北江流域有机碳侵蚀通量的初步研究

选取北江的河口站断面,对径流进行了5个季节的采样分析.结果表明,北江径流中颗粒有机碳含量随总悬浮物含量的变化而同步变化;溶解有机碳含量与总悬浮物含量之间有时表现微弱的正相关,有时表现微弱的负相关.随着水体总悬浮物含量的增加,总悬浮物中有机碳的质量分数呈对数趋势降低.洪峰时期径流对有机碳的搬运是全年总搬运量的主要部分,这种现象对于溶解有机碳更为显著.初步估算,北江流域的有机碳侵蚀通量为10.01×10⁶g·km^-2·a^-1,其中以颗粒有机碳为主,达到6.54×10⁶g·km^-2·a^-1,溶解有机碳的侵蚀通量为3.47×10⁶g·km^-2·a^-1.北江流域有机碳侵蚀通量的总量和组成特点与多数季风流域具有更大的一致性.

A Preliminary Study on the Organic Carbon Weathering Fluxes in Beijiang River Drainage

Riverine water samples were collected from Hekou hydrometric station of Beijiang River in five hydrological seasons. The samples were analyzed of their organic carbon and total suspended substance, which demonstrated that the concentrations of particulate organic carbon (POC) changed synchronically with the concentrations of total suspended substance (TSS) in riverine water. The correlation between the concentrations of TSS and dissolved organic carbon (DOC), however, is sometimes positive and sometimes negative, and the correlation is not so notable as that between TSS and POC. With the concentration of total suspended substances increasing, the quality partition of organic carbon in total suspended substance decreased in a logarithm tendency. The transportation of organic carbon, especially of DOC, mainly takes place in flood peak periods. The weathering flux of organic carbon in Beijiang River drainage basin is about 10.01×10⁶g·km^-2·a^-1 , which is constituted by 6.54×10⁶g·km^-2·a^-1 of POC and 3.47×10⁶g·km^-2·a^-1 of DOC. This pattern of organic carbon weathering flux in Beijiang drainage basin is consistent with that of most of the monsoon drainage basins.