Study on effect of physical and chemical properties of marls on sediment yield, using rainfall simulator

Marl units generate the most sediment yield rate among the geological formations in the watershed basins. Therefore, they notably affect on useful lifetime of dams and water electric constructions, flooding processes, sedimentation in the water transport channels and the existence of aqueous creatures. Study and classification on the effective characteristics of erodibility of marls could notably help to remediation activities on them. In this research, the amount of sediment yield in each marl units were compared using a portable rainfall simulator at field. The amounts of runoff and produced sediments in each marl units at three repetitions were measured. The relation between physico- chemical characteristics of marl units as independent variables and the amounts of produced sediments as dependant variables was analyzed using multivariate linear regression method. Some characteristics such as SAR, EC, and K show 89, 3.5 and 1.5 percent of total variance of produced sediments at each marl units respectively. On the basis of ANOVA analysis of sediment data, the marl units have classified in four groups: A (include of Ols unit), B (include M3 unit), C (include M1 and M2) and D (include Olg and O-M units). The erodibility rate and sediment yield decrease from A to D group. Physico- chemical characteristics of four above mentioned groups have analyzed using variance analyze. The results show significant difference at level 0.5,. 01, and. 001 for some parameters such as SAR, EC, K+1, Na+1, Cl-1. Meanwhile, the mean amounts of sediment yield of various marl units obtained from rainfall simulator test show that evaporative marls of Neogene age (M1, M2 and M3) potentially produce sediment 27 to 100 times more than Qom formation marine marls and Kond formation lacustrine marls.