科研之友
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摘要
Turbidity measurements at high temporal resolution from several sites within the distribution network gave a more complete record of the variability of turbidity than previously possible, showing that there are frequent movements of sediment at low concentrations. Knowledge of the availability of sediment was shown to be important to the prediction of turbidity, as the correlation of hydraulic disturbance (indicated by pressure change) alone with changes in turbidity was weak. These data sets also showed with greater confidence than previously possible that mains flushing frequently resulted in the incomplete removal of sediment. Given that knowledge of sediment availability is required to reduce uncertainty in the prediction of turbidity, measurements at high temporal and spatial resolutions were used to calculate sediment mass balances and determine sediment distribution within the study area. A net accumulation of 0.923 kg of sediment was observed within 2,482 m of the main, equivalent to 5.212 gm(-1)y(-1); it was also possible to identify the impact of hydraulic disturbance in changing sediment sinks to sources during the monitored period. In addition, the sediment fluxes gave some insight into the processes of deposition and resuspension. The former was shown to be unaffected by sediment concentration, and an increase in the latter was seen to persist for several days following a hydraulic disturbance of < 15 min. High-resolution monitoring may be useful for improving the targeting and evaluation of current reactive maintenance strategies for reducing discoloration and may also form the basis of more proactive strategies. The latter may be possible by using sediment budgets in conjunction with operational intervention to actuate mild hydraulic disturbances to encourage sediment throughput and maintain the discoloration risk below a critical limit. DOI: 10.1061/(ASCE)EE.1943-7870.0000521.
- 出版日期2012-6
