LIU Yijun1, YUAN Jie2, WANG Baoli1 and Khan Md Golam Mostofa1
（1. Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072;
2. Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029.）
Abstract: This study investigated sources, characteristics and transformation of dissolved organic matter (DOM) in the Pingzhai Reservoir along the Sancha River Basin, SW China, by using fluorescence properties of three-dimensional excitation emission matrix (3-D EEM) spectroscopy and parallel factor (PARAFAC) analysis. The results demonstrated that several fluorescent DOM (FDOM) components were identified in waters of incoming, surface layer (0~5 m), deeper layer (10~60 m) and outgoing of the Pingzhai reservoir and they could be denoted as terrestrial humic-like substances, autochthonous humic-like substances, protein-like substances, tryptophan-like substances, tyrosine-like substances. The fluorescence intensity of terrestrial humic-like substances in outgoing waters decreased slightly in comparison with that in incoming waters, suggesting that the terrestrial humic-like substances are relatively recalcitrant to degradation during the transportation from inflowing to reservoir and then outgoing water. Conversely, the fluorescence intensity of the autochthonous humic-like substances was higher in the reservoir than in the incoming and outgoing waters, suggesting that the autochthonous humic-like substances are simultaneously produced from autochthonous organic matter and then degraded under influences of photochemical, microbial and dam-barrier physical processes. Similar results were also observed for other fluorescent substances. Temperature (T), pH, DO and CDOM showed the similar seasonal change. These results suggest that the influences of photochemical and microbial processes along with dam-barrier physical processes are responsible for space-time transformation dynamics of FDOM components in the incoming, reservoir area surface water, reservoir area deeper water and outgoing waters of the Pingzhai reservoir.
Key words: Pingzhai Reservoir; fluorescent dissolved organic matter; excitation-emission matrix spectra; parallel factor analysis; fluorescence component
EARTH AND ENVIRONMENT Vol.47, No.6, Tot No.332, 2019, Page 795-804
