Modelling Breaches in Banks and Linear Structures
A manual breach can be defined for the following objects:
- River Reaches (left and right bank)
- Inline Banks (used as a 1D - 2D link)
- Base Linear Structures (2D)
A breach is modelled by using Real Time Control (RTC) definitions to specify vertical movement of bank/linear structure points (vertices) with respect to time.
The RTC definitions to be used at section points are specified in the Sections Editor of the bank or linear structure.
RTC definitions for modelling breaches
RTC definitions to be used to control movement of a section point must be defined as global definitions (and therefore not associated with any particular regulator).
The same RTC definition may be used to set the value of one or more points on one or more banks/linear structures. Several different RTC definitions may be used to control points on the same bank/linear structure.
The RTC definition of a section point may be set to an RTC definition that does not exist; in this case the point will not be moved.
The only definition types that can be used to control points are:
- Tables
- Variables
The measurement for a variable, or output measurement for a table must be one of the following:
- Height above datum: level of point is set to the height value defined by the RTC definition
- Depth: level of point is set by subtracting depth value defined by RTC from: bank level specified at inline bank / river reach bank; crest level specified at base linear structure.
At each run timestep, InfoWorks ICM evaluates RTC definitions and uses them to set the current elevation of any points with an RTC definition specified.
Note:
- In the 1D network, the elevation of a point will not be set below the object that the bank abuts. This will either be the lowest level of a storage node, the lowest cross-section level for a river reach, or the elevation of a 2D element.
- In the 2D network, the point elevations are used to calculate the new elevation of the faces that from the linear structure (the flow calculation through faces is based on the face level, not on the level of the vertices). Face elevation will not be set below the level of the adjacent elements.
- During simulation, bank /crest levels may be adjusted to ensure that the points are not below adjacent 2D elements. However, any depth setting is still based on the level specified on the network object property sheet.
- When modelling two river reaches with adjoining banks, the banks and the breach are merged. If the adjoining banks are not identical, the merged bank uses the points and RTC from both banks to form a composite. In the case of coincident points where only one of the points has RTC, then that RTC will be used. In the case of coincident points where both points have RTC, only one of the RTCs will be used.
Viewing varying levels at a point
A graph of varying bank/crest level can be displayed, when simulation results are loaded on the GeoPlan Window, by clicking on a bank or crest level vertex that has an RTC definition applied using the graph pick tool 
on the Results Toolbar.
