Interaction Effect of Slope Aspect and Precipitation Intensity in Runoff and Sediment in Acid Rainfall

Soils are severely damaged by acid rain; acid rain also leads to excessive dissolving of minerals and valuable nutrients in the soil, which weakens vegetation. In this study, in order to determine the interaction effect between the slope aspect and precipitation intensity relative to acid rainfall in the Aghajari and Gachsaran formations, a part of Margha and Kuhe Gach watersheds of Izeh city with an area of 1609 and 1202 hectares were selected. A sampling of runoff and sediment was done in 16 points with three replicates in northern, southern, eastern, and western aspects of Aghajari and Gachsaran formations at different rainfall intensity of 1 and 1.25 mm/min and in distilled water, acidity 4 and 5 using Kamphorst rain simulator. The results showed that in both Gachsaran and Aghajari formations, rainfall intensity has the highest effect on runoff and sediment production in three concentrations of precipitation and also The interaction effect between precipitation intensity and slope aspect plays the least effect on in runoff and sediment production, and in Gachsaran and Aghajari formations, a runoff was much more sensitive to sediment production than the interaction effect between slope aspect and precipitation intensity.