Experimental Measurement for Nitrous Oxide Flux on Flat Bed and Dune in the Movable Bed Flume
Abstract
Various studies have been conducted for adaptation to climate change in the hydro-environmental conditions. Especially, river system is reported as a potential source of greenhouse gas emissions, and there is much interest in measuring greenhouse gas emitted from rivers. Recently it has been presented that the potential greenhouse gas emissions of river system can be naturally reduced by hyporheic flow with different bedforms. In this study, in order to understand the influence of river bedform on Nitrous Oxide (N2 O) emissions, hydraulic experiments to measure N2 O flux around flat bed and sand dune were performed in the movable bed flume. The amounts of N2 O emissions on flat bed and the vicinity of dune were measured to investigate the effects of bedforms on N2 O emission in the flow. Experimental flume was 37 m long, 1.0 m wide, and 1.0 m deep. N2 O flux was measured by 32 times using a chamber on a flat bed and dune by circulating water for a week in the experimental flume. With the measurement of N2 O, the components of water quality and velocity were also measured at the same time. The experiment was conducted at an average discharge of 0.0158 m3/s and velocity of 0.0506 m/s. N2 O flux tended to decrease over time from 59.84 N2 O-N g/m2 to 30.77 N2 O-N g/m2in a flat bed and from 157.22 N2 O-N g/m2 to 74.26 N2 O-N g/m2 in the vicinity of sand dune . Based on the decreasing tendency of N2 O flux , NO3-N was also initially measured at a maximum of 3.54 mg/L, however it was reduced to 1.72 mg/L.
ACKNOWLEDGMENTS : This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF-2017R1A2B4007131).- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMEP51E2133A
- Keywords:
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- 1824 Geomorphology: general;
- HYDROLOGY;
- 1825 Geomorphology: fluvial;
- HYDROLOGY;
- 1830 Groundwater/surface water interaction;
- HYDROLOGY;
- 1856 River channels;
- HYDROLOGY