IMPORT XPRAFTS Dialog

When values are exported from XPRAFTS, their units of measurement are not exported. In XPRAFTS, model units are either small, e.g. millimetres or large e.g. kilometres.

This option allows you to choose if the values being imported are in Small (default) or Large units.

This section is only displayed if the network being imported contains subcatchments.

Allows you to choose whether or not XPRAFTS First and Second Subcatchments should be imported into ICM as one combined subcatchment or as two individual subcatchments.

The options are:

• Combine 1st and 2nd subcatchments into a single polygon (default)

  XPRAFTS First and Second Subcatchments are imported as one combined subcatchment in ICM.

  Note: The subcatchments will only be combined in ICM if the polygon geometry of the XPRAFTS First Subcatchment and Second Subcatchment are the same.

  They will also not be combined if either of their runoff surface type is set as Impervious=100 or Pervious=0 in the XPX file being imported. In such cases, the First Subcatchment and Second Subcatchment will be imported as separate subcatchments.

  Normally, if the subcatchments being combined have different property values (for example, the slope of subcatchment 1 is different from that of subcatchment 2), only the property of subcatchment 1 is imported.

• Split 1st and 2nd subcatchments to separate polygons

  XPRAFTS First and Second Subcatchments are imported as two individual subcatchments in ICM.

This section is only displayed if the network being imported contains lags links.

ICM does not have an equivalent to an XPRAFTS lag type of link, however, lag link data can still be imported either as part of an ICM subcatchment or converted to a channel type of link in ICM.

You can choose how the lag links, which are located downstream of XPRAFTS routing links, are to be handled on import by selecting one of the following options:

• Split network downstream of channel links and maintain lag link data

  Lag link data will be imported but there will be no connectivity between the lag links and nodes in the network.

• Maintain network connectivity by converting downstream lag links to channel links

  Downstream lag links are imported as channel links so connectivity is maintained.

The selected import option also influences subcatchment drainage set by the Drains to property. If a node is connected by a lag link, the first subcatchment of the upstream node of a lag link will drain to the first subcatchment of its downstream node. If a node is not connected by a lag link, it will drain to a node.

An illustration of how a network is imported using each of the import methods is shown in the example below.

Example

Example of XPRAFTS network to be imported:

In this network, links 1, 2, 3, 4, 5, 7 and 9 (shown in black) are XPRAFTS lag links. Links 6, 8 and 10 (shown in blue) are XPRAFTS routing links.

Lag links 1, 2, 3 and 4 are upstream of routing links 6, 8 and 9, while lag links 5, 7 and 9 are downstream of the routing links.

Imported using the Split network downstream of channel links and maintain lag link data option:	Imported using the Maintain network connectivity by converting downstream lag links to channel links option:
Note that the arrows indicate a 'drains to' flow to a subctachment in the network
XPRAFTS routing links 6, 8 and 10 are imported as ICM channel links.	XPRAFTS lag links 5 to 10 have been converted to ICM channel links as these are located downstream of the XPRAFTS routing links 6, 8 and 10. XPRAFTS lag links 1 to 4 are not converted as these are located upstream of the routing links 6, 8 and 10.
If a node is connected by a lag link, the first subcatchment of the upstream node of a lag link drains to the first subcatchment of its downstream node. If a node is not connected by a lag link, it will drain to a node. The XPRAFTS data shown in the example network will therefore be imported to the ICM subcatchments Drains to field as shown below:
Imported using the Split network downstream of channel links and maintain lag link data option:	Imported using the Maintain network connectivity by converting downstream lag links to channel links option: