作者：Chen, YN; Chen, NW; Li, Y; Hong, HS

影响因子：3.73

刊物名称：JOURNAL OF HYDROLOGY

出版年份：2018

卷：560 页码：160-172

Hydrological processes regulating sediment transport from land to sea have been widely studied. However, anthropogenic factors controlling the river flow-sediment regime and subsequent response of the estuary are still poorly understood. Here we conducted a multi-timescale analysis on flow and sediment discharges during the period 1967–2014 for the two tributaries of the Jiulong River in Southeast China. The long-term flow-sediment relationship remained linear in the North River throughout the period, while the linearity showed a remarkable change after 1995 in the West River, largely due to construction of dams and reservoirs in the upland watershed. Over short timescales, rainstorm events caused the changes of suspended sediment concentration (SSC) in the rivers. Regression analysis using synchronous SSC data in a wet season (2009) revealed a delayed response (average 5 days) of the estuary to river input, and a box-model analysis established a quantitative relationship to further describe the response of the estuary to the river sediment input over multiple timescales. The short-term response is determined by both the vertical SSC-salinity changes and the sediment trapping rate in the estuary. However, over the long term, the reduction of riverine sediment yield increased marine sediments trapped into the estuary. The results of this study indicate that human activities (e.g., dams) have substantially altered sediment delivery patterns and river-estuary interactions at multiple timescales.

Figure 10. The schematic graph of estuarine mixing model of Jiulong Jiang Estuary, including the riverine input (Qr = river flow discharge, Sr = river flow salinity, Cr = sediment concentration of river input), the riverine output (Q0 = flow discharge to the sea, S0 = salinity of flow to the sea, C0 = sediment concentration of flow to the sea), the tidal input (Qi = flow discharge of tidal input, Si = salinity of tidal input, Ci = sediment concentration of tidal input) and the sedimentation of the seabed (Fc). The gray line marks the front between fresh water and salt water, which varies with mixing conditions. The A3 is where the North River meets the West River, which is used as the upper stream boundary of the box model.