Relevance of methane flux on the intertidal flat sediments in Taean, west coast of Korea

Abstract

The CH4 is a powerful greenhouse gas, third in importance to CO2 and H2O and is the most abundant hydrocarbon. The wetland has been known as a major biogenic source of CH4 in the atmosphere. In the global scale, the amounts of 55~150 Tg CH4 are released into the atmosphere annually from wetlands. From March 2013 to September 2014, the emission of major gases (CH4, CO2 and O2) was measured using closed static chamber method on the intertidal flat sediments at Sogeun-ri(36°48’ 52.3”N, 126°11’ 03.8”E) and Eoeun-ri(36°49’ 11.0”N, 126°19’ 19.0”E) in Taean. The average of gas flux at Sogeun-ri during the experimental period was +0.28 mg m-2 hr-1 (+0.06~+0.60 mg m-2 hr-1) for CH4, +75.72 mg m-2 hr-1 (+58.45~+95.58 mg m-2 hr-1) for CO2 and -0.08 mg m-2 hr-1 (-0.02~-0.20 mg m-2 hr-1) for O2. At Sogeun-ri, the CH4 flux to mean size of sediments and temperature of inner chamber exhibited strong positive correlation (R2=-0.97 and R2=-0.89, respectively). It may indicate that temperature have significant role in determining whether the CH4 and CO2 source or sink take place. The average of gas flux at Eoeun-ri during the experimental period was -0.02 mg m-2 hr-1 (-0.02~+0.02 mg m-2 hr-1) for CH4, -118.58 mg m-2 hr-1 (-137.00~-81.73 mg m-2 hr-1) for CO2 and -0.01 mg m-2 hr-1 (-0.03~+0.01 mg m-2 hr-1) for O2. At Eoeun-ri, the CH4 flux before low tide was -0.02 mg m-2 hr-1 (R2=-0.56). The CH4 flux after low tide reached are released into the atmosphere annually from wetlands. From March 2013 to September 2014, the emission of major gases (CH4, CO2 and O2) was measured using closed static chamber method on the intertidal flat sediments at Sogeun-ri(36°48’ 52.3”N, 126°11’ 03.8”E) and Eoeun-ri(36°49’ 11.0”N, 126°19’ 19.0”E) in Taean. The average of gas flux at Sogeun-ri during the experimental period was +0.28 mg m-2 hr-1 (+0.06~+0.60 mg m-2 hr-1) for CH4, +75.72 mg m-2 hr-1 (+58.45~+95.58 mg m-2 hr-1) for CO2 and -0.08 mg m-2 hr-1 (-0.02~-0.20 mg m-2 hr-1) for O2. At Sogeun-ri, the CH4 flux to mean size of sediments and temperature of inner chamber exhibited strong positive correlation (R2=-0.97 and R2=-0.89, respectively). It may indicate that temperature have significant role in determining whether the CH4 and CO2 source or sink take place. The average of gas flux at Eoeun-ri during the experimental period was -0.02 mg m-2 hr-1 (-0.02~+0.02 mg m-2 hr-1) for CH4, -118.58 mg m-2 hr-1 (-137.00~-81.73 mg m-2 hr-1) for CO2 and -0.01 mg m-2 hr-1 (-0.03~+0.01 mg m-2 hr-1) for O2. At Eoeun-ri, the CH4 flux before low tide was -0.02 mg m-2 hr-1 (R2=-0.56). The CH4 flux after low tide reached