Navigation Locks
- Kester Scandrett
A navigation lock is a structure in a waterway designed to create a safe passage for navigation between two water pools at different levels.
EEMS provides the option of setting a navigation lock, and the option is set by clicking the Boundary Conditions item in the menu in the Model Control form and RCM on Hydraulic Structure and select New Boundary Group. The Add BC Group form will then be displayed. The user can set the Boundary Group Name as desired (Figure 1).
Figure 1. New Boundary Group
The Hydraulic Structure Boundary Conditions will be presented and contain several requirements for configuring the navigation lock. These requirements include Boundary Group Conditions, Current Boundary Cell, Time-Variable Hydraulic Structure Control, and Navigation Lock Filling/Draining Options (Figure 2). Each of these pieces of information is described below.
Boundary Group Conditions
In the Boundary Group Conditions menu, the user can change the Group Name. In the Flow Control Type menu, select the Navigation Lock option. The Use Default Masks to Control U/D Flow function should be enabled as the default (Figure 2).
Current Boundary Cell
In the Current Boundary Cell, the user can see in the Number of Cells text box. This represents the total number of cells they have set for one gate of the navigation lock. This number depends on the actual navigation lock gate width. The user can add or remove cells as required.
In the Upstream (outflow) Cell and Downstream Cell, input the necessary information for L, I, J, Bottom, Depth, Initial WSEL, and Vertical Offset. An example configuration is shown in Figure 3. L, I, and J can be extracted from the 2DH View function. The cell bottom elevation can also be obtained from the 2DH View after you have set the bottom elevation for the model. The user should also set the initial WSEL correctly. The Depth will be automatically calculated, which is equal to the initial WSEL minus the bottom elevation.
Time-Variable Hydraulic Structure Control
In the Time-Variable Hydraulic Structure Control section, click Edit. The Boundary Data Series will be displayed. Click Add New and input the necessary information, including Time (days), Opening Height (m), Opening Width (m), and Sill level change (m) as shown in Figure 4. Time (days) is the period for simulation. Opening Height and Width refer to the vertical and horizontal dimensions of the opening, respectively. Typically, these are observed values.
Figure 4. Boundary Data Series