Sediment and Runoff Measurement in Different Rangeland Vegetation Types using Rainfall Simulator

Soil erosion is an abstruse phenomenon which contains segregation and transmission of soil particles and runoff from rainfall and infiltration. Runoff and sediment generation was compared using rainfall simulator in grassland (St. parviflora-Br. tomentellus) and shrubland (As. parrowianus-As. gossipinus). For this purpose, vegetation map was supplied for two vegetation types four main aspects and two slope classes (12%-20% and 20%-40%) and corresponding work units were accordingly determined Three points were selected in each unit and rainfall simulator set inside them through a randomized pattern. The intensity of rainfall simulation was 1.6 mm min-1 with 10 minute duration and then runoff and sediment were measured. One soil sample (depth of 0–40 cm) was collected and assessed for pH, OM, EC, P, K, Ca, Mg and texture in the laboratory at the vicinity of the study area. The results of Duncan test and multiple regressions showed that grassland had more runoff and sediment than shrubland, but initial time of runoff in grassland was less than shrubland. Also aspects, slopes and soil characteristics (EC, Ca, Clay, P) had significant effects on runoff, sediment and initial time and they had linear correlation with runoff and sediment.