龙川江流域碳侵蚀特征的初步研究

选取龙川江楚雄站断面,于2007年9月至2009年9月对水体内悬浮颗粒物及各形态碳的含量进行连续采样分析.结果表明,汛期水体内总有机碳(TOC)含量主要取决于颗粒有机碳(POC)含量,非汛期水体内总有机碳主要源于溶解性有机碳(DOC),而溶解性无机碳(DIC)的季节变化不明显.洪水过境过程中,POC随即表现出"峰值现象";DOC峰值出现的时间较晚,反映出DOC化学侵蚀的溶出相对于POC的机械侵蚀作用所需时间较长;DIC在洪水发生过程中呈现出与流量变化相反的趋势,说明其主要受稀释作用的影响.在对碳含量随悬浮颗粒物(TSS)变化的分析中发现,POC与TSS之间呈现出显著的正相关关系,但悬浮泥沙中有机碳的质量分数与TSS之间却存在显著的负相关关系,DOC与TSS间的相关性较弱,表现出吸附作用和释放作用的共同影响.

A preliminary study on the carbon weathering in Longchuan River

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.