Vol15 No.2: 319-326
【Title】Tempo-spatial variations of sediment-associated nutrients and contaminants in the Ruxi tributary of the Three Gorges Reservoir, China
【Author】SHI Zhong-lin1; WANG Yong-yan1,2*; WEN An-bang1; YAN Dong-chun1; CHEN Jia-cun1,2
【Addresses】1 Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China; 2 University of Chinese Academy of Sciences, Beijing 100049, China
【Citation】Shi ZL, Wang YY, Wen AB, et al. (2018) Tempo-spatial variations of sediment-associated nutrients and contaminants in the Ruxi tributary of the Three Gorges Reservoir, China. Journal of Mountain Science 15(2). https://doi.org/10.1007/s11629-017-4486-9
【Abstract】Ruxi River is a tributary of the Three Gorges Reservoir. This study examined the temporal and spatial dynamics in particle size characteristics and the associated nutrients and contaminants of the fluvial suspended and deposited sediments along the Ruxi River. Temporal variations in the particle size distribution of the suspended sediment are controlled mainly by differences in sediment source during different seasons. Total organic carbon (TOC), total nitrogen (TN) and total phosphorous (TP) in the < 62 μm fraction of the suspended sediment exhibit considerably higher concentrations in spring, indicating high probability of algal blooms in the backwater areas. Downstream trends in the nutrient contents of < 62 μm deposited sediments imply the greatest potential for eutrophication in the backwater ends, where highest nutrient concentrations were detected. Assessment of metal contamination shows that the sediments deposited in the water-level fluctuation zone were moderately to strongly contaminated by Cadmium (Cd), with a considerably high potential ecological risk. The findings reported have emphasized the impacts of reservoir impoundment on aquatic and/or terrestrial environment in this region. More information on physical, chemical and biological processes of sediment and sediment-associated materials are needed for developing environmentally and ecologically sound policies of water and sediment management.
【Keywords】Sediments; Nutrients; Trace metals; Water-level fluctuation zone; Ruxi tributary; Three Gorges Reservoir