| Budget Amount *help |
¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000)
Fiscal Year 2016: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2015: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
|
|---|
| Outline of Final Research Achievements |
Sulfate and DO were both shown to influence the methane production, which suggests that clarifying the role of sulfate and DO in the methane production may allow modelling of the differences in methane emission. Therefore, we conducted field observations in Lake Abashiri, which is a typical brackish lake. Sulfate concentrations decreased rapidly from 900 mg/L at the top of the benthic sediment to nearly 0 mg/L at a sediment depth of 0.05 m. Accordingly, the methane production was almost uniform across sediment depths of 0.05 to 0.25 m, 1400 to 1800 micro mol m2/d. The methane production was a function of DO concentrations at the sediment surface and can be modelled by a logistic function; constant production at 1400 micro mol m2/d for DO concentrations of 0.0 to 3.0 mg/L, and rapidly decreasing to 0 micro mol m2/d over DO concentrations of 3.0 to 6.0 mg/L, which was verified by using a simple one-dimensional vertical methane model with a good agreement with filed observation results.
|
