Emission Coefficient of Methane for Natural Wetlands in Southern Taiwan

• Main Authors: Wei-Yao Li, 李偉搖
• Other Authors: Chih-Sheng Lee
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/00601021961705696274

碩士 === 崑山科技大學 === 環境工程研究所 === 99 === The study aims to survey methane emission coefficients and monitor water quality of two marshlands in southern Taiwan, for interpreting attributions of methane emission in different types of marshlands. The study started by selecting two distinct types of marshlands: Si-Cao Swamp, a natural coastal marshland and Hu-Lu-Pi Swamp, a natural inland marshland and followed by in-situ sampling of actual methane emission of respective locations together with water quality tests including water temperature, dissolved oxygen, pH value, sulfates, salinity, ORP, etc. Discussions were made on water quality variations that influenced methane emissions. Further calculations were conducted to obtain methane emission coefficient and its contribution. Survey results gathered from March 2010 to May 2011 show that Methane emission coefficient of Si-Cao Swamp is –0.59 ~ 0.48 mg/m2/h, averaging 0.1 ± 0.3 mg/m2/h; that of Hu-Lu-Pi Swamp is –0.02 ~ 6.70 mg/m2/h, averaging 0.9 ± 1.9 mg/m2/h; indicating a significantly higher methane emission in Hu-Lu-Pi Swamp than Si-Cao Swamp. Further water quality tests show that Methane emission in Si-Cao Swamp is positively related to temperature, dissolved oxygen, sulfides and pH value but negatively related to salinity; the ORP relation is insignificant. The results are partly inconsistent with relevant domestic and foreign documents; we suggest further studies to be made. However the Methane emission in Hu-Lu-Pi Swamp is positively related to temperature, salinity, pH value, sulfates and ORP but negatively related to dissolved oxygen. The results in dissolved oxygen are similar to study papers of mangrove in southern India, Thailand and Indonesia. These results show that generation of methane gas in the marshland is affected by complex environment factors; the current study has only gathered samples of 15 months, it is therefore insufficient to thoroughly interpret the entire mechanism of methane gas dynamics and distribution variations in the marshland. We suggest that a sustaining long-term survey shall be established.