comparing the accuracy of soil map prepared by geopedology and usual method of iran (case study: kouhin)

today, extensive improvements in fields of soil mapping have increased the purity and accuracy ofsoil maps. usual mapping methods moreover depend on skills and experience of surveyor inidentifying and delineating the boundaries, also need the high cost and time consuming that face thesoil mapping with restrictions. in this study, aerial photographs with 1/40000 scale were used in orderto preparation of the initial interpretive map and determination of sample region. then, the numbers of24 profiles were described in determined units. after sampling and necessary physicochemical tests,soil map of kouhin (qazvin) was prepared and accuracy of map was calculated in two methods in alllevels of taxonomy. the first method was formation of error matrix and calculation of kappa index andsecond was comparison the geopedological map with described profiles and evaluation the results ofeach. then a part of a geopedological map that had overlapping with map prepared by usual methodwas compared with this map. results showed the overall accuracy of 67.5, 90.5 and 98.5 percent inlevels of family- subgroup and great group- suborder and order of soil for geopedological methodrespectively.