Model attributes (Water Overlay)

The water overlay's model calculations depend on a number of calculation-wide parameters. These parameters are available as attributes of the water overlay and can be modified as such.

Icon	Attribute	Unit	Description
	ALLOWED_WATER_INCREASE_M	m	The amount by which the water level on a water terrain must increase before it is considered stressed by water. This is used to compute the WATER_STRESS result type.
	CULVERT_DEM_THRESHOLD_M	m	The maximum distance a culvert's height can be below the terrain, for the terrain height to be adjusted to the height of the culvert.
	DESIGN_FLOOD_ELEVATION_M	m	Constructions in the 3D world are assumed to have at most this height compared to the surface of the terrain. Greater values can create a more accurate model but will impact performance.
	GRAVITY	m/s²	Used constant for gravitational acceleration.
	GROUND_BOTTOM_DISTANCE_M	m	Assumed distance under the terrain surface where the soil becomes impenetrable for water. The groundwater level cannot go below this depth, relative to the surface. The maximum amount of water that can be stored underground is equal to this attribute multiplied by the local terrain's WATER_STORAGE_PERCENTAGE.
	GROUND_WATER	boolean	Whether water in the underground is simulated during the calculation. If this is deactivated, surface and underground infiltration, and underground evaporation do not occur. Water flowing in- and out of the sewer are still simulated when sewers are present.
	GROUND_WATERTABLE_WITH_SURFACE	boolean	Whether the ground watertable result type should also include the surface water level, when the groundwater levels are close to the surface.
	IMPACT_FLOOD_THRESHOLD_M	m	The amount of water a construction must experience before it is considered impacted by water. Water must reach this height either on one of the cells the construction is on, or on one of the cells adjacent to it. This is used to compute the IMPACTED BUILDINGS result type.
	INFILTRATION	boolean	Whether surface water can infiltrate into the unsaturated zone of the ground layer.
	LIMIT_RAIN	integer	Whether the to be calculated project is the whole project area, or limited to water level areas or to a self defined area.
	MAX_WATER_BOTTOM_M	m + datum	The maximum height for the bottoms of water terrains. Any water terrain with a bottom at a higher datum height has its bottom lowered to this value.
	MAX_WATER_DEPTH_M	m	The maximum depth of water on a cell that is able to move horizontally. This parameter can be set to influence the wave part in the Saint-Venant equations.
	MINIMAL_CULVERT_DIAMETER_M	m	The minimal culvert diameter in meters.
	OBJECT_CORRECTION	boolean	Objects (culverts, pumps, weirs) can sometimes overlap each other and then one or more objects become inactive. When this happens the rasterizer automatically moves the inactive object(s) start/end point(s) by a maximum of one cell so the object(s) become active.
	SEWER_OVERFLOW_THRESHOLD	fraction (m/m)	How much of a sewer's storage must be filled with water before the sewer's overflows are allowed to overflow water.
	SHORELINE	boolean	When a Waterway polygon is not correctly positioned in relation to the DEM this can result in filling up the nearby land with water at the start of the simulation. This will result in a lower water level then is expected from the water level area value. To correct this, a "shoreline" is added at neighbouring cells. At the start of the simulation, these shoreline cells will also be filled with water up to the nearby water level to prevent the initial flush. By default this option is turned on, but can be turned off by changing the attribute to 0.
	SHOW_DURATION_FLOOD_LEVEL_M	m	The amount of water which must be present in a specific location before the duration of surface water can be recorded. This is used to compute the SURFACE_DURATION result type.
	SURFACE_WATER_EVAPORATION_FACTOR	factor	The factor by which the weather's evaporation factor is multiplied to compute the amount of evaporation which takes place on the surface.
	TIMEFRAMES	integer	The number of intermediate results recorded during the calculation. Each timeframe becomes a snapshot of data which can be viewed and analysed.

---

Water Module

Water Module

Tutorials

Overview

Theory

Benchmarks

Group

Model attributes

Model attributes

Allowed water increase m • Avg shore width m • Avg terrain width m • Avg terrain storage m • Breach measurement distance m • Bridge elevation • Culvert dem threshold m • Design flood elevation m • Extended reconstruction • Ground bottom distance m • Ground bottom pressure m • Ground water • Ground water depth m • Ground watertable with surface • Impact flood threshold m • Impact range m • Increased resolution • Infiltration factor s

Limit area • Limit rain • Max infiltration m • Max water bottom m • Microrelief storage fraction • Min max elevation • Object entry correction • Prequel surface level relative • Rise rate distance m • Sewer overflow threshold • Shoreline • Show duration flood level m • Stabilizer angle • Start date ms • Surface water • Surface water evaporation factor • Timeframe times • Timeframes • Unsaturated fraction • Weir dam multiplier • Weir move interval s • Weir move range m • Weir move step m

Related

Building attributes • Hydrological features • Hydraulic structures •  Terrain attributes • Results • Simulation data