Check 2098 Could not find a SC connection snapped to SH boundary

From Tuflow
Jump to: navigation, search

Error Message

When reviewing the TUFLOW messages I get the following check message:

  • CHECK 2098 - Could not find a SC connection snapped to SH boundary.

Reason

This usually occurs because the objects are not snapped together in the 2d_bc layers(s). If you were using a pump to discharge water out of the catchment e.g. for flood relief pumping, it is common to not have a connection object for the pump because you are not modelling where the pumped water is moved to. However, in Module 14 the pump is transferring water to a location within our 2D model domain. Therefore we do in this instance require a connecting object to transfer the pumped water.

The SH boundary object (the pump) needs to be snapped to the end of the SC connection line, allowing the transfer of pumped flow to the new location in our 2D domain. The connectivity between the layers and objects is based on their snapping. Where these features are not snapped, Check 2098 will occur with flow in or out of the SH boundary lost, adding to model mass error.

Solution

To locate where the problem is occurring, import or load the _messages layer into your GIS package. This file is saved in the log directory. In the tutorial model this is TUFLOW\runs\log\ and will have the same name as the TUFLOW simulation. In Module 14 the messages layer is called either:

  • M14_5m_001_messages.mif (GIS FORMAT == MIF); or
  • M14_5m_001_messages_P.shp (GIS FORMAT == SHP).

This GIS layer contains information on where the error is occurring and is viewed by zooming to the message.

Tip: the zoom to layer extent function in your GIS package can help here.

You may need to zoom in very closely to the area but the SH and SC objects will not be correctly snapped. To overcome the problem:
For MapInfo users:
Ensure that the "snap tool" is enabled and the layer you are snapping to is selectable. The "Reshape" option can be used to move a vertex.
For QGIS users:
Ensure the layer you are snapping to has snapping enabled (see the Settings >> Snapping Options... menu) and an appropriate snap tolerance is specified (5-10 map units/metres). The "Node Tool" may be used to move vertices.

Additional Information

The following .tcf file command may also be used to set the snap tolerance in TUFLOW. The default is 0.001 metres (1mm).
Snap Tolerance == <value in metres>