This paper presents data of a 8-year time series of particulate organic carbon (POC) and dissolved organic carbon (DOC), and isotopic composition (Δ14C, δ13C) of suspended sediment at Makou section of the Xijiang River.We also discuss the sources of suspended sediment, using natural 14C method.The results of organic carbon concentration show temporal variation.Among them, POC content ranges from 0.13 mg/L to 4.98 mg/L with the average value of 1.35 mg/L and DOC content range from 0.98 mg/L to 4.17 mg/L with the average value of 1.86 mg/L.The content of DOC is slightly higher than that of POC in most cases, indicating that POC produced by mechanical erosion is not dominant, while DOC resulting from decomposition of organic matter was dominant in the Xijiang River.The DOC/POC ratio is 1.34, higher than that of the Changjiang (Yangtze) River and the Huanghe (Yellow) Rivers.In recent years, suspended POCδ13C ranges from -21.3‰ to -26.1‰, showing drift phenomenon with the time, and indicating the overall improvement of the ecological environment in the Xijiang River basin.The suspended sediment Δ14C values ranges from -132‰ to -425‰, whose variation were closely related to soil erosion produced by precipitation during the sampling period.The deeper soil erosion contributes more to "negative" suspended sediment POCΔ14C value and aged organic carbon; while the shallow soil erosion contributes more to "positive" suspended sediment POCΔ14C value and young organic carbon.
WEI Xiu-guo, LI Ning-li, SHEN Cheng-de, GUO Zhi-xing
. Riverine Organic Carbon Content and Significance of Carbon Isotopic Composition in the Xijiang River, China[J]. SCIENTIA GEOGRAPHICA SINICA, 2011
, 31(2)
: 166
-171
.
DOI: 10.13249/j.cnki.sgs.2011.02.166
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