TY - JOUR ID - 60020 TI - Effectiveness thresholdsof rainfall intensity and slope gradient on erosion process in rainfed landsinKalaleh region,Golestan Province JO - Iranian journal of Ecohydrology JA - IJE LA - en SN - 2423-6098 AU - Aliramayee, Ramyar AU - Khaledi Darvishan, Abdulvahed AU - Arabkhedri, Mahmood AD - M.Sc. Student, Department of Watershed Management Engineering, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran AD - Department of Watershed Management Engineering, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran AD - Soil Conservation and Watershed Management Research Institute, Tehran, Iran Y1 - 2016 PY - 2016 VL - 3 IS - 3 SP - 293 EP - 301 KW - Field capacity KW - Rainfall simulator KW - Rainfed land KW - Sediment KW - Soil loss DO - 10.22059/ije.2016.60020 N2 - The purpose of the present study was to evaluate the response thresholds of the main steps of erosion and sediment transport at plot scale in rainfed lands in Kalaleh region, Golestan province. The rainfall was simulated using Kamphorst simulator with plot dimensions of 25 × 25 cm considering rainfall intensities of 33, 64, 80 and 110 mm hr-1and three slope gradients of 6, 12 and 25% infour replications. Sediment concentration and soil loss were calculated by measuring runoff and sediment at the plot outlets and the results were analyzed in rainfall intensity and slope treatments.Based on the results of statistical analysis, the amount of sediment concentration increased with increasing rainfall intensity on all studied slopes. The main effect of rainfall intensity and slope gradient on sediment concentration and soil loss was significant (P≥0.05), but their interaction effect was not significant. The results of determining subsets using Duncan test showed that sediment concentration had significant change between rainfall intensities of 33 and 64mm hr-1and the slope gradient of6 and 12%, while about soil loss, the subsets were 64 and 80 mm hr-1 and the 12 and 25%, respectively. In other words, with consumption of the linear trends, the plot hydrological response threshold of sediment concentration (sediment detachment and entertainment) wasabout 50 mm hr-1 of rainfall intensity and9% of slope, while in case ofsoil loss (sediment transport) was at the higher rainfall intensities (about 72 mm hr-1) and higher slope gradients (about 18%).         UR - https://ije.ut.ac.ir/article_60020.html L1 - https://ije.ut.ac.ir/article_60020_abf5b7b8c008bf5d4d27cdc3b4e14976.pdf ER -