InfoWorks ICM supports spatially varying rainfall by the use of rain gauge boundaries which define which region is covered by a particular rain gauge. Boundaries are imported or digitised onto the GeoPlan view and then associated with a Rainfall event. InfoWorks ICM can then apply the correct rain gauge to subcatchments, buildings and 2D mesh elements falling within the rain gauge boundaries.
Rain gauge boundaries can be created automatically in InfoWorks ICM using the Thiessen Polygon method.
To 'move' a rain gauge; create a new rain gauge with the profile number of the rain gauge to be moved. The old point will be removed, and a new point will be created at the location clicked on in the GeoPlan view.
The process of importing rain gauge boundary data is the same regardless of the GIS component being used in the GeoPlan window. The file containing the data to import must included specific fields that are detailed below.
Rain gauge boundary data can be imported from a theme or layer containing rain gauge boundaries appropriately coded so they can be associated with rainfall profiles in InfoWorks ICM. The layer for import must include a field named "PROFILE" of type, Number.
The profile numbers in the theme / layer must match the profile numbers in the rainfall events to which the boundaries are to be associated.
Rain gauge boundary data can be imported from a MapInfo table containing rain gauge boundaries appropriately coded so they can be associated with rainfall profiles in InfoWorks ICM. The table for import must include a field of type Integer, that contains the profile numbers of the rainfall events to which the boundaries are to be associated.
To import rain gauge boundaries:
This displays the Import Raingauge Boundary dialog.
The boundary data is now imported as a temporary boundary layer on the GeoPlan view. The next task is to assign these boundaries to one or more rainfall events. Details on how to continue can be found in Associating Rain Gauge Regions with a Rainfall Event.
To associate rain gauge boundaries with a Rainfall event:
This displays the Common Tree Selection dialog.
InfoWorks ICM uses the rain gauge profile number to apply the boundary data to the rainfall event. If there is a profile in the rainfall event with a profile number that matches a rainfall boundary, the boundary information is added to the Gauge data field for the profile.
All profiles in the event must have boundary information before spatial rainfall can be used in simulations. Simulations will fail if there are profiles without boundary information.
Simulations will fail if subcatchment or building centroids fall outside of the defined rain gauge boundaries.
To check that rain gauge boundaries have been saved correctly:
Rain gauge boundary data associated with a Rainfall event can be loaded onto the GeoPlan window and then saved to a different rainfall event.
To copy rain gauge boundary information between rainfall events
As an alternative to stage 2 above:
The temporary boundary layer that contains imported regions can be removed from the GeoPlan window by choosing, from the GeoPlan menu:
When the GeoPlan view is closed the temporary layer will be removed automatically and will not be shown next time the network is opened.