Inflow objects

Impervious surface

Definition of 0D inflow surface using the Dutch NWRW system. If you are using ‘impervious surfaces’, the inflow parameters are predefined for your convenience, in accordance to the Dutch NWRW model for sewerage inflow.

See Rainfall on 0D node (inflow) for further details.

Table 36 Impervious surface attributesv

Parameter

Type

Unit

Description

area

decimal number

m2

The area that is used to calculate the precipitation input to the inflow model. The area of the feature’s geometry is not used for this.

surface_class

text

N/A

Type of surface. See the table below.

surface_inclination

text

N/A

Surface slope type. See the table below.

The parametrisation for the impervious surface types is fixed. It uses the following parameters:

Table 37 Inflow model parameters for each available combination of surface class and inclination

Surface class

Surface inclination

Outflow delay \(k_q\) (min-1)

Surface storage (mm)

Infiltration (boolean)

Maximum infiltration rate \(f_0\) (mm/h)

Minimum infiltration rate \(f_c\) (mm/h)

Infiltration decay constant \(k_d\) (h-1)

Infiltration recovery constant \(k_r\) (h-1)

gesloten verharding

hellend

0.5

0.0

False

0.0

0.0

0.0

0.0

vlak

0.2

0.5

False

0.0

0.0

0.0

0.0

vlak uitgestrekt

0.1

1.0

False

0.0

0.0

0.0

0.0

open verharding

hellend

0.5

0.0

True

2.0

0.5

3.0

0.1

vlak

0.2

0.5

True

2.0

0.5

3.0

0.1

vlak uitgestrekt

0.1

1.0

True

2.0

0.5

3.0

0.1

dak

hellend

0.5

0.0

False

0.0

0.0

0.0

0.0

vlak

0.2

2.0

False

0.0

0.0

0.0

0.0

vlak uitgestrekt

0.1

4.0

False

0.0

0.0

0.0

0.0

onverhard

hellend

0.5

2.0

True

5.0

1.0

3.0

0.1

vlak

0.2

4.0

True

5.0

1.0

3.0

0.1

vlak uitgestrekt

0.1

6.0

True

5.0

1.0

3.0

0.1

Impervious surface map

Connection between an impervious surface and its target connection node.

Table 38 Parameters when using ‘surface’ inflow

Parameter

Type

Unit

Description

connection_node_id

integer

N/A

Reference to the connection node to which the inflow from the referenced Impervious surface should be mapped

percentage

decimal number

N/A

Percentage of the runoff produced by the referenced Impervious surface that should flow to the referenced connection_node

surface_id

integer

N/A

Reference to the Impervious surface feature to be mapped

Surface

Definition of 0D inflow surface using custom rainfall-runoff parameters. If you are using ‘surfaces’, you have full freedom to set the inflow parameters that characterize the inflow of a surface.

See Rainfall on 0D node (inflow) for further details.

Table 39 Surface attributes

Parameter

Type

Unit

Description

area

decimal number

m2

The area that is used to calculate the precipitation input to the inflow model. The area of the feature’s geometry is not used for this.

surface_parameters_id

integer

N/A

Reference to the row in the Surface parameters table that is to be used for this surface

Surface map

Connection between a surface and its target connection node.

Table 40 Surface map attributes

Parameter

Type

Unit

Description

connection_node_id

integer

N/A

Reference to the connection node to which the inflow from the referenced Surface should be mapped

percentage

decimal number

N/A

Percentage of the runoff produced by the referenced Surface that should flow to the referenced connection_node

surface_id

integer

N/A

Reference to the Surface feature to be mapped

Surface parameters

Custom rainfall-runoff parameters to be used by surfaces

Table 41 Surface parameters

Parameter

Type

Unit

Description

infiltration

boolean

N/A

Switch infiltration on (1) or off (0)

infiltration_decay_constant

decimal number

h-1

Infiltration decay constant \(k_d\)

infiltration_recovery_constant

decimal number

h-1

Infiltration recovery constant \(k_r\)

max_infiltration_capacity

decimal number

mm/h

Initial (maximum) infiltration rate \(f_0\)

min_infiltration_capacity

decimal number

mm/h

Equilibrium (minimum) infiltration rate \(f_c\)

outflow_delay

decimal number

min-1

Outflow delay constant \(k_q\)

surface_layer_thickness

decimal number

mm

Storage on the surface