CMS-Flow/TideGates

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.

• Implementation of Structures in the CMS: Part IV, Tide Gate

Future SMS versions (13.4.x)

SMS 13.4 CMS-Flow model coverages.

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.
• 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.

List of tide gate structure parameters

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

SMS will handle the assignment of the appropriate values for Number of Cells and Cell IDs.

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	YES	1, 2, 3, or 4		Direction of Sea side: 1= North, 2= East, 3= South, 4= West
FLOW_COEFFICIENT_FROM_BAY	YES	<real>
FLOW_COEFFICIENT_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                       1            !1= North, 2= East, 3= South, 4= West
  FLOW_COEFFICIENT_FROM_BAY         0.5 
  FLOW_COEFFICIENT_FROM_SEA         0.46  
  OPEN_HEIGHT                       2.0  
  BOTTOM_ELEVATION                  -1.0  
  METH                              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                       1            !1= North, 2= East, 3= South, 4= West
  FLOW_COEFFICIENT_FROM_BAY         0.45 
  FLOW_COEFFICIENT_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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