Dynamics of Nitrous Oxide Emissions from Aquatic Systems - IAHR World Congress, 2019 Water Connecting the World

Youngsun Kim ¹ Un Ji ^1,2 Jungeun Gu ¹ Jongmin Ko ³ Hojeong Kang ³

¹Department of Land, Water and Environment Research, Korea Institute of Civil Engineering and Building Technology (KICT), South Korea
²Smart City and Construction Engineering, Korea University of Science and Technology, South Korea
³School of Civil and Environmental Engineering, Yonsei University, South Korea

Nitrous oxide (N₂O) is one of the most important non-CO₂ greenhouse gases with a global warming potential 265 times greater than that of CO₂ over a 100-year time span, making it a major contributor to climate change. Recent studies have shown the importance of aquatic systems, including rivers and estuaries, as a major potential source of N₂O. Global estimates of N₂O emissions from aquatic systems are 0.25 to 1.26 Tg N yr^-1 but clarification remains necessary. To consider the effects of vegetation on water flow and sediment transport, N₂O measurements were conducted at three different points (with dense, sparse, and no vegetation) of the hyporheic zone in a straight channel on October 10^th, 2018. To determine the nitrogen dynamics in aquatic systems, the physical properties of water such as water temperature, pH, dissolved oxygen (DO) and electrical conductivity (EC) were measured simultaneously at the same points, while N₂O measurements and water samples were collected to analyze the concentrations of total nitrogen (TN), ammonia-nitrogen (NH₃-N), and nitrate nitrogen (NO₃-N) in surface water.