Author(s): Chen Qi; Zhijing Li; Shiming Yao; Zhongwu Jin; Yinjun Zhou
Linked Author(s): Shiming Yao
Keywords: Three Gorges Reservoir; Sedimentation; Dissolved CH4 Content; Green house gas
Abstract: With the increasing prominence of global climate change, the rise in methane (CH4) emissions, a significant greenhouse gas, has a marked impact on climate change. Reservoirs, as artificial lakes, have become a focal point of research for their dissolved CH4 emissions. This study statistically analyzed the concentrations of dissolved CH4 in different areas of the Three Gorges Reservoir, total sediment accumulation, and typical cross-section sediment thickness. Additionally, it explored the relationship between sedimentation and dissolved CH4 concentrations in conjunction with physical and chemical factors such as total nitrogen and phosphorus concentrations in sediments and reservoir depth. The results indicate that the dissolved CH4 concentrations in the Three Gorges Reservoir exhibit significant spatiotemporal heterogeneity and are closely related to the degree of sedimentation. In the near-dam area (downstream of Yunyang), the surface water dissolved CH4 content is very low (0.8 umol/L), significantly correlated with sedimentation above 145 meters (R2=0.6832). In the fluctuating backwater area (Fuling to Changshou), the surface water dissolved CH4 content gradually decreases from downstream to upstream, possibly influenced by reservoir scouring and higher dissolved oxygen levels. These findings are significant for understanding the impact of sedimentation on reservoir ecosystems and provide new perspectives for reservoir capacity management and sustainable utilization of the Three Gorges Reservoir.
Year: 2024