Abstract:Comparative analyses about the differences of optical characteristics and composition of riverine waters in the East/West tributaries and the stem of Liaohe River were conducted and the influenced factors impacting on chromophoric dissolved organic matter (CDOM) and dissolve organic carbon (DOC) in different sub-watersheds were examined based on the absorption and fluorescent optical properties. Relationship between CDOM absorption and DOC concentration in the stem of Liaohe River exhibited the best (R = 0.89, P < 0.01) compared with that in the East Liaohe River (R = 0.75) and the West Liaohe River (R = 0.81). Close relationships between two water qualities (total suspended matter [TSM] and total alkalinity) and ratios of CDOM and DOC (CDOM/DOC) were obtained in this investigation. CDOM and DOC concentrations showed great variability in different sub-watersheds. CDOM and DOC concentrations in West Liaohe River were higher than that in East and the stem of Liaohe River. Land use/cover and climate conditions exerted great influences on CDOM and DOC. Significant negative correlations were obtained between forest area and CDOM and DOC, with the R = -0.41 and -0.56respectively. Positive correlations were observed between cropland area and CDOM and DOC (R = 0.40 for CDOM and R =0.32 for DOC). Furthermore, negative correlations were obtained between precipitations and CDOM and DOC, with the R = -0.53 and -0.38 respectively, which demonstrated that dilute effect of rainfall exhibited great influence on CDOM and DOC concentrations. Moreover, relationships between Fn (355) and CDOM absorption in different sub-watersheds showed strong correlations, especially in the West Liaohe River (R = 0.96, P < 0.01). All the samples exhibited fairly strong humic-like fluorophore (fluorophore A and fluorophore C) in the fluorescence excitation-emission matrices (EEMs). Meantime, samples in the main stem of Liaohe River showed strong protein-like fluorophore (fluorophore T). Main sources of CDOM in the studied rivers were terrestrial (allochthonous) origins, which showed the high weight molecular substances based on the S, FI and HIX values. However, molecular weights in West Liaohe River and the main stem of Liaohe River were inclined to be lower than that in the East Liaohe River.
邵田田, 宋开山, 丁智, 李思佳, 赵莹, 张柏. 辽河东西支流与干流水体光学特性和组分对比研究[J]. 中国环境科学, 2015, 35(9): 2794-2804.
SHAO Tian-Tian, SONG Kai-Shan, DING Zhi, LI Si-Jia, ZHAO Ying, ZHANG Bai. Comparative characterization of optically active components in waters from the east/west tributaries and the stem of Liaohe River. CHINA ENVIRONMENTAL SCIENCECE, 2015, 35(9): 2794-2804.