Hydraulic structures (Water Overlay)

The water system can be enhanced with a number of hydraulic structures. These are constructions which transport water to and between specified cells, according to their flow model and given parameters. The behavior of these constructions can be adjusted by adjusting the related attributes.

In general, for ease of use, hydraulic structures are by default imported as underground constructions.

Icon	Name	Category	Type	Identification key Template:WaterOverlay table row Template:WaterOverlay table row Template:WaterOverlay table row Template:WaterOverlay table row Template:WaterOverlay table row

Geometry type

Hydraulic structures can be either line-based or point-based:

Line-based constructions
Line-based constructions form a direct connection between two exact cells, allowing water to flow from one point to another. The flow is dictated by the construction's formula. The endpoints of a line-based construction, the exact cells which are connected by the construction, are computed based on the orientation and size of their polygon. Essentially, the furthest ends of the polygon are used as end-points. Because the cells are considered adjacent, any calculated flow through line-based hydraulic structures is instantaneous.
Point-based constructions
Point-based constructions add or remove water in one or more computational layers, based on their formula's. The center-point of a point-based construction, the exact cell where the effect takes place, is is the geometric center of the construction's polygon.

Note that the more complex the polygon is, the more difficult it is for the Tygron Platform to resolve it to a simple line or center point.

When the calculation of the water overlay completes, the total amount of water which has flowed through a specific construction is stored in an attribute in that construction. By default, this attribute is OBJECT_OUTPUT_FLOW, and the flow is expressed in m3. If multiple water overlays exist in the project simultaneously, the attribute name is appended with a number so that each overlay (as they are added to the project) has a unique attribute it writes its results to.

Identification

Constructions can be identified as a hydraulic structure when this construction has the identification attribute. This is the first attribute in the described table of attributes for each hydraulic structure. For clearance they are also mention in the table above.
The identification process is further facilitated through the system of Keys. Keys are stored in a table in the Water Overlay. Keys allow users to provide an alternative attribute name for each hydraulic structure attribute, which is useful when self provided geo-data is used.
More on this topic is described in Keys for water overlays.

Notes

Only one hydraulic structure can be assigned to a particular grid cell.
The Base type result overlay visualizes which type of hydraulic structures are placed where.
If a single construction has attributes related to multiple hydraulic structures, only one is selected. The selection order is: Weir, Sewer overflow, Inlet, Pump, Culvert.