Investigation on erodibility and soil loss of Marly drived soils in west ‎Azarbaijan Province, Iran

Considering to high distribution of the marly lands in west Azarbaijan province and high sediment yield of such lands, in this research, the relation among the form and the rate of erosion on marls with their erodibility properties were studied. So marly regions of province with the special properties were recognized and soils were sampled. Soil erodibility indices were determined and analyzed by statistical methods considering the form and the rate of erosion. Also portable rain simulator were used to study of the runoff and sediment yield potential of such soils. Finally the factors affected the soil erodibility were determined by variance analysis. Results showed erosion rate could be classified as moderate. Gully erosion had highest number in Gara-agaj and Gara-tape areas whereas rill erosion had high number in all area of marlly lands. Surface runoff volume ranged between 255 to 577 cm3 in Shabanlu and surface runoff coefficient 0.23 to 0.53 in Gara-tapeh. Maximum yielded turbidity was 180 gr/lit in Gara-Agaj area. Clay ratio was the effective factor to gully form and Surface runoff volume also was the factor to form surface and rill erosion.