CH₄ variation and main influencing factors of bottom water column in the middle section of Three Gorges Reservoir

???CH4???????????????????????????.?????????????????CH4?????????.????????????????-???????????????????CH4???????????????.????????????????????????CH4?????????????????2017?8?-2018?11??????????????????????????????????????????????????.????????????????CH4?????0.02~0.91 ?mol/L??????CO2??????0.006~0.105 mmol/L????????????7~90 g/kg????????0.27~45.6 g/kg.???????????????5—9?????????????????????????????CH4???????.???????????10?-??4???????????????????CH4???????????????????????????????????????CH4????????????.;Methane (CH4) is an important greenhouse gas contributing to global climate change. The Three Gorges Reservoir (TGR) the largest reservoir in China and has been receiving concerns for its potential CH4 emissions during past decades. However, current research TGR mainly focuses on observation of water-air interface fluxes, knowledge relationship between bottom sediments concentrations variation water column still lacking. To explore main influencing factors middle section TGR, this study collects overlying sediment respectively at Nanling Town Fuling, Shibaozhai Zhongxian Xiaozhou Wanzhou August 2017 November 2018, analyzing data combined with operation characteristics. results indicate that ranges from 0.02 ?mol/L 0.91 ?mol/L, carbon dioxide (CO2) 0.006 mmol/L 0.105 mmol/L, organic (OC) content 7 g/kg 90 g/kg, total nitrogen 0.27 45.6 g/kg. During low level period (May September), a large amount allochthonous OC input upstream terrestrial sources sufficient condition accumulation TGR. high (October April following year), runoff variations have no obvious effect relative proportion autochthonous matter increased, temperature aquatic environmental factor affected distribution.