A preliminary study of carbon balance and the uncertainty for Lake Gaoyang, Pengxi River of the Three Gorges Reservoir

To understanding the carbon budget, our research chose Lake Gaoyang as object and established an estimate method of carbon budget. From September 2011 to August 2012, we analyzed the main path of carbon budget for the Lake Gaoyang in Pengxi River. The main conclusions for the one year are as follows: input carbon fluxes of river transport were 133548.55 t C, output carbon fluxes of river transport were 125651.82 t C, diffusive fluxes of water to air interface were 762.56 t C, diffusive fluxes of water-level-fluctuating zone were 123.74 t C, ebullition fluxes were 0.38 t C, input carbon fluxes of precipitation were 104.58 t C, and net accumulation of carbon fluxes of the Lake Gaoyang were 7114.63 t C. It was mainly in the form of dissolved inorganic carbon. The carbon in the water of the Lake Gaoyang in Pengxi River showed the characteristics of longitudinal transport along the river channel. Lots of carbon went into the uplift air and deposited in Lake Gaoyang from upstream. It may be the main source of greenhouse gases on the water to air interface. As a whole, Lake Gaoyang presents the characteristic of carbon accumulation throughout the year, but some methods remains uncertain for the spatial and temporal heterogeneity of water-gas interface diffusion flux and air release flux. We need more systematic and long-term work to verify or modify. © 2017 by Journal of Lake Sciences.