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.

Attribute	Unit	Range	Description	Default value
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.	0.4
AVG_SHORE_WIDTH_M	m	0 to 10000 grid cells	With the surface water mode set to Grid Averaging, identified water average areas can be extended to include nearby shorelines within the configured distance.	3
AVG_TERRAIN_WIDTH_M	m	0 to 10000 grid cells	With the surface water mode set to Avg Terrain, identified water average areas can be extended to include surrounding terrain within the configured distance.	1000
AVG_TERRAIN_STORAGE_M	m	0 to 10000	When determining the water level of a land cell that will be averaged, the level will ignore the part that is reserved for storage.	0,05
BREACH_MEASUREMENT_DISTANCE_M	m		Distance from the breach area to the automatically placed measurement point for the downstream water level of the breach, in the direction of the breach.	100
BRIDGE_ELEVATION	nominal	0 to 2	Specifies the mode by which bridges are include in the elevation model, used for the water calculations.	Lowest
CULVERT_DEM_THRESHOLD_M	m	0 to 10000	The maximum distance a culvert's height can be below the terrain, for the terrain height to be adjusted to the threshold of the culvert.	10
DESIGN_FLOOD_ELEVATION_M	m		Buildings in the model 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.	1
EXTENDED_RECONSTRUCTION	boolean	0 or 1	When selected, a well-balanced reconstruction method for drying and wetting fronts described by Bollermann et. al. is used. This approach is useful when interested in a lake at rest situation and is applied to shorelines. When water flow is more important, this option should be unchecked.	1
GROUND_BOTTOM_DISTANCE_M	m	0 to 10000	Assumed distance under the surface terrain where the bottom boundary is situated.	10
GROUND_BOTTOM_PRESSURE_M	m		Optional: The additional head of higher areas outside the project causing water to flow in or out of the ground from deeper ground layers through the bottom boundary.	0
GROUND_WATER	nominal value		Whether and how water in the ground is simulated during the calculation.	Infiltration Only
GROUND_WATER_DEPTH_M	m	-10000 to 10000	The default depth of ground water in meters.	1
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.	True
HYDRAULIC_CONDUCTIVITY_WITH_THICKNESS	boolean		When selected, the Terrain value HYDRAULIC_CONDUCTIVITY_WITH_THICKNESS_MD is used for horizontal groundwater flow calculations, otherwise HYDRAULIC_CONDUCTIVITY_MD is used.	0
IMPACT_FLOOD_THRESHOLD_M	m		The amount of water a Building must experience before it is considered impacted by water.	0,1
IMPACT_RANGE_M	m		the width in meters of the water next to or against the building that have to be flooded before the building is considered impacted by water.	3
INCREASED_RESOLUTION	boolean		Load the DEM at twice the resolution.	False
INFILTRATION_FACTOR_S	factor	-10 to 10	This value is multiplied with the surface infiltration speed and can be used to adjust the infiltration over time. Default is 1 (no adjustment).	1
LIMIT_AREA	nominal value		Whether and how calculations in the simulation should be limited to specific locations of the project area.	0 (Entire map)
LIMIT_RAIN	nominal value		Whether rainfall can be overridden by rainfall defined in rain areas across the project area.	0 (Entire map)
MAX_INFILTRATION_M	m		Assumed maximum amount of infiltrated water that can be stored in the ground layer.	1
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.	10000
MICRORELIEF_STORAGE_FRACTION	fraction (m/m)	0.0 to 1.0	Storage Fraction defines how much space is between Microrelief hills that can be used to store water. Setting this value to zero disables the Microrelief functionality all together.	1.0
MIN_MAX_ELEVATION	boolean		Whether to use highest and lowest elevations found for a grid cell for land and water respectively when interpreting the elevation model.	1.0
OBJECT_ENTRY_CORRECTION	cells	0 to 3 cells	How many cells allowed to move a hydraulic structure's entry point when it overlaps with another hydraulic building.	2
PREQUEL_SURFACE_LEVEL_RELATIVE	boolean		Whether the SURFACE_LEVEL prequel is considered relative instead of a datum height.	0
RISE_RATE_DISTANCE_M	m	0 to 10000	The water height threshold for computing the Flood rise rate result type.	1.5
SEWER_OVERFLOW_THRESHOLD	fraction (m/m)	0 to 1	How much of a sewer's storage must be filled with water before the sewer overflows are allowed to overflow water.	0.9
SHORELINE	boolean		Whether to automatically fill cells near a water terrain when there is a mismatch between the extend of the water terrain and the DEM.	True
SHOW_DURATION_FLOOD_LEVEL_M	m	-10000 to 10000	The amount of water which must be exceeded in a specific location before the duration of surface water can be recorded. This is used to compute the SURFACE_DURATION result type.	0
STABILIZER_ANGLE	angle (0-90°)	0 to 90	A partly flooded cell (especially at the edges of waterways) can become unstable when the angles in X and Y direction are too far apart. In this case the fluxes in U and V cannot easily be resolved mathematically while preserving balance. To prevent unrealistic fluxes from appearing, only the flux in the primary direction will be preserved. A stabilizer angle of zero means that all cells can be considered partly flooded cells, while an angle of 90 degrees will disable the stabilizer.	10
START_DATE_MS	long		The date and time which is considered the starting moment of the simulation.	0
SURFACE_WATER	Nominal value		Whether and how water on the surface is simulated during the calculation.	Shallow
SURFACE_WATER_EVAPORATION_FACTOR	factor	0 to 10	The factor by which the weather evaporation factor is multiplied to compute the amount of evaporation which takes place on the surface.	1.3
TIMEFRAME_TIMES	integer	0 to	The time of individual timeframes in seconds relative to the start date of the simulation.	0
TIMEFRAMES	integer	1 to 1000	The number of intermediate results recorded during the calculation. Each timeframe becomes a snapshot of data which can be viewed and analysed.	10
UNSATURATED_FRACTION	fraction		The initial fraction of the maximum storage capacity of the unsaturated zone which is filled with water.	0
WEIR_DAM_MULTIPLIER	factor		The width with which the weir's dam should be generated perpendicular to it's direction, relative to its flow width.	3
WEIR_MOVE_INTERVAL_S	seconds	0 to 3.4028235E38	Interval between Weir height adjustments in seconds. The Weir moves up/down to reach the target upstream water level.	10
WEIR_MOVE_STEP_M	m		When the move interval has passed the Weir height is adjusted up/down by this step distance in meters.	0.01
WEIR_MOVE_RANGE_M	seconds	0 to 3.4028235E38	When the Weir height is adjusted up/down it is clamped by this value in meters.	0.5
PARTIAL_START_SEC	seconds	0 to 3.4028235E38	Starting point in simulation time (as defined in the overlay's weather). Can be used to e.g. start one hour (3600) later then the time array in the weather.	0
PARTIAL_END_SEC	seconds	0 to 3.4028235E38	End point in simulation time (as defined in the overlay's weather). Can be used to e.g. stop earlier then the time array in the weather.	3.4028235E38