storm-wise sediment production of gully erosion in the west of iran

different types of soil erosion including gully erosion occur in many parts of iran. the west of iran is further threatened by gully erosion due to its specific physical and climatic conditions. however, few studies have been carried out to study the sediment production of gully erosion in iran. this research was therefore conducted to measure storm-wise sediment production of gully erosion in the west of iran. to achieve the study objectives, 48 gullies located in three small watersheds viz. darreh-shahr, abbas-abad and hollowsh in ilam and lorestan provinces were monitored. the volumes of gullies were measured before and after 5 rainstorms for darreh-shahr and abbas abad watersheds and 6 rainstorms for hollowsh watershed from 2005 to 2007. sediment production was calculated on storm basis for each gully. the results revealed that the minimum and maximum volumes of gully erosion were 0.002 and 1.010 m3, respectively, for one millimeter of rainfall. the results indicated that soil moisture, percentage of silt and clay, amount and intensity of rainfall and drainage area were the most important factors on formation and sediment production of gully erosion.