Abstract:Inland waters are an important natural source of methane to the atmosphere, a potent greenhouse gas. The potential of sediment methane production (PMP) under anaerobic conditions is a key indicator for the level of atmospheric emissions of methane. However, there is a lack of cross-system studies on the sediment PMP in inland waters. The underlying driving mechanisms are still unclear. In this study, we collected data on PMP in inland waters in China including reservoirs, lakes, rivers and wetlands. Combined with some unpublished data (a total of 210 data points), the temporal and spatial distribution of sediment PMP in several different systems was explored, and the drivers of the sediment PMP were identified. We found that PMP is seasonally variable, showing a trend of being significantly greater in the rainy season than in the dry season (~3.5 times, p<0.01)); damming causes a significant increase in PMP by more than ten times, and sediment PMP in reservoirs and lakes is significantly (p<0.01) greater than that of rivers or wetlands. Correlation analysis shows that eutrophication caused by human activities has a significant (p<0.05) driving effect on sediment PMP. Water temperature, water depth and sediment organic matter content have a significant (p<0.01) positive stimulating effect on sediment PMP, while salinity has a significant (p<0.01) inhibitory effect. In the context of global climate change, in order to make good future projections of carbon emissions from inland waters, human disturbances such as damming and eutrophication must be well incorporated, in addition to the natural process of global warming.