Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Hydrol. Earth Syst. Sci., 20, 787-801, 2016
http://www.hydrol-earth-syst-sci.net/20/787/2016/
doi:10.5194/hess-20-787-2016
© Author(s) 2016. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
19 Feb 2016
Influence of environmental factors on spectral characteristics of chromophoric dissolved organic matter (CDOM) in Inner Mongolia Plateau, China
Z. D. Wen1, K. S. Song1, Y. Zhao1, J. Du1, and J. H. Ma1,2 1Northeast Institute of Geography and Agroecology, CAS, Changchun, China
2University of Chinese Academy of Sciences, Beijing, China
Abstract. Spectral characteristics of chromophoric dissolved organic matter (CDOM) were examined in conjunction with environmental factors in the waters of rivers and terminal lakes within the Hulun Buir plateau, northeast China. Dissolved organic carbon (DOC), total nitrogen (TN), and total phosphorous (TP) were significantly higher in terminal lakes than rivers waters (p  <  0.01). Principal component analysis (PCA) indicated that non-water light absorption and anthropogenic nutrient disturbances were the likely causes of the diversity of water quality parameters. CDOM absorption in river waters was significantly lower than terminal lakes. Analysis of the ratio of absorption at 250 to 365 nm (E250 : 365), specific ultraviolet (UV) absorbance (SUVA254), and the spectral slope ratio (Sr) indicated that CDOM in river waters had higher aromaticity, molecular weight, and vascular plant contribution than in terminal lakes. Furthermore, results showed that DOC concentration, CDOM light absorption, and the proportion of autochthonous sources of CDOM in plateau waters were all higher than in other freshwater rivers reported in the literature. The strong evapoconcentration, intense ultraviolet irradiance, and landscape features of the Hulun Buir plateau may be responsible for the above phenomenon. Redundancy analysis (RDA) indicated that the environmental variables total suspended matter (TSM), TN, and electrical conductivity (EC) had a strong correlation with light absorption characteristics, followed by total dissolved solid (TDS) and chlorophyll a. In most sampling locations, CDOM was the dominant non-water light-absorbing substance. Light absorption by non-algal particles often exceeded that by phytoplankton in the plateau waters. Study of these optical–physicochemical correlations is helpful in the evaluation of the potential influence of water quality factors on non-water light absorption in cold plateau water environments. The construction of a correlation between DOC concentration and water quality factors may help contribute to regional estimates of carbon sources and fate for catchment carbon budget assessments.

Citation: Wen, Z. D., Song, K. S., Zhao, Y., Du, J., and Ma, J. H.: Influence of environmental factors on spectral characteristics of chromophoric dissolved organic matter (CDOM) in Inner Mongolia Plateau, China, Hydrol. Earth Syst. Sci., 20, 787-801, doi:10.5194/hess-20-787-2016, 2016.
Publications Copernicus
Download
Short summary
The study indicated that CDOM in rivers had higher aromaticity, molecular weight, and vascular plant contribution than in terminal lakes in the Hulun Buir plateau, Northeast China. The autochthonous sources of CDOM in plateau waters were higher than in other freshwater rivers reported in the literature. Study of the optical–physicochemical correlations is helpful in the evaluation of the potential influence of water quality factors on non-water light absorption in plateau water environments.
The study indicated that CDOM in rivers had higher aromaticity, molecular weight, and vascular...
Share