lower surrounded plain in hillsides, high density sediments in adjacent mountains, and influence of seasonal network in northwest of the region as well as low height valley. moreover the reasons of increasing the number of pastoral sites in pastures are: higher altitude and unsuitable agricultural grounds and shallow extended sites in every parts of region