Bridge elevation (Water Overlay): Difference between revisions
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[[File:Wateroverlay_wizard_bridge_elevation.png|thumb|right|Bridge elevation can be configured in ''Structure Settings'' step of a [[Water Overlay]] wizard.]] | |||
{{Overlay attributes|<onlyinclude> | {{Overlay attributes|<onlyinclude> | ||
{{Overlay attributes|type=row|overlay=Water | {{Overlay attributes|type=row|overlay=Water | ||
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|defaultvalue=Lowest | |defaultvalue=Lowest | ||
|icon=waterwizard_icon_bridges.png | |icon=waterwizard_icon_bridges.png | ||
|range=0 to 2 | |||
}}</onlyinclude>}} | }}</onlyinclude>}} | ||
The water model uses an elevation model for the surface flow calculations. This setting defines how to include bridges in this elevation model: | |||
{{nominal list|zeroindex=true | {{nominal list|zeroindex=true | ||
||'''Lowest''': | ||'''Lowest''': The lowest elevation point from the terrain elevation (DTM) below bridge is used, when the terrain is '''[[Water (Terrain Attribute)|water]]'''. Otherwise the behavior is similar to '''Terrain'''. | ||
||'''Terrain''': | ||'''Terrain''': Under bridges, the terrain elevation (DTM) is used, otherwise the [[#Notes|limited]] surface elevation (DSM) is used. Water can flow under the bridge according to the terrain elevation. | ||
||'''Bridge''' : Use bridge deck as elevation. Bridges and [[Align elevation (Function Value)|floating]] | ||'''Bridge''' : Use bridge deck as elevation. Bridges and [[Align elevation (Function Value)|floating]] buildings are included in the DEM, blocking water flow. | ||
}} | }} | ||
====Example==== | |||
The following images show the effect of the different options on both land and water under a bridge. The elevation data is set up such that it is slightly raised under the bridge, as often happens; the bridge deck itself is included in the terrain elevation data, or its support pillars, both on land and water. As can be seen below, the '''Lowest''' option selects the lowest terrain value under the bridge for water, but not on land. | |||
<gallery widths="300px> | |||
File:bridge_surface_elevation_lowest_water.png|Lowest option measured on water | |||
File:bridge_surface_elevation_terrain_water.png|Terrain option measured on water | |||
File:bridge_surface_elevation_bridge_water.png|Bridge option measured on water | |||
</gallery> | |||
<gallery widths="300px> | |||
File:bridge_surface_elevation_lowest_land.png|Lowest option measured on land | |||
File:bridge_surface_elevation_terrain_land.png|Terrain option measured on land | |||
File:bridge_surface_elevation_bridge_land.png|Bridge option measured on land | |||
</gallery> | |||
{{article end | {{article end | ||
|notes= | |notes= | ||
* When using '''Bridge''' mode, it is still possible to model the flow from one side of a bridge to the other by using a [[Culvert (Water Overlay)|Culvert]]. | * When using '''Bridge''' mode, it is still possible to model the flow from one side of a bridge to the other by using a [[Culvert (Water Overlay)|Culvert]]. | ||
* The surface elevation (DSM) always limits the height of the buildings to the [[Design flood elevation m (Water Overlay)|design flood elevation]]. | |||
|howtos= | |howtos= | ||
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|videos= | |videos= | ||
}} | }} | ||
{{WaterOverlay model attribute nav}} | {{WaterOverlay model attribute nav}} |
Latest revision as of 10:58, 28 February 2024
Icon | Attribute | Unit | Range | Description | Default value |
---|---|---|---|---|---|
BRIDGE_ELEVATION | nominal | 0 to 2 | Specifies the mode by which bridges are include in the elevation model, used for the water calculations. | Lowest |
The water model uses an elevation model for the surface flow calculations. This setting defines how to include bridges in this elevation model:
0. | Lowest: The lowest elevation point from the terrain elevation (DTM) below bridge is used, when the terrain is water. Otherwise the behavior is similar to Terrain. |
1. | Terrain: Under bridges, the terrain elevation (DTM) is used, otherwise the limited surface elevation (DSM) is used. Water can flow under the bridge according to the terrain elevation. |
2. | Bridge : Use bridge deck as elevation. Bridges and floating buildings are included in the DEM, blocking water flow. |
Example
The following images show the effect of the different options on both land and water under a bridge. The elevation data is set up such that it is slightly raised under the bridge, as often happens; the bridge deck itself is included in the terrain elevation data, or its support pillars, both on land and water. As can be seen below, the Lowest option selects the lowest terrain value under the bridge for water, but not on land.
Notes
- When using Bridge mode, it is still possible to model the flow from one side of a bridge to the other by using a Culvert.
- The surface elevation (DSM) always limits the height of the buildings to the design flood elevation.