How to create a link to ESTRY

You may be interested in connecting your Flood Modeller model to ESTRY. A typical application of components linked in this way would be representation of an inundation of an urban area, with the river modelled by the Flood Modeller's 1D river solver and culverts and other structures on the inundated area modelled in the ESTRY component of TUFLOW.
To physically link the models together, as with the link from the 1D river solver to TUFLOW only (i.e. TUFLOW 2D), it is possible to link the 1D river solver to TUFLOW (1D) (i.e. TUFLOW with ESTRY component) in two ways, either by:

1. Flood Modeller's 1D river solver calculating the water level and TUFLOW calculating the discharge (X1DH link), or
2. Flood Modeller's 1D river solver calculating the discharge and TUFLOW calculating the water level (X1DQ link)

Typically, the X1DH link (i) will apply when the TUFLOW component is discharging into the 1D solver. The discharge will be applied to the Flood Modeller 1D river network as a lateral inflow, in the same way as the HX link applies for the link to TUFLOW (2D); conversely, the X1DQ link (ii) will typically apply when Fthe river network is discharging into the TUFLOW component, in the same way that the SX link applies for the link to TUFLOW (2D). The water level calculated by TUFLOW is applied as a dynamic head boundary (HTBDY) in the 1D river solver.
A river network and ESTRY nodes will be considered as linked if:

1. A TUFLOW 1D (ESTRY) node in a 1d_nwk layer, and an 1D solver node in a ”Read GIS ISIS Nodes ==” or ”Read GIS ISIS Network ==” layer are snapped.
2. By default, the link will be assumed to be an X1DH link; alternatively, to specify an X1DQ link instead, one should additionally set the 1d_nwk Conn_2D attribute (formerly called Topo_ID) to ”X1DQ” for the ESTRY node to complete the link. Note that the upstream and downstream Inverts for the node should be set to -99999 if there is not already a node (i.e. a new node is created for the purposes of the link). One can also set the Conn_2D attribute (formerly called Topo_ID) to ”X1DH” to reaffirm that the connection is an X1DH, although since this is the default behaviour, this is not mandatory, but may be used for clarification purposes.

Tips and Tricks

• The Flood Modeller 1D model's node on the receiving end of an X1DH connection must be a channel unit (i.e. RIVER, INTERPOLATE, REPLICATE or CONDUIT) and must not have a distance to next cross-section of zero (i.e. not an end node of a reach).
• The Flood Modeller 1D model's node on the receiving end of an X1DQ connection must be an HTBDY unit. This does not need to contain any data (any data within will be overridden), since the water level values are supplied by TUFLOW. Normal 1D solver connectivity rules regarding an HTBDY apply.
• A connector ”X” channel type can be used to connect the end of the linked ESTRY channel to the ESTRY node snapped to the 1D model's node.
• Typically, an ESTRY timestep will be smaller than the 1D Model's timestep. In such cases, the total volume is accumulated over all ESTRY timesteps within a 1D Model's timestep, and applied to the 1D Model as a discharge by dividing the volume by the 1D Model's timestep.