A preliminary study on the carbon weathering in Longchuan River

Abstract

Riverine water samples from September 2007 to September 2009 were collected for the suspended solid and various forms of carbon from Chuxiong Station located along Longchuan River. The organic carbon and total suspended substance extracted from samples were analyzed. Results indicated that the Total Organic Carbon (TOC) mainly depended on the Particle Organic Carbon (POC) in flood season and on Dissolved Organic Carbon (DOC) in dry season, respectively. The Dissolved Inorganic Carbon (DIC) did not exhibit an evident fluctuation over the seasons. During the flooding period, POC peaked more quickly than DOC, indicating that the mechanical erosion happened more directly and quickly than the chemical erosion. Owing to the dilution effect, the correlation between the concentrations of DIC and discharge turned to be negative. The POC was significantly related to the Total Suspended Substance (TSS) in riverine water. As the concentration of the TSS increased, the mass fraction of organic carbon in TSS decreased. For the effect of the adsorption and liberation, the DOC variation was relatively independent of the TSS variation.