title: Export of non-point source suspended sediment, nitrogen, and phosphorus from sloping highland agricultural fields in the East Asian monsoon region.
abstract: Excess sediment and nutrient export from agricultural fields with steep slopes is a major concern linked to surface water quality in Korea. In this study, the export of suspended sediment (SS), total nitrogen (TN), and total phosphorus (TP) and their event mean concentrations (EMCs) in surface runoff from a highland mixed land use (61% forested, 30% cropped, 9% other) watershed were quantified. In 2007, the Korean Ministry of Environment (MoE) declared the study area as a priority region for non-point source (NPS) pollution management and initiated various best management practices (BMPs) in the study watershed. SS, TN, and TP concentrations in Mandae Stream were monitored for 5 years (2009-2013) to evaluate the effectiveness of BMPs. Average EMCs for SS, TN, and TP were as high as 986, 3.4 and 0.8 mg/L, respectively. The agricultural export coefficients of agricultural land in the study watershed for SS, TN, and TP were 5611, 171, and 6.83 kg/ha/year, respectively. A comparison with results from other studies shows that both EMCs and agricultural export coefficients in the study watershed were much higher than most of the results reported for watersheds in other regions. The results show that sediment and nutrient export from intensive agriculture areas with steep slopes continue to be a major concern for the downstream reservoir, Lake Soyang. Remedial strategies should be directed towards controlling sources of SS, TN, and TP to improve downstream water quality in sloping highland agricultural areas in Korea.
authors.affiliation: Department of Environmental Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
authors.forename: Arif
authors.initials: A
authors.lastname: Reza
authors.affiliation: Department of Environmental Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
authors.forename: Jaesung
authors.initials: J
authors.lastname: Eum
authors.affiliation: Department of Environmental Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
authors.forename: Sungmin
authors.initials: S
authors.lastname: Jung
authors.affiliation: Department of Environmental Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
authors.forename: Youngsoon
authors.initials: Y
authors.lastname: Choi
authors.affiliation: Department of Environmental Science, Hankuk University of Foreign Studies, Yongin, 17035, Republic of Korea.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Owen
authors.affiliation: Department of Environmental Science, Kangwon National University, Chuncheon, 24341, Republic of Korea. bkim@kangwon.ac.kr.
authors.forename: Bomchul
authors.initials: B
authors.lastname: Kim
mesh_terms: D000383:Agriculture; D004784:Environmental Monitoring; D005068:Eutrophication; D019015:Geologic Sediments / Q000032:analysis*; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D056910:Republic of Korea; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen
keywords: Event mean concentration (EMC); Korea; Monsoon; Nitrogen; Non-point source; Phosphorus