Model attributes (Water Overlay)

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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
Waterwizard icon allowed water increase.png 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.
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 underground water flow is simulated during the calculation. If this is deactivated, surface infiltration, underground infiltration, and underground evaporation do not occur. Water flowing in- and out of the sewer are still simulated when sewers are present.
Waterwizard icon allowed water increase.png 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.
LIMIT_RAIN boolean Whether rainfall locations should be limited to water level areas (1) or everywhere (0).
SEWER_OVERFLOW_THRESHOLD fraction How much of a sewer's storage must be filled with water before the sewer's overflows are allowed to overflow water.
Waterwizard icon allowed water increase.png 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. The total simulation time is divided by this value, and at each interval of that period of time a snapshot of the results so far is made. Note that the first timeframe does not contain the starting conditions of the simulation, but the state of the simulation after the first period of time has passed.
OBJECT_CORRECTION boolean Objects (culverts, pumps, weirs) sometimes overlap each other and then one object becomes inactive. When this happens the rasterizer automatically moves the object start/end point by a maximum of one cell so both object are connected.
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. Although this is not much it will result in a lower water level then is to be expected from the water area value. To correct this we have added a "shoreline" at neighbouring cells. These shoreline cell will also be filled with water from the start, thus preventing the flush.