Blockage Data Fields

A Blockage models a time-varying obstruction with user-defined contraction and expansion loss coefficients.

Blockage data can be edited on either the Blockage Grid View of the Links Grid or the Blockage Property Sheet.

To view and edit all blockage data, use the Property Sheet.

The following table describes all the blockage specific data which can be used to define a blockage in a channel, conduit or river reach. For details of results fields, see the Link Results Data Fields topic.

Common Data Fields

Fields that are common to the majority of objects can be found in the Common Fields topic.

Blockage Data

Database Table Name: hw_blockage

Show Columns

Database Names

Size, Type and Units

Defaults and Error Limits

Field Name

Help Text

Database Field

Data Type

Size

Units

Precision

Default

Error Lower Limit

Error Upper Limit

Warning Lower Limit

Warning Upper Limit

US node ID

Identity of the upstream node for this blockage.

us_node_id Text 64   0          
DS node ID Identity of the downstream node for this blockage. ds_node_id Text 64   0          
Link suffix

Link suffix of the conduit, channel or river reach with which this blockage is associated.

link_suffix Text 1   0          
Link type The type of link. Default is BLKAGE (blockage). link_type Text 6   0 BLKAGE        

Asset ID

For reference only. Designed as a reference to an asset database, but could be used for anything.

asset_id

Text

64

 

0

 

0

 

 

 

Sewer reference

An optional reference to identify the sewer to which an associated conduit is a part.

sewer_reference

Text

80

 

0

 

 

 

 

 

Length The length between the US node ID and the DS node ID is automatically calculated when both fields have been specified.                    

System type

Choose the system type from the dropdown list. See System Type for more information.

system_type

Text

10

 

0

Other

 

 

 

 

Branch ID

Numeric field used to identify to which long section the link is associated.

Can be set manually or automatically (see Defining Branches topic for more information).

branch_id

Long Integer

 

 

0

 

0

 

 

 

US settlement efficiency (%)

Closed

Water Quality

This section is relevant only to Water Quality Simulations. If the icon is at the start of a paragraph, then that paragraph is only relevant to water quality simulations. If the icon is at the top of a topic, or a section (underneath a section title), or a row in a table, then the complete topic, section or row is only relevant to water quality simulations.

The settlement efficiency fields allow you to set the effectiveness of an overflow for trapping out sediment. The overflow is a link (normally a pipe) attached to a node acting as a storage tank (storage node or manhole).

Normally the upstream end of the link will be attached to the node and act as the overflow.

The upstream settlement efficiency determines the efficiency for the overflow.

In some circumstances the link may be reversed (storage tank at the downstream end) and the downstream settlement efficiency will be used.

In many cases an overflow will attach to an outfall from the system.

It would be very unusual to have both upstream settlement efficiency and downstream settlement efficiency set to non-zero values.

The valid range is 0-100%. 0% means the overflow acts as a normal continuation link. 100% means that the overflow traps out as much sediment as possible.

us_settlement_eff

Long Integer

 

 

0

0

0

100

 

 

DS settlement efficiency (%)

Closed

Water Quality

This section is relevant only to Water Quality Simulations. If the icon is at the start of a paragraph, then that paragraph is only relevant to water quality simulations. If the icon is at the top of a topic, or a section (underneath a section title), or a row in a table, then the complete topic, section or row is only relevant to water quality simulations.

See the description of US Settlement Efficiency.

ds_settlement_eff

Long Integer

 

 

0

0

0

100

 

 

Blockage type

The type of blockage can be set to:

  • Local (default)
  • Entry
  • Exit
  • Contraction
  • Expansion

See the Blockage topic for further information.

blockage_type Text       Local        
Initial blockage The initial blockage proportion can be set to between 0.0 (no blockage - free flow) and 1.0 (fully blocked - no flow). blockage_proportion Double     3 0 0 1    
Inlet loss coefficient The inlet loss coefficient must be greater or equal to 0.0. Default is 1.5. Inlet_loss_coefficient Double     3 1.5 0      
Outlet loss coefficient The outlet loss coefficient greater or equal to 0.0. Default is 1.0. Outlet_loss_coefficient Double     3 1.0 0      
Positive blocking rate

The rate at which the proportion of the blockage goes from one state to another in a positive direction.

The value must be greater than zero.

positive_prop_change Double   RS 5 0.1 0.000001      
Negative blocking rate

The rate at which the proportion of the blockage goes from one state to another in a negative direction.

The value must be greater than zero.

negative_prop_change Double   RS 5 0.1 0.000001      

Threshold

The minimum blockage proportion step which the software will implement.

Any changes below this threshold will be ignored. This prevents oscillation.

threshold

Double

 

 

5

0

0

 

 

 

InfoAsset unique ID

Unique ID associated with the corresponding object in an InfoAsset Manager database. When importing from InfoAsset Manager, the InfoAsset ID can be copied from the InfoAsset database in order to maintain links between the two networks.

asset_uid

GUID

 

 

0

 

0

0

0

0

Regulators

Property Sheets

Links Grid

Blockages

Link Results Data Fields