Appendix B: ArcView/EPANET Data Model

Subsections

• Identity
• Node
• Junction
• Tank
• Pump
• Valve
• Pipe
• Reservoir
• Feature
• Pattern
• Options
• Report
• Times
• VirtualLine
• Curve

ArcView/EPANET Data Model

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This document describes version 2.00 of the ArcView/EPANET Data Model. Note that the units will change if EPANET is not set to use litres per second (LPS) as units. Refer to the EPANET documentation (especially the toolkit help) for further information.

Identity

Inherited by Feature
Inherited by Pattern
Inherited by Curve

• dc_ID: string Unique ID throughout the whole database. Should not contains spaces.

Node

Inherits from Feature
Inherited by Junction
Inherited by Tank
Inherited by Reservoir
Inherited by VirtualLine

• Shape: Point Spatial data.
• Elevation: float Elevation above Sea Level in m.
• result_demand: float EPANET analysis result: Demand in litres per second.
• result_head: float EPANET analysis result: Total Head in m.
• result_pressure: float EPANET analysis result: Pressure in m.
• ElevationSource: CodedValue Integer field containing a coded value that describes the origin of the elevation information for this node. The following values have been used in the Al Koura project:
  • 0: Unknown Source
  • 1: 100 m Contours DEM
  • 2: SOGREAH Procedure models
  • 3: Altimeter Survey
  • 4: Paper maps
  • 5: estimated
  • 6: 25 m Contours DEM

Junction

Inherits from Node

• Demand: float Base demand flow in litres per second.
• Pattern: string Demand Pattern ID. If no demand pattern is supplied then the junction follows the Default Demand Pattern provided in the Options Table, or Pattern 1 if no Default Pattern is specified. If none of the patterns exist, the demand will remain constant.

Tank

Inherits from Node

• Initiallevel: float Initial water level above the tank bottom level (the elevation field) in m.
• Minimumlevel: float Minimum water level above the tank bottom level in m.
• Maximumlevel: float Maximum water level above the tank bottom level in m.
• Diameter: float Nominal Diameter of the tank in m. If a volume curve is supplied this can be any non-zero number.
• Minimumvolume: float The minimum volume of the tank in cubic metres. Can be zero.
• Volumecurve: string The id of the volumecurve - for non-cylindrical tanks.

Pump

Inherits from VirtualLine

• Properties: string EPANET properties of the pump. Keyword(s) followed by value(s). Keywords consist of:
  • POWER pump power in kW
  • HEAD id of the head curve describing this pump
  • SPEED relative speed of the pump: 1.0 is normal, 0 means that the pump is off.
  • PATTERN id of the time pattern describing pump operation.
    

• power_kw: integer The power of the pump in kW.

Valve

Inherits from VirtualLine

• Diameter: integer Diameter of the valve in mm.
• Type: string Type of the valve. The following EPANET valve types are valid:
  • PRV pressure reducing valve
  • PSV pressure sustaining valve
  • PBV pressure breaker valve
  • FCV flow control valve
  • TCV throttle control valve
  • GPV general purpose valve
  Additional valve types supported by the DC Water Design Extension:
  

• CV check valve
  • SOV shutoff valve

EPANET models these as pipes. The extension will create them on the fly.

• Setting: string Valve type dependent setting. The setting field takes the following values for the different valve types:
  • PRV the pressure in m
  • PSV the pressure in m
  • PBV the pressure in m
  • FCV the flow in litres per second
  • TCV the loss coefficient
  • GPV the id of the head loss curve
  • CV the setting value will be mapped to the status field of the pipe
  • SOV the setting value will be mapped to the status field of the pipe
    

• Minorloss: float Minor loss coefficient of the valve.

Pipe

Inherits from Feature

• Shape: Polyline Spatial data.
• node1: string Start node dc_id.
• node2: string End node dc_id.
• length: float The length of the pipe in m.
• diameter: integer Nominal pipe diameter in mm.
• roughness: float Pipe roughness coefficient in mm.
• minorloss: float Minor loss coefficient.
• status: string Status of the pipe. The following values are valid:
  • OPEN
  • CLOSED
  • CV (check valve)
• Material: CodedValue Integer field containing a coded value describing the material of the pipe. The following values have been used in the Al Koura project:
  • 0: steel
  • 1: galvanized iron
  • 2: PVC
  • 3: PE
  • 4: Ductile Cast Iron
  • 9: unknown
• result_flow: float EPANET analysis result: The flow in litres per second.
• result_velocity: float EPANET analysis result: Flow velocity in metres per second.
• result_headloss: float Headloss over the pipe in m.

Reservoir

Inherits from Node

• Head: float The hydraulic head of the reservoir. Elevation + pressure head.
• Pattern: string Optional head pattern id.

Feature

Inherited by Node

Inherited by Pipe

Inherits from Identity

• Installation_date: date The date of installation. If this is a date in the future, the feature is planned.
• Abandon_date: date The date when the feature was abandoned.
• dcSubtype: CodedValue Integer field containing coded values describing the feature. Different Domains are applied to the Feature classes.
• BitcodeZone: integer Integer containing a bit-coded that describes the zones in which the Feature is used. The following bitcodes were used in the Al Koura project:
  • Bit 0: Judayta village

Pattern

Inherits from Identity

• multiplier: float The multiplier that describes how to adjust the base quantity.

Options

• Units: string LPS (litres per second) should be used. See the EPANET documentation for other flow units. Using other flow units will render the units specified in this document invalid.
• Headloss: string Headloss equation. D-W (Darcy-Weissbach) should be used.
• Hydraulics: string Allows to specify a filename for the hydraulic solution. Leave empty.
• Viscosity: float The kinematic viscosity of the fluid being modeled relative to that of water at 20°C. The default value is 1.0.
• Diffusity: float The molecular diffusity of the chemical being analyzed relative to that of chlorine in water. The default value is 1.0.
• Specificgravity: float The ratio of the density of the fluid being modeled to that of water at 4°C.
• Trials: integer The maximum number of trials used to solve the network hydraulics for each time step. The default is 40.
• Accuracy: float Convergence criterion that describes when a hydraulic solution is found. The default is 0.001.
• Unbalanced: string Determines what happens if no hydraulic solution can be found within the prescribed number of time steps. The following values are valid:
  • STOP
  • CONTINUE
  • CONTINUE n
  The default is STOP

• pattern: string The default demand pattern id that is applied to all junctions that do not have a pattern specified. If this is empty, the default "1" is used.
• Demandmultiplier: float Global Demand multiplier. Applied to all base demands of junctions. The default value is 1.0.
• emitterexponent: float Specifies the power to which the pressure at a junction is raised when computing the flow issuing from an emitter. The default is 0.5.   
• tolerance: float The difference in water quality level below which parcels of water are considered of equal value. The default is 0.01. 
• map: string The name of a file containing junction coordinates.

Report

• Pagesize: integer The number of lines on one page of the output report. The default is 0 meaning that no limit of lines per page is in effect.
• File: string The name of the report file. Leave empty if the DC Water Design Extension is used.
• Status: string Determines whether hydraulic status messages should be written to the report file. The following values are valid:
  • YES
  • NO
  • FULL
  The default is NO.

• Summary: string Determines whether a Summary is generated. The following values are valid:
  • YES
  • NO
  Default is YES.

• Messages: string Determines whether warning and error messages are written to the report. The following values are valid:
  • YES
  • NO
  The default is YES.

• Energy: string Determines whether energy and energy cost reports for pumps should be written to the report file. The following values are valid:
  • YES
  • NO
  The default is NO.

• Nodes: string Determines which nodes will be reported on. The following values are valid:
  • NONE
  • ALL
  • dc_id1 dc_id2 dc_id3 ...
  The default is NONE.

• Links: string Determines which links will be reported on. The following values are valid:
  • NONE
  • ALL
  • dc_id1 dc_id2 dc_id3 ...
  The default is NONE.

Times

Times can be specified in SECONDS(SEC), MINUTES (MIN), HOURS or DAYS. Just enter the unit name after the value. The default time unit is hours.

• Duration: string The duration of the simulation.
• Hydraulictimestep: string Determines how often a new hydraulic solution is computed. The default is 1 hours.
• Qualitytimestep: string Determines how often the water quality is computed. The default is 1/10 of the hydraulic time step.
• Ruletimestep: string Used with rule-based controls. Defaults to 1/10 of the hydraulic time step.
• Patterntimestep: string The interval between time periods in all time patterns. The default is 1 hour.
• Patternstart: string Describes when the pattern cycle will be started. Defaults to 0.
• Reporttimestep: string The interval in which results will be reported. The default is 1 hour.
• Reportstart: string Determines the time when reporting starts. The default is 0.
• Startclocktime: string The time of the day at which the simulation starts. The default is 12 AM (midnight).
• Statistic: string Determines the type of statistical post-processing. The following values are valid:
  • NONE
  • AVERAGED
  • MINIMUM
  • MAXIMUM
  • RANGE

VirtualLine

Inherited by Pump

Inherited by Valve

Inherits from Node

• result_flow: float EPANET analysis result: The flow in litres per second.
• result_velocity: float EPANET analysis result: Flow velocity in metres per second. result_headloss: float Headloss over the pipe in m.

Curve

Inherits from Identity

• dc_x: float X value.
• dc_y: float Y value.

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