title: Risk assessment of watershed erosion at Naesung Stream, South Korea.
abstract: A three-tiered approach was used to assess erosion risks within the Nakdong River Basin in South Korea and included: (1) a screening based on topography and land use; (2) a lumped parameter analysis using RUSLE; and (3) a detailed analysis using TREX, a fully distributed watershed model. These tiers span a range of spatial and temporal scales, with each tier providing increasing detail and resolution. The first two tiers were applied to the entire Nakdong River Basin and the Naesung Stream watershed was identified as having the highest soil erosion risk and potential for sedimentation problems. For the third tier, the TREX watershed model simulated runoff, channel flow, soil erosion, and stream sediment transport in the Naesung Stream watershed at very high resolution. TREX was calibrated for surface flows and sediment transport, and was used to simulate conditions for a large design storm. Highly erosive areas were identified along ridgelines in several headwater areas, with the northeast area of Songriwon having a particularly high erosion potential. Design storm simulations also indicated that sediment deposition of up to 55 cm could occur.
authors.affiliation: River and Coastal Research Division, Korea Institute of Construction Technology, Goyang-Si, South Korea. Electronic address: jiuncivil@gmail.com.
authors.forename: Un
authors.initials: U
authors.lastname: Ji
authors.affiliation: HDR|HydroQual, Mahwah, NJ, USA. Electronic address: Mark.Velleux@hdrinc.com.
authors.forename: Mark
authors.initials: M
authors.lastname: Velleux
authors.affiliation: Dept. of Civil and Env. Engineering, Colorado State Univ., Fort Collins, CO, USA. Electronic address: pierre@engr.colostate.edu.
authors.forename: Pierre Y
authors.initials: PY
authors.lastname: Julien
authors.affiliation: Water Resource Research Center, Korea Water Resource Corporation, Daejeon, South Korea. Electronic address: hwangmh@kwater.or.kr.
authors.forename: Manha
authors.initials: M
authors.lastname: Hwang
mesh_terms: D002138:Calibration; D016208:Databases, Factual; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D008962:Models, Theoretical; D056910:Republic of Korea; D018570:Risk Assessment; D045483:Rivers / Q000737:chemistry*; D012987:Soil / Q000737:chemistry
chemical_list: D012987:Soil
keywords: Design storm modeling; Naesung Stream; Risk assessment; Soil erosion; Watershed erosion