Runoff Losses of Suspended Sediment, Nitrogen, and Phosphorus from a Small Watershed in Korea
- Jong A. Chuna,
- Richard A. Cookeb,
- Moon S. Kang *c,
- Minha Choid,
- Dennis Timlina and
- Seung W. Parkc
- a USDA–ARS Crop Systems and Global Change Lab, Bldg. 001, 10300 Baltimore Ave., Beltsville, MD 20705
b Dep. of Agricultural and Biological Engineering, Univ. of Illinois at Urbana-Champaign, 1304 W. Pennsylvania Ave., Urbana, IL 61801
c Dep. of Rural System Engineering, Research Institute for Agriculture and Life Sciences, Seoul National Univ., San 56-1, Sillim-dong, Gwanak-gu, Seoul 151-742, Republic of Korea
d Dep. of Civil and Environmental Engineering, Hanyang Univ., 17 Haengdang-dong, Seongdong-gu, Seoul 133-791, Republic of Korea; Assigned to Associate Editor Joshua McGrath
Nutrients and sediments in runoff lead to the degradation of water quality of lakes and streams. The development of schemes to mitigate such degradation requires a characterization of the underlying transport processes. The objectives of this study were to develop annual and seasonal load–discharge relationships for suspended sediment (SS), total nitrogen (TN), and total phosphorus (TP) losses from a small mixed land use watershed and to use these relationships to explicate the annual and monthly patterns of losses of these species. Data from 1996 to 2004 were used to develop load–discharge relationships for SS, TN, and TP at the HP#6 watershed, a subwatershed of the Balhan reservoir watershed located in Bongdam-myun and Paltan-myun, Gyeonggi-do, Korea. Standard least squares curve fitting and S-estimation procedures were used to fit power functions to the data collected over this time period. The fitted load–discharge relationships are indicative of seasonal variations in SS and TN and of TP losses from HP#6. The exponents of the fitted power functions for TN and TP in the fall, for TP in summer season, and for SS in all seasons are >1, indicating that the concentrations of these species increase as flow rate increases. Most of the SS, TN, and TP transported in runoff left the watershed between April and September; thus, cost-efficient strategies can be established by focusing on this period. Further study of the seasonal variations is required for a better characterization of seasonal losses of SS, TN, and TP in runoff from the HP#6 watershed.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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