Classification of soils based on double ring measured permeability in Zarrineh-Roud Delta, western Azarbayejan, Iran

A physical method of soil classification based on soil permeability as a preliminary quick way prior to slow and expensive chemical conventional method was conducted in regional scale using 40 test stations. Double ring method used for permeability measurements in the area. The results clearly differentiated development of various soil types and quality in the area under investigation. The results clearly indicate the physical method of double ring measurement permeability is able to identify various soil types in regional scale and the later chemical methods could be used in local scale for detailed classification. NaCl content of soils was reflected by the amount of infiltration rate. Permeability ranged as high, medium and low, corresponded with loamy sand, loamy and clay soils respectively. Permeability in the vicinity of the higher water flows was high due to leaching of NaCl in the soil. NaCl is considered to be the main factor of impermeability reduction in the area associated with clay and soil textures.