Methane dynamics and thermal response in impoundments of the Rhine River, Germany.
Methane dynamics and thermal response in impoundments of the Rhine River, Germany.
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DOI：
10.1016/j.scitotenv.2018.12.424
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发表时间：
2019-04
期刊：
影响因子：
--
通讯作者：
J. Wilkinson;P. Bodmer;A. Lorke
中科院分区：
文献类型：
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作者：
J. Wilkinson;P. Bodmer;A. Lorke
河流蓄水已被确定为温室气体甲烷的重要排放热点。在这项研究中，我们调查了甲烷动力学的五个河流蓄水池在两年内使用各种方法，从沉积物孵化测量甲烷形成率（MF），自动气泡陷阱和回声测深调查，以评估沸腾通量，并估计扩散的甲烷通量通过溶解在水中的浓度和计算的传输系数通过风速。MF被认为主要是acetochlastic，较高的孔隙水乙酸盐浓度与较高的MF。此外，沉积物MF表现出一致的深度剖面，当深度集成，MF是可比的气泡阱沸腾时间序列测量。我们的系统和广泛的文献数据的热响应分析表明，一致的平均值，但温度系数Q10（1.6至7.0）的不同研究的大范围。年平均沸腾率在不同地点之间的变化超过一个数量级（0.03至1.85 mgCH4l−1d−1），表明河流蓄水并不都是热点。今后的工作应调查沉积物输送、沉积模式和管理对沸腾甲烷排放的作用。
River impoundments have been identified as important emission hot spots of the greenhouse gas methane. In this study, we investigated methane dynamics of five river impoundments within a two year period using a variety of methods ranging from sediment incubations for measuring methane formation rates (MF), automatic bubble-traps and echo-sounding surveys to assess ebullition fluxes, and estimated diffusive methane fluxes via dissolved concentrations in the water and calculated transport coefficients via wind speed. MF was found to be predominantly acetoclastic, and higher porewater acetate concentrations were associated with higher MF. Moreover, sediment MF showed consistent depth profiles, and when depth-integrated, MF was comparable to bubble-trap ebullition time-series measurements. Thermal response analysed for our systems and a wide range of literature data demonstrated a consistent mean value, but a large range of temperature coefficientQ10(1.6 to 7.0) for different studies. Annual mean ebullition rates varied over more than one order of magnitude from site to site (0.03 to 1.85 mgCH4l−1d−1), demonstrating that river impoundments are not all hot-spots. Future work should investigate the role of sediment delivery, deposition patterns and management on methane emissions by ebullition.