7.4. Prepare Data

7.4.1. QGEP - SWMM correspondances

7.4.1.1. Title/Notes:

No correspondance in QGEP. This parameter must be set by the user in the template .inp file or before running the simulation.

  • Copied from the template input file if exists.

7.4.1.2. Options:

No correspondance in QGEP. This parameter must be set by the user in the template .inp file or before running the simulation.

  • Copied from the template input file if exists.

7.4.1.3. Climatology:

No correspondance in QGEP. This parameter must be set by the user in the template .inp file or before running the simulation.

  • Copied from the template input file if exists.

7.4.1.4. Hydrology:

Rain Gauges [Gages in SWMM]:

QGEP_SWMM creates one raingage for each subcatchment.

By default:

  • Time serie: Each raingage is related to a default rain time serie called default_qgep_raingage_timeserie. The time serie must be created and the value Series Name updated accordingly.

  • Format is set to ‘INTENSITY’. Format in which the rain data are supplied: INTENSITY: each rainfall value is an average rate in inches/hour (or mm/hour) over the recording interval. VOLUME: each rainfall value is the volume of rain that fell in the recording interval (in inches or millimeters). CUMULATIVE: each rainfall value represents the cumulative rainfall that has occurred since the start of the last series of non-zero values (in inches or millimeters).

  • Interval is set to ‘0:15’ (15 seconds). Recording time interval between gage readings in decimal hours or hours:minutes format.

  • Other parameters have default SWMM values. If you want to use another Format or Interval, you have to adapt the view.

See vw_swmm_raingages.sql for details.

Aquifers:

QGEP_SWMM creates an aquifer for each QGEP aquifiers.

By default:

  • An aquifer is created for each QGEP aquifiers

  • The bottom elevation is set to the minimal_groundwater_level

  • The water table elevation is set to the average_groundwater_level

  • Other parameters have default SWMM values

See vw_swmm_aquifers.sql for details.

Subcatchment:

QGEP_SWMM creates a subcatchment for each QGEP catchment area.

By default:

  • A subcatchment is created for each QGEP wastewater_networkelement linked to the catchment area (max. 4: fk_wastewater_networkelement_rw_current, fk_wastewater_networkelement_rw_planned, fk_wastewater_networkelement_ww_current, fk_wastewater_networkelement_ww_planned)

  • it is linked to a rain gage.

  • The width is computed from the mean of the minimal / maximal distance between the outlet and the catchment area contour. If the outlet is unknown the centroid is used rather than the outlet.

  • The coverages (attribute land uses) are computed from the intersection between the catchment area and the planning zone (see vw_swmm_coverages.sql)

  • SWMM Dry Weather Flow:

    • are set to 0 for rain water subcatchments

    • are set to waste_water_production[_current,_planned] if set

    • else it computed from the subcatchement area and population_density[_current,_planned]

  • Other parameters have default SWMM values

The subcatchment can be linked to an aquifer via the groundwater attribute.

See vw_swmm_subcatchments.sql, vw_swmm_subareas.sql, vw_swmm_dwf.sql and vw_swmm_coverages.sql for details.

Snow Packs

No correspondance in QGEP. This parameter must be set by the user in the template .inp file or before running the simulation.

  • Copied from the template input file if exists.

Unit hydrographs

No correspondance in QGEP. This parameter must be set by the user in the template .inp file or before running the simulation.

  • Copied from the template input file if exists.

LID Controls

No correspondance in QGEP. This parameter must be set by the user in the template .inp file or before running the simulation.

  • Copied from the template input file if exists.

7.4.1.5. Hydraulics

Junctions

  • QGEP_SWMM creates a junction for each QGEP manhole, some kind of special structures and the wastewater nodes linking primary pipes without a wastewater structure.

See vw_swmm_junctions.sql for details.

Outfalls

  • QGEP_SWMM creates an outfall for each QGEP discharge_point.

See vw_swmm_outfalls.sql for details.

Dividers

  • QGEP_SWMM creates a divider for the manholes and special structures having the function separating_structure

  • See vw_swmm_dividers.sql for details.

Storage Units

  • QGEP_SWMM creates a storage for some kind of QGEP infiltration installations and some kind of QGEP special structures.

  • See vw_swmm_storages.sql for details.

Conduits

  • QGEP_SWMM creates a conduit for each QGEP reach.

  • Roughness is created from coefficient_of_friction, wall_roughness or swmm_default_coefficient_of_friction (see: Coefficient of friction)

  • QGEP profile type are matched to SWMM profile type, dimensions are computed from reach.clear_height and pipe_profile.height_width_ratio

  • Custom pipe profile described by a curve are currently not exported

  • See vw_swmm_conduits.sql and vw_swmm_xsections.sql for details.

Pumps

  • QGEP_SWMM creates a pump for each QGEP pump. When a curve qgep_od.hq_relation is liked to the pump it is exported as a SWMM curve.

  • See vw_swmm_pumps.sql and vs_swmm_curves.sql for details.

Orifices

No correspondance in QGEP. Orifices are not created from QGEP objects. An empty table is created

  • See vw_swmm_orifices.sql for details.

Weirs

  • Are created from QGEP prank weir (without H/Q relation) and leaping weir.

  • See vw_swmm_weirs.sql for details.

Outlets

No correspondance in QGEP. However, outlets are created to export QGEP prank weir having a H/Q relation.

  • See vw_swmm_outlets.sql for details.

Transects

No correspondance in QGEP. This parameter must be set by the user in the template .inp file or before running the simulation.

  • Copied from the template input file if exists.

Controls

No correspondance in QGEP. This parameter must be set by the user in the template .inp file or before running the simulation.

  • Copied from the template input file if exists.

7.4.1.6. Quality

Land uses

  • QGEP_SWMM creates a SWMM land use kind for each QGEP planning zone kind.

  • See vw_swmm_landuses.sql

Pollutants

No correspondance in QGEP. This parameter must be set by the user in the template .inp file or before running the simulation.

  • Copied from the template input file if exists.

7.4.1.7. Curves

  • Are created for pumps linked to a qgep_od.hq_relation and for wastewater structures linked to a qgep_od.hydr_geom_relation

  • See vw_swmm_curves.sql for details.

7.4.1.8. Time series

No correspondance in QGEP. This parameter must be set by the user in the template .inp file or before running the simulation.

  • Copied from the template input file if exists.

7.4.1.9. Time patterns

No correspondance in QGEP. This parameter must be set by the user in the template .inp file or before running the simulation.

  • Copied from the template input file if exists.

7.4.1.10. Labels

No correspondance in QGEP. This parameter must be set by the user in the template .inp file or before running the simulation.

  • Copied from the template input file if exists.

7.5. QGEP-SWMM data requirements

To run a sucessful simulation in SWMM the following minimal data has to be filled in to be matched to the swmm objects

JUNCTIONS and COORDINATES

SWMM attribute

Description

QGEP equivalent

Name

User-assigned junction name.

wastewater_node.obj_id

X-Coordinate / Y-Coordinate

Coordinate of node [COORDINATES]

wastewater_node.situation_geometry

Description

Description of node

wastewater_structure.identifier

Tag

Optional label used to categorize or classify the junction.

manhole.obj_id

Invert El.

Invert elevation of the junction

wastewater_node.bottom_level

Max. Depth

Maximum depth at the junction (i.e., the distance from the invert to the ground surface) (feet or meters). If zero, then the distance from the invert to the top of the highest connecting link will be used.

Difference of cover.level minus wastewater_node.bottom_level
CONDUITS

SWMM attribute

Description

QGEP equivalent

Name

User-assigned conduit name.

wastewater_node.obj_id

Inlet Node

Name of node on the inlet end of the conduit (which is normally the end at higher elevation).

from wastewater_node.obj_id

Outlet Node

Name of node on the outlet end of the conduit (which is normally the end at lower elevation).

from wastewater_node.obj_id

Description

Description of conduit

wastewater_networkelement.identifier

Tag

Optional label used to categorize or classify the conduit.

wastewater_networkelement.fk_wastewater_structure

Max. Depth

Maximum depth of the conduit’s cross section

Difference of Cover.level minus Wastewater_node.bottom_level

Length

Conduit length

reach.length_effective or calculated from reach.progression_geometry if length_effective is empty

Roughness

Manning’s roughness coefficient.

reach.wall_roughness

InletOffset

Depth or elevation of the conduit invert above the node invert at the inlet end of the conduit

reach_point_from.level minus from_wastewater_node.bottom_level

OutletOffset

Depth or elevation of the conduit invert above the node invert at the outlet end of the conduit

reach_point_to.level minus to_wastewater_node.bottom_level
XSECTIONS

SWMM attribute

Description

QGEP equivalent

Shape

geometric properties of the conduit’s cross section e.g. CIRCULAR.

pipe_profile.profile_type

Geom1

Maximum height of conduit

reach.clear_height/1000 [m] to [mm]

7.5.1. Coefficient of friction

  • The plugin will export the roughness according to these priorities:

    • If reach.coefficient_of_friction is set then it is converted (1/coefficient_of_friction) and exported to SWMM

    • Else if reach.wall_roughness and reach.clear_height are set, it is converted ((1/(4 * SQRT(9.81)*POWER((32/re.clear_height/1000),(1/6))*LOG(((3.71*re.clear_height/1000)/(re.wall_roughness/1000)))))) and exported.

    • Else if reach.swmm_default_coefficient_of_friction is set then it is used

    • Else a default value of 0.01 is set

    • See vw_swmm_conduites.sql for details

Note

The formula to convert from Strickler to Coolebrook is documented in *ATV-DVWK STANDARD ATV-DVWK-A 110E, Hydraulic Dimensioning and Performance Verification of Sewers and Drains September 2001*

7.5.1.1. Populate default coefficient of friction

The table qgep_swmm.reach_coefficient_of_friction contains default coefficient of Strickler for the reach materials. The file ../project/qml/reach_coefficient_of_friction.qml is the layer definition, that you can import in your QGIS project. If the default values don’t match your needs you can edit them. The function SWMM Set default coefficient of friction will put in qgep_od.reach.swmm_default_coefficient_of_friction these default values. You can choose if you want to overwrite or not the values existing in this attribute.

Launch SWMM Set default coefficient of friction:

  • Overwrite existing default values: If checked the values stored in swmm_default_coefficient_of_friction will be overwrited with new values.