Location

Portland, OR

Start Date

29-6-2016 1:30 PM

End Date

29-6-2016 3:30 PM

DOI

doi:10.15142/T3690628160853

Description

Previous research has concluded that upland wetlands could be effective to control small floods, yet for large floods their value may be greatly reduced as their storage capacity may be exceeded. A potential solution could be to release water from wetlands ahead of (e.g., few days before) a heavy rainfall event that is forecasted to produce flooding. In this case, the wetlands would be partially empty when this rainfall occurs. This work is part of a long term project which aims at developing a decision support system (DSS) that will determine optimal flooding scenarios with dynamic management of wetlands using siphons. This DSS will incorporate simulation and optimization models with the aim of minimizing flooding losses. The success of this project hinges on the automation of a siphon that can be fully controlled (opened and closed) remotely and that can initiate the flow regardless of the opening time of the valve. To make possible the remote and dynamic release of water from wetlands, we designed and built a siphon system that can be remotely operated by a SCADA-type control. In practice, flood control managers would remotely open and close hundreds or thousands of this type of siphon simultaneously or in arrays. This first paper presents an experimental, numerical (3D) and analytical study of the initiation of siphon flows regulated with a downstream ball valve for rapid and slow valve openings. Three initial water depths in the upstream tank, four different final opening positions for the valve and three opening times of the valve were investigated. The rate of depletion of the water surface in the upstream tank obtained numerically and analytically agreed well with the experimental results. Furthermore, the proposed siphon system was found to initiate the flow regardless of the opening time of the valve. Overall, the proposed siphon system could be an effective and inexpensive method to dynamically manage the storage of ponds and wetlands for flood control.

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Jun 29th, 1:30 PM Jun 29th, 3:30 PM

A Remotely Controlled Siphon System for Dynamic Water Storage Management

Portland, OR

Previous research has concluded that upland wetlands could be effective to control small floods, yet for large floods their value may be greatly reduced as their storage capacity may be exceeded. A potential solution could be to release water from wetlands ahead of (e.g., few days before) a heavy rainfall event that is forecasted to produce flooding. In this case, the wetlands would be partially empty when this rainfall occurs. This work is part of a long term project which aims at developing a decision support system (DSS) that will determine optimal flooding scenarios with dynamic management of wetlands using siphons. This DSS will incorporate simulation and optimization models with the aim of minimizing flooding losses. The success of this project hinges on the automation of a siphon that can be fully controlled (opened and closed) remotely and that can initiate the flow regardless of the opening time of the valve. To make possible the remote and dynamic release of water from wetlands, we designed and built a siphon system that can be remotely operated by a SCADA-type control. In practice, flood control managers would remotely open and close hundreds or thousands of this type of siphon simultaneously or in arrays. This first paper presents an experimental, numerical (3D) and analytical study of the initiation of siphon flows regulated with a downstream ball valve for rapid and slow valve openings. Three initial water depths in the upstream tank, four different final opening positions for the valve and three opening times of the valve were investigated. The rate of depletion of the water surface in the upstream tank obtained numerically and analytically agreed well with the experimental results. Furthermore, the proposed siphon system was found to initiate the flow regardless of the opening time of the valve. Overall, the proposed siphon system could be an effective and inexpensive method to dynamically manage the storage of ponds and wetlands for flood control.