Understanding 1D urban drainage models

00:03

The basic principles of building 1D urban drainage models in InfoWorks ICM

00:09

revolve around creating wastewater or surface water sewer networks with flows predominantly driven from urbanized areas.

00:17

The fundamental modeling concept is that one or more time-varying inputs, such as rainfall events, inflows, and levels,

00:25

can be specified for use as a boundary condition for hydraulic calculations.

00:32

The first step of any model simulation will be to either apply these boundary conditions directly,

00:37

for example, the water level at a tidal outfall, or convert the input data into an acceptable hydraulic boundary condition.

00:46

The objects that are simulated in a basic 1D drainage model are subcatchments, nodes, and links,

00:53

each with properties that can be set in ICM.

00:56

Subcatchments are polygons, which represent the physical area from which a system collects water, be it wastewater or surface water.

01:05

Subcatchment parameters detail how an event, such as wastewater, rainfall, or groundwater, is applied to a node or link.

01:14

Defining subcatchments is the most onerous task to building a new 1D urban drainage model,

01:20

because these polygons may not have been previously defined in GIS.

01:24

There are a number of properties and data associated with subcatchments that need to be populated as a result.

01:31

ICM provides tools to help speed up this process.

01:35

Nodes represent a specific point in the network, such as a manhole location.

01:41

This is where inflows from subcatchments or from inflow events are assigned to the network.

01:47

Generally, nodes represent a physical structure in the drainage system,

01:51

but you may need to use dummy nodes to allow connections in your models.

01:56

The node types that are supported for InfoWorks networks include Manhole, Outfall, Break, Storage, and Pond.

02:05

If you are undertaking 2D modeling, you also have Outfall 2D or Connect 2D.

02:11

Depending on the node type, there are different properties that you can set.

02:16

For example, for a storage or pond node, you must populate a level area table to define the shape and volume.

02:23

For manholes, there are different ways to define flooding when modeling 1D systems, such as Sealed or Stored.

02:30

Links represent structures that connect nodes.

02:34

The most obvious links are conduits or pipes, but they're also used to represent many types of structures,

02:40

such as pumps, weirs, or screens.

02:45

In the InfoWorks network, each node must be connected by a link to at least one other node.

02:51

A single node may have several links to other nodes.

02:56

For each link, one of the nodes must be specified as the upstream end.

03:01

This identifies the primary direction of flow as the direction from upstream to downstream

03:06

in which equations for controls will be applied, such as pumps.

03:12

This can be easy to visualize when you have a simple sewer network with pipes and manholes represented as conduits and nodes.

03:19

If, however, you consider a complex pumping station, each of the chambers require its own node and each of the hydraulic structures,

03:27

such as weirs, screens, and pumps, require their own links.

03:32

So, it is important that you visualize these structures in a clear manner.

03:37

This is where modeling can become somewhat of an art form.

03:41

Your urban drainage model of subcatchments, nodes, and links helps simulate rainfall-runoff events.

03:48

In ICM, there are several runoff volume models that you can configure for your needs.

03:53

There are many ways that you can quickly and efficiently build or update a model network.

03:59

If you have existing model data outside of ICM, then you can use one of several methods to import it directly into a network,

04:06

such as importing from CSV or using the Open Data Import Centre (ODIC).

04:13

The ODIC allows for data to be mapped automatically to the relevant InfoWorks ICM object data table.

04:21

You can also manually add subcatchments, nodes, links, or other elements to your model network.

04:28

There are also several built-in tools to help you build and update your urban drainage model:

04:34

Define Branches:

04:36

This tool divides the network into long sections by setting the Branch ID field of link objects.

04:42

Inference:

04:44

Missing network values can be inferred from existing data, allowing gaps in data to be filled with reasonable values.

04:52

Population Data:

04:54

Subcatchment population data can be imported from a GIS layer containing address point, seed point, or census data.

05:02

Area Take Off:

05:03

Automates the distribution of runoff surface areas from an Impermeable Area Survey (IAS).

05:10

SQL:

05:13

Not a single tool, but InfoWorks ICM implements its own subset of Structured Query Language

05:19

for selecting and updating network objects.

05:22

This allows you to quickly update and manipulate network data.

05:27

SQL queries can be saved for future use, allowing you to build up a library of commonly used query tasks.

Video transcript

00:03

The basic principles of building 1D urban drainage models in InfoWorks ICM

00:09

revolve around creating wastewater or surface water sewer networks with flows predominantly driven from urbanized areas.

00:17

The fundamental modeling concept is that one or more time-varying inputs, such as rainfall events, inflows, and levels,

00:25

can be specified for use as a boundary condition for hydraulic calculations.

00:32

The first step of any model simulation will be to either apply these boundary conditions directly,

00:37

for example, the water level at a tidal outfall, or convert the input data into an acceptable hydraulic boundary condition.

00:46

The objects that are simulated in a basic 1D drainage model are subcatchments, nodes, and links,

00:53

each with properties that can be set in ICM.

00:56

Subcatchments are polygons, which represent the physical area from which a system collects water, be it wastewater or surface water.

01:05

Subcatchment parameters detail how an event, such as wastewater, rainfall, or groundwater, is applied to a node or link.

01:14

Defining subcatchments is the most onerous task to building a new 1D urban drainage model,

01:20

because these polygons may not have been previously defined in GIS.

01:24

There are a number of properties and data associated with subcatchments that need to be populated as a result.

01:31

ICM provides tools to help speed up this process.

01:35

Nodes represent a specific point in the network, such as a manhole location.

01:41

This is where inflows from subcatchments or from inflow events are assigned to the network.

01:47

Generally, nodes represent a physical structure in the drainage system,

01:51

but you may need to use dummy nodes to allow connections in your models.

01:56

The node types that are supported for InfoWorks networks include Manhole, Outfall, Break, Storage, and Pond.

02:05

If you are undertaking 2D modeling, you also have Outfall 2D or Connect 2D.

02:11

Depending on the node type, there are different properties that you can set.

02:16

For example, for a storage or pond node, you must populate a level area table to define the shape and volume.

02:23

For manholes, there are different ways to define flooding when modeling 1D systems, such as Sealed or Stored.

02:30

Links represent structures that connect nodes.

02:34

The most obvious links are conduits or pipes, but they're also used to represent many types of structures,

02:40

such as pumps, weirs, or screens.

02:45

In the InfoWorks network, each node must be connected by a link to at least one other node.

02:51

A single node may have several links to other nodes.

02:56

For each link, one of the nodes must be specified as the upstream end.

03:01

This identifies the primary direction of flow as the direction from upstream to downstream

03:06

in which equations for controls will be applied, such as pumps.

03:12

This can be easy to visualize when you have a simple sewer network with pipes and manholes represented as conduits and nodes.

03:19

If, however, you consider a complex pumping station, each of the chambers require its own node and each of the hydraulic structures,

03:27

such as weirs, screens, and pumps, require their own links.

03:32

So, it is important that you visualize these structures in a clear manner.

03:37

This is where modeling can become somewhat of an art form.

03:41

Your urban drainage model of subcatchments, nodes, and links helps simulate rainfall-runoff events.

03:48

In ICM, there are several runoff volume models that you can configure for your needs.

03:53

There are many ways that you can quickly and efficiently build or update a model network.

03:59

If you have existing model data outside of ICM, then you can use one of several methods to import it directly into a network,

04:06

such as importing from CSV or using the Open Data Import Centre (ODIC).

04:13

The ODIC allows for data to be mapped automatically to the relevant InfoWorks ICM object data table.

04:21

You can also manually add subcatchments, nodes, links, or other elements to your model network.

04:28

There are also several built-in tools to help you build and update your urban drainage model:

04:34

Define Branches:

04:36

This tool divides the network into long sections by setting the Branch ID field of link objects.

04:42

Inference:

04:44

Missing network values can be inferred from existing data, allowing gaps in data to be filled with reasonable values.

04:52

Population Data:

04:54

Subcatchment population data can be imported from a GIS layer containing address point, seed point, or census data.

05:02

Area Take Off:

05:03

Automates the distribution of runoff surface areas from an Impermeable Area Survey (IAS).

05:10

SQL:

05:13

Not a single tool, but InfoWorks ICM implements its own subset of Structured Query Language

05:19

for selecting and updating network objects.

05:22

This allows you to quickly update and manipulate network data.

05:27

SQL queries can be saved for future use, allowing you to build up a library of commonly used query tasks.

Video quiz

Required for course completion

Which of the following is NOT an object that is simulated in a basic 1D drainage model?

(Select one)
Select an answer

1/1 questions left unanswered

The basic principles of building 1D urban drainage models in InfoWorks ICM revolve around creating wastewater or surface water sewer networks with flows predominantly driven from urbanized areas.

One or more time-varying inputs can be specified for use as a boundary condition for hydraulic calculations. You can apply these boundary conditions directly or convert the input data into an acceptable hydraulic boundary condition.

Subcatchments, nodes, and links objects are simulated in a basic 1D drainage model and have properties that can be set in ICM.

  • Subcatchments are polygons, which represent the physical area from which a system collects water. Subcatchment parameters detail how an event is applied to a node or link.

A presentation slide showing notes on subcatchments on the left and images of subcatchment functionality on the right.

  • Nodes represent a specific point in the network where inflows from subcatchments or from inflow events are assigned. The node types supported for InfoWorks networks include Manhole, Outfall, Break, Storage, and Pond. If you are undertaking 2D modeling, you also have Outfall 2D or Connect 2D.

A presentation slide summarizing node properties for storage ponds and manholes on the left, with an image of the Pond : 29_S : Storage array dialog box, in which pond parameters can be set.

  • Links represent structures that connect nodes. In the InfoWorks network, each node must be connected by a link to at least one other node. One of the nodes must be specified as the upstream end.

A presentation slide summarizing links and how they connect nodes, with a graphic on the right showing links as red arrows that connect nodes as green dots.

Your urban drainage model of subcatchments, nodes, and links helps simulate rainfall-runoff events. In ICM, there are several runoff volume models that you can configure for your needs.

There are many ways that you can quickly and efficiently build or update a model network. If you have existing model data outside of ICM, you can import it directly into a network by importing from CSV or using the Open Data Import Centre (ODIC). You can also manually add subcatchments, nodes, links, or other elements to your model network.

A presentation slide explaining how networks in InfoWorks ICM make it easy to visualize simple and complex networks, with an image of a complex network on the right.

There are also several built-in tools to help you build and update your urban drainage model:

  1. Define Branches: Divides the network into long sections by setting the Branch ID field of link objects.
  2. Inference: Infer missing network values from existing data, allowing gaps in data to be filled with reasonable values.
  3. Population Data: Import subcatchment population data from a GIS layer containing address point, seed point, or census data.
  4. Area Take Off: Automate the distribution of runoff surface areas from an Impermeable Area Survey (IAS).
  5. SQL: Quickly update and manipulate network data. Save SQL queries for future use to build up a library of commonly used query tasks.
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