Long-term agricultural non-point source pollution loading dynamics and correlation with outlet sediment geochemistry

JOURNAL OF HYDROLOGY

卷:540

Article

Ouyang, Wei¹  Jiao, Wei¹  Li, Xiaoming¹  Giubilato, Elisa²  Critto, Andrea² 

[1] Beijing Normal Univ, Sch Environm, State Key Lab Water Environm Simulat, Beijing 100875, Peoples R China

[2] Ca Foscari Univ Venice, Dept Environm Sci Informat & Stat, I-30123 Venice, Italy

关键词: Agricultural non-point source pollution;    Sediment core;    Pb-210;    Heavy metals;    Watershed water quality;   

DOI  :  10.1016/j.jhydrol.2016.06.043

来源: Elsevier

【 摘 要 】

Some agricultural non-point source (NPS) pollutants accumulate in sediments in the outlet sections of watersheds. It is crucial to evaluate the historical interactions between sediment properties and watershed NPS loading. Therefore, a sediment core from the outlet of an agricultural watershed was collected. The core age was dated using the Pb-210 method, and sedimentation rates were determined using the constant rate of supply (CRS) model. The total nitrogen (TN), total phosphorus (TP), Cd, Pb, Cu, Ni and Cr accumulations in the sediment generally showed fluctuating increases, with the highest sedimentation fluxes all occurring in approximately 1998. The measurement of specific mass sedimentation rates reflected a record of watershed soil erosion dynamics. Using SWAT (Soil and Water Assessment Tool) to simulate long-term watershed agricultural NPS pollution loadings, the historical interactions between sediment properties and NPS loadings were further evaluated. The N leaching process weakened these interactions, but the historical accumulations of TP and heavy metals in sediments generally correlated well with watershed NPS TP loading. The regression analysis suggested that Pb and Cr were the most suitable indexes for assessing long-term NPS TN and TP pollution, respectively. Assessing the NPS loading dynamics using the vertical characteristics of sediment geochemistry is a new method. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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