CMS-Flow Tide Gates
UNDER CONSTRUCTION
Introduction
A tide gate is an opening structure built across a river or a channel in an estuarine system. By preventing saltwater intrusion to farm land and allowing freshwater drainage to the estuary, tide gates are commonly used for flow and flooding control, and salinity and sediment management. Because a tide gate is a significant component of hydrodynamic and sediment transport controls in the coastal zone, it is important to incorporate the structure and to simulate its effect in the CMS.
Usage of Tide Gages for CMS in the SMS
Early SMS versions (< 13.4)
Previous documentation (Link given below) described the formulation and implementation of Tide Gates in CMS, detailing input requirements for SMS versions up to 11.2. This implementation required hand-manipulation of the CMS-Flow parameter files to add in lists of cells and option values.
Future SMS versions (13.4.x)
A "Structures" coverage has been added beneath the CMS-Flow model option in SMS 13.4 and later. This one coverage will handle Tide Gates as well as three other types: Rubble Mounds, Weirs, and Culverts.
Tide Gates are added to this coverage with the placement of Feature Arcs.
- Simply create a new feature arc within the new Structures coverage.
- Select the arc and double click the arc to open the dialog.
- Choose "Tide Gate" for the type and then enter the needed information on the right side of the dialog.
- When finished, the "Structures" coverage will need to be applied to the CMS Simulation in order to export the appropriate cards to the parameter file.
Values needed by the CMS for each Tide Gate are listed in the table below. If there is a user-definable option in the dialog for the user to enter a value, the word 'Dialog' is shown in column 2, otherwise the words 'No dialog' are written in column 2.
| Number of Cells | No dialog |
| Cell IDs | No dialog |
| Distribution Coefficient | Dialog |
| Orientation of Tide Gate | Dialog |
| Type of Weir | Dialog |
| Flow Coefficient Bay to Sea | Dialog |
| Flow Coefficient Sea to Bay | Dialog |
| Gate Opening Height | Dialog |
| Bottom Elevation of Tide Gate | Dialog |
| Calculation Method | Dialog |
| Schedule Operation Type | Dialog |
| Regular Start Time | Dialog |
| Regular Open Frequency | Dialog |
| Regular Open Duration | Dialog |
| Designated Start Time | Dialog |
| Designated Open Duration | Dialog |
SMS will handle the assignment of the appropriate values for Number of Cells and Cell IDs. See the table below for any dependencies for the above parameters.
CMS-Flow specific information
The parameters/selections for each Tide Gate feature arc will be exported to the ‘.cmcards’ file in the form of a block of values.
This implementation is being tested with CMS 5.3.12 and later.
- The Tide gate parameter cards needed for each gate are added to a structure block with a corresponding BEGIN/END statement for each gate are listed in the table below.
- For readability and to be consistent with other cards in the .cmcards file, all values should start in column 36 and 3 spaces written between each value per line if more than one.
| Cardname | Indent 2 spaces? | Type of value written | Dependent on | Notes |
|---|---|---|---|---|
| TIDEGATE_STRUCT_BEGIN | NO | N/A | ||
| CELL_IDS | YES | <int> <multiple int> | Total number of cells (n) followed by a
list of all cell ids (from 1 to n). | |
| DISTRIBUTION_COEFFICIENT | YES | <real> | ||
| ORIENTATION_SEA | YES | 'NORTH', 'SOUTH', 'EAST', 'WEST' | Direction of Sea side | |
| FLOW_COEFF_FROM_BAY | YES | <real> | ||
| FLOW_COEFF_FROM_SEA | YES | <real> | ||
| OPENING_HEIGHT | YES | <real> | How large the opening for the gate is. | |
| BOTTOM_ELEVATION | YES | <real> | Positive is upward | |
| METHOD | YES | 1 or 2 | 1= Approach 1, 2= Approach 2 (see literature) | |
| SCHED_OPERATION_TYPE | YES | 'REG', 'DES', 'EBB', 'UCG' |
'REG' - regular time interval 'DES' - designated times and durations 'EBB' - open gate for ebb tide, close for flood 'UCG' - uncontrolled gate | |
| REG_START_TIME | YES | <int> | Operation type == 'REG' | Start time (hour) |
| REG_OPEN_FREQUENCY | YES | <int> | Operation type == 'REG' | Opening frequency (hour) |
| REG_OPEN_DURATION | YES | <int> | Operation type == 'REG' | Open duration (hour) |
| NUM_DESIGNATED_TIMES | YES | <int> | Operation type == 'DES' | |
| DES_START_TIME | YES | multiple <int> | Operation type == 'DES' | Start time (hour) Repeated for number of designated times |
| DES_OPEN_DURATION | YES | multiple <int> | Operation type == 'DES' | Open duration (hour) Repeated for number of designated times |
| TIDEGATE_STRUCT_END | NO |
An example configuration for two tide gates is shown below:
TIDEGATE_STRUCT_BEGIN CELLS 3 20 50 70 DISTRIBUTION_COEFFICIENT 0.9 ORIENTATION_SEA NORTH !NORTH, EAST, SOUTH, WEST FLOW_COEFF_FROM_BAY 0.5 FLOW_COEFF_FROM_SEA 0.46 OPEN_HEIGHT 2.0 BOTTOM_ELEVATION -1.0 METHOD 1 !1= Approach 1, 2= Approach 2 SCHED_OPERATION_TYPE REG !REG, DES, EBB, or UCG REG_START_TIME 0 !-- This is elapsed hours from start (immediately on first day) REG_OPEN_FREQUENCY 18 !-- Reopen every 18 hours after the initial opening REG_OPEN_DURATION 6 !-- Keep gate open for 6 hours each time. TIDEGATE_STRUCT_END TIDEGATE_STRUCT_BEGIN CELLS 2 600 620 DISTRIBUTION_COEFFICIENT 0.8 ORIENTATION_SEA NORTH !NORTH, EAST, SOUTH, WEST FLOW_COEFF_FROM_BAY 0.45 FLOW_COEFF_FROM_SEA 0.4 OPEN_HEIGHT 1.5 BOTTOM_ELEVATION -1.5 METHOD 1 !1= Approach 1, 2= Approach 2 SCHED_OPERATION_TYPE DES !REG, DES, EBB, or UCG NUM_DESIGNATED_TIMES 3 DES_START_TIME 15 35 56 !-- Open gate at 15, 35, and 56 hours after start of run DES_OPEN_DURATION 6 7 6 !-- Keep gate open for 6, 7, and 6 hours, respectively. TIDEGATE_STRUCT_END
Last update 9/25/2024
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