A comprehensive dataset for river carbon cycling in China

Rivers play a vital role in the global carbon cycle, connecting atmospheric, terrestrial, and oceanic carbon reservoirs. Once viewed merely as conduits transporting carbon from land to sea, rivers are now recognized as "biogeochemical reactors" that actively metabolize organic carbon, resulting in the net emission of carbon dioxide (CO₂) and methane (CH₄). Accurately estimating the carbon budgets of rivers requires accounting for their spatial heterogeneity and diverse physical and biogeochemical characteristics, making extensive data collection a prerequisite. This study compiles a comprehensive dataset for river carbon cycling in China, including the following data: 1) flux data, such as CO₂ and CH₄ fluxes at the water-atmosphere interface and water-sediment interface, as well as the lateral organic or inorganic carbon flux exported by runoff; (2) water attributes, including dissolved and particulate organic carbon contents, partial pressure of CO₂ and CH₄, water temperature, dissolved oxygen, salinity, pH, chlorophyll content, and isotopes; (3) watershed attributes, encompassing watershed area, climate and topographic indices, and land cover/use proportions. Compared to existing dataset, this dataset covers both riverine and watershed-scale variables, making it particularly suited for integrated analysis from a systematic perspective.