Sediment Control Practices in Sloping Alpine Fields in Korea

Soil erosion and muddy runoff from sloping alpine agricultural fields located at the uppermost of major river systems in Korea have caused serious water quality problems in providing domestic water supply and maintaining river ecosystem. The government designated the upper Soyang dam watershed as a priority NPS management region in the middle of 2007 and began to introduce various BMPs extensively to reduce soil erosion, muddy runoff and other NPS pollution discharges. Soil, crop, agricultural management practices and rainfall characteristics of the watershed were explained. Typical BMPs introduced were VFS, vegetated levee, concrete drain channel, concrete diversion, gabion wall, masonry wall, drop structure, slope stabilization, sediment trap, perennial crop, and furrow dam. The functions of these BMPs were explained and recommendations were made for better implementation in future. Most of the BMPs were not target source control and the necessities of source control were emphasized. It also was recommended that MOE and MOFAFF need to cooperate in controlling and managing agricultural NPS pollution, reducing the possibility of implementing wrong policies and programs, and helping improve water quality effectively and economically.