Premium
Characterization of CDOM of river waters in China using fluorescence excitation‐emission matrix and regional integration techniques
Author(s) -
Zhao Ying,
Song Kaishan,
Shang Yingxin,
Shao Tiantian,
Wen Zhidan,
Lv Lili
Publication year - 2017
Publication title -
journal of geophysical research: biogeosciences
Language(s) - English
Resource type - Journals
eISSN - 2169-8961
pISSN - 2169-8953
DOI - 10.1002/2017jg003820
Subject(s) - humus , dissolved organic carbon , fluorescence , environmental chemistry , principal component analysis , drainage basin , environmental science , chemistry , colored dissolved organic matter , matrix (chemical analysis) , analytical chemistry (journal) , ecology , biology , geography , soil science , physics , mathematics , chromatography , soil water , statistics , cartography , phytoplankton , quantum mechanics , nutrient
Abstract The spatial characteristics of fluorescent dissolved organic matter (FDOM) components in river waters in China were first examined by excitation‐emission matrix spectra and fluorescence regional integration (FRI) with the data collected during September to November between 2013 and 2015. One tyrosine‐like (R1), one tryptophan‐like (R2), one fulvic‐like (R3), one microbial protein‐like (R4), and one humic‐like (R5) components have been identified by FRI method. Principal component analysis (PCA) was conducted to assess variations in the five FDOM components ( F Rί ( ί = 1, 2, 3, 4, and 5)) and the humification index for all 194 river water samples. The average fluorescence intensities of the five fluorescent components and the total fluorescence intensities F SUM differed under spatial variation among the seven major river basins (Songhua, Liao, Hai, Yellow and Huai, Yangtze, Pearl, and Inflow Rivers) in China. When all the river water samples were pooled together, the fulvic‐like F R3 and the humic‐like F R5 showed a strong positive linear relationship ( R 2 = 0.90, n = 194), indicating that the two allochthonous FDOM components R3 and R5 may originate from similar sources. There is a moderate strong positive correlation between the tryptophan‐like F R2 and the microbial protein‐like F R4 ( R 2 = 0.71, n = 194), suggesting that parts of two autochthonous FDOM components R2 and R4 are likely from some common sources. However, the total allochthonous substance F R(3+5) and the total autochthonous substances F R(1+2+4) exhibited a weak correlation ( R 2 = 0.40, n = 194). Significant positive linear relationships between F R3 ( R 2 = 0.69, n = 194), F R5 ( R 2 = 0.79, n = 194), and chromophoric DOM (CDOM) absorption coefficient a (254) were observed, which demonstrated that the CDOM absorption was dominated by the allochthonous FDOM components R3 and R5.