A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Transport of suspended sediment during the breakup of the ice cover, Saint John River, Canada
Abstract River concentrations of suspended sediment and particulate contaminants, such as trace metals, increase sharply during ice breakup, with potentially detrimental ecological impacts that may be complicated by changing climatic conditions. To enhance the very limited knowledge on this issue, comprehensive data have been collected on the Saint John River (SJR). During breakup, the suspended sediment concentration (SSC) was found to rise gradually, crest, and decline, roughly in step with the runoff, but occasionally spiked to extremely high peaks. The latter ranged from 4.2 to 6.5 times the runoff-generated peak concentrations (RPCs), which ranged from 35 to 150mg/L. Peak RPCs and individual-event sediment loads generally increased with flow discharge. The sediment spikes were invariably associated with waves resulting from releases of upstream ice jams and with the ensuing ice runs. Concentration–discharge graphs exhibited pronounced clockwise hysteresis, indicative of sediment supply constraints. This feature is more prominent in high-runoff events and typically associated with a lag of 1–3days between peak concentration and peak discharge, which arrives later. Prediction of SSC via sediment-rating curves is hopeless, but such curves can be helpful in computing loads associated with individual events using a modified approach that terminates load computation 3days after the arrival of peak discharge. The bulk of the sediment load is delivered on the rising limb of the hydrograph and is likely to be missed in routine sediment monitoring programs. Practical steps to capture this information are suggested. Increases in SJR spring flows during recent decades are projected to continue under a warming climate, resulting in considerable increases of SSCs and loads by the end of this century.
Highlights High loads of suspended sediment during spring breakup affect river water quality Detailed data sets are presented for the Saint John River Suspended sediment concentrations can reach extreme values Breakup loads comprise sizeable fractions of annual loads Simple methodology to predict sediment loads in terms of river flow is developed
Transport of suspended sediment during the breakup of the ice cover, Saint John River, Canada
Abstract River concentrations of suspended sediment and particulate contaminants, such as trace metals, increase sharply during ice breakup, with potentially detrimental ecological impacts that may be complicated by changing climatic conditions. To enhance the very limited knowledge on this issue, comprehensive data have been collected on the Saint John River (SJR). During breakup, the suspended sediment concentration (SSC) was found to rise gradually, crest, and decline, roughly in step with the runoff, but occasionally spiked to extremely high peaks. The latter ranged from 4.2 to 6.5 times the runoff-generated peak concentrations (RPCs), which ranged from 35 to 150mg/L. Peak RPCs and individual-event sediment loads generally increased with flow discharge. The sediment spikes were invariably associated with waves resulting from releases of upstream ice jams and with the ensuing ice runs. Concentration–discharge graphs exhibited pronounced clockwise hysteresis, indicative of sediment supply constraints. This feature is more prominent in high-runoff events and typically associated with a lag of 1–3days between peak concentration and peak discharge, which arrives later. Prediction of SSC via sediment-rating curves is hopeless, but such curves can be helpful in computing loads associated with individual events using a modified approach that terminates load computation 3days after the arrival of peak discharge. The bulk of the sediment load is delivered on the rising limb of the hydrograph and is likely to be missed in routine sediment monitoring programs. Practical steps to capture this information are suggested. Increases in SJR spring flows during recent decades are projected to continue under a warming climate, resulting in considerable increases of SSCs and loads by the end of this century.
Highlights High loads of suspended sediment during spring breakup affect river water quality Detailed data sets are presented for the Saint John River Suspended sediment concentrations can reach extreme values Breakup loads comprise sizeable fractions of annual loads Simple methodology to predict sediment loads in terms of river flow is developed
Transport of suspended sediment during the breakup of the ice cover, Saint John River, Canada
Beltaos, Spyros (author) / Burrell, Brian C. (author)
Cold Regions, Science and Technology ; 129 ; 1-13
2016-05-14
13 pages
Article (Journal)
Electronic Resource
English
Breakup , Climate , Concentration , Discharge , Load , River ice , Suspended sediment
Transport of suspended sediment during the breakup of the ice cover, Saint John River, Canada
| Online Contents | 2016
Suspended sediment concentrations in the Saint John River during ice breakup
| British Library Conference Proceedings | 2000
Extreme sediment pulses during ice breakup, Saint John River, Canada
| Elsevier | 2016